Semiconductor Nonlinear Waveguide Devices and Integrated-Mirror Etalons

NASA Astrophysics Data System (ADS)

Chuang, Chih-Li.

This dissertation investigates different III-V semiconductor devices for applications in nonlinear photonics. These include passive and active nonlinear directional couplers, current-controlled optical phase shifter, and integrated -mirror etalons. A novel method to find the propagation constants of an optical waveguide is introduced. The same method is applied, with minor modifications, to find the coupling length of a directional coupler. The method presented provides a tool for the design of optical waveguide devices. The design, fabrication, and performance of a nonlinear directional coupler are presented. This device uses light intensity to control the direction of light coming out. This is achieved through photo-generated-carriers mechanism in the picosecond regime and through the optical Stark effect in the femtosecond regime. A two-transverse -dimensions beam-propagation computation is used to model the switching behavior in the nonlinear directional coupler. It is found that, by considering the pulse degradation effect, the computation agrees well with experiments. The possibility of operating a nonlinear directional coupler with gain is investigated. It is concluded that by injecting current into the nonlinear directional coupler does not provide the advantages hoped for and the modelling using 2-D beam -propagation methods verifies that. Using current injection to change the refractive index of a waveguide, an optical phase shifter is constructed. This device has the merit of delivering large phase shift with almost no intensity modulation. A phase shift as large as 3pi is produced in a waveguide 400 μm in length. Finally, a new structure, grown by the molecular beam epitaxy machine, is described. The structure consists of two quarter-wave stacks and a spacer layer to form an integrated-mirror etalon. The theory, design principles, spectral analyses are discussed with design examples to clarify the ideas. Emphasis is given to the vertical-cavity surface-emitting laser constructed from this structure. Here we demonstrated the cw operation of the VCSEL at room temperature.

Optical isolation with nonlinear topological photonics

NASA Astrophysics Data System (ADS)

Zhou, Xin; Wang, You; Leykam, Daniel; Chong, Y. D.

2017-09-01

It is shown that the concept of topological phase transitions can be used to design nonlinear photonic structures exhibiting power thresholds and discontinuities in their transmittance. This provides a novel route to devising nonlinear optical isolators. We study three representative designs: (i) a waveguide array implementing a nonlinear 1D Su-Schrieffer-Heeger model, (ii) a waveguide array implementing a nonlinear 2D Haldane model, and (iii) a 2D lattice of coupled-ring waveguides. In the first two cases, we find a correspondence between the topological transition of the underlying linear lattice and the power threshold of the transmittance, and show that the transmission behavior is attributable to the emergence of a self-induced topological soliton. In the third case, we show that the topological transition produces a discontinuity in the transmittance curve, which can be exploited to achieve sharp jumps in the power-dependent isolation ratio.

Mechanical Kerr nonlinearities due to bipolar optical forces between deformable silicon waveguides.

PubMed

Ma, Jing; Povinelli, Michelle L

2011-05-23

We use an analytical method based on the perturbation of effective index at fixed frequency to calculate optical forces between silicon waveguides. We use the method to investigate the mechanical Kerr effect in a coupled-waveguide system with bipolar forces. We find that a positive mechanical Kerr coefficient results from either an attractive or repulsive force. An enhanced mechanical Kerr coefficient several orders of magnitude larger than the intrinsic Kerr coefficient is obtained in waveguides for which the optical mode approaches the air light line, given appropriate design of the waveguide dimensions.

High efficiency all-optical plasmonic diode based on a nonlinear side-coupled waveguide-cavity structure with broken symmetry

NASA Astrophysics Data System (ADS)

Liang, Hong-Qin; Liu, Bin; Hu, Jin-Feng; He, Xing-Dao

2018-05-01

An all-optical plasmonic diode, comprising a metal-insulator-metal waveguide coupled with a stub cavity, is proposed based on a nonlinear Fano structure. The key technique used is to break structural spatial symmetry by a simple reflector layer in the waveguide. The spatial asymmetry of the structure gives rise to the nonreciprocity of coupling efficiencies between the Fano cavity and waveguides on both sides of the reflector layer, leading to a nonreciprocal nonlinear response. Transmission properties and dynamic responses are numerically simulated and investigated by the nonlinear finite-difference time-domain method. In the proposed structure, high-efficiency nonreciprocal transmission can be achieved with a low power threshold and an ultrafast response time (subpicosecond level). A high maximum transmittance of 89.3% and an ultra-high transmission contrast ratio of 99.6% can also be obtained. The device can be flexibly adjusted for working wavebands by altering the stub cavity length.

Ultra-fast all-optical plasmon induced transparency in a metal–insulator–metal waveguide containing two Kerr nonlinear ring resonators

NASA Astrophysics Data System (ADS)

Nurmohammadi, Tofiq; Abbasian, Karim; Yadipour, Reza

2018-05-01

In this work, an ultra-fast all-optical plasmon induced transparency based on a metal–insulator–metal nanoplasmonic waveguide with two Kerr nonlinear ring resonators is studied. Two-dimensional simulations utilizing the finite-difference time-domain method are used to show an obvious optical bistability and significant switching mechanisms of the signal light by varying the pump-light intensity. The proposed all-optical switching based on plasmon induced transparency demonstrates femtosecond-scale feedback time (90 fs), meaning ultra-fast switching can be achieved. The presented all-optical switch may have potential significant applications in integrated optical circuits.

Efficient Second Harmonic Generation in 3D Nonlinear Optical-Lattice-Like Cladding Waveguide Splitters by Femtosecond Laser Inscription

PubMed Central

Nie, Weijie; Jia, Yuechen; Vázquez de Aldana, Javier R.; Chen, Feng

2016-01-01

Integrated photonic devices with beam splitting function are intriguing for a broad range of photonic applications. Through optical-lattice-like cladding waveguide structures fabricated by direct femtosecond laser writing, the light propagation can be engineered via the track-confined refractive index profiles, achieving tailored output beam distributions. In this work, we report on the fabrication of 3D laser-written optical-lattice-like structures in a nonlinear KTP crystal to implement 1 × 4 beam splitting. Second harmonic generation (SHG) of green light through these nonlinear waveguide beam splitter structures provides the capability for the compact visible laser emitting devices. With Type II phase matching of the fundamental wavelength (@ 1064 nm) to second harmonic waves (@ 532 nm), the frequency doubling has been achieved through this three-dimensional beam splitter. Under 1064-nm continuous-wave fundamental-wavelength pump beam, guided-wave SHG at 532 nm are measured with the maximum power of 0.65 mW and 0.48 mW for waveguide splitters (0.67 mW and 0.51 mW for corresponding straight channel waveguides), corresponding to a SH conversion efficiency of approximately ~14.3%/W and 13.9%/W (11.2%/W, 11.3%/W for corresponding straight channel waveguides), respectively. This work paves a way to fabricate compact integrated nonlinear photonic devices in a single chip with beam dividing functions. PMID:26924255

Efficient Second Harmonic Generation in 3D Nonlinear Optical-Lattice-Like Cladding Waveguide Splitters by Femtosecond Laser Inscription.

PubMed

Nie, Weijie; Jia, Yuechen; Vázquez de Aldana, Javier R; Chen, Feng

2016-02-29

Integrated photonic devices with beam splitting function are intriguing for a broad range of photonic applications. Through optical-lattice-like cladding waveguide structures fabricated by direct femtosecond laser writing, the light propagation can be engineered via the track-confined refractive index profiles, achieving tailored output beam distributions. In this work, we report on the fabrication of 3D laser-written optical-lattice-like structures in a nonlinear KTP crystal to implement 1 × 4 beam splitting. Second harmonic generation (SHG) of green light through these nonlinear waveguide beam splitter structures provides the capability for the compact visible laser emitting devices. With Type II phase matching of the fundamental wavelength (@ 1064 nm) to second harmonic waves (@ 532 nm), the frequency doubling has been achieved through this three-dimensional beam splitter. Under 1064-nm continuous-wave fundamental-wavelength pump beam, guided-wave SHG at 532 nm are measured with the maximum power of 0.65 mW and 0.48 mW for waveguide splitters (0.67 mW and 0.51 mW for corresponding straight channel waveguides), corresponding to a SH conversion efficiency of approximately ~14.3%/W and 13.9%/W (11.2%/W, 11.3%/W for corresponding straight channel waveguides), respectively. This work paves a way to fabricate compact integrated nonlinear photonic devices in a single chip with beam dividing functions.

Ultrafast nonlinear dynamics of thin gold films due to an intrinsic delayed nonlinearity

NASA Astrophysics Data System (ADS)

Bache, Morten; Lavrinenko, Andrei V.

2017-09-01

Using long-range surface plasmon polaritons light can propagate in metal nano-scale waveguides for ultracompact opto-electronic devices. Gold is an important material for plasmonic waveguides, but although its linear optical properties are fairly well understood, the nonlinear response is still under investigation. We consider the propagation of pulses in ultrathin gold strip waveguides, modeled by the nonlinear Schrödinger equation. The nonlinear response of gold is accounted for by the two-temperature model, revealing it as a delayed nonlinearity intrinsic in gold. The consequence is that the measured nonlinearities are strongly dependent on pulse duration. This issue has so far only been addressed phenomenologically, but we provide an accurate estimate of the quantitative connection as well as a phenomenological theory to understand the enhanced nonlinear response as the gold thickness is reduced. In comparison with previous works, the analytical model for the power-loss equation has been improved, and can be applied now to cases with a high laser peak power. We show new fits to experimental data from the literature and provide updated values for the real and imaginary parts of the nonlinear susceptibility of gold for various pulse durations and gold layer thicknesses. Our simulations show that the nonlinear loss is inhibiting efficient nonlinear interaction with low-power laser pulses. We therefore propose to design waveguides suitable for the mid-IR, where the ponderomotive instantaneous nonlinearity can dominate over the delayed hot-electron nonlinearity and provide a suitable plasmonics platform for efficient ultrafast nonlinear optics.

Evaluation of polymer based third order nonlinear integrated optics devices

NASA Astrophysics Data System (ADS)

Driessen, A.; Hoekstra, H. J. W. M.; Blom, F. C.; Horst, F.; Krijnen, G. J. M.; van Schoot, J. B. P.; Lambeck, P. V.; Popma, Th. J. A.; Diemeer, M. B.

1998-01-01

Nonlinear polymers are promising materials for high speed active integrated optics devices. In this paper we evaluate the perspectives polymer based nonlinear optical devices can offer. Special attention is directed to the materials aspects. In our experimental work we applied mainly Akzo Nobel DANS side-chain polymer that exhibits large second and third order coefficients. This material has been characterized by third harmonic generation, z-scan and pump-probe measurements. In addition, various waveguiding structures have been used to measure the nonlinear absorption (two photon absorption) on a ps time-scale. Finally an integrated optics Mach Zehnder interferometer has been realized and evaluated. It is shown that the DANS side-chain polymer has many of the desired properties: the material is easily processable in high-quality optical waveguiding structures, has low linear absorption and its nonlinearity has a pure electronic origin. More materials research has to be done to arrive at materials with higher nonlinear coefficients to allow switching at moderate light intensity ( < 1 W peak power) and also with lower nonlinear absorption coefficients.

Nonlinear optical coupler using a doped optical waveguide

DOEpatents

Pantell, Richard H.; Sadowski, Robert W.; Digonnet, Michel J. F.; Shaw, Herbert J.

1994-01-01

An optical mode coupling apparatus includes an Erbium-doped optical waveguide in which an optical signal at a signal wavelength propagates in a first spatial propagation mode and a second spatial propagation mode of the waveguide. The optical signal propagating in the waveguide has a beat length. The coupling apparatus includes a pump source of perturbational light signal at a perturbational wavelength that propagates in the waveguide in the first spatial propagation mode. The perturbational signal has a sufficient intensity distribution in the waveguide that it causes a perturbation of the effective refractive index of the first spatial propagation mode of the waveguide in accordance with the optical Kerr effect. The perturbation of the effective refractive index of the first spatial propagation mode of the optical waveguide causes a change in the differential phase delay in the optical signal propagating in the first and second spatial propagation modes. The change in the differential phase delay is detected as a change in the intensity distribution between two lobes of the optical intensity distribution pattern of an output signal. The perturbational light signal can be selectively enabled and disabled to selectively change the intensity distribution in the two lobes of the optical intensity distribution pattern.

Giant nonlinear interaction between two optical beams via a quantum dot embedded in a photonic wire

NASA Astrophysics Data System (ADS)

Nguyen, H. A.; Grange, T.; Reznychenko, B.; Yeo, I.; de Assis, P.-L.; Tumanov, D.; Fratini, F.; Malik, N. S.; Dupuy, E.; Gregersen, N.; Auffèves, A.; Gérard, J.-M.; Claudon, J.; Poizat, J.-Ph.

2018-05-01

Optical nonlinearities usually appear for large intensities, but discrete transitions allow for giant nonlinearities operating at the single-photon level. This has been demonstrated in the last decade for a single optical mode with cold atomic gases, or single two-level systems coupled to light via a tailored photonic environment. Here, we demonstrate a two-mode giant nonlinearity with a single semiconductor quantum dot (QD) embedded in a photonic wire antenna. We exploit two detuned optical transitions associated with the exciton-biexciton QD level scheme. Owing to the broadband waveguide antenna, the two transitions are efficiently interfaced with two free-space laser beams. The reflection of one laser beam is then controlled by the other beam, with a threshold power as low as 10 photons per exciton lifetime (1.6 nW ). Such a two-color nonlinearity opens appealing perspectives for the realization of ultralow-power logical gates and optical quantum gates, and could also be implemented in an integrated photonic circuit based on planar waveguides.

Free-carrier-induced soliton fission unveiled by in situ measurements in nanophotonic waveguides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Husko, Chad; Wulf, Matthias; Lefrancois, Simon

Solitons are localized waves formed by a balance of focusing and defocusing effects. These nonlinear waves exist in diverse forms of matter yet exhibit similar properties including stability, periodic recurrence and particle-like trajectories. One important property is soliton fission, a process by which an energetic higher-order soliton breaks apart due to dispersive or nonlinear perturbations. Here we demonstrate through both experiment and theory that nonlinear photocarrier generation can induce soliton fission. Using near-field measurements, we directly observe the nonlinear spatial and temporal evolution of optical pulses in situ in a nanophotonic semiconductor waveguide. We develop an analytic formalism describing themore » free-carrier dispersion (FCD) perturbation and show the experiment exceeds the minimum threshold by an order of magnitude. We confirm these observations with a numerical nonlinear Schrodinger equation model. Finally, these results provide a fundamental explanation and physical scaling of optical pulse evolution in free-carrier media and could enable improved supercontinuum sources in gas based and integrated semiconductor waveguides.« less

Free-carrier-induced soliton fission unveiled by in situ measurements in nanophotonic waveguides

DOE PAGES

Husko, Chad; Wulf, Matthias; Lefrancois, Simon; ...

2016-04-15

Solitons are localized waves formed by a balance of focusing and defocusing effects. These nonlinear waves exist in diverse forms of matter yet exhibit similar properties including stability, periodic recurrence and particle-like trajectories. One important property is soliton fission, a process by which an energetic higher-order soliton breaks apart due to dispersive or nonlinear perturbations. Here we demonstrate through both experiment and theory that nonlinear photocarrier generation can induce soliton fission. Using near-field measurements, we directly observe the nonlinear spatial and temporal evolution of optical pulses in situ in a nanophotonic semiconductor waveguide. We develop an analytic formalism describing themore » free-carrier dispersion (FCD) perturbation and show the experiment exceeds the minimum threshold by an order of magnitude. We confirm these observations with a numerical nonlinear Schrodinger equation model. Finally, these results provide a fundamental explanation and physical scaling of optical pulse evolution in free-carrier media and could enable improved supercontinuum sources in gas based and integrated semiconductor waveguides.« less

NOLM-based all-optical 40 Gbit/s format conversion through sum-frequency generation (SFG) in a PPLN waveguide

NASA Astrophysics Data System (ADS)

Wang, Jian; Sun, Junqiang

2005-11-01

A novel all-optical format conversion scheme from NRZ to RZ based on sum-frequency generation (SFG) in a periodically poled LiNbO 3 (PPLN) waveguide is proposed, using a nonlinear optical loop mirror (NOLM). The conversion mechanism relies on the combination of attenuation and nonlinear phase shift induced on the clockwise signal field during the SFG process. The SFG between pump, and co- and counter- propagating signals in the PPLN waveguide are numerically studied, showing that counter-propagating SFG can be ignored when quasi-phase matching (QPM) for SFG during co-propagating interaction. The nonlinear phase shift induced on the clockwise signal field is analyzed in detail, showing that it is more effective to yield large values for nonlinear phase shift when appropriately phase mismatched for the SFG process. Two tuning schemes are proposed depend on whether the sum-frequency wavelength is variable or fixed. It is found that the latter has a rather wide 3dB signal conversion bandwidth approximately 154nm. Finally, the influence of reversible process of SFG is discussed and the optimum arrangement of pump and signal peak powers is theoretically demonstrated. The result shows that proper power arrangement, pump width, and waveguide length are necessary for achieving a good conversion effect.

Ridge Waveguide Structures in Magnesium-Doped Lithium Niobate

NASA Technical Reports Server (NTRS)

Himmer, Phillip; Battle, Philip; Suckow, William; Switzer, Greg

2011-01-01

This work proposes to establish the feasibility of fabricating isolated ridge waveguides in 5% MgO:LN. Ridge waveguides in MgO:LN will significantly improve power handling and conversion efficiency, increase photonic component integration, and be well suited to spacebased applications. The key innovation in this effort is to combine recently available large, high-photorefractive-damage-threshold, z-cut 5% MgO:LN with novel ridge fabrication techniques to achieve high-optical power, low-cost, high-volume manufacturing of frequency conversion structures. The proposed ridge waveguide structure should maintain the characteristics of the periodically poled bulk substrate, allowing for the efficient frequency conversion typical of waveguides and the high optical damage threshold and long lifetimes typical of the 5% doped bulk substrate. The low cost and large area of 5% MgO:LN wafers, and the improved performance of the proposed ridge waveguide structure, will enhance existing measurement capabilities as well as reduce the resources required to achieve high-performance specifications. The purpose of the ridge waveguides in MgO:LN is to provide platform technology that will improve optical power handling and conversion efficiency compared to existing waveguide technology. The proposed ridge waveguide is produced using standard microfabrication techniques. The approach is enabled by recent advances in inductively coupled plasma etchers and chemical mechanical planarization techniques. In conjunction with wafer bonding, this fabrication methodology can be used to create arbitrarily shaped waveguides allowing complex optical circuits to be engineered in nonlinear optical materials such as magnesium doped lithium niobate. Researchers here have identified NLO (nonlinear optical) ridge waveguide structures as having suitable value to be the leading frequency conversion structures. Its value is based on having the low-cost fabrication necessary to satisfy the challenging pricing requirements as well as achieve the power handling and other specifications in a suitably compact package.

Nonclassical-light generation in a photonic-band-gap nonlinear planar waveguide

NASA Astrophysics Data System (ADS)

Peřina, Jan, Jr.; Sibilia, Concita; Tricca, Daniela; Bertolotti, Mario

2004-10-01

The optical parametric process occurring in a photonic-band-gap planar waveguide is studied from the point of view of nonclassical-light generation. The nonlinearly interacting optical fields are described by the generalized superposition of coherent signals and noise using the method of operator linear corrections to a classical strong solution. Scattered backward-propagating fields are taken into account. Squeezed light as well as light with sub-Poissonian statistics can be obtained in two-mode fields under the specified conditions.

Nonlinear Kerr enhancement of the Sagnac effect in a coherently coupled array of optical microresonators

NASA Astrophysics Data System (ADS)

Wang, Chao; Search, Christopher

2013-03-01

Optical gyroscopes based on the Sagnac effect are of great interest both theoretically and practically. Previously it has been suggested a nonlinear Kerr medium inserted into a ring resonator gyroscope can largely increase the rotation sensitivity due to an instability caused by the non-reciprocal self-phase and cross-phase modulations. Recently, coupled microresonator arrays such as Side-Coupled Integrated Spaced Sequence of Resonators (SCISSOR) and Coupled Resonator Optical Waveguides (CROW) have drawn interest as potential integrated gyroscopes due to the sensitivity enhancement resulting from distributed interference between resonators. Here we analyze a SCISSOR system, which consists of an array of microresonators evanescently coupled to two parallel bus waveguides in the presence of a strong intra-resonator Kerr nonlinearity. We show that the distributed interference in the waveguides combined with the nonlinearly enhanced Sagnac effect in the resonators can further improve the sensitivity compared with either a single resonator of equal footprint or SCISSOR without a Kerr nonlinearity. Numerical simulation shows that bistability in the SCISSOR occurs and the rotation sensitivity dIoutput/dω can go to infinity near the boundaries of the bistable region.

Nonlinear dynamics of solitary and optically injected two-element laser arrays with four different waveguide structures: a numerical study.

PubMed

Li, Nianqiang; Susanto, H; Cemlyn, B R; Henning, I D; Adams, M J

2018-02-19

We study the nonlinear dynamics of solitary and optically injected two-element laser arrays with a range of waveguide structures. The analysis is performed with a detailed direct numerical simulation, where high-resolution dynamic maps are generated to identify regions of dynamic instability in the parameter space of interest. Our combined one- and two-parameter bifurcation analysis uncovers globally diverse dynamical regimes (steady-state, oscillation, and chaos) in the solitary laser arrays, which are greatly influenced by static design waveguiding structures, the amplitude-phase coupling factor of the electric field, i.e. the linewidth-enhancement factor, as well as the control parameter, e.g. the pump rate. When external optical injection is introduced to one element of the arrays, we show that the whole system can be either injection-locked simultaneously or display rich, different dynamics outside the locking region. The effect of optical injection is to significantly modify the nature and the regions of nonlinear dynamics from those found in the solitary case. We also show similarities and differences (asymmetry) between the oscillation amplitude of the two elements of the array in specific well-defined regions, which hold for all the waveguiding structures considered. Our findings pave the way to a better understanding of dynamic instability in large arrays of lasers.

Generation of Nonclassical Biphoton States through Cascaded Quantum Walks on a Nonlinear Chip

NASA Astrophysics Data System (ADS)

Solntsev, Alexander S.; Setzpfandt, Frank; Clark, Alex S.; Wu, Che Wen; Collins, Matthew J.; Xiong, Chunle; Schreiber, Andreas; Katzschmann, Fabian; Eilenberger, Falk; Schiek, Roland; Sohler, Wolfgang; Mitchell, Arnan; Silberhorn, Christine; Eggleton, Benjamin J.; Pertsch, Thomas; Sukhorukov, Andrey A.; Neshev, Dragomir N.; Kivshar, Yuri S.

2014-07-01

We demonstrate a nonlinear optical chip that generates photons with reconfigurable nonclassical spatial correlations. We employ a quadratic nonlinear waveguide array, where photon pairs are generated through spontaneous parametric down-conversion and simultaneously spread through quantum walks between the waveguides. Because of the quantum interference of these cascaded quantum walks, the emerging photons can become entangled over multiple waveguide positions. We experimentally observe highly nonclassical photon-pair correlations, confirming the high fidelity of on-chip quantum interference. Furthermore, we demonstrate biphoton-state tunability by spatial shaping and frequency tuning of the classical pump beam.

Chi 3 dispersion in planar tantalum pentoxide waveguides in the telecommunications window.

PubMed

Chen, Ruiqi Y; Charlton, Martin D B; Lagoudakis, Pavlos G

2009-04-01

We report on the dispersion of the third-order nonlinear susceptibility (chi(3) or "Chi 3") in planar Ta2O5 waveguides in the telecommunications spectral window. We utilize the observation of third-harmonic generation under ultrashort pulsed excitation as a reference-free characterization method of chi(3) and obtain a large nonlinear coefficient, 2x10(-13) esu, at 1550 nm. Our observation of efficient third-harmonic generation in Ta2O5 waveguides in the telecoms window reveals the potential of this material system in high-speed integrated nonlinear optical switches.

Wideband nonlinear spectral broadening in ultra-short ultra - silicon rich nitride waveguides.

PubMed

Choi, Ju Won; Chen, George F R; Ng, D K T; Ooi, Kelvin J A; Tan, Dawn T H

2016-06-08

CMOS-compatible nonlinear optics platforms with high Kerr nonlinearity facilitate the generation of broadband spectra based on self-phase modulation. Our ultra - silicon rich nitride (USRN) platform is designed to have a large nonlinear refractive index and low nonlinear losses at 1.55 μm for the facilitation of wideband spectral broadening. We investigate the ultrafast spectral characteristics of USRN waveguides with 1-mm-length, which have high nonlinear parameters (γ ∼ 550 W(-1)/m) and anomalous dispersion at 1.55 μm wavelength of input light. USRN add-drop ring resonators broaden output spectra by a factor of 2 compared with the bandwidth of input fs laser with the highest quality factors of 11000 and 15000. Two - fold self phase modulation induced spectral broadening is observed using waveguides only 430 μm in length, whereas a quadrupling of the output bandwidth is observed with USRN waveguides with a 1-mm-length. A broadening factor of around 3 per 1 mm length is achieved in the USRN waveguides, a value which is comparatively larger than many other CMOS-compatible platforms.

Engineered Quasi-Phase Matching for Nonlinear Quantum Optics in Waveguides

NASA Astrophysics Data System (ADS)

Van Camp, Mackenzie A.

Entanglement is the hallmark of quantum mechanics. Quantum entanglement--putting two or more identical particles into a non-factorable state--has been leveraged for applications ranging from quantum computation and encryption to high-precision metrology. Entanglement is a practical engineering resource and a tool for sidestepping certain limitations of classical measurement and communication. Engineered nonlinear optical waveguides are an enabling technology for generating entangled photon pairs and manipulating the state of single photons. This dissertation reports on: i) frequency conversion of single photons from the mid-infrared to 843nm as a tool for incorporating quantum memories in quantum networks, ii) the design, fabrication, and test of a prototype broadband source of polarization and frequency entangled photons; and iii) a roadmap for further investigations of this source, including applications in quantum interferometry and high-precision optical metrology. The devices presented herein are quasi-phase-matched lithium niobate waveguides. Lithium niobate is a second-order nonlinear optical material and can mediate optical energy conversion to different wavelengths. This nonlinear effect is the basis of both quantum frequency conversion and entangled photon generation, and is enhanced by i) confining light in waveguides to increase conversion efficiency, and ii) quasi-phase matching, a technique for engineering the second-order nonlinear response by locally altering the direction of a material's polarization vector. Waveguides are formed by diffusing titanium into a lithium niobate wafer. Quasi-phase matching is achieved by electric field poling, with multiple stages of process development and optimization to fabricate the delicate structures necessary for broadband entangled photon generation. The results presented herein update and optimize past fabrication techniques, demonstrate novel optical devices, and propose future avenues for device development. Quantum frequency conversion from 1848nm to 843nm is demonstrated for the first time, with >75% single-photon conversion efficiency. A new electric field poling methodology is presented, combining elements from multiple historical techniques with a new fast-feedback control system. This poling technique is used to fabricate the first chirped-and-apodized Type-II quasi-phase-matched structures in titanium-diffused lithium niobate waveguides, culminating in a measured phasematching spectrum that is predominantly Gaussian ( R2 = 0.80), nearly eight times broader than the unchirped spectrum, and agrees well with simulations.

Preparation of polymeric diacetylene thin films for nonlinear optical applications

NASA Technical Reports Server (NTRS)

Frazier, Donald O. (Inventor); Mcmanus, Samuel P. (Inventor); Paley, Mark S. (Inventor); Donovan, David N. (Inventor)

1995-01-01

A method for producing polymeric diacetylene thin films having desirable nonlinear optical characteristics has been achieved by producing amorphous diacetylene polymeric films by simultaneous polymerization of diacetylene monomers in solution and deposition of polymerized diacetylenes on to the surface of a transparent substrate through which ultraviolet light has been transmitted. These amorphous polydiacetylene films produced by photo-deposition from solution possess very high optical quality and exhibit large third order nonlinear optical susceptibilities, such properties being suitable for nonlinear optical devices such as waveguides and integrated optics.

Ultra-low loss Si3N4 waveguides with low nonlinearity and high power handling capability.

PubMed

Tien, Ming-Chun; Bauters, Jared F; Heck, Martijn J R; Blumenthal, Daniel J; Bowers, John E

2010-11-08

We investigate the nonlinearity of ultra-low loss Si3N4-core and SiO2-cladding rectangular waveguides. The nonlinearity is modeled using Maxwell's wave equation with a small amount of refractive index perturbation. Effective n2 is used to describe the third-order nonlinearity, which is linearly proportional to the optical intensity. The effective n2 measured using continuous-wave self-phase modulation shows agreement with the theoretical calculation. The waveguide with 2.8-μm wide and 80-nm thick Si3N4 core has low loss and high power handling capability, with an effective n2 of about 9×10(-16) cm2/W.

FIBER AND INTEGRATED OPTICS: Nonlinearity of a channel-waveguide phase modulator

NASA Astrophysics Data System (ADS)

Parygin, V. N.; Zhmakin, I. N.; Baglikov, V. B.

1993-09-01

The phase velocity of light in a channel waveguide using a LiNbO3 crystal is analyzed as a function of the voltage applied to the crystal. A refinement of the method of an effective refractive index is proposed. This refinement makes it possible to use the method near the cutoff for a waveguide mode. At voltages on the order of 10 V, the nonlinearity of the phase characteristic amounts to ~ 5 · 10- 4 of the linear phase shift.

Heterogeneous integration of lithium niobate and silicon nitride waveguides for wafer-scale photonic integrated circuits on silicon.

PubMed

Chang, Lin; Pfeiffer, Martin H P; Volet, Nicolas; Zervas, Michael; Peters, Jon D; Manganelli, Costanza L; Stanton, Eric J; Li, Yifei; Kippenberg, Tobias J; Bowers, John E

2017-02-15

An ideal photonic integrated circuit for nonlinear photonic applications requires high optical nonlinearities and low loss. This work demonstrates a heterogeneous platform by bonding lithium niobate (LN) thin films onto a silicon nitride (Si₃N₄) waveguide layer on silicon. It not only provides large second- and third-order nonlinear coefficients, but also shows low propagation loss in both the Si₃N₄ and the LN-Si₃N₄ waveguides. The tapers enable low-loss-mode transitions between these two waveguides. This platform is essential for various on-chip applications, e.g., modulators, frequency conversions, and quantum communications.

FDTD modeling of anisotropic nonlinear optical phenomena in silicon waveguides.

PubMed

Dissanayake, Chethiya M; Premaratne, Malin; Rukhlenko, Ivan D; Agrawal, Govind P

2010-09-27

A deep insight into the inherent anisotropic optical properties of silicon is required to improve the performance of silicon-waveguide-based photonic devices. It may also lead to novel device concepts and substantially extend the capabilities of silicon photonics in the future. In this paper, for the first time to the best of our knowledge, we present a three-dimensional finite-difference time-domain (FDTD) method for modeling optical phenomena in silicon waveguides, which takes into account fully the anisotropy of the third-order electronic and Raman susceptibilities. We show that, under certain realistic conditions that prevent generation of the longitudinal optical field inside the waveguide, this model is considerably simplified and can be represented by a computationally efficient algorithm, suitable for numerical analysis of complex polarization effects. To demonstrate the versatility of our model, we study polarization dependence for several nonlinear effects, including self-phase modulation, cross-phase modulation, and stimulated Raman scattering. Our FDTD model provides a basis for a full-blown numerical simulator that is restricted neither by the single-mode assumption nor by the slowly varying envelope approximation.

Giant nonlinear response at a plasmonic nanofocus drives efficient four-wave mixing

NASA Astrophysics Data System (ADS)

Nielsen, Michael P.; Shi, Xingyuan; Dichtl, Paul; Maier, Stefan A.; Oulton, Rupert F.

2017-12-01

Efficient optical frequency mixing typically must accumulate over large interaction lengths because nonlinear responses in natural materials are inherently weak. This limits the efficiency of mixing processes owing to the requirement of phase matching. Here, we report efficient four-wave mixing (FWM) over micrometer-scale interaction lengths at telecommunications wavelengths on silicon. We used an integrated plasmonic gap waveguide that strongly confines light within a nonlinear organic polymer. The gap waveguide intensifies light by nanofocusing it to a mode cross-section of a few tens of nanometers, thus generating a nonlinear response so strong that efficient FWM accumulates over wavelength-scale distances. This technique opens up nonlinear optics to a regime of relaxed phase matching, with the possibility of compact, broadband, and efficient frequency mixing integrated with silicon photonics.

Thermal and Kerr nonlinear properties of plasma-deposited silicon nitride/ silicon dioxide waveguides.

PubMed

Ikeda, Kazuhiro; Saperstein, Robert E; Alic, Nikola; Fainman, Yeshaiahu

2008-08-18

We introduce and present experimental evaluations of loss and nonlinear optical response in a waveguide and an optical resonator, both implemented with a silicon nitride/ silicon dioxide material platform prepared by plasma-enhanced chemical vapor deposition with dual frequency reactors that significantly reduce the stress and the consequent loss of the devices. We measure a relatively small loss of approximately 4dB/cm in the waveguides. The fabricated ring resonators in add-drop and all-pass arrangements demonstrate quality factors of Q=12,900 and 35,600. The resonators are used to measure both the thermal and ultrafast Kerr nonlinearities. The measured thermal nonlinearity is larger than expected, which is attributed to slower heat dissipation in the plasma-deposited silicon dioxide film. The n2 for silicon nitride that is unknown in the literature is measured, for the first time, as 2.4 x 10(-15)cm(2)/W, which is 10 times larger than that for silicon dioxide.

Peptide Integrated Optics.

PubMed

Handelman, Amir; Lapshina, Nadezda; Apter, Boris; Rosenman, Gil

2018-02-01

Bio-nanophotonics is a wide field in which advanced optical materials, biomedicine, fundamental optics, and nanotechnology are combined and result in the development of biomedical optical chips. Silk fibers or synthetic bioabsorbable polymers are the main light-guiding components. In this work, an advanced concept of integrated bio-optics is proposed, which is based on bioinspired peptide optical materials exhibiting wide optical transparency, nonlinear and electrooptical properties, and effective passive and active waveguiding. Developed new technology combining bottom-up controlled deposition of peptide planar wafers of a large area and top-down focus ion beam lithography provides direct fabrication of peptide optical integrated circuits. Finding a deep modification of peptide optical properties by reconformation of biological secondary structure from native phase to β-sheet architecture is followed by the appearance of visible fluorescence and unexpected transition from a native passive optical waveguiding to an active one. Original biocompatibility, switchable regimes of waveguiding, and multifunctional nonlinear optical properties make these new peptide planar optical materials attractive for application in emerging technology of lab-on-biochips, combining biomedical photonic and electronic circuits toward medical diagnosis, light-activated therapy, and health monitoring. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-reflection of extremely short light pulses in nonlinear optical waveguides

NASA Astrophysics Data System (ADS)

Kurasov, Alexander E.; Kozlov, Sergei A.

2004-07-01

An equation describing the generation of reflected radiation during the propagation of high-intensity extremely short pulses in a nonlinear optical waveguide is derived. The phenomena taking place during the strong self-inducted changes of the temporal structure of the forward wave are studied. It is shown that the duration of the backward pulse is much greater than the duration of the forward pulse and that the main part of the energy of the backward wave is carried by lower frequencies than the central frequency of the forward wave.

Highly nonlinear sub-micron silicon nitride trench waveguide coated with gold nanoparticles

NASA Astrophysics Data System (ADS)

Huang, Yuewang; Zhao, Qiancheng; Sharac, Nicholas; Ragan, Regina; Boyraz, Ozdal

2015-05-01

We demonstrate the fabrication of a highly nonlinear sub-micron silicon nitride trench waveguide coated with gold nanoparticles for plasmonic enhancement. The average enhancement effect is evaluated by measuring the spectral broadening effect caused by self-phase-modulation. The nonlinear refractive index n2 was measured to be 7.0917×10-19 m2/W for a waveguide whose Wopen is 5 μm. Several waveguides at different locations on one wafer were measured in order to take the randomness of the nanoparticle distribution into consideration. The largest enhancement is measured to be as high as 10 times. Fabrication of this waveguide started with a MEMS grade photomask. By using conventional optical lithography, the wide linewidth was transferred to a <100> wafer. Then the wafer was etched anisotropically by potassium hydroxide (KOH) to engrave trapezoidal trenches with an angle of 54.7º. Side wall roughness was mitigated by KOH etching and thermal oxidation that was used to generate a buffer layer for silicon nitride waveguide. The guiding material silicon nitride was then deposited by low pressure chemical vapor deposition. The waveguide was then patterned with a chemical template, with 20 nm gold particles being chemically attached to the functionalized poly(methyl methacrylate) domains. Since the particles attached only to the PMMA domains, they were confined to localized regions, therefore forcing the nanoparticles into clusters of various numbers and geometries. Experiments reveal that the waveguide has negligible nonlinear absorption loss, and its nonlinear refractive index can be greatly enhanced by gold nano clusters. The silicon nitride trench waveguide has large nonlinear refractive index, rendering itself promising for nonlinear applications.

Wideband nonlinear spectral broadening in ultra-short ultra - silicon rich nitride waveguides

PubMed Central

Choi, Ju Won; Chen, George F. R.; Ng, D. K. T.; Ooi, Kelvin J. A.; Tan, Dawn T. H.

2016-01-01

CMOS-compatible nonlinear optics platforms with high Kerr nonlinearity facilitate the generation of broadband spectra based on self-phase modulation. Our ultra – silicon rich nitride (USRN) platform is designed to have a large nonlinear refractive index and low nonlinear losses at 1.55 μm for the facilitation of wideband spectral broadening. We investigate the ultrafast spectral characteristics of USRN waveguides with 1-mm-length, which have high nonlinear parameters (γ ∼ 550 W−1/m) and anomalous dispersion at 1.55 μm wavelength of input light. USRN add-drop ring resonators broaden output spectra by a factor of 2 compared with the bandwidth of input fs laser with the highest quality factors of 11000 and 15000. Two – fold self phase modulation induced spectral broadening is observed using waveguides only 430 μm in length, whereas a quadrupling of the output bandwidth is observed with USRN waveguides with a 1-mm-length. A broadening factor of around 3 per 1 mm length is achieved in the USRN waveguides, a value which is comparatively larger than many other CMOS-compatible platforms. PMID:27272558

Photonic Switching Devices Using Light Bullets

NASA Technical Reports Server (NTRS)

Goorjian, Peter M. (Inventor)

1997-01-01

The present invention is directed toward a unique ultra-fast, all-optical switching device or switch made with readily available, relatively inexpensive, highly nonlinear photonic glasses. These photonic glasses have a sufficiently negative group velocity dispersion and high nonlinear index of refraction to support stable light bullets. The light bullets counterpropagate through, and interact within the waveguide to selectively change each others' directions of propagation into predetermined channels. In one embodiment, the switch utilizes a rectangularly planar slab waveguide, and further includes two central channels and a plurality of lateral channels for guiding the light bullets into and out of the waveguide. One advantage presented by the present all-optical switching device lies in its practical use of light bullets, thus preventing the degeneration of the pulses due to dispersion and diffraction at the front and back of the pulses. Another feature of the switching device is the relative insensitivity of the collision process to the time difference in which the counter-propagating pulses enter the waveguide. since. contrary to conventional co-propagating spatial solitons, the relative phase of the colliding pulses does not affect the interaction of these pulses. Yet another feature of the present all-optical switching device is the selection of the light pulse parameters which enables the generation of light bullets in highly nonlinear glasses.

Tunable Picosecond Laser Pulses via the Contrast of Two Reverse Saturable Absorption Phases in a Waveguide Platform

PubMed Central

Tan, Yang; Chen, Lianwei; Wang, Dong; Chen, Yanxue; Akhmadaliev, Shavkat; Zhou, Shengqiang; Hong, Minghui; Chen, Feng

2016-01-01

How to enhance the optical nonlinearity of saturable absorption materials is an important question to improve the functionality of various applications ranging from the high power laser to photonic computational devices. We demonstrate the saturable absorption (SA) of VO2 film attributed to the large difference of optical nonlinearities between the two states of the phase-transition materials (VO2). Such VO2 film demonstrated significantly improved performance with saturation intensity higher than other existing ultrathin saturable absorbers by 3 orders due to its unique nonlinear optical mechanisms in the ultrafast phase change process. Owing to this feature, a Q-switched pulsed laser was fabricated in a waveguide platform, which is the first time to achieve picosecond pulse duration and maintain high peak power. Furthermore, the emission of this VO2 waveguide laser can be flexibly switched between the continuous-wave (CW) and pulsed operation regimes by tuning the temperature of the VO2 film, which enables VO2-based miniature laser devices with unique and versatile functions. PMID:27188594

Frequency-degenerate phase-sensitive optical parametric amplification based on four-wave mixing in graphene–silicon slot waveguide

NASA Astrophysics Data System (ADS)

Li, Zhen; Liu, Hongjun; Huang, Nan; Wang, Zhaolu; Han, Jing

2018-06-01

The phase-sensitive amplification process of a hybrid graphene–silicon (HyGS) slot waveguide with trilayers of graphene is investigated in this paper. Numerical simulation shows that a relatively high extinction ratio (42 dB) is achieved, because of the ultrahigh nonlinear coefficients, with a waveguide length of only 680 µm. In addition, the graphene layer provides the possibility of modulating the phase status and gain of the output signal. This study is expected to be highly beneficial to applications such as integrated optics and graphene-related active optical devices.

Near-infrared lasers and self-frequency-doubling in Nd:YCOB cladding waveguides.

PubMed

Ren, Yingying; Chen, Feng; Vázquez de Aldana, Javier R

2013-05-06

A design of cladding waveguides in Nd:YCOB nonlinear crystals is demonstrated in this work. Compact Fabry-Perot oscillation cavities are employed for waveguide laser generation at 1062 nm and self-frequency-doubling at 531 nm, under optical pump at 810 nm. The waveguide laser shows slope efficiency as high as 55% at 1062 nm. The SFD green waveguide laser emits at 531 nm with a maximum power of 100 μW.

Nonlinear Light Dynamics in Multi-Core Structures

DTIC Science & Technology

2017-02-27

be generated in continuous- discrete optical media such as multi-core optical fiber or waveguide arrays; localisation dynamics in a continuous... discrete nonlinear system. Detailed theoretical analysis is presented of the existence and stability of the discrete -continuous light bullets using a very...and pulse compression using wave collapse (self-focusing) energy localisation dynamics in a continuous- discrete nonlinear system, as implemented in a

Optical Studies and Poling of DNA NLO Waveguides

NASA Astrophysics Data System (ADS)

Heckman, Emily; Grote, James

2005-04-01

Deoxyribonucleic acid (DNA), extracted from salmon sperm through an enzyme isolation process, is precipitated with a surfactant complex, cetyltrimethl-ammonium (CTMA), for application as a nonlinear optical material. Preliminary characterization studies suggest that DNA-CTMA may be suitable for use as the host material in the poled core layer of electro-optically-active waveguide devices. Poling results and techniques for poled chromophore-DNA-CTMA films will be discussed. Optical characterization studies of the DNA-CTMA films, including optical propagation losses and considerations in making DNA-CTMA an optical quality material, will be presented.

Surface normal coupling to multiple-slot and cover-slotted silicon nanocrystalline waveguides and ring resonators

NASA Astrophysics Data System (ADS)

Covey, John; Chen, Ray T.

2014-03-01

Grating couplers are ideal for coupling into the tightly confined propagation modes of semiconductor waveguides. In addition, nonlinear optics has benefited from the sub-diffraction limit confinement of horizontal slot waveguides. By combining these two advancements, slot-based nonlinear optics with mode areas less than 0.02 μm2 can become as routine as twisting fiber connectors together. Surface normal fiber alignment to a chip is also highly desirable from time, cost, and manufacturing considerations. To meet these considerable design challenges, a custom genetic algorithm is created which, starting from purely random designs, creates a unique four stage grating coupler for two novel horizontal slot waveguide platforms. For horizontal multiple-slot waveguides filled with silicon nanocrystal, a theoretical fiber-towaveguide coupling efficiency of 68% is obtained. For thin silicon waveguides clad with optically active silicon nanocrystal, known as cover-slot waveguides, a theoretical fiber-to-waveguide coupling efficiency of 47% is obtained, and 1 dB and 3 dB theoretical bandwidths of 70 nm and 150 nm are obtained, respectively. Both waveguide platforms are fabricated from scratch, and their respective on-chip grating couplers are experimentally measured from a standard single mode fiber array that is mounted surface normally. The horizontal multiple-slot grating coupler achieved an experimental 60% coupling efficiency, and the horizontal cover-slot grating coupler achieved an experimental 38.7% coupling efficiency, with an extrapolated 1 dB bandwidth of 66 nm. This report demonstrates the promise of genetic algorithm-based design by reducing to practice the first large bandwidth vertical grating coupler to a novel silicon nanocrystal horizontal cover-slot waveguide.

Ultra-wideband and high-gain parametric amplification in telecom wavelengths with an optimally mode-matched PPLN waveguide.

PubMed

Sua, Yong Meng; Chen, Jia-Yang; Huang, Yu-Ping

2018-06-15

We report a wideband optical parametric amplification (OPA) over 14 THz covering telecom S, C, and L bands with observed maximum parametric gain of 38.3 dB. The OPA is realized through cascaded second-harmonic generation and difference-frequency generation (cSHG-DFG) in a 2 cm periodically poled LiNbO 3 (PPLN) waveguide. With tailored cross section geometry, the waveguide is optimally mode matched for efficient cascaded nonlinear wave mixing. We also identify and study the effect of competing nonlinear processes in this cSHG-DFG configuration.

Unambiguous demonstration of soliton evolution in slow-light silicon photonic crystal waveguides with SFG-XFROG.

PubMed

Li, Xiujian; Liao, Jiali; Nie, Yongming; Marko, Matthew; Jia, Hui; Liu, Ju; Wang, Xiaochun; Wong, Chee Wei

2015-04-20

We demonstrate the temporal and spectral evolution of picosecond soliton in the slow light silicon photonic crystal waveguides (PhCWs) by sum frequency generation cross-correlation frequency resolved optical grating (SFG-XFROG) and nonlinear Schrödinger equation (NLSE) modeling. The reference pulses for the SFG-XFROG measurements are unambiguously pre-characterized by the second harmonic generation frequency resolved optical gating (SHG-FROG) assisted with the combination of NLSE simulations and optical spectrum analyzer (OSA) measurements. Regardless of the inevitable nonlinear two photon absorption, high order soliton compressions have been observed remarkably owing to the slow light enhanced nonlinear effects in the silicon PhCWs. Both the measurements and the further numerical analyses of the pulse dynamics indicate that, the free carrier dispersion (FCD) enhanced by the slow light effects is mainly responsible for the compression, the acceleration, and the spectral blue shift of the soliton.

Coherent centres for light amplification in coupled waveguide arrays

NASA Astrophysics Data System (ADS)

Tripathi, Aditya; Kumar, Sunil

2018-07-01

In the study of optical lattices of waveguides, incorporation of nearest neighbour coupling and controllable nonlinearity can result in many interesting phenomena such as discrete diffraction, Anderson localization, diffusive transport, self-defocusing, discrete spatial solitons and discrete photonic resonances. The question of reflecting boundaries at the surfaces has been ignored most often. In the present study, we have shown through a simple one-dimensional waveguide array that light propagation gets completely modified along the length if effects from reflecting boundaries are also considered. We have shown only by considering the coupling on between neighbouring waveguides that there are periodic maximum power centres along the length of the excited waveguides which can be desirable for placing optical amplifiers in short or long distance communication and other applications.

A silicon Brillouin laser

NASA Astrophysics Data System (ADS)

Otterstrom, Nils T.; Behunin, Ryan O.; Kittlaus, Eric A.; Wang, Zheng; Rakich, Peter T.

2018-06-01

Brillouin laser oscillators offer powerful and flexible dynamics as the basis for mode-locked lasers, microwave oscillators, and optical gyroscopes in a variety of optical systems. However, Brillouin interactions are markedly weak in conventional silicon photonic waveguides, stifling progress toward silicon-based Brillouin lasers. The recent advent of hybrid photonic-phononic waveguides has revealed Brillouin interactions to be one of the strongest and most tailorable nonlinearities in silicon. In this study, we have harnessed these engineered nonlinearities to demonstrate Brillouin lasing in silicon. Moreover, we show that this silicon-based Brillouin laser enters a regime of dynamics in which optical self-oscillation produces phonon linewidth narrowing. Our results provide a platform to develop a range of applications for monolithic integration within silicon photonic circuits.

Tuning group-velocity dispersion by optical force.

PubMed

Jiang, Wei C; Lin, Qiang

2013-07-15

We propose an optomechanical approach for dispersion dynamic tuning and microengineering by taking advantage of the optical force in nano-optomechanical structures. Simulations of a suspended coupled silicon waveguide show that the zero-dispersion wavelength can be tuned by 40 nm by an optical pump power of 3 mW. Our approach exhibits great potential for broad applications in dispersion-sensitive processes, which not only offers a new root toward versatile tunable nonlinear photonics but may also open up a great avenue toward a new regime of nonlinear dynamics coupling between nonlinear optical and optomechanical effects.

All-optical Integrated Switches Based on Azo-benzene Liquid Crystals on Silicon

DTIC Science & Technology

2011-11-01

Glass D263 SU8 Polymer Polymer NLC n̂ n̂ Refractive index @1.55 µm Materials n// = 1.689 n⊥= 1.502 n = 1.575 n = 1.516 E7 Glass D263 SU8 ...In the other case we have a nonlinear LCW based on glass substrates. It consists in a rectangular hollow realized in SU8 photoresist two glass...and discussion 5. All optical polymeric waveguide: methods, assumptions and procedure 6. All optical polymeric waveguide: results and discussion 7

Ultrashort optical waveguide excitations in uniaxial silica fibers: elastic collision scenarios.

PubMed

Kuetche, Victor K; Youssoufa, Saliou; Kofane, Timoleon C

2014-12-01

In this work, we investigate the dynamics of an uniaxial silica fiber under the viewpoint of propagation of ultimately ultrashort optical waveguide channels. As a result, we unveil the existence of three typical kinds of ultrabroadband excitations whose profiles strongly depend upon their angular momenta. Looking forward to surveying their scattering features, we unearth some underlying head-on scenarios of elastic collisions. Accordingly, we address some useful and straightforward applications in nonlinear optics through secured data transmission systems, as well as laser physics and soliton theory with optical soliton dynamics.

Solitary wave for a nonintegrable discrete nonlinear Schrödinger equation in nonlinear optical waveguide arrays

NASA Astrophysics Data System (ADS)

Ma, Li-Yuan; Ji, Jia-Liang; Xu, Zong-Wei; Zhu, Zuo-Nong

2018-03-01

We study a nonintegrable discrete nonlinear Schrödinger (dNLS) equation with the term of nonlinear nearest-neighbor interaction occurred in nonlinear optical waveguide arrays. By using discrete Fourier transformation, we obtain numerical approximations of stationary and travelling solitary wave solutions of the nonintegrable dNLS equation. The analysis of stability of stationary solitary waves is performed. It is shown that the nonlinear nearest-neighbor interaction term has great influence on the form of solitary wave. The shape of solitary wave is important in the electric field propagating. If we neglect the nonlinear nearest-neighbor interaction term, much important information in the electric field propagating may be missed. Our numerical simulation also demonstrates the difference of chaos phenomenon between the nonintegrable dNLS equation with nonlinear nearest-neighbor interaction and another nonintegrable dNLS equation without the term. Project supported by the National Natural Science Foundation of China (Grant Nos. 11671255 and 11701510), the Ministry of Economy and Competitiveness of Spain (Grant No. MTM2016-80276-P (AEI/FEDER, EU)), and the China Postdoctoral Science Foundation (Grant No. 2017M621964).

Growth and nonlinear optical characterization of organic single crystal films

NASA Astrophysics Data System (ADS)

Zhou, Ligui

1997-12-01

Organic single crystal films are important for various future applications in photonics and integrated optics. The conventional method for inorganic crystal growth is not suitable for organic materials, and the high temperature melting method is not good for most organic materials due to decomposition problems. We developed a new method-modified shear method-to grow large area organic single crystal thin films which have exceptional nonlinear optical properties and high quality surfaces. Several organic materials (NPP, PNP and DAST) were synthesized and purified before the thin film crystal growth. Organic single crystal thin films were grown from saturated organic solutions using modified shear method. The area of single crystal films were about 1.5 cm2 for PNP, 1 cm2 for NPP and 5 mm2 for DAST. The thickness of the thin films which could be controlled by the applied pressure ranged from 1μm to 10 μm. The single crystal thin films of organic materials were characterized by polarized microscopy, x-ray diffraction, polarized UV-Visible and polarized micro-FTIR spectroscopy. Polarized microscopy showed uniform birefringence and complete extinction with the rotation of the single crystal thin films under crossed- polarization, which indicated high quality single crystals with no scattering. The surface orientation of single crystal thin films was characterized by x-ray diffraction. The molecular orientation within the crystal was further studied by the polarized UV-Visible and Polarized micro-FTIR techniques combined with the x-ray and polarized microscopy results. A Nd:YAG laser with 35 picosecond pulses at 1064nm wavelength was employed to perform the nonlinear optical characterization of the organic single crystal thin films. Two measurement techniques were used to study the crystal films: second harmonic generation (SHG) and electro-optic (EO) effect. SHG results showed that the nonlinear optical coefficient of NPP was 18 times that of LiNbO3, a standard inorganic crystal material, and the nonlinear optical coefficient of PNP was 11 times that of LiNbO3. Electro-optic measurements showed that r11 = 65 pm/V for NPP and r12 = 350 pm/V for DAST. EO modulation effect was also observed using Fabry-Perot interferometry. Waveguide devices are very important for integrated optics. But the fabrication of waveguide devices on the organic single crystal thin films was difficult due to the solubility of the film in common organic solvents. A modified photolithographic technique was employed to make channel waveguides and poly(vinyl alcohol) (PVA) was used as a protective layer in the fabrication of the waveguides. Waveguides with dimensions about 7/mum x 1μm x 1mm were obtained.

Low loss GaN waveguides at the visible spectral wavelengths for integrated photonics applications.

PubMed

Chen, Hong; Fu, Houqiang; Huang, Xuanqi; Zhang, Xiaodong; Yang, Tsung-Han; Montes, Jossue A; Baranowski, Izak; Zhao, Yuji

2017-12-11

We perform comprehensive studies on the fundamental loss mechanisms in III-nitride waveguides in the visible spectral region. Theoretical analysis shows that free carrier loss dominates for GaN under low photon power injection. When optical power increases, the two photon absorption loss becomes important and eventually dominates when photon energy above half-bandgap of GaN. When the dimensions of the waveguides reduce, the sidewall scattering loss will start to dominate. To verify the theoretical results, a high performance GaN-on-sapphire waveguide was fabricated and characterized. Experimental results are consistent with the theoretical findings, showing that under high power injection the optical loss changed significantly for GaN waveguides. A low optical loss ~2 dB/cm was achieved on the GaN waveguide, which is the lowest value ever reported for the visible spectral range. The results and fabrication processes developed in this work pave the way for the development of III-nitride integrated photonics in the visible and potentially ultraviolet spectral range for nonlinear optics and quantum photonics applications.

Methods for discrete solitons in nonlinear lattices.

PubMed

Ablowitz, Mark J; Musslimani, Ziad H; Biondini, Gino

2002-02-01

A method to find discrete solitons in nonlinear lattices is introduced. Using nonlinear optical waveguide arrays as a prototype application, both stationary and traveling-wave solitons are investigated. In the limit of small wave velocity, a fully discrete perturbative analysis yields formulas for the mode shapes and velocity.

Low loss hollow-core waveguide on a silicon substrate

NASA Astrophysics Data System (ADS)

Yang, Weijian; Ferrara, James; Grutter, Karen; Yeh, Anthony; Chase, Chris; Yue, Yang; Willner, Alan E.; Wu, Ming C.; Chang-Hasnain, Connie J.

2012-07-01

Optical-fiber-based, hollow-core waveguides (HCWs) have opened up many new applications in laser surgery, gas sensors, and non-linear optics. Chip-scale HCWs are desirable because they are compact, light-weight and can be integrated with other devices into systems-on-a-chip. However, their progress has been hindered by the lack of a low loss waveguide architecture. Here, a completely new waveguiding concept is demonstrated using two planar, parallel, silicon-on-insulator wafers with high-contrast subwavelength gratings to reflect light in-between. We report a record low optical loss of 0.37 dB/cm for a 9-μm waveguide, mode-matched to a single mode fiber. Two-dimensional light confinement is experimentally realized without sidewalls in the HCWs, which is promising for ultrafast sensing response with nearly instantaneous flow of gases or fluids. This unique waveguide geometry establishes an entirely new scheme for low-cost chip-scale sensor arrays and lab-on-a-chip applications.

Coupling Ideality of Integrated Planar High-Q Microresonators

NASA Astrophysics Data System (ADS)

Pfeiffer, Martin H. P.; Liu, Junqiu; Geiselmann, Michael; Kippenberg, Tobias J.

2017-02-01

Chip-scale optical microresonators with integrated planar optical waveguides are useful building blocks for linear, nonlinear, and quantum-optical photonic devices alike. Loss reduction through improving fabrication processes results in several integrated microresonator platforms attaining quality (Q ) factors of several millions. Beyond the improvement of the quality factor, the ability to operate the microresonator with high coupling ideality in the overcoupled regime is of central importance. In this regime, the dominant source of loss constitutes the coupling to a single desired output channel, which is particularly important not only for quantum-optical applications such as the generation of squeezed light and correlated photon pairs but also for linear and nonlinear photonics. However, to date, the coupling ideality in integrated photonic microresonators is not well understood, in particular, design-dependent losses and their impact on the regime of high ideality. Here we investigate design-dependent parasitic losses described by the coupling ideality of the commonly employed microresonator design consisting of a microring-resonator waveguide side coupled to a straight bus waveguide, a system which is not properly described by the conventional input-output theory of open systems due to the presence of higher-order modes. By systematic characterization of multimode high-Q silicon nitride microresonator devices, we show that this design can suffer from low coupling ideality. By performing 3D simulations, we identify the coupling to higher-order bus waveguide modes as the dominant origin of parasitic losses which lead to the low coupling ideality. Using suitably designed bus waveguides, parasitic losses are mitigated with a nearly unity ideality and strong overcoupling (i.e., a ratio of external coupling to internal resonator loss rate >9 ) are demonstrated. Moreover, we find that different resonator modes can exchange power through the coupler, which, therefore, constitutes a mechanism that induces modal coupling, a phenomenon known to distort resonator dispersion properties. Our results demonstrate the potential for significant performance improvements of integrated planar microresonators for applications in quantum optics and nonlinear photonics achievable by optimized coupler designs.

Dark Solitons in High Velocity Waveguide Polariton Fluids.

PubMed

Walker, P M; Tinkler, L; Royall, B; Skryabin, D V; Farrer, I; Ritchie, D A; Skolnick, M S; Krizhanovskii, D N

2017-09-01

We study exciton-polariton nonlinear optical fluids in the high momentum waveguide regime for the first time. We demonstrate the formation of dark solitons with the expected dependence of width on fluid density for both main classes of soliton-forming fluid defects. The results are well described by numerical modeling of the fluid propagation. We deduce a continuous wave nonlinearity more than ten times that on picosecond time scales, arising due to interaction with the exciton reservoir.

Monolithic integration of active and second-order nonlinear functionality in Bragg reflection waveguides

NASA Astrophysics Data System (ADS)

Bijlani, Bhavin J.

2011-07-01

This thesis explored the theory, design, fabrication and characterization of AlGaAs Bragg reflection waveguides (BRW) towards the goal of a platform for monolithic integration of active and optically nonlinear devices. Through integration of a diode laser and nonlinear phase-matched cavity, the possibility of on-chip nonlinear frequency generation was explored. Such integrated devices would be highly useful as a robust, alignment free, small footprint and electrically injected alternative to bulk optic systems. A theoretical framework for modal analysis of arbitrary 1-D photonic crystal defect waveguides is developed. This method relies on the transverse resonance condition. It is then demonstrated in the context of several types of Bragg reflection waveguides. The framework is then extended to phase-match second-order nonlinearities and incorporating quantum-wells for diode lasers. Experiments within a slab and ridge waveguide demonstrated phase-matched Type-I second harmonic generation at fundamental wavelength of 1587 and 1600 nm, respectively; a first for this type of waveguide. For the slab waveguide, conversion efficiency was 0.1 %/W. In the more strongly confined ridge waveguides, efficiency increased to 8.6 %/W owing to the increased intensity. The normalized conversion efficiency was estimated to be at 600 %/Wcm2. Diode lasers emitting at 980 nm in the BRW mode were also fabricated. Verification of the Bragg mode was performed through imaging the near- field of the mode. Propagation loss of this type of mode was measured directly for the first time at ≈ 14 cm-1. The lasers were found to be very insensitive with characteristic temperature at 215 K. Two designs incorporating both laser and phase-matched nonlinearity within the same cavity were fabricated, for degenerate and non-degenerate down-conversion. Though the lasers were sub-optimal, a parametric fluorescence signal was readily detected. Fluorescence power as high as 4 nW for the degenerate design and 5 nW for the non-degenerate design were detected. The conversion efficiency was 4176 %/Wcm2 and 874 %/Wcm2, respectively. Neither design was found to emit near the design wavelength. In general, the signal is between 1600-1800 nm and the idler is between 2200-2400 nm. Improvements in laser performance are expected to drastically increase the conversion efficiency.

Electro-optical modulator in a polymerinfiltrated silicon slotted photonic crystal waveguide heterostructure resonator.

PubMed

Wülbern, Jan Hendrik; Petrov, Alexander; Eich, Manfred

2009-01-05

We present a novel concept of a compact, ultra fast electro-optic modulator, based on photonic crystal resonator structures that can be realized in two dimensional photonic crystal slabs of silicon as core material employing a nonlinear optical polymer as infiltration and cladding material. The novel concept is to combine a photonic crystal heterostructure cavity with a slotted defect waveguide. The photonic crystal lattice can be used as a distributed electrode for the application of a modulation signal. An electrical contact is hence provided while the optical wave is kept isolated from the lossy metal electrodes. Thereby, well known disadvantages of segmented electrode designs such as excessive scattering are avoided. The optical field enhancement in the slotted region increases the nonlinear interaction with an external electric field resulting in an envisaged switching voltage of approximately 1 V at modulation speeds up to 100 GHz.

Nonlinear and non-Hermitian optical systems applied to the development of filters and optical sensors

NASA Astrophysics Data System (ADS)

Amaro de Faria Júnior, A. C.

2015-09-01

In this work we present a method of investigation of nonlinear optical beams generated from non-Hermitian optical systems1 . This method can be applied in the development of optical filters and optical sensors to process, analyze and choose the passband of the propagation modes of an optical pulse from an non-Hermitian optical system. Non-Hermitian optical systems can be used to develop optical fiber sensors that suppress certain propagation modes of optical pulses that eventually behave as quantum noise. Such systems are described by the Nonlinear Schrödinger-like Equation with Parity-Time (PT) Symmetric Optical Potentials. There are optical fiber sensors that due to high laser intensity and frequency can produce quantum noise, such as Raman and Brillouin scattering. However, the optical fiber, for example, can be designed so that its geometry suppress certain propagation modes of the beam. We apply some results of non- Hermitian optical systems with PT symmetry to simulate optical lattice by a appropriate potential function, which among other applications, can naturally suppress certain propagation modes of an optical beam propagating through a waveguide. In other words, the optical system is modeled by a potential function in the Nonlinear Schrödinger-like Equation that one relates with the geometric aspects of the wave guides and with the optical beam interacting with the waveguide material. The paper is organized as follows: sections 1 and 2 present a brief description about nonlinear optical systems and non-Hermitian optical systems with PT symmetry. Section 3 presents a description of the dynamics of nonlinear optical pulses propagating through optical networks described by a optical potential non-Hermitian. Sections 4 and 5 present a general description of this non-Hermitian optical systems and how to get them from a more general model. Section 6 presents some conclusions and comment and the final section presents the references. Begin the abstract two lines below author names and addresses.

Coupling and Switching in Optically Resonant Periodic Electrode Structures

NASA Astrophysics Data System (ADS)

Bieber, Amy Erica

This thesis describes coupling and switching of optical radiation using metal-semiconductor-metal (MSM) structures, specifically in a metal-on-silicon waveguide configuration. The structures which are the subject of this research have the special advantage of being VLSI -compatible; this is very important for the ultimate acceptance of any integrated optoelectronics technology by the mainstream semiconductor community. To date, research efforts in VLSI electronics, MSM detectors, metal devices, and optical switching have existed as separate entities with decidedly different goals. This work attempts to unite these specialties; an interdigitated array of metal fingers on a silicon waveguide allows for (1) fabrication processes which are well-understood and compatible with current or next-generation semiconductor manufacturing standards, (2) electrical bias capability which can potentially provide modulation, tuning, and enhanced speed, and (3) potentially efficient waveguide coupling which takes advantage of TM coupling. The latter two items are made possible by the use of metallic gratings, which sets this work apart from previous optical switching results. This MSM structure represents an important step in uniting four vital technologies which, taken together, can lead to switching performance and operational flexibility which could substantially advance the capabilities of current optoelectronic devices. Three different designs were successfully used to examine modulation and optical switching based upon nonlinear interactions in the silicon waveguide. First, a traditional Bragg reflector design with input and output couplers on either side was used to observe switching of nanosecond-regime Nd:YAG pulses. This structure was thermally tuned to obtain a variety of switching dynamics. Next, a phase-shift was incorporated into the Bragg reflector, and again thermally-tunable switching dynamics were observed, but with the added advantage of a reduction in the energy requirements for optical switching. Finally, the roles of the coupler and Bragg reflector were combined in a normal -incidence structure which exhibited nonlinear reflectivity modulation. This has not only been the first experimental demonstration of optical switching in a metal-semiconductor waveguide structure, but, to our knowledge, one of the first such demonstrations using a nonlinear phase-shifted or normal incidence grating of any kind.

Observation of nonlinear optical interactions of ultralow levels of light in a tapered optical nanofiber embedded in a hot rubidium vapor.

PubMed

Spillane, S M; Pati, G S; Salit, K; Hall, M; Kumar, P; Beausoleil, R G; Shahriar, M S

2008-06-13

We report the observation of low-light level optical interactions in a tapered optical nanofiber (TNF) embedded in a hot rubidium vapor. The small optical mode area plays a significant role in the optical properties of the hot vapor Rb-TNF system, allowing nonlinear optical interactions with nW level powers even in the presence of transit-time dephasing rates much larger than the intrinsic linewidth. We demonstrate nonlinear absorption and V-type electromagnetically induced transparency with cw powers below 10 nW, comparable to the best results in any Rb-optical waveguide system. The good performance and flexibility of the Rb-TNF system makes it a very promising candidate for ultralow power resonant nonlinear optical applications.

Quasi-phase-matched χ(3 )-parametric interactions in sinusoidally tapered waveguides

NASA Astrophysics Data System (ADS)

Saleh, Mohammed F.

2018-01-01

In this article, I show how periodically tapered waveguides can be employed as efficient quasi-phase-matching schemes for four-wave mixing parametric processes in third-order nonlinear materials. As an example, a thorough study of enhancing third-harmonic generation in sinusoidally tapered fibers has been conducted. The quasi-phase-matching condition has been obtained for nonlinear parametric interactions in these structures using Fourier-series analysis. The dependencies of the conversion efficiency of the third harmonic on the modulation amplitude, tapering period, longitudinal-propagation direction, and pump wavelength have been studied. In comparison to uniform waveguides, the conversion efficiency has been enhanced by orders of magnitudes. I envisage that this work will have a great impact in the field of guided nonlinear optics using centrosymmetric materials.

Nanoscale light–matter interactions in atomic cladding waveguides

PubMed Central

Stern, Liron; Desiatov, Boris; Goykhman, Ilya; Levy, Uriel

2013-01-01

Alkali vapours, such as rubidium, are being used extensively in several important fields of research such as slow and stored light nonlinear optics quantum computation, atomic clocks and magnetometers. Recently, there is a growing effort towards miniaturizing traditional centimetre-size vapour cells. Owing to the significant reduction in device dimensions, light–matter interactions are greatly enhanced, enabling new functionalities due to the low power threshold needed for nonlinear interactions. Here, taking advantage of the mature platform of silicon photonics, we construct an efficient and flexible platform for tailored light–vapour interactions on a chip. Specifically, we demonstrate light–matter interactions in an atomic cladding waveguide, consisting of a silicon nitride nano-waveguide core with a rubidium vapour cladding. We observe the efficient interaction of the electromagnetic guided mode with the rubidium cladding and show that due to the high confinement of the optical mode, the rubidium absorption saturates at powers in the nanowatt regime. PMID:23462991

Design of ultra-broadband terahertz polymer waveguide emitters for telecom wavelengths using coupled mode theory.

PubMed

Vallejo, Felipe A; Hayden, L Michael

2013-03-11

We use coupled mode theory, adequately incorporating optical losses, to model ultra-broadband terahertz (THz) waveguide emitters (0.1-20 THz) based on difference frequency generation of femtosecond infrared (IR) optical pulses. We apply the model to a generic, symmetric, five-layer, metal/cladding/core waveguide structure using transfer matrix theory. We provide a design strategy for an efficient ultra-broadband THz emitter and apply it to polymer waveguides with a nonlinear core composed of a poled guest-host electro-optic polymer composite and pumped by a pulsed fiber laser system operating at 1567 nm. The predicted bandwidths are greater than 15 THz and we find a high conversion efficiency of 1.2 × 10(-4) W(-1) by balancing both the modal phase-matching and effective mode attenuation.

Flexible integration of free-standing nanowires into silicon photonics.

PubMed

Chen, Bigeng; Wu, Hao; Xin, Chenguang; Dai, Daoxin; Tong, Limin

2017-06-14

Silicon photonics has been developed successfully with a top-down fabrication technique to enable large-scale photonic integrated circuits with high reproducibility, but is limited intrinsically by the material capability for active or nonlinear applications. On the other hand, free-standing nanowires synthesized via a bottom-up growth present great material diversity and structural uniformity, but precisely assembling free-standing nanowires for on-demand photonic functionality remains a great challenge. Here we report hybrid integration of free-standing nanowires into silicon photonics with high flexibility by coupling free-standing nanowires onto target silicon waveguides that are simultaneously used for precise positioning. Coupling efficiency between a free-standing nanowire and a silicon waveguide is up to ~97% in the telecommunication band. A hybrid nonlinear-free-standing nanowires-silicon waveguides Mach-Zehnder interferometer and a racetrack resonator for significantly enhanced optical modulation are experimentally demonstrated, as well as hybrid active-free-standing nanowires-silicon waveguides circuits for light generation. These results suggest an alternative approach to flexible multifunctional on-chip nanophotonic devices.Precisely assembling free-standing nanowires for on-demand photonic functionality remains a challenge. Here, Chen et al. integrate free-standing nanowires into silicon waveguides and show all-optical modulation and light generation on silicon photonic chips.

Guest-host polymer fibers for nonlinear optics

NASA Astrophysics Data System (ADS)

Kuzyk, M. G.; Paek, U. C.; Dirk, C. W.

1991-08-01

We report on the fabrication of poly(methyl methacrylate) (PMMA) nonlinear optical fibers with dye-doped cores. The dye-doped cores have an elevated refractive index that defines a waveguiding region with a large third-order susceptibility and with single-mode dimensions. The measured third-order susceptibility of a squarylium-doped PMMA film material and the measured optical loss of the dye-doped fiber core results in a figure of merit that is suitable for all-optical device applications at λ=1.3 μm. The impact of further improvements in PMMA loss and chromophore nonlinearity are also discussed.

Novel optical waveguides by in-depth controlled electronic damage with swift ions

NASA Astrophysics Data System (ADS)

Olivares, J.; García-Navarro, A.; Méndez, A.; Agulló-López, F.; García, G.; García-Cabañes, A.; Carrascosa, M.

2007-04-01

We review recent results on a novel method to modify crystalline dielectric materials and fabricate optical waveguides and integrated optics devices. It relies on irradiation with medium-mass high-energy ions (2-50 MeV) where the electronic stopping power is dominant over that one associated to nuclear collisions. By exploiting the processing capabilities of the method, novel optical structures can be achieved at moderate (1014 cm-2) and even low and ultralow (1012 cm-2) fluences. In particular, step-like waveguides with a high index jump Δn ∼ 0.1-0.2, guiding both ordinary and extraordinary modes, have been prepared with F and O ions (20 MeV) at moderate fluences. They present good non-linear and electrooptic perfomance and low losses. (1 dB/cm). Moreover, useful optical waveguiding has been also achieved at ultralow frequencies (isolated track regime), using Cl and Si ions (40-45 MeV). In this latter case, the individual amorphous nanotracks, whose radius increases with depth, create an effective optical medium causing optical trapping.

Fabrication of ultrafast laser written low-loss waveguides in flexible As₂S₃ chalcogenide glass tape.

PubMed

Lapointe, Jerome; Ledemi, Yannick; Loranger, Sébastien; Iezzi, Victor Lambin; Soares de Lima Filho, Elton; Parent, Francois; Morency, Steeve; Messaddeq, Younes; Kashyap, Raman

2016-01-15

As2S3 glass has a unique combination of optical properties, such as wide transparency in the infrared region and a high nonlinear coefficient. Recently, intense research has been conducted to improve photonic devices using thin materials. In this Letter, highly uniform rectangular single-index and 2 dB/m loss step-index optical tapes have been drawn by the crucible technique. Low-loss (<0.15  dB/cm) single-mode waveguides in chalcogenide glass tapes have been fabricated using femtosecond laser writing. Optical backscatter reflectometry has been used to study the origin of the optical losses. A detailed study of the laser writing process in thin glass is also presented to facilitate a repeatable waveguide inscription recipe.

Integrated optical devices based on sol – gel waveguides using the temperature dependence of the effective refractive index

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavlov, S V; Trofimov, N S; Chekhlova, T K

2014-07-31

A possibility of designing optical waveguide devices based on sol – gel SiO{sub 2} – TiO{sub 2} films using the temperature dependence of the effective refractive index is shown. The dependences of the device characteristics on the parameters of the film and opticalsystem elements are analysed. The operation of a temperature recorder and a temperature limiter with a resolution of 0.6 K mm{sup -1} is demonstrated. The film and output-prism parameters are optimised. (fibreoptic and nonlinear-optic devices)

Tunable all-optical plasmonic rectifier in nanoscale metal-insulator-metal waveguides.

PubMed

Xu, Yi; Wang, Xiaomeng; Deng, Haidong; Guo, Kangxian

2014-10-15

We propose a tunable all-optical plasmonic rectifier based on the nonlinear Fano resonance in a metal-insulator-metal plasmonic waveguide and cavities coupling system. We develop a theoretical model based on the temporal coupled-mode theory to study the device physics of the nanoscale rectifier. We further demonstrate via the finite difference time domain numerical experiment that our idea can be realized in a plasmonic system with an ultracompact size of ~120×800  nm². The tunable plasmonic rectifier could facilitate the all-optical signal processing in nanoscale.

Nonlinearity-dependent asymmetric transmission in a sawtooth photonic lattice with defects

NASA Astrophysics Data System (ADS)

Ji, Kaiwen; Qi, Xinyuan; Li, Shasha; Han, Kun; Wen, Zengrun; Zhang, Guoquan; Bai, Jintao

2018-04-01

We study both theoretically and numerically the asymetric transmission of a Gaussian beam in a two-dimensional nonlinear sawtooth lattice with two defects. The results show that quasi-total reflection, asymmetric propagation and asymmetric reflection can all be achieved in such a system by adjusting the input intensity, the magnitude of defects and the number of nonlinear waveguides. This study may provide a new way to realize an optical switch and optical diode.

Semi-automatic engineering and tailoring of high-efficiency Bragg-reflection waveguide samples for quantum photonic applications

NASA Astrophysics Data System (ADS)

Pressl, B.; Laiho, K.; Chen, H.; Günthner, T.; Schlager, A.; Auchter, S.; Suchomel, H.; Kamp, M.; Höfling, S.; Schneider, C.; Weihs, G.

2018-04-01

Semiconductor alloys of aluminum gallium arsenide (AlGaAs) exhibit strong second-order optical nonlinearities. This makes them prime candidates for the integration of devices for classical nonlinear optical frequency conversion or photon-pair production, for example, through the parametric down-conversion (PDC) process. Within this material system, Bragg-reflection waveguides (BRW) are a promising platform, but the specifics of the fabrication process and the peculiar optical properties of the alloys require careful engineering. Previously, BRW samples have been mostly derived analytically from design equations using a fixed set of aluminum concentrations. This approach limits the variety and flexibility of the device design. Here, we present a comprehensive guide to the design and analysis of advanced BRW samples and show how to automatize these tasks. Then, nonlinear optimization techniques are employed to tailor the BRW epitaxial structure towards a specific design goal. As a demonstration of our approach, we search for the optimal effective nonlinearity and mode overlap which indicate an improved conversion efficiency or PDC pair production rate. However, the methodology itself is much more versatile as any parameter related to the optical properties of the waveguide, for example the phasematching wavelength or modal dispersion, may be incorporated as design goals. Further, we use the developed tools to gain a reliable insight in the fabrication tolerances and challenges of real-world sample imperfections. One such example is the common thickness gradient along the wafer, which strongly influences the photon-pair rate and spectral properties of the PDC process. Detailed models and a better understanding of the optical properties of a realistic BRW structure are not only useful for investigating current samples, but also provide important feedback for the design and fabrication of potential future turn-key devices.

Self-Organization of Light in Optical Media with Competing Nonlinearities.

PubMed

Maucher, F; Pohl, T; Skupin, S; Krolikowski, W

2016-04-22

We study the propagation of light beams through optical media with competing nonlocal nonlinearities. We demonstrate that the nonlocality of competing focusing and defocusing nonlinearities gives rise to self-organization and stationary states with stable hexagonal intensity patterns, akin to transverse crystals of light filaments. Signatures of this long-range ordering are shown to be observable in the propagation of light in optical waveguides and even in free space. We consider a specific form of the nonlinear response that arises in atomic vapor upon proper light coupling. Yet, the general phenomenon of self-organization is a generic consequence of competing nonlocal nonlinearities, and may, hence, also be observed in other settings.

Guided-wave phase-matched second-harmonic generation in KTiOPO4 waveguide produced by swift heavy-ion irradiation

NASA Astrophysics Data System (ADS)

Cheng, Yazhou; Jia, Yuechen; Akhmadaliev, Shavkat; Zhou, Shengqiang; Chen, Feng

2014-11-01

We report on the guided-wave second-harmonic generation in a KTiOPO4 nonlinear optical waveguide fabricated by a 17 MeV O5+ ion irradiation at a fluence of 1.5×1015 ions/cm2. The waveguide guides light along both TE and TM polarizations, which is suitable for phase-matching frequency doubling. Second harmonics of green light at a wavelength of 532 nm have been generated through the KTiOPO4 waveguide platform under an optical pump of fundamental wave at 1064 nm in both continuous-wave and pulsed regimes, reaching optical conversion efficiencies of 5.36%/W and 11.5%, respectively. The propagation losses have been determined to be ˜3.1 and ˜5.7 dB/cm for the TE and TM polarizations at a wavelength of 632.8 nm, respectively.

Single photons to multiple octaves: Engineering nonlinear optics in micro- and nano-structured media

DTIC Science & Technology

2017-05-18

generation and amplification of ultrafast IR pulses. Both efforts took advantage of microstructured nonlinear media, e.g. quasi -phasematched (QPM...enhance the wave-mixing efficiency, especially for low-power devices. Because errors in fabrication of waveguides and quasi - phasematching gratings are... experimental demonstration of optical parametric chirped pulse amplifiers (OPCPA) in apodized aperiodic QPMgratings for high repetition rate, high

FIBER AND INTEGRATED OPTICS: Propagation of radiation in a light-induced active waveguide

NASA Astrophysics Data System (ADS)

Afanas'ev, Anatolii A.; Samson, B. A.; Drits, V. V.; Yukhimenko, S. I.; Yakite, R. V.

1990-10-01

An investigation is reported of the properties of the normal modes of an active light-induced waveguide. It is shown that, in contrast to a dielectric waveguide, the presence of the active component may increase considerably the number of the normal modes and the angles of their scattering. In the case of an active light-induced waveguide in the form of a thin filament the normal modes exist and are amplified only in the case when the nonlinear correction to the refractive index is positive.

Coupled resonator optical waveguides based on silicon-on-insulator photonic wires

NASA Astrophysics Data System (ADS)

Xia, Fengnian; Sekaric, Lidija; O'Boyle, Martin; Vlasov, Yurii

2006-07-01

Coupled resonator optical waveguides (CROWs) comprised of up to 16 racetrack resonators based on silicon-on-insulator (SOI) photonic wires were fabricated and characterized. The optical properties of the CROWs were simulated using measured single resonator parameters based on a matrix approach. The group delay property of CROWs was also analyzed. The SOI based CROWs consisting of multiple resonators have extremely small footprints and can find applications in optical filtering, dispersion compensation, and optical buffering. Moreover, such CROW structure is a promising candidate for exploration of low light level nonlinear optics due to its resonant nature and compact mode size (˜0.1μm2) in photonic wire.

Fabrication and Characterization of Linear and Nonlinear Photonic Devices in Fused Silica by Femtosecond Laser Writing

NASA Astrophysics Data System (ADS)

Ng, Jason Clement

Femtosecond laser processing is a flexible, three-dimensional (3D) fabrication technique used to make integrated low-loss photonic devices in fused silica. My work expanded the suite of available optical devices through the design and optimization of linear optical components such as low-loss (< 0.5 dB) curved waveguides, directional couplers (DCs), and Mach-Zehnder interferometers (MZIs). The robustness and consistency of this maturing fabrication process was also reinforced through the scalable design and integration of a more complex, multi-component flat-top interleaver over a wide >70-nm spectral window. My work further complemented femtosecond laser processing with the development of nonlinear device capabilities. While thermal poling is a well known process, significant challenges had restricted the development of nonlinear devices in fused silica. The laser writing process would erase the induced nonlinearity (erasing) while a written waveguide core acted as a barrier to the thermal poling process (blocking). Using second harmonic (SH) microscopy, the effectiveness of thermal poling on laser-written waveguides was systematically analyzed leading to the technique of "double poling", which effectively overcomes the two challenges of erasing and blocking. In this new process the substrate is poled before and after waveguide writing to restore the induced nonlinearity within the vicinity of the waveguide to enable effective poling for inducing a second-order nonlinearity (SON) in fused silica. A new flexible, femtosecond laser based erasure process was also developed to enable quasi-phase matching and to form arbitrarily chirped gratings. Following this result, second harmonic generation (SHG) in a quasiphase-matched (QPM) femtosecond laser written waveguide device was demonstrated. SHG in a chirped QPM structure was also demonstrated to illustrate the flexibility of the femtosecond laser writing technique. These are the first demonstration of frequency doubling in an all-femtosecond-laser-written structure. A maximum SHG conversion efficiency of 1.3 +/- 0.1x10 -11/W-cm-2 was achieved for the fundamental wavelength of 1552.8 nm with a phase-matching bandwidth of 4.4 nm for a 10.0-mm-long waveguide. For a shorter sample, an effective SON of chi(2) = 0:020 +/- 0:002 pm/V was measured. The results collectively demonstrate the versatility of femtosecond laser additive and subtractive fabrication and opens up the development of integrated nonlinear applications and photonic devices for future lab-on-a-chip and lab-in-a-fiber devices.

Optical Arbitrary Waveform Generators Based on Temporal and Spectral Shaping of Optical Pulses in Nonlinear Metamaterials

DTIC Science & Technology

2011-06-01

of a flat-top (thin lines) and a kink (thick lines) soliton . Here = 0.25,Q = 1.786 553 604 650 208 for the dark soliton (Q = 1.786 553 7 for the flat...localization and transport in different physical settings, ranging from metal-dielectric (i.e. plasmonic) to photonic crystal waveguides. The solitons ...settings, ranging from metal--dielectric (i.e. plasmonic) to photonic crystal waveguides. The solitons exist for focusing, defocusing and even for

Two-dimensional solitons in conservative and parity-time-symmetric triple-core waveguides with cubic-quintic nonlinearity

NASA Astrophysics Data System (ADS)

Feijoo, David; Zezyulin, Dmitry A.; Konotop, Vladimir V.

2015-12-01

We analyze a system of three two-dimensional nonlinear Schrödinger equations coupled by linear terms and with the cubic-quintic (focusing-defocusing) nonlinearity. We consider two versions of the model: conservative and parity-time (PT ) symmetric. These models describe triple-core nonlinear optical waveguides, with balanced gain and losses in the PT -symmetric case. We obtain families of soliton solutions and discuss their stability. The latter study is performed using a linear stability analysis and checked with direct numerical simulations of the evolutional system of equations. Stable solitons are found in the conservative and PT -symmetric cases. Interactions and collisions between the conservative and PT -symmetric solitons are briefly investigated, as well.

Numerical investigation of an all-optical switch in a graded nonlinear plasmonic grating.

PubMed

Wang, Guoxi; Lu, Hua; Liu, Xueming; Gong, Yongkang

2012-11-09

We have proposed and numerically investigated an all-optical switch based on a metal-insulator-metal waveguide with graded nonlinear plasmonic gratings. The influences of grating depth and refractive index of a Kerr nonlinear medium on the transmission of the switch are exactly analyzed by utilizing transmission line theory. The finite-difference time-domain simulation results show that the highly compact structure possesses excellent switch function by tuning the incident electric field intensity. In addition, the simulation results show that this all-optical switch has an ultrawide operating frequency regime and femtosecond-scale response time (~130 fs). Such a switch can find potential applications for all-optical signal processing and optical communication.

Cross-linked polyimides for integrated optics

NASA Astrophysics Data System (ADS)

Singer, Kenneth D.; Kowalczyk, Tony C.; Nguyen, Hung D.; Beuhler, Allyson J.; Wargowski, David A.

1997-01-01

We have investigated a promising class of polyimide materials for both passive and active electro-optic devices, namely crosslinkable polyimides. These fluorinated polyimides are soluble in the imidized form and are both thermally and photo-crosslinkable leading to easy processability into waveguide structures and the possibility of stable electro-optic properties. We have fabricated channel and slab waveguides and investigated the mechanism of optical propagation loss using photothermal deflection spectroscopy and waveguide loss spectroscopy, and found the losses to arise from residual absorption due to the formation of charge transfer states. The absorption is inhibited by fluorination leading to propagation losses as low as 0.3 dB/cm in the near infrared. Because of the ability to photocrosslink, channel waveguides are fabricated using a simple wet-etch process. Channel waveguides so formed are observed to have no excess loss over slab structures. Solubility followed by thermal cross-linking allows the formation of multilayer structures. We have produced electro-optic polymers by doping with the nonlinear optical chromophores, DCM and DADC; and a process of concurrent poling and thermal crosslinking. Multilayer structures have been investigated and poling fields optimized in the active layer by doping the cladding with an anti-static agent. The high glass-transition temperature and cross-linking leads to very stable electro-optic properties. We are currently building electro-optic modulators based on these materials. Progress and results in this area also are reported.

Design of a terahertz parametric oscillator based on a resonant cavity in a terahertz waveguide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saito, K., E-mail: k-saito@material.tohoku.ac.jp; Oyama, Y.; Tanabe, T.

We demonstrate ns-pulsed pumping of terahertz (THz) parametric oscillations in a quasi-triply resonant cavity in a THz waveguide. The THz waves, down converted through parametric interactions between the pump and signal waves at telecom frequencies, are confined to a GaP single mode ridge waveguide. By combining the THz waveguide with a quasi-triply resonant cavity, the nonlinear interactions can be enhanced. A low threshold pump intensity for parametric oscillations can be achieved in the cavity waveguide. The THz output power can be maximized by optimizing the quality factors of the cavity so that an optical to THz photon conversion efficiency, η{submore » p}, of 0.35, which is near the quantum-limit level, can be attained. The proposed THz optical parametric oscillator can be utilized as an efficient and monochromatic THz source.« less

Development of Device Quality Nonlinear Optical Materials and Definition of Mechanisms of Optical Nonlinearity

DTIC Science & Technology

1994-09-01

Methods. We arbitrarily divide sequential synthesis methods into the following four categories: (1) traditional Langmuir - Blodgett methods, (2) techniques... Langmuir - Blodgett methods. Films from small amphiphilic molecules, fabricated by Langmuir - Blodgett methods, have been extensively investigated.", 48 -54,67...fabrication of Langmuir - Blodgett films. We shall see in the next section that photochemical reactions can be used to define buried channel waveguides

Nonlinear characterization of a silicon integrated Bragg waveguide filter.

PubMed

Massara, Micol Previde; Menotti, Matteo; Bergamasco, Nicola; Harris, Nicholas C; Baehr-Jones, Tom; Hochberg, Michael; Galland, Christophe; Liscidini, Marco; Galli, Matteo; Bajoni, Daniele

2018-03-01

Bragg waveguides are promising optical filters for pump suppression in spontaneous four-wave mixing (FWM) photon sources. In this work, we investigate the generation of unwanted photon pairs in the filter itself. We do this by taking advantage of the relation between spontaneous and classical FWM, which allows for the precise characterization of the nonlinear response of the device. The pair generation rate estimated from the classical measurement is compared with the theoretical value calculated by means of a full quantum model of the filter, which also allows investigation of the spectral properties of the generated pairs. We find a good agreement between theory and experiment, confirming that stimulated FWM is a valuable approach to characterize the nonlinear response of an integrated filter, and that the pairs generated in a Bragg waveguide are not a serious issue for the operation of a fully integrated nonclassical source.

Nonlinear optical properties of As20S80 system chalcogenide glass using Z-scan and its strip waveguide under bandgap light using the self-phase modulation

NASA Astrophysics Data System (ADS)

Zou, L. E.; He, P. P.; Chen, B. X.; Iso, M.

2017-02-01

Optical nonlinearities in the undoped As20S80, low doped P2As20S78 and Sn1As20S79 chacogenide glasses are investigated by using Z-scan method. These experiments show that at 1064 nm the figure of merit (FOM) for As20S80 is ˜1.02, while for Sn1As20S79 increases to ˜1.42, and for P2As20S78 decreases to ˜0.83. These resulted data indicate the addition of Sn in As20S80 system chalcogenide glass can enhance FOM due to creating narrow energy gaps. In addition, the self-phase modulation (SPM) width experiment for Sn1As20S79 strip waveguide displays that the full width half maximum (FWHM) of spectral width increases approximately 0.8 nm under the induction of bandgap light, meaning that the bandgap light can induce to enhance its optical nonlinearity with the nonlinear refractive index of n2≅5.27×10-14 cm2/W.

Enhancing a slow and weak optomechanical nonlinearity with delayed quantum feedback

PubMed Central

Wang, Zhaoyou; Safavi-Naeini, Amir H.

2017-01-01

A central goal of quantum optics is to generate large interactions between single photons so that one photon can strongly modify the state of another one. In cavity optomechanics, photons interact with the motional degrees of freedom of an optical resonator, for example, by imparting radiation pressure forces on a movable mirror or sensing minute fluctuations in the position of the mirror. Here, we show that the optical nonlinearity arising from these effects, typically too small to operate on single photons, can be sufficiently enhanced with feedback to generate large interactions between single photons. We propose a protocol that allows photons propagating in a waveguide to interact with each other through multiple bounces off an optomechanical system. The protocol is analysed by evolving the full many-body quantum state of the waveguide-coupled system, illustrating that large photon–photon interactions mediated by mechanical motion may be within experimental reach. PMID:28677674

Enhancing a slow and weak optomechanical nonlinearity with delayed quantum feedback

NASA Astrophysics Data System (ADS)

Wang, Zhaoyou; Safavi-Naeini, Amir H.

2017-07-01

A central goal of quantum optics is to generate large interactions between single photons so that one photon can strongly modify the state of another one. In cavity optomechanics, photons interact with the motional degrees of freedom of an optical resonator, for example, by imparting radiation pressure forces on a movable mirror or sensing minute fluctuations in the position of the mirror. Here, we show that the optical nonlinearity arising from these effects, typically too small to operate on single photons, can be sufficiently enhanced with feedback to generate large interactions between single photons. We propose a protocol that allows photons propagating in a waveguide to interact with each other through multiple bounces off an optomechanical system. The protocol is analysed by evolving the full many-body quantum state of the waveguide-coupled system, illustrating that large photon-photon interactions mediated by mechanical motion may be within experimental reach.

NONLINEAR AND FIBER OPTICS: Transmission of submillimeter laser beams along hollow-core dielectric waveguides

NASA Astrophysics Data System (ADS)

Epishin, V. A.; Maslov, Vyacheslav A.; Ryabykh, V. N.; Svich, V. A.; Topkov, A. N.

1990-04-01

Theoretical and experimental investigations are reported of the propagation of axisymmetric linearly polarized laser radiation beams along hollow-core dielectric waveguides. The conditions for transmission with minimum distortion of the complex amplitude and minimum excitation losses are established for beams in the form of Gaussian-Laguerre modes. A scaling relationship is obtained for the attenuation constant of the EH11 mode in glass waveguides acting as transmission lines and for laser cells handling submillimeter wavelengths.

Cross-phase-modulation-induced temporal reflection and waveguiding of optical pulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plansinis, Brent W.; Donaldson, William R.; Agrawal, Govind P.

Cross-phase modulation (XPM) is commonly viewed as a nonlinear process that chirps a probe pulse and modifies its spectrum when an intense pump pulse overlaps with it. Here we present an alternative view of XPM in which the pump pulse creates a moving refractive-index boundary that splits the probe pulse into two parts with distinct optical spectra through temporal reflection and refraction inside a dispersive nonlinear medium. The probe even undergoes a temporal version of total internal reflection for sufficiently intense pump pulses, a phenomenon that can be exploited for making temporal waveguides. In this paper we investigate the practicalmore » conditions under which XPM can be exploited for temporal reflection and waveguiding. The width and shape of pump pulses as well as the nature of medium dispersion at the pump and probe wavelength (normal versus anomalous) play important roles. A super-Gaussian shape of pump pulses is particularly helpful because of its relatively sharp edges. When the pump wavelength lies in the anomalous-dispersion regime, the pump pulse can form a soliton,whose unique properties can be exploited to advantage. We also discuss a potential application of XPM-induced temporal waveguides for compensating timing jitter.« less

Cross-phase-modulation-induced temporal reflection and waveguiding of optical pulses

DOE PAGES

Plansinis, Brent W.; Donaldson, William R.; Agrawal, Govind P.

2018-01-31

Cross-phase modulation (XPM) is commonly viewed as a nonlinear process that chirps a probe pulse and modifies its spectrum when an intense pump pulse overlaps with it. Here we present an alternative view of XPM in which the pump pulse creates a moving refractive-index boundary that splits the probe pulse into two parts with distinct optical spectra through temporal reflection and refraction inside a dispersive nonlinear medium. The probe even undergoes a temporal version of total internal reflection for sufficiently intense pump pulses, a phenomenon that can be exploited for making temporal waveguides. In this paper we investigate the practicalmore » conditions under which XPM can be exploited for temporal reflection and waveguiding. The width and shape of pump pulses as well as the nature of medium dispersion at the pump and probe wavelength (normal versus anomalous) play important roles. A super-Gaussian shape of pump pulses is particularly helpful because of its relatively sharp edges. When the pump wavelength lies in the anomalous-dispersion regime, the pump pulse can form a soliton,whose unique properties can be exploited to advantage. We also discuss a potential application of XPM-induced temporal waveguides for compensating timing jitter.« less

Arrayed waveguide Sagnac interferometer.

PubMed

Capmany, José; Muñoz, Pascual; Sales, Salvador; Pastor, Daniel; Ortega, Beatriz; Martinez, Alfonso

2003-02-01

We present a novel device, an arrayed waveguide Sagnac interferometer, that combines the flexibility of arrayed waveguides and the wide application range of fiber or integrated optics Sagnac loops. We form the device by closing an array of wavelength-selective light paths provided by two arrayed waveguides with a single 2 x 2 coupler in a Sagnac configuration. The equations that describe the device's operation in general conditions are derived. A preliminary experimental demonstration is provided of a fiber prototype in passive operation that shows good agreement with the expected theoretical performance. Potential applications of the device in nonlinear operation are outlined and discussed.

Ultra-fast pulse propagation in nonlinear graphene/silicon ridge waveguide

NASA Astrophysics Data System (ADS)

Liu, Ken; Zhang, Jian Fa; Xu, Wei; Zhu, Zhi Hong; Guo, Chu Cai; Li, Xiu Jian; Qin, Shi Qiao

2015-11-01

We report the femtosecond laser propagation in a hybrid graphene/silicon ridge waveguide with demonstration of the ultra-large Kerr coefficient of graphene. We also fabricated a slot-like graphene/silicon ridge waveguide which can enhance its effective Kerr coefficient 1.5 times compared with the graphene/silicon ridge waveguide. Both transverse-electric-like (TE-like) mode and transverse-magnetic-like (TM-like) mode are experimentally measured and numerically analyzed. The results show nonlinearity dependence on mode polarization not in graphene/silicon ridge waveguide but in slot-like graphene/silicon ridge waveguide. Great spectral broadening was observed due to self-phase modulation (SPM) after propagation in the hybrid waveguide with length of 2 mm. Power dependence property of the slot-like hybrid waveguide is also measured and numerically analyzed. The results also confirm the effective Kerr coefficient estimation of the hybrid structures. Spectral blue shift of the output pulse was observed in the slot-like graphene/silicon ridge waveguide. One possible explanation is that the blue shift was caused by the ultra-fast free carrier effect with the optical absorption of the doped graphene. This interesting effect can be used for soliton compression in femtosecond region. We also discussed the broadband anomalous dispersion of the Kerr coefficient of graphene.

Silicon photonics: Design, fabrication, and characterization of on-chip optical interconnects

NASA Astrophysics Data System (ADS)

Hsieh, I.-Wei

In recent years, the research field of silicon photonics has been developing rapidly from a concept to a demonstrated technology, and has gathered much attention from both academia and industry communities. Its many potential applications in long-haul telecommunication, mid-range data-communication, on-chip optical interconnection networks, and nano-scale sensing as well as its compatibility with electronic integrated circuits have driven much effort in realizing silicon photonics both as a disruptive technology for existing markets and as an enabling technology for new ones. Despite the promising future of silicon photonics, many fundamental issues still remain to be understood---both in the linear- and nonlinear-optical regimes. There are also many engineering challenges to make silicon photonics the gold standard in photonic integrated circuits. In this thesis, we focus on the design, fabrication, and characterization of active and passive silicon-on-insulator (SOI) photonic devices. The SOI material system differs from most conventional optical material platforms because of its high-refractive-index-contrast, which enables engineers to design very compact integrated photonic networks with sub-micron transverse waveguide dimensions and sharp bends. On the other hand, because most analytical formulas for designing waveguide devices are valid only in low-index-contrast cases, SOI photonic devices need to be analyzed numerically for accurate results. The second chapter of this thesis describes some common numerical methods such as Beam Propagation Method (BPM) and Finite Element Method (FEM) for waveguide-design simulations, and presents two design studies based on these methods. The compatibility of silicon photonic integrated circuits with conventional CMOS fabrication technology is another important aspect that distinguishes silicon photonics from others such as III-V materials and lithium niobate. However, the requirements for fabricating silicon photonic devices are quite different from those of electronic devices. Minimizing propagation losses by reducing sidewall roughness to nanometer scale over a device length of several millimeters or even centimeters has prompted researchers in academia and industry to refine the fabrication process. Chapter 3 of this thesis summarizes our efforts in fabricating silicon photonic devices using standard CMOS technology. Chapter 4 describes the characterization of nonlinear effects, including self-phase modulation (SPM), cross-phase modulation (XPM), and supercontinuum generation in silicon-wire waveguides. Silicon-wire waveguides are strip waveguides with submicron transverse dimensions, which allow strong light confinement inside the silicon core. This strong optical confinement, in addition to the large third-order nonlinear optical susceptibility of crystalline silicon, leads to a net nonlinearity which is several orders of magnitude higher than the nonlinearity of silica fiber. Significant nonlinear effects can be observed and characterized over a device length of only several millimeters in silicon wires with very small input power. These effects provide opportunities for engineers to design active silicon photonic devices which are compact and energy-efficient. Chapter 5 presents a realization of an integrated SOI optical isolator, which is a critical yet often overlooked component in photonic integrated circuits. This study shows the feasibility to make a hybrid garnet/SOI active device with very promising results. Finally, Chapter 6 summarizes our demonstration of transmitting terabit-scale data streams in silicon-wire waveguides, which is an important first-step towards enabling intra-chip interconnection networks with ultra-high bandwidths. Although the scope of this thesis is limited to providing only fractional views of the whole silicon photonics area, it provides enough references for interested readers to conduct further literature research in other aspects of silicon photonics. It is the author's hope that the thesis would convey to its readers the significance and potential of this exciting emerging technology.

PPLN-waveguide-based polarization entangled QKD simulator

NASA Astrophysics Data System (ADS)

Gariano, John; Djordjevic, Ivan B.

2017-08-01

We have developed a comprehensive simulator to study the polarization entangled quantum key distribution (QKD) system, which takes various imperfections into account. We assume that a type-II SPDC source using a PPLN-based nonlinear optical waveguide is used to generate entangled photon pairs and implements the BB84 protocol, using two mutually unbiased basis with two orthogonal polarizations in each basis. The entangled photon pairs are then simulated to be transmitted to both parties; Alice and Bob, through the optical channel, imperfect optical elements and onto the imperfect detector. It is assumed that Eve has no control over the detectors, and can only gain information from the public channel and the intercept resend attack. The secure key rate (SKR) is calculated using an upper bound and by using actual code rates of LDPC codes implementable in FPGA hardware. After the verification of the simulation results, such as the pair generation rate and the number of error due to multiple pairs, for the ideal scenario, available in the literature, we then introduce various imperfections. Then, the results are compared to previously reported experimental results where a BBO nonlinear crystal is used, and the improvements in SKRs are determined for when a PPLN-waveguide is used instead.

Forward and backward THz-wave difference frequency generations from a rectangular nonlinear waveguide.

PubMed

Huang, Yen-Chieh; Wang, Tsong-Dong; Lin, Yen-Hou; Lee, Ching-Han; Chuang, Ming-Yun; Lin, Yen-Yin; Lin, Fan-Yi

2011-11-21

We report forward and backward THz-wave difference frequency generations at 197 and 469 μm from a PPLN rectangular crystal rod with an aperture of 0.5 (height in z) × 0.6 (width in y) mm(2) and a length of 25 mm in x. The crystal rod appears as a waveguide for the THz waves but as a bulk material for the optical mixing waves near 1.54 μm. We measured enhancement factors of 1.6 and 1.8 for the forward and backward THz-wave output powers, respectively, from the rectangular waveguide in comparison with those from a PPLN slab waveguide of the same length, thickness, and domain period under the same pump and signal intensity of 100 MW/cm(2). © 2011 Optical Society of America

From SHG to mid-infrared SPDC generation in strained silicon waveguides

NASA Astrophysics Data System (ADS)

Castellan, Claudio; Trenti, Alessandro; Mancinelli, Mattia; Marchesini, Alessandro; Ghulinyan, Mher; Pucker, Georg; Pavesi, Lorenzo

2017-08-01

The centrosymmetric crystalline structure of Silicon inhibits second order nonlinear optical processes in this material. We report here that, by breaking the silicon symmetry with a stressing silicon nitride over-layer, Second Harmonic Generation (SHG) is obtained in suitably designed waveguides where multi-modal phase-matching is achieved. The modeling of the generated signal provides an effective strain-induced second order nonlinear coefficient of χ(2) = (0.30 +/- 0.02) pm/V. Our work opens also interesting perspectives on the reverse process, the Spontaneous Parametric Down Conversion (SPDC), through which it is possible to generate mid-infrared entangled photon pairs.

Time-domain measurement of optical transport in silicon micro-ring resonators.

PubMed

Pernice, Wolfram H P; Li, Mo; Tang, Hong X

2010-08-16

We perform time-domain measurements of optical transport dynamics in silicon nano-photonic devices. Using pulsed optical excitation the thermal and carrier induced optical nonlinearities of micro-ring resonators are investigated, allowing for identification of their individual contributions. Under pulsed excitation build-up of free carriers and heat in the waveguides leads to a beating oscillation of the cavity resonance frequency. When employing a burst of pulse trains shorter than the carrier life-time, the slower heating effect can be separated from the faster carrier effect. Our scheme provides a convenient way to thermally stabilize optical resonators for high-power time-domain applications and nonlinear optical conversion.

Optoelectronic Information Processing

DTIC Science & Technology

2012-03-07

plasmon laser, superlens, hyperlens, plasmonic solitons, slot waveguide, “ Metasurface ” collimator etc "Oscar for Inventors," the Lemelson-MIT...Operating beyond the diffraction limit Nonlinear effects Metamaterials/TrOptics / Metasurfaces Nanofabrication gernot.pomrenke

Efficient numerical method for analyzing optical bistability in photonic crystal microcavities.

PubMed

Yuan, Lijun; Lu, Ya Yan

2013-05-20

Nonlinear optical effects can be enhanced by photonic crystal microcavities and be used to develop practical ultra-compact optical devices with low power requirements. The finite-difference time-domain method is the standard numerical method for simulating nonlinear optical devices, but it has limitations in terms of accuracy and efficiency. In this paper, a rigorous and efficient frequency-domain numerical method is developed for analyzing nonlinear optical devices where the nonlinear effect is concentrated in the microcavities. The method replaces the linear problem outside the microcavities by a rigorous and numerically computed boundary condition, then solves the nonlinear problem iteratively in a small region around the microcavities. Convergence of the iterative method is much easier to achieve since the size of the problem is significantly reduced. The method is presented for a specific two-dimensional photonic crystal waveguide-cavity system with a Kerr nonlinearity, using numerical methods that can take advantage of the geometric features of the structure. The method is able to calculate multiple solutions exhibiting the optical bistability phenomenon in the strongly nonlinear regime.

Photonic crystal based 1-bit full-adder optical circuit by using ring resonators in a nonlinear structure

NASA Astrophysics Data System (ADS)

Alipour-Banaei, Hamed; Seif-Dargahi, Hamed

2017-05-01

In this paper we proposed a novel design for realizing all optical 1*bit full-adder based on photonic crystals. The proposed structure was realized by cascading two optical 1-bit half-adders. The final structure is consisted of eight optical waveguides and two nonlinear resonant rings, created inside rod type two dimensional photonic crystal with square lattice. The structure has ;X;, ;Y; and ;Z; as input and ;SUM; and ;CARRY; as output ports. The performance and functionality of the proposed structure was validated by means of finite difference time domain method.

On-chip integratable all-optical quantizer using strong cross-phase modulation in a silicon-organic hybrid slot waveguide

PubMed Central

Kang, Zhe; Yuan, Jinhui; Zhang, Xianting; Sang, Xinzhu; Wang, Kuiru; Wu, Qiang; Yan, Binbin; Li, Feng; Zhou, Xian; Zhong, Kangping; Zhou, Guiyao; Yu, Chongxiu; Farrell, Gerald; Lu, Chao; Yaw Tam, Hwa; Wai, P. K. A.

2016-01-01

High performance all-optical quantizer based on silicon waveguide is believed to have significant applications in photonic integratable optical communication links, optical interconnection networks, and real-time signal processing systems. In this paper, we propose an integratable all-optical quantizer for on-chip and low power consumption all-optical analog-to-digital converters. The quantization is realized by the strong cross-phase modulation and interference in a silicon-organic hybrid (SOH) slot waveguide based Mach-Zehnder interferometer. By carefully designing the dimension of the SOH waveguide, large nonlinear coefficients up to 16,000 and 18,069 W−1/m for the pump and probe signals can be obtained respectively, along with a low pulse walk-off parameter of 66.7 fs/mm, and all-normal dispersion in the wavelength regime considered. Simulation results show that the phase shift of the probe signal can reach 8π at a low pump pulse peak power of 206 mW and propagation length of 5 mm such that a 4-bit all-optical quantizer can be realized. The corresponding signal-to-noise ratio is 23.42 dB and effective number of bit is 3.89-bit. PMID:26777054

Analytical study of optical bistability in silicon-waveguide resonators.

PubMed

Rukhlenko, Ivan D; Premaratne, Malin; Agrawal, Govind P

2009-11-23

We present a theoretical model that describes accurately the nonlinear phenomenon of optical bistability in silicon-waveguide resonators but remains amenable to analytical results. Using this model, we derive a transcendental equation governing the intensity of a continuous wave transmitted through a Fabry-Perot resonator formed using a silicon-on-insulator waveguide. This equation reveals a dual role of free carriers in the formation of optical bistability in silicon. First, it shows that free-carrier absorption results in a saturation of the transmitted intensity. Second, the free-carrier dispersion and the thermo-optic effect may introduce phase shifts far exceeding those resulting from the Kerr effect alone, thus enabling one to achieve optical bistability in ultrashort resonators that are only a few micrometers long. Bistability can occur even when waveguide facets are not coated because natural reflectivity of the silicon- r interface can provide sufficient feedback. We find that it is possible to control the input-output characteristics of silicon-based resonators by changing the free-carrier lifetime using a reverse-biased p-n junction. We show theoretically that such a technique is suitable for realization of electronically assisted optical switching at a fixed input power and it may lead to silicon-based, nanometer-size, optical memories.

Electrical Transfer Function and Poling Mechanisms for Nonlinear Optical Polymer Modulators

NASA Technical Reports Server (NTRS)

Watson, Michael Dale

2004-01-01

Electro-Optic Polymers hold great promise in increased electro-optic coefficients as compared to their inorganic corollaries. Many researchers have focused on quantum chemistry to describe how the dipoles respond to temperature and electric fields. Much work has also been done for single layer films to confirm these results. For optical applications, waveguide structures are utilized to guide the optical waves in 3 layer stacks. Electrode poling is the only practical poling method for these structures. This research takes an electrical engineering approach to develop poling models and electrical and optical transfer functions of the waveguide structure. The key aspect of the poling model is the large boundary charge density deposited during the poling process. The boundary charge density also has a large effect on the electrical transfer function which is used to explain the transient response of the system. These models are experimentally verified. Exploratory experiment design is used to study poling parameters including time, temperature, and voltage. These studies verify the poling conditions for CLDX/APC and CLDZ/APEC guest host electro optic polymer films in waveguide stacks predicted by the theoretical developments.

High-Power, High-Speed Electro-Optic Pockels Cell Modulator

NASA Technical Reports Server (NTRS)

Hawthorne, Justin; Battle, Philip

2013-01-01

Electro-optic modulators rely on a change in the index of refraction for the optical wave as a function of an applied voltage. The corresponding change in index acts to delay the wavefront in the waveguide. The goal of this work was to develop a high-speed, high-power waveguide- based modulator (phase and amplitude) and investigate its use as a pulse slicer. The key innovation in this effort is the use of potassium titanyl phosphate (KTP) waveguides, making the highpower, polarization-based waveguide amplitude modulator possible. Furthermore, because it is fabricated in KTP, the waveguide component will withstand high optical power and have a significantly higher RF modulation figure of merit (FOM) relative to lithium niobate. KTP waveguides support high-power TE and TM modes - a necessary requirement for polarization-based modulation as with a Pockels cell. High-power fiber laser development has greatly outpaced fiber-based modulators in terms of its maturity and specifications. The demand for high-performance nonlinear optical (NLO) devices in terms of power handling, efficiency, bandwidth, and useful wavelength range has driven the development of bulk NLO options, which are limited in their bandwidth, as well as waveguide based LN modulators, which are limited by their low optical damage threshold. Today, commercially available lithium niobate (LN) modulators are used for laser formatting; however, because of photorefractive damage that can reduce transmission and increase requirements on bias control, LN modulators cannot be used with powers over several mW, dependent on wavelength. The high-power, high-speed modulators proposed for development under this effort will enable advancements in several exciting fields including lidarbased remote sensing, atomic interferometry, free-space laser communications, and others.

Hybrid organic-inorganic sol-gel materials and components for integrated optoelectronics

NASA Astrophysics Data System (ADS)

Lu, Dong

On the technical platform of hybrid organic-inorganic sol-gel, the integrated optoelectronics in the forms of heterogeneous integration between the hybrid sol-gel waveguide and the high refractive index semiconductors and the nonlinear functional doping of disperse red chromophore into hybrid sol-gel is developed. The structure of hybrid sol-gel waveguide on high index semiconductor substrate is designed with BPM-CAD software. A hybrid sol-gel based on MAPTMS and TEOS suitable for lower cladding for the waveguide is developed. The multi-layer hybrid sol-gel waveguide with good mode confinement and low polarization dependence is fabricated on Si and InP. As proof of concept, a 1 x 12 beam splitter based on multimode interference is fabricated on silicon substrate. The device shows excess loss below 0.65 dB and imbalance below 0.28 dB for both TE and TM polarization. A nonlinear active hybrid sol-gel doped with disperse red 13 has been developed by simple co-solvent method. It permits high loading concentration and has low optical loss at 1550 nm. The second-order nonlinear property of the active sol-gel is induced with corona poling and studied with second harmonic generation. A 3-fold of enhancement in the poling efficiency is achieved by blue light assisted corona poling. The chromophore alignment stability is improved by reducing the free volume of the formed inorganic network from the sol-gel condensation reaction. An active sol-gel channel waveguide has been fabricated using active and passive hybrid sol-gel materials by only photopatterning and spin-coating. An amplitude modulator based on the active sol-gel containing 30 wt.% of DR13 shows an electro-optic coefficient of 14 pm/V at 1550 nm and stable operation within the observation time of 24 days.

Supercontinuum generation in silicon waveguides relying on wave-breaking.

PubMed

Castelló-Lurbe, David; Silvestre, Enrique

2015-10-05

Four-wave-mixing processes enabled during optical wave-breaking (OWB) are exploited in this paper for supercontinuum generation. Unlike conventional approaches based on OWB, phase-matching is achieved here for these nonlinear interactions, and, consequently, new frequency production becomes more efficient. We take advantage of this kind of pulse propagation to obtain numerically a coherent octave-spanning mid-infrared supercontinuum generation in a silicon waveguide pumping at telecom wavelengths in the normal dispersion regime. This scheme shows a feasible path to overcome limits imposed by two-photon absorption on spectral broadening in silicon waveguides.

FIBER OPTICS. ACOUSTOOPTICS: Compression of random pulses in fiber waveguides

NASA Astrophysics Data System (ADS)

Aleshkevich, Viktor A.; Kozhoridze, G. D.

1990-07-01

An investigation is made of the compression of randomly modulated signal + noise pulses during their propagation in a fiber waveguide. An allowance is made for a cubic nonlinearity and quadratic dispersion. The relationships governing the kinetics of transformation of the time envelope, and those which determine the duration and intensity of a random pulse are derived. The expressions for the optimal length of a fiber waveguide and for the maximum degree of compression are compared with the available data for regular pulses and the recommendations on selection of the optimal parameters are given.

Midinfrared wavelength conversion in hydrogenated amorphous silicon waveguides

NASA Astrophysics Data System (ADS)

Wang, Jiang; Wang, Zhaolu; Huang, Nan; Han, Jing; Li, Yongfang; Liu, Hongjun

2017-10-01

Midinfrared (MIR) wavelength conversion based on degenerate four-wave mixing is theoretically investigated in hydrogenated amorphous silicon (a-Si:H) waveguides. The broadband phase mismatch is achieved in the normal group-velocity dispersion regime. The conversion bandwidth is extended to 900 nm, and conversion efficiency of up to -14 dB with a pump power of 70 mW in a 2-mm long a-Si:H rib waveguides is obtained. This low-power on-chip wavelength converter will have potential for application in a wide range of MIR nonlinear optic devices.

Raman gain and nonlinear optical absorption measurements in a low-loss silicon waveguide

NASA Astrophysics Data System (ADS)

Rong, Haisheng; Liu, Ansheng; Nicolaescu, Remus; Paniccia, Mario; Cohen, Oded; Hak, Dani

2004-09-01

We fabricated a low-loss (˜0.22dB/cm) rib waveguide (WG) in silicon-on-insulator with a small effective core area of ˜1.57μm2 and measured the stimulated Raman scattering gain in the WG. We obtained 2.3dB Raman gain in a 4.8-cm-long S-shaped WG using a 1455nm pump laser with a cw power of 0.9W measured before the WG. In addition, we observed nonlinear dependence of Raman gain and optical propagation loss as a function of the pump power. Our study shows that this mainly is due to two-photon absorption (TPA) induced free carrier absorption in the silicon WG. We experimentally determined the TPA induced free carrier lifetime of 25ns, which agrees well with our modeling.

All-optical diode structure based on asymmetrical coupling by a micro-cavity and FP cavity at two sides of photonic crystal waveguide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Bin, E-mail: liubin-d@126.com; Liu, Yun-Feng; He, Xing-Dao

2016-06-15

A high efficiency all-optical diode based on photonic crystal (PC) waveguide has been proposed and numerically investigated by finite-difference time-domain (FDTD) method. The structure is asymmetrically coupled by a micro-cavity containing nonlinear Kerr medium and a FP cavity at sides of PC waveguide. Because of interference between two cavities, Fano peak and FP peak can both appear in transmission spectra and unidirectional transmission can be achieved. The working wavelength can set between two peaks and near to the Fano peak. For forward launch with suitable light intensity, nonlinear Kerr effect of micro-cavity can been excited. It will result in redmore » shift of Fano peak and achieving forward transmission. But for backward launch, a stronger incidence light is needed to the excite Kerr effect due to the design of asymmetric structure. This design has many advantages, including high maximum transmittance, high transmittance contrast ratio, low power threshold, short response time, and ease of integration.« less

Heuristic modelling of laser written mid-infrared LiNbO₃ stressed-cladding waveguides.

PubMed

Nguyen, Huu-Dat; Ródenas, Airán; Vázquez de Aldana, Javier R; Martínez, Javier; Chen, Feng; Aguiló, Magdalena; Pujol, Maria Cinta; Díaz, Francesc

2016-04-04

Mid-infrared lithium niobate cladding waveguides have great potential in low-loss on-chip non-linear optical instruments such as mid-infrared spectrometers and frequency converters, but their three-dimensional femtosecond-laser fabrication is currently not well understood due to the complex interplay between achievable depressed index values and the stress-optic refractive index changes arising as a function of both laser fabrication parameters, and cladding arrangement. Moreover, both the stress-field anisotropy and the asymmetric shape of low-index tracks yield highly birefringent waveguides not useful for most applications where controlling and manipulating the polarization state of a light beam is crucial. To achieve true high performance devices a fundamental understanding on how these waveguides behave and how they can be ultimately optimized is required. In this work we employ a heuristic modelling approach based on the use of standard optical characterization data along with standard computational numerical methods to obtain a satisfactory approximate solution to the problem of designing realistic laser-written circuit building-blocks, such as straight waveguides, bends and evanescent splitters. We infer basic waveguide design parameters such as the complex index of refraction of laser-written tracks at 3.68 µm mid-infrared wavelengths, as well as the cross-sectional stress-optic index maps, obtaining an overall waveguide simulation that closely matches the measured mid-infrared waveguide properties in terms of anisotropy, mode field distributions and propagation losses. We then explore experimentally feasible waveguide designs in the search of a single-mode low-loss behaviour for both ordinary and extraordinary polarizations. We evaluate the overall losses of s-bend components unveiling the expected radiation bend losses of this type of waveguides, and finally showcase a prototype design of a low-loss evanescent splitter. Developing a realistic waveguide model with which robust waveguide designs can be developed will be key for exploiting the potential of the technology.

Guided wave methods and apparatus for nonlinear frequency generation

DOEpatents

Durfee, III, Charles G.; Rundquist, Andrew; Kapteyn, Henry C.; Murnane, Margaret M.

2000-01-01

Methods and apparatus are disclosed for the nonlinear generation of sum and difference frequencies of electromagnetic radiation propagating in a nonlinear material. A waveguide having a waveguide cavity contains the nonlinear material. Phase matching of the nonlinear generation is obtained by adjusting a waveguide propagation constant, the refractive index of the nonlinear material, or the waveguide mode in which the radiation propagates. Phase matching can be achieved even in isotropic nonlinear materials. A short-wavelength radiation source uses phase-matched nonlinear generation in a waveguide to produce high harmonics of a pulsed laser.

Ring-Gaussian laser pulse filamentation in a self-induced diffraction waveguide

NASA Astrophysics Data System (ADS)

Geints, Yu E.; Zemlyanov, A. A.

2017-10-01

Self-action in air of a high-power femtosecond laser pulse with the spatial form of a ring-Gaussian beam (‘dressed’ beam) is studied theoretically. Pulse self-focusing and filamentation is analyzed in detail through the numerical solution of the spectral propagation equation, taking into account medium optical nonlinearity and plasma generation. Pulse propagation dynamics and energy fluxes inside the beam are visualized by means of averaged diffraction ray tracing. We clearly show that, in terms of diffraction optics, the outer ring forms a specific nonmaterial diffractive waveguide, favoring long-range self-channeling of the central part of a beam by delivering optical energy to a filament. The spatial robustness and stability of such diffractive waveguides strongly depends on the energy stored in the ring, as well as on its position relative to the beam axis. The striking advantage of such ‘dressed’ beams is their reduced angular divergence during plasma-free (post-filamentation) evolution.

Narrow linewidth comb realized with a mode-locked fiber laser using an intra-cavity waveguide electro-optic modulator for high-speed control.

PubMed

Iwakuni, Kana; Inaba, Hajime; Nakajima, Yoshiaki; Kobayashi, Takumi; Hosaka, Kazumoto; Onae, Atsushi; Hong, Feng-Lei

2012-06-18

We have developed an optical frequency comb using a mode-locked fiber ring laser with an intra-cavity waveguide electro-optic modulator controlling the optical length in the laser cavity. The mode-locking is achieved with a simple ring configuration and a nonlinear polarization rotation mechanism. The beat note between the laser and a reference laser and the carrier envelope offset frequency of the comb were simultaneously phase locked with servo bandwidths of 1.3 MHz and 900 kHz, respectively. We observed an out-of-loop beat between two identical combs, and obtained a coherent δ-function peak with a signal to noise ratio of 70 dB/Hz.

Nonlinear Optics and Applications

NASA Technical Reports Server (NTRS)

Abdeldayem, Hossin A. (Editor); Frazier, Donald O. (Editor)

2007-01-01

Nonlinear optics is the result of laser beam interaction with materials and started with the advent of lasers in the early 1960s. The field is growing daily and plays a major role in emerging photonic technology. Nonlinear optics play a major role in many of the optical applications such as optical signal processing, optical computers, ultrafast switches, ultra-short pulsed lasers, sensors, laser amplifiers, and many others. This special review volume on Nonlinear Optics and Applications is intended for those who want to be aware of the most recent technology. This book presents a survey of the recent advances of nonlinear optical applications. Emphasis will be on novel devices and materials, switching technology, optical computing, and important experimental results. Recent developments in topics which are of historical interest to researchers, and in the same time of potential use in the fields of all-optical communication and computing technologies, are also included. Additionally, a few new related topics which might provoke discussion are presented. The book includes chapters on nonlinear optics and applications; the nonlinear Schrodinger and associated equations that model spatio-temporal propagation; the supercontinuum light source; wideband ultrashort pulse fiber laser sources; lattice fabrication as well as their linear and nonlinear light guiding properties; the second-order EO effect (Pockels), the third-order (Kerr) and thermo-optical effects in optical waveguides and their applications in optical communication; and, the effect of magnetic field and its role in nonlinear optics, among other chapters.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Arvind, E-mail: arvindsharma230771@gmail.com; Nagar, A. K., E-mail: ajaya.nagar@gmail.com

We investigate the interaction of optical vector soliton with a symmetric thin-film gallium-silica waveguide structure using the equivalent particle theory. The relevant nonlinear Schrodinger equation has been solved by the method of phase plane analysis. The analysis shows beam break up into transmitted, reflected and nonlinear surface waves at the interface. The stability properties of the solitons so formed have been discussed.

Fabrication and characterization of on-chip optical nonlinear chalcogenide nanofiber devices.

PubMed

Zhang, Qiming; Li, Ming; Hao, Qiang; Deng, Dinghuan; Zhou, Hui; Zeng, Heping; Zhan, Li; Wu, Xiang; Liu, Liying; Xu, Lei

2010-11-15

Chalcogenide (As(2)S(3)) nanofibers as narrow as 200 nm in diameter are drawn by the fiber pulling method, are successfully embedded in SU8 polymer, and form on-chip waveguides and high-Q microknot resonators (Q = 3.9 × 10(4)) with smooth cleaved end faces. Resonance tuning of resonators is realized by localized laser irradiation. Strong supercontinuum generation with a bandwidth of 500 nm is achieved in a 7-cm-long on-chip chalcogenide waveguide. Our result provides a method for the development of compact, high-optical-quality, and robust photonic devices.

Generation and tunable enhancement of a sum-frequency signal in lithium niobate nanowires

NASA Astrophysics Data System (ADS)

Sergeyev, Anton; Reig Escalé, Marc; Grange, Rachel

2017-02-01

Recent developments in the fabrication of lithium niobate (LiNbO3) structures down to the nanoscale opens up novel applications of this versatile material in nonlinear optics. Current nonlinear optical studies in sub-micron waveguides are mainly restricted to the generation of second and third harmonics. In this work, we demonstrate the generation and waveguiding of the sum-frequency generation (SFG) signal in a single LiNbO3 nanowire with a cross-section of 517 nm  ×  654 nm. Furthermore, we enhance the guided SFG signal 17.9 times by means of modal phase matching. We also display tuning of the phase-matched wavelength by varying the nanowire cross-section and changing the polarization of the incident laser. The results prove that LiNbO3 nanowires can be successfully used for nonlinear wave-mixing applications and assisting the miniaturization of optical devices. , which features invited work from the best early-career researchers working within the scope of J Phys D. This project is part of the Journal of Physics series’ 50th anniversary celebrations in 2017. Rachel Grange was selected by the Editorial Board of J Phys D as an Emerging Leader.

Synthesis and Characterization of Electroresponsive Materials with Applications In: Part I. Second Harmonic Generation. Part II. Organic-Lanthanide Ion Complexes for Electroluminescence and Optical Amplifiers.

NASA Astrophysics Data System (ADS)

Claude, Charles

1995-01-01

Materials for optical waveguides were developed from two different approaches, inorganic-organic composites and soft gel polymers. Inorganic-organic composites were developed from alkoxysilane and organically modified silanes based on nonlinear optical chromophores. Organically modified silanes based on N-((3^' -trialkoxysilyl)propyl)-4-nitroaniline were synthesized and sol-gelled with trimethoxysilane. After a densification process at 190^circC with a corona discharge, the second harmonic of the film was measured with a Nd:YAG laser with a fundamental wavelength of 1064nm, d_{33} = 13pm/V. The decay of the second harmonic was expressed by a stretched bi-exponential equation. The decay time (tau _2) was equal to 3374 hours, and was comparable to nonlinear optical systems based on epoxy/Disperse Orange 1. The processing temperature of the organically modified silane was limited to 200^circC due to the decomposition of the organic chromophore. Soft gel polymers were synthesized and characterized for the development of optical waveguides with dc-electrical field assisted phase-matching. Polymers based on 4-nitroaniline terminated poly(ethylene oxide-co-propylene oxide) were shown to exhibit second harmonic generation that were optically phase-matched in an electrical field. The optical signals were stable and reproducible. Siloxane polymers modified with 1-mercapto-4-nitrobenzene and 1-mercapto-4-methylsulfonylstilbene nonlinear optical chromophores were synthesized. The physical and the linear and nonlinear optical properties of the polymers were characterized. Waveguides were developed from the polymers which were optically phase -matched and had an efficiency of 8.1%. The siloxane polymers exhibited optical phase-matching in an applied electrical field and can be used with a semiconductor laser. Organic lanthanide ion complexes for electroluminescence and optical amplifiers were synthesized and characterized. The complexes were characterized for their thermal and oxidative stability and for their optical properties. Organic-europium ion complexes based on derivatives of 2-benzoyl benzoate are stable to a temperature 70^circ C higher than the europium beta -diketonate complexes. The optical and fluorescence properties of the organic-europium ion complexes were characterized. The methoxy and the t-butyl derivatives of the europium 2-benzoylbenzoate complexes exhibited fluorescence quantum efficiencies that were comparable to europium tris(thenoyl trifluoroacetonate) in methylene chloride but the extinction coefficient was two-thirds of the europium thenoyltrifluoroacetonate complexes. The last complex characterized was the europium bis(diphenylphosphino)imine complex. The complex exhibited thermal stability to 550 ^circC under nitrogen.

Design of a high-speed optical dark-soliton detector using a phase-shifted waveguide Bragg grating in reflection.

PubMed

Ngo, Nam Quoc

2007-12-01

A theoretical study of a new application of a simple pi-phase-shifted waveguide Bragg grating (PSWBG) in reflection mode as a high-speed optical dark-soliton detector is presented. The PSWBG consists of two concatenated identical uniform waveguide Bragg gratings with a pi phase shift between them. The reflective PSWBG, with grating reflectivities equal to 0.9, a free spectral range of 1.91 THz, and a nonlinear phase response, can convert a 40 Gbit/s noisy dark-soliton signal into a high-quality 40 Gbit/s return-to-zero signal with a peak power level of approximately 17.5 dB greater than that by the existing Mach-Zehnder interferometer with free spectral range of 1.91 THz and a linear phase response.

Broadband wavelength conversion in hydrogenated amorphous silicon waveguide with silicon nitride layer

NASA Astrophysics Data System (ADS)

Wang, Jiang; Li, Yongfang; Wang, Zhaolu; Han, Jing; Huang, Nan; Liu, Hongjun

2018-01-01

Broadband wavelength conversion based on degenerate four-wave mixing is theoretically investigated in a hydrogenated amorphous silicon (a-Si:H) waveguide with silicon nitride inter-cladding layer (a-Si:HN). We have found that enhancement of the non-linear effect of a-Si:H waveguide nitride intermediate layer facilitates broadband wavelength conversion. Conversion bandwidth of 490 nm and conversion efficiency of 11.4 dB were achieved in a numerical simulation of a 4 mm-long a-Si:HN waveguide under 1.55 μm continuous wave pumping. This broadband continuous-wave wavelength converter has potential applications in photonic networks, a type of readily manufactured low-cost highly integrated optical circuits.

Exact states in waveguides with periodically modulated nonlinearity

NASA Astrophysics Data System (ADS)

Ding, E.; Chan, H. N.; Chow, K. W.; Nakkeeran, K.; Malomed, B. A.

2017-09-01

We introduce a one-dimensional model based on the nonlinear Schrödinger/Gross-Pitaevskii equation where the local nonlinearity is subject to spatially periodic modulation in terms of the Jacobi {dn} function, with three free parameters including the period, amplitude, and internal form-factor. An exact periodic solution is found for each set of parameters and, which is more important for physical realizations, we solve the inverse problem and predict the period and amplitude of the modulation that yields a particular exact spatially periodic state. A numerical stability analysis demonstrates that the periodic states become modulationally unstable for large periods, and regain stability in the limit of an infinite period, which corresponds to a bright soliton pinned to a localized nonlinearity-modulation pattern. The exact dark-bright soliton complex in a coupled system with a localized modulation structure is also briefly considered. The system can be realized in planar optical waveguides and cigar-shaped atomic Bose-Einstein condensates.

Engineering Photon-Photon Interactions within Rubidium-Filled Waveguides

NASA Astrophysics Data System (ADS)

Perrella, C.; Light, P. S.; Vahid, S. Afshar; Benabid, F.; Luiten, A. N.

2018-04-01

Strong photon-photon interactions are a required ingredient for deterministic two-photon optical quantum logic gates. Multiphoton transitions in dense atomic vapors have been shown to be a promising avenue for producing such interactions. The strength of a multiphoton interaction can be enhanced by conducting the interaction in highly confined geometries such as small-cross-section optical waveguides. We demonstrate, both experimentally and theoretically, that the strength of such interactions scale only with the optical mode diameter, d , not d2 as might be initially expected. This weakening of the interaction arises from atomic motion inside the waveguides. We create an interaction between two optical signals, at 780 and 776 nm, using the 5 S1 /2→5 D5 /2 two-photon transition in rubidium vapor within a range of hollow-core fibers with different core sizes. The interaction strength is characterized by observing the absorption and phase shift induced on the 780-nm beam, which is in close agreement with theoretical modeling that accounts for the atomic motion inside the fibers. These observations demonstrate that transit-time effects upon multiphoton transitions are of key importance when engineering photon-photon interactions within small-cross-section waveguides that might otherwise be thought to lead to enhanced optical nonlinearity through increased intensities.

Colloidal PbS nanocrystals integrated to Si-based photonics for applications at telecom wavelengths

NASA Astrophysics Data System (ADS)

Humer, M.; Guider, R.; Jantsch, W.; Fromherz, T.

2013-05-01

In the last decade, Si based photonics has made major advances in terms of design, fabrication, and device implementation. But due to Silicon's indirect bandgap, it still remains a challenge to create efficient Si-based light emitting devices. In order to overcome this problem, an approach is to develop hybrid systems integrating light-emitting materials into Si. A promising class of materials for this purpose is the class of semiconducting nanocrystal quantum dots (NCs) that are synthesized by colloidal chemistry. As their absorption and emission wavelength depends on the dot size, which can easily be controlled during synthesis, they are extremely attractive as building blocks for nanophotonic applications. For applications in telecom wavelength, Lead chalcogenide colloidal NCs are optimum materials due to their unique optical, electronic and nonlinear properties. In this work, we experimentally demonstrate the integration of PbS nanocrystals into Si-based photonic structures like slot waveguides and ring resonators as optically pumped emitters for room temperature applications. In order to create such hybrid structures, the NCs were dissolved into polymer resists and drop cast on top of the device. Upon optical pumping, intense photoluminescence emission from the resonating modes is recorded at the output of the waveguide with transmission quality factors up to 14000. The polymer host material was investigated with respect to its ability to stabilize the NC's photoluminescence emission against degradation under ambient conditions. The waveguide-ring coupling efficiency was also investigated as function of the NCs concentrations blended into the polymer matrix. The integration of colloidal quantum dots into Silicon photonic structures as demonstrated in this work is a very versatile technique and thus opens a large range of applications utilizing the linear and nonlinear optical properties of PbS NCs at telecom wavelengths.

Non-degenerate two-photon absorption in silicon waveguides. Analytical and experimental study

DOE PAGES

Zhang, Yanbing; Husko, Chad; Lefrancois, Simon; ...

2015-06-22

We theoretically and experimentally investigate the nonlinear evolution of two optical pulses in a silicon waveguide. We provide an analytic solution for the weak probe wave undergoing non-degenerate two-photon absorption (TPA) from the strong pump. At larger pump intensities, we employ a numerical solution to study the interplay between TPA and photo-generated free carriers. We develop a simple and powerful approach to extract and separate out the distinct loss contributions of TPA and free-carrier absorption from readily available experimental data. Our analysis accounts accurately for experimental results in silicon photonic crystal waveguides.

Linearized finite-element method solution of the ion-exchange nonlinear diffusion model

NASA Astrophysics Data System (ADS)

Badr, Mohamed M.; Swillam, Mohamed A.

2017-04-01

Ion-exchange process is one of the most common techniques used in glass waveguide fabrication. This has many advantages, such as low cost, ease of implementation, and simple equipment requirements. The technology is based on the substitution of some of the host ions in the glass (typically Na+) with other ions that possess different characteristics in terms of size and polarizability. The newly diffused ions produce a region with a relatively higher refractive index in which the light could be guided. A critical issue arises when it comes to designing such waveguides, which is carefully and precisely determining the resultant index profile. This task has been proven to be hideous as the process is generally governed by a nonlinear diffusion model with no direct general analytical solution. Furthermore, numerical solutions become unreliable-in terms of stability and mean squared error-in some cases, especially the K+-Na+ ion-exchanged waveguide, which is the best candidate to produce waveguides with refractive index differences compatible with those of the commercially available optical fibers. Linearized finite-element method formulations were used to provide a reliable tool that could solve the nonlinear diffusion model of the ion-exchange in both one- and two-dimensional spaces. Additionally, the annealed channel waveguide case has been studied. In all cases, unprecedented stability and minimum mean squared error could be achieved.

Excitation of epsilon-near-zero resonance in ultra-thin indium tin oxide shell embedded nanostructured optical fiber.

PubMed

Minn, Khant; Anopchenko, Aleksei; Yang, Jingyi; Lee, Ho Wai Howard

2018-02-05

We report a novel optical waveguide design of a hollow step index fiber modified with a thin layer of indium tin oxide (ITO). We show an excitation of highly confined waveguide mode in the proposed fiber near the wavelength where permittivity of ITO approaches zero. Due to the high field confinement within thin ITO shell inside the fiber, the epsilon-near-zero (ENZ) mode can be characterized by a peak in modal loss of the hybrid waveguide. Our results show that such in-fiber excitation of ENZ mode is due to the coupling of the guided core mode to the thin-film ENZ mode. We also show that the phase matching wavelength, where the coupling takes place, varies depending on the refractive index of the constituents inside the central bore of the fiber. These ENZ nanostructured optical fibers have many potential applications, for example, in ENZ nonlinear and magneto-optics, as in-fiber wavelength-dependent filters, and as subwavelength fluid channel for optical and bio-photonic sensing.

A nonlinear plasmonic waveguide based all-optical bidirectional switching

NASA Astrophysics Data System (ADS)

Bana, Xiaoqiang; Pang, Xingxing; Li, Xiaohui; Hu, Bin; Guo, Yixuan; Zheng, Hairong

2018-01-01

In this paper, an all-optical switching with a nanometer coupled ring resonator is demonstrated based on the nonlinear material. By adjusting the light intensity, we implement the resonance wavelength from 880 nm to 940 nm in the nonlinear material structure monocyclic. In the bidirectional switch structure, the center wavelength (i.e. 880 nm) is fixed. By changing the light intensity from I = 0 to I = 53 . 1 MW /cm2, the function of optical switching can be obtained. The results demonstrate that both the single-ring cavity and the T-shaped double-ring structure can realize the optical switching effect. This work takes advantage of the simple structure. The single-ring cavity plasmonic switches have many advantages, such as nanoscale size, low pumping light intensity, ultrafast response time (femtosecond level), etc. It is expected that the proposed all-optical integrated devices can be potentially applied in optical communication, signal processing, and signal sensing, etc.

Ultra-fast all-optical plasmonic switching in near infra-red spectrum using a Kerr nonlinear ring resonator

NASA Astrophysics Data System (ADS)

Nurmohammadi, Tofiq; Abbasian, Karim; Yadipour, Reza

2018-03-01

In this paper, an all-optical plasmonic switch based on metal-insulator-metal (MIM) nanoplasmonic waveguide with a Kerr nonlinear ring resonator is introduced and studied. Two-dimensional simulations utilizing the finite-difference time-domain algorithm are used to demonstrate an apparent optical bistability and significant switching mechanisms (in enabled-low condition: T(ON/OFF) =21.9 and in enabled-high condition: T(ON/OFF) =24.9) of the signal light arisen by altering the pump-light intensity. The proposed all-optical switching demonstrates femtosecond-scale feedback time (90 fs) and then ultra-fast switching can be achieved. The offered all-optical switch may recognize potential significant applications in integrated optical circuits.

Attenuation, dispersion and nonlinearity effects in graphene-based waveguides

PubMed Central

Mota, João Cesar Moura; Sombra, Antonio Sergio Bezerra

2015-01-01

Summary We simulated and analyzed in detail the behavior of ultrashort optical pulses, which are typically used in telecommunications, propagating through graphene-based nanoribbon waveguides. In this work, we showed the changes that occur in the Gaussian and hyperbolic secant input pulses due to the attenuation, high-order dispersive effects and nonlinear effects. We concluded that it is possible to control the shape of the output pulses with the value of the input signal power and the chemical potential of the graphene nanoribbon. We believe that the obtained results will be highly relevant since they can be applied to other nanophotonic devices, for example, filters, modulators, antennas, switches and other devices. PMID:26171299

All-optical 40Gbit/s format conversion from NRZ to RZ based on SFG in a PPLN waveguide

NASA Astrophysics Data System (ADS)

Wang, Jian; Sun, Junqiang

2006-01-01

A novel all-optical 40Gbit/s NRZ-to-RZ data format conversion scheme based on sum-frequency generation (SFG) interaction in a periodically poled LiNbO 3 (PPLN) waveguide is presented for the first time, using a Mach-Zehnder interferometer (MZI). The conversion mechanism relies on the combination of attenuation and nonlinear phase shift Φ NL induced on the signal field. The performance of the conversion is numerically evaluated, with the result showing that it is more effective to yield Φ NL when appropriately phase mismatched for SFG process but Φ NL~0 when quasi-phase-matching (QPM). Compared with the cascaded second-order nonlinear interactions (SHG+DFG) with the influence of walk-off effect, a high conversion efficiency and good performance are achieved with peak power 500mw and width 2ps of the pump, which can be used in super high-speed situation (40Gbit/s and above). Finally, the inverse process of SFG and corresponding walk-off effect are analyzed and the optimum arrangement of power is proposed, showing that proper power, pump width, and waveguide length are necessary for achieving a satisfied conversion effect.

Controlling soliton refraction in optical lattices.

PubMed

Prilepsky, Jaroslaw E; Derevyanko, Stanislav A; Gredeskul, Sergey A

2011-08-19

We show in the framework of the 1D nonlinear Schrödinger equation that the value of the refraction angle of a fundamental soliton beam passing through an optical lattice can be controlled by adjusting either the shape of an individual waveguide or the relative positions of the waveguides. In the case of the shallow refractive index modulation, we develop a general approach for the calculation of the refraction angle change. The shape of a single waveguide crucially affects the refraction direction due to the appearance of a structural form factor in the expression for the density of emitted waves. For a lattice of scatterers, wave-soliton interference inside the lattice leads to the appearance of an additional geometric form factor. As a result, the soliton refraction is more pronounced for the disordered lattices than for the periodic ones. © 2011 American Physical Society

Graphene-doped polymer nanofibers for low-threshold nonlinear optical waveguiding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, Chao; Yu, Shao-Liang; Wang, Hong -Qing

Graphene-doped polymer nanofibers are fabricated by taper drawing of solvated polyvinyl alcohol doped with liquid-phase exfoliated graphene flakes. Nanofibers drawn this way typically have diameters measured in hundreds of nanometers and lengths in tens of millimeters; they show excellent uniformity and surface smoothness for optical waveguiding. Owing to their tightly confined waveguiding behavior, light–matter interaction in these subwavelength-diameter nanofibers is significantly enhanced. Using approximately 1350-nm-wavelength femto-second pulses, we demonstrate saturable absorption behavior in these nanofibers with a saturation threshold down to 0.25 pJ pulse -1 (peak power ~1.3 W). Additionally, using 1064-nm-wavelength nanosecond pulses as switching light, we show all-opticalmore » modulation of a 1550-nm-wavelength signal light guided along a single nanofiber with a switching peak power of ~3.2 W.« less

Graphene-doped polymer nanofibers for low-threshold nonlinear optical waveguiding

DOE PAGES

Meng, Chao; Yu, Shao-Liang; Wang, Hong -Qing; ...

2015-11-06

Graphene-doped polymer nanofibers are fabricated by taper drawing of solvated polyvinyl alcohol doped with liquid-phase exfoliated graphene flakes. Nanofibers drawn this way typically have diameters measured in hundreds of nanometers and lengths in tens of millimeters; they show excellent uniformity and surface smoothness for optical waveguiding. Owing to their tightly confined waveguiding behavior, light–matter interaction in these subwavelength-diameter nanofibers is significantly enhanced. Using approximately 1350-nm-wavelength femto-second pulses, we demonstrate saturable absorption behavior in these nanofibers with a saturation threshold down to 0.25 pJ pulse -1 (peak power ~1.3 W). Additionally, using 1064-nm-wavelength nanosecond pulses as switching light, we show all-opticalmore » modulation of a 1550-nm-wavelength signal light guided along a single nanofiber with a switching peak power of ~3.2 W.« less

Tapered polysilicon core fibers for nonlinear photonics.

PubMed

Suhailin, Fariza H; Shen, Li; Healy, Noel; Xiao, Limin; Jones, Maxwell; Hawkins, Thomas; Ballato, John; Gibson, Ursula J; Peacock, Anna C

2016-04-01

We propose and demonstrate a novel approach to obtaining small-core polysilicon waveguides from the silicon fiber platform. The fibers were fabricated via a conventional drawing tower method and, subsequently, tapered down to achieve silicon core diameters of ∼1  μm, the smallest optical cores for this class of fiber to date. Characterization of the material properties have shown that the taper process helps to improve the local crystallinity of the silicon core, resulting in a significant reduction in the material loss. By exploiting the combination of small cores and low losses, these tapered fibers have enabled the first observation of nonlinear transmission within a polycrystalline silicon waveguide of any type. As the fiber drawing method is highly scalable, it opens a route for the development of low-cost and flexible nonlinear silicon photonic systems.

Dynamic Time Expansion and Compression Using Nonlinear Waveguides

DOEpatents

Findikoglu, Alp T.; Hahn, Sangkoo F.; Jia, Quanxi

2004-06-22

Dynamic time expansion or compression of a small amplitude input signal generated with an initial scale is performed using a nonlinear waveguide. A nonlinear waveguide having a variable refractive index is connected to a bias voltage source having a bias signal amplitude that is large relative to the input signal to vary the reflective index and concomitant speed of propagation of the nonlinear waveguide and an electrical circuit for applying the small amplitude signal and the large amplitude bias signal simultaneously to the nonlinear waveguide. The large amplitude bias signal with the input signal alters the speed of propagation of the small-amplitude signal with time in the nonlinear waveguide to expand or contract the initial time scale of the small-amplitude input signal.

Dynamic time expansion and compression using nonlinear waveguides

DOEpatents

Findikoglu, Alp T [Los Alamos, NM; Hahn, Sangkoo F [Los Alamos, NM; Jia, Quanxi [Los Alamos, NM

2004-06-22

Dynamic time expansion or compression of a small-amplitude input signal generated with an initial scale is performed using a nonlinear waveguide. A nonlinear waveguide having a variable refractive index is connected to a bias voltage source having a bias signal amplitude that is large relative to the input signal to vary the reflective index and concomitant speed of propagation of the nonlinear waveguide and an electrical circuit for applying the small-amplitude signal and the large amplitude bias signal simultaneously to the nonlinear waveguide. The large amplitude bias signal with the input signal alters the speed of propagation of the small-amplitude signal with time in the nonlinear waveguide to expand or contract the initial time scale of the small-amplitude input signal.

Enhancement of Optical Nonlinearities in Composite Media and Structures via Local Fields and Electromagnetic Coupling Effects

NASA Technical Reports Server (NTRS)

Smith, David D.

2002-01-01

This talk will review the linear and nonlinear optical properties of metal nanoparticles and dielectric microparticles, with an emphasis on local field effects, and whispering gallery modes (WGMs), as well as the conjunction of these two effects for enhanced Raman. In particular, enhanced optical properties that result from electromagnetic coupling effects will be discussed in the context of Mie scattering from concentric spheres and bispheres. Predictions of mode splitting and photonic bandgaps in micro-spheres will be presented and will be shown to be analogous to effects that occur in coupled resonator optical waveguides (CROW). Slow and fast light in SCISSOR / CROW configurations will also be discussed.

Atom-field dressed states in slow-light waveguide QED

NASA Astrophysics Data System (ADS)

Calajó, Giuseppe; Ciccarello, Francesco; Chang, Darrick; Rabl, Peter

2016-03-01

We discuss the properties of atom-photon bound states in waveguide QED systems consisting of single or multiple atoms coupled strongly to a finite-bandwidth photonic channel. Such bound states are formed by an atom and a localized photonic excitation and represent the continuum analog of the familiar dressed states in single-mode cavity QED. Here we present a detailed analysis of the linear and nonlinear spectral features associated with single- and multiphoton dressed states and show how the formation of bound states affects the waveguide-mediated dipole-dipole interactions between separated atoms. Our results provide both a qualitative and quantitative description of the essential strong-coupling processes in waveguide QED systems, which are currently being developed in the optical and microwave regimes.

Nonlinear optical polymers for electro-optic signal processing

NASA Technical Reports Server (NTRS)

Lindsay, Geoffrey A.

1991-01-01

Photonics is an emerging technology, slated for rapid growth in communications systems, sensors, imagers, and computers. Its growth is driven by the need for speed, reliability, and low cost. New nonlinear polymeric materials will be a key technology in the new wave of photonics devices. Electron-conjubated polymeric materials offer large electro-optic figures of merit, ease of processing into films and fibers, ruggedness, low cost, and a plethora of design options. Several new broad classes of second-order nonlinear optical polymers were developed at the Navy's Michelson Laboratory at China Lake, California. Polar alignment in thin film waveguides was achieved by electric-field poling and Langmuir-Blodgett processing. Our polymers have high softening temperatures and good aging properties. While most of the films can be photobleached with ultraviolet (UV) light, some have excellent stability in the 500-1600 nm range, and UV stability in the 290-310 nm range. The optical nonlinear response of these polymers is subpicosecond. Electro-optic switches, frequency doublers, light modulators, and optical data storage media are some of the device applications anticipated for these polymers.

Integrated optical circuit engineering IV; Proceedings of the Meeting, Cambridge, MA, Sept. 16, 17, 1986

NASA Astrophysics Data System (ADS)

Mentzer, Mark A.; Sriram, S.

The design and implementation of integrated optical circuits are discussed in reviews and reports. Topics addressed include lithium niobate devices, silicon integrated optics, waveguide phenomena, coupling considerations, processing technology, nonlinear guided-wave optics, integrated optics for fiber systems, and systems considerations and applications. Also included are eight papers and a panel discussion from an SPIE conference on the processing of guided-wave optoelectronic materials (held in Los Angeles, CA, on January 21-22, 1986).

DNA-based nonlinear photonic materials

NASA Astrophysics Data System (ADS)

Heckman, Emily M.; Grote, James G.; Yaney, Perry P.; Hopkins, F. K.

2004-10-01

Deoxyribonucleic acid (DNA), extracted from salmon sperm through an enzyme isolation process, is a by-product of Japan"s fishing industry. To make DNA a suitable material for nonlinear optic (NLO) applications, it is precipitated with a surfactant complex, hexadecyltrimethlammonium chloride (CTMA). Preliminary characterization studies suggest DNA-CTMA may be a suitable host material for guest-host NLO polymer based electro-optic (EO) waveguide devices. The optical and electromagnetic properties of DNA-CTMA, as well as the development and EO measurement of a disperse red 1 (DR1) guest / DNA/CTMA host NLO material, are reported. Comparisons to a DR1 guest / poly(methyl methacrylate) (PMMA) host NLO material are made.

Integrated optical components in thin films of polymers

NASA Technical Reports Server (NTRS)

Sarkisov, Sergey; Abdeldayem, Hossin; Venkateswarlu, Putcha; Teague, Zedric

1995-01-01

The results will be reported on the study of integrated optical components based on nonlinear optical polymeric films. Polymers poly(methyl methacrylate) (PMMA) and polyimide (PI) doped with organic laser dyes 4-dicyanomethylene-2-methyl-6-p dimethylaminostyryl-4H pyran (DCM) and 1, 3, 5, 7, 8 - pentamethyl-2,6 -diethyl-pyrromethene -BF2-complex (Pyrommethene 567, PM-567) were selected as materials for light guiding films. Additionally, UV polymerized polydiacetylene (PDA) on glass substrate was used as a waveguide material. Optical waveguides were fabricated using spin coating of preoxidized silicon wafers (1.5 micrometer silicon oxide layer) with organic dye/polymer solution followed by soft baking. the modes in slab waveguides were studied using prism coupling techniques. Measured values of mode coupling angles in multimode waveguides were used to calculate film thickness and refractive index for different polarizations. Refractive index anisotropy was found in PDA waveguide. The optimal conditions of spin coating for single mode waveguide fabrication were estimated. Propagation losses were measured by collecting the light scattered from the trace of a propagating mode either by scanning photo detector or by CCD camera. Different types of light coupling techniques were used including end-dire coupling, prism and grating coupling. Mechanical printing technique was developed for coupling grating fabrication resulting in gratings with 4% diffraction efficiency. The gratings demonstrated good stability with diffraction efficiency relaxation rate 2.4 dB/hour at a temperature approximately 15-20 C below glass transition point. Dye doped waveguides were transversally pumped with frequency doubled Nd:YAG Q-switched laser producing intensive light emission with apparent 6 kW/sq cm pump threshold and spectrum narrowing near 617 nm peak in the case of DCM doped waveguide. PM-567 doped waveguide pumped with CW Ar(+) laser (514 nm wavelength) far below threshold (0.1 W/sq.cm pump power) demonstrated emission spectrum narrowing near 616 nm peak with 18% power conversion slope efficiency. In this case emission spectrum modification was caused by the enhanced light absorption along the direction of propagating waveguide modes. Changing length, thickness, and other morphlogical waveguide parameters one can modify emission spectrum in predictable direction. The results show that polymeric waveguides, especially based on high temperature polymers such as Pl, can be used to produce a varietiy of active and passive silicon compatible integrated optical components for aerospace applications.

Supercontinuum generation in quadratic nonlinear waveguides without quasi-phase matching.

PubMed

Guo, Hairun; Zhou, Binbin; Steinert, Michael; Setzpfandt, Frank; Pertsch, Thomas; Chung, Hung-ping; Chen, Yen-Hung; Bache, Morten

2015-02-15

Supercontinuum generation (SCG) is most efficient when the solitons can be excited directly at the pump laser wavelength. Quadratic nonlinear waveguides may induce an effective negative Kerr nonlinearity, so temporal solitons can be directly generated in the normal (positive) dispersion regime overlapping with common ultrafast laser wavelengths. There is no need for waveguide dispersion engineering. Here, we experimentally demonstrate SCG in standard lithium niobate (LN) waveguides without quasi-phase matching (QPM), pumped with femtosecond pulses in the normal dispersion regime. The observed large bandwidths (even octave spanning), together with other experimental data, indicate that negative nonlinearity solitons are indeed excited, which is backed up by numerical simulations. The QPM-free design reduces production complexity, extends the maximum waveguide length, and limits undesired spectral resonances. Finally, nonlinear crystals can be used where QPM is inefficient or impossible, which is important for mid-IR SCG. QPM-free waveguides in mid-IR nonlinear crystals can support negative nonlinearity solitons, as these waveguides have a normal dispersion at the emission wavelengths of mid-IR ultrafast lasers.

Thick optical waveguides in lithium niobate induced by swift heavy ions (approximately 10 MeV/amu) at ultralow fluences.

PubMed

Olivares, José; Crespillo, Miguel L; Caballero-Calero, Olga; Ynsa, María D; García-Cabañes, Angel; Toulemonde, Marcel; Trautmann, Christina; Agulló-López, Fernando

2009-12-21

Heavy mass ions, Kr and Xe, having energies in the approximately 10 MeV/amu range have been used to produce thick planar optical waveguides at the surface of lithium niobate (LiNbO3). The waveguides have a thickness of 40-50 micrometers, depending on ion energy and fluence, smooth profiles and refractive index jumps up to 0.04 (lambda = 633 nm). They propagate ordinary and extraordinary modes with low losses keeping a high nonlinear optical response (SHG) that makes them useful for many applications. Complementary RBS/C data provide consistent values for the partial amorphization and refractive index change at the surface. The proposed method is based on ion-induced damage caused by electronic excitation and essentially differs from the usual implantation technique using light ions (H and He) of MeV energies. It implies the generation of a buried low-index layer (acting as optical barrier), made up of amorphous nanotracks embedded into the crystalline lithium niobate crystal. An effective dielectric medium approach is developed to describe the index profiles of the waveguides. This first test demonstration could be extended to other crystalline materials and could be of great usefulness for mid-infrared applications.

Design of a LiNbO(3) ribbon waveguide for efficient difference-frequency generation of terahertz wave in the collinear configuration.

PubMed

Takushima, Y; Shin, S Y; Chung, Y C

2007-10-29

We propose and investigate a ribbon waveguide for difference-frequency generation of terahertz (THz) wave from infrared light sources. The proposed ribbon waveguide is composed of a nonlinear optic crystal and has a thickness less than the wavelength of the THz wave to support the surface-wave mode in the THz region. By utilizing the waveguide dispersion of the surface-wave mode, the phase matching condition between infrared pump, idler and THz waves can be realized in the collinear configuration. Owing to the weak mode confinement of the THz wave, the absorption coefficient can also be reduced. We design the ribbon waveguide which uses LiNbO(3) crystal and discuss the phase-matching condition for DFG of THz wave. Highly efficient THz-wave generation is confirmed by numerical simulations.

FIBER AND INTEGRATED OPTICS. FIBER WAVEGUIDE DEVICES: Vector solitons in fiber waveguides with a random birefringence

NASA Astrophysics Data System (ADS)

Kivshar', Yu S.; Konotop, V. V.

1990-12-01

A study is made of the propagation of soliton pulses in single-mode fiber waveguides with a birefringence that gives rise to a nonlinear interaction between the polarizations and to a difference between their group velocities. It is shown that a vector soliton decays if a parameter representing the birefringence intensity exceeds a certain critical value. The case when the birefringence can be described by a random function is of special interest. It is demonstrated that fluctuations of the birefringence then split the vector solitons into separate polarizations and the characteristic distance governing such splitting is calculated analytically.

Low threshold all-optical crossbar switch on GaAs-GaAlAs channel waveguide arrays

NASA Astrophysics Data System (ADS)

Jannson, Tomasz; Kostrzewski, Andrew

1994-09-01

During the Phase 2 project entitled 'Low Threshold All-Optical Crossbar Switch on GaAs - GaAlAs Channel Waveguide Array,' Physical Optics Corporation (POC) developed the basic principles for the fabrication of all-optical crossbar switches. Based on this development. POC fabricated a 2 x 2 GaAs/GaAlAs switch that changes the direction of incident light with minimum insertion loss and nonlinear distortion. This unique technology can be used in both analog and digital networks. The applications of this technology are widespread. Because the all-optical network does not have any speed limitations (RC time constant), POC's approach will be beneficial to SONET networks, phased array radar networks, very high speed oscilloscopes, all-optical networks, IR countermeasure systems, BER equipment, and the fast growing video conferencing network market. The novel all-optical crossbar switch developed in this program will solve interconnect problems. and will be a key component in the widely proposed all-optical 200 Gb/s SONET/ATM networks.

Ultrafast modulators based on nonlinear photonic crystal waveguides

NASA Astrophysics Data System (ADS)

Liu, Zhifu; Li, Jianheng; Tu, Yongming; Ho, Seng-Tiong; Wessels, Bruce W.

2011-03-01

Nonlinear photonic crystal (PhC) waveguides are being developed for ultrafast modulators. To enable phase velocity matching we have investigated one- and two-dimensional structures. Photonic crystal (PhC) waveguides based on epitaxial barium titanate (BTO) thin film in a Si3N4/BTO/MgO multilayer structure were fabricated by electron beam lithography or focused ion beam (FIB) milling. For both one- and two-dimensional PhCs, simulation shows that sufficient refractive index contrast is achieved to form a stop band. For one-dimensional Bragg reflector, we measured its slow light properties and the group refractive index of optical wave. For a millimeter long waveguide a 27 nm wide stop band was obtained at 1550 nm. A slowing of the light was observed, the group refractive indices at the mid band gap and at the band edges were estimated to be between 8.0 and 12 for the transverse electric (TE) mode, and 6.9 and 13 for the transverse magnetic (TM) mode. For TE optical modes, the enhancement factor of EO coefficient ranges from 7 to 13, and for the TM mode, the factor ranges from 5.9 to 15. Measurements indicate that near velocity phase matching can be realized. Upon realizing the phase velocity matching condition, devices with a small foot print with bandwidths at 490 GHz can be attained. Two-dimensional PhC crystal with a hexagonal lattice was also investigated. The PhCs were fabricated from epitaxial BTO thin film multilayers using focused ion beam milling. The PhCs are based on BTO slab waveguide and air hole arrays defined within Si3N4 and BTO thin films. A refractive index contrast of 0.4 between the barium titanate thin film multilayers and the air holes enables strong light confinement. For the TE optical mode, the hexagonal photonic crystal lattice with a diameter of 155 nm and a lattice constant of 740 nm yields a photonic bandgap over the wavelength range from 1525 to 1575 nm. The transmission spectrum of the PhC waveguide exhibits stronger Fabry Perot resonance compared to that of conventional waveguide. Measured transmission spectra show a bandgap in the ΓM direction in the reciprocal lattice that is in agreement with the simulated results using the finite-difference time-domain (FDTD) method. Compared to polarization intensity EO modulator with a half-wave voltage length product of 4.7 V•mm. The PhC based EO modulator has a factor of 6.6 improvement in the figure of merit performance. The thin film PhC waveguide devices show considerable potential for ultra-wide bandwidth electro-optic modulators as well as tunable optical filters and switches.

Design and implementation of optical switches based on nonlinear plasmonic ring resonators: Circular, square and octagon

NASA Astrophysics Data System (ADS)

Ghadrdan, Majid; Mansouri-Birjandi, Mohammad Ali

2018-05-01

In this paper, all-optical plasmonic switches (AOPS) based on various configurations of circular, square and octagon nonlinear plasmonic ring resonators (NPRR) were proposed and numerically investigated. Each of these configurations consisted of two metal-insulator-metal (MIM) waveguides coupled to each other by a ring resonator (RR). Nonlinear Kerr effect was used to show switching performance of the proposed NPRR. The result showed that the octagon switch structure had lower threshold power and higher transmission ratio than square and circular switch structures. The octagon switch structure had a low threshold power equal to 7.77 MW/cm2 and the high transmission ratio of approximately 0.6. Therefore, the octagon switch structure was an appropriate candidate to be applied in optical integration circuits as an AOPS.

Magnetoplasmonic RF mixing and nonlinear frequency generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Firby, C. J., E-mail: firby@ualberta.ca; Elezzabi, A. Y.

2016-07-04

We present the design of a magnetoplasmonic Mach-Zehnder interferometer (MZI) modulator facilitating radio-frequency (RF) mixing and nonlinear frequency generation. This is achieved by forming the MZI arms from long-range dielectric-loaded plasmonic waveguides containing bismuth-substituted yttrium iron garnet (Bi:YIG). The magnetization of the Bi:YIG can be driven in the nonlinear regime by RF magnetic fields produced around adjacent transmission lines. Correspondingly, the nonlinear temporal dynamics of the transverse magnetization component are mapped onto the nonreciprocal phase shift in the MZI arms, and onto the output optical intensity signal. We show that this tunable mechanism can generate harmonics, frequency splitting, and frequencymore » down-conversion with a single RF excitation, as well as RF mixing when driven by two RF signals. This magnetoplasmonic component can reduce the number of electrical sources required to generate distinct optical modulation frequencies and is anticipated to satisfy important applications in integrated optics.« less

Multiplicity of transmission coefficients in photonic crystal and split ring resonator waveguides with Kerr nonlinear impurities

NASA Astrophysics Data System (ADS)

Rai, Buddhi; McGurn, Arthur R.

2015-02-01

Photonic crystal and split ring resonator (SRR) metamaterial waveguides with Kerr nonlinear dielectric impurities are studied. The transmission coefficients for two guided modes of different frequencies scattering from the Kerr impurities are computed. The systems are shown to exhibit multiple transmission coefficient solutions arising from the Kerr nonlinearity. Multiple transmission coefficients occur when different input intensities into a waveguide result in the same transmitted output intensities past its nonlinear impurities. (In the case of a single incident guided mode the multiplicity of transmission coefficients is known as optical bistability.) The analytical conditions under which the transmission coefficients are single and multiple valued are determined, and specific examples of both single and multiple valued transmission coefficient scattering are presented. Both photonic crystal and split ring resonator systems are studied as the Kerr nonlinearity enters the photonic crystal and SRR systems in different ways. This allows for an interesting comparison of the differences in behaviors of these two types of system which are described by distinctly different mathematical structures. Both the photonic crystal and SRR models used in the calculations are based on a difference equation approach to the system dynamics. The difference equation approach has been extensively employed in previous papers to model the basic properties of these systems. The paper is a continuation of work on the optical bistability of single guided modes interacting with Kerr impurities in photonic crystals originally considered by McGurn [Chaos 13, 754 (2003), 10.1063/1.1568691] and work on the resonant scattering from Kerr impurities in photonic crystal waveguides considered by McGurn [J. Phys.: Condens. Matter 16, S5243 (2004), 10.1088/0953-8984/16/44/021]. It generalizes this work making the extension to the more complex interaction of two guided modes at different frequencies. It extends the two guided mode treatment by McGurn [Organ. Electron. 8, 227 (2007), 10.1016/j.orgel.2006.06.008] which was limited to a special case of one of the photonic crystal systems considered here.

SPM of nonlinear surface plasmon waveguides

NASA Astrophysics Data System (ADS)

Li, Yuee; Zhang, Xiaoping

2008-10-01

Pulse propagation equation of nonlinear dispersion surface plasmon waveguide is educed strictly from wave equation. The nonlinear coefficient is defined and then used to assess and compare the nonlinear characteristic of three popular 1-D surface plasmon waveguides: the single metal-dielectric interface, the metal slab bounded by dielectric and the dielectric slab bounded by metal. SPM (self-phase modulation) of the typical surface plasmon waveguide is predicted and discussed.

Demonstration of pulse controlled all-optical switch/modulator.

PubMed

Akin, Osman; Dinleyici, M S

2014-03-15

An all-optical pulse controlled switch/modulator based on evanescent coupling between a polymer slab waveguide and a single mode fiber is demonstrated. Very fast all-optical modulation/switching is achieved via Kerr effect of the nonlinear polymer placed in the evanescent region of the optical fiber. Local refractive index perturbation (Δn=-1.45612×10(-5)) on the thin film leads to 0.374 nW power modulation at the fiber output, which results in a switching efficiency of ≈1.5%.

Scattering of a cross-polarized linear wave by a soliton at an optical event horizon in a birefringent nanophotonic waveguide.

PubMed

Ciret, Charles; Gorza, Simon-Pierre

2016-06-15

The scattering of a linear wave on an optical event horizon, induced by a cross-polarized soliton, is experimentally and numerically investigated in integrated structures. The experiments are performed in a dispersion-engineered birefringent silicon nanophotonic waveguide. In stark contrast with copolarized waves, the large difference between the group velocity of the two cross-polarized waves enables a frequency conversion almost independent of the soliton wavelength. It is shown that the generated idler is only shifted by 10 nm around 1550 nm over a pump tuning range of 350 nm. Simulations using two coupled full vectorial nonlinear Schrödinger equations fully support the experimental results.

Rogue Waves for a (2+1)-Dimensional Coupled Nonlinear Schrödinger System with Variable Coefficients in a Graded-Index Waveguide

NASA Astrophysics Data System (ADS)

Du, Zhong; Tian, Bo; Wu, Xiao-Yu; Yuan, Yu-Qiang

2018-05-01

Studied in this paper is a (2+1)-dimensional coupled nonlinear Schrödinger system with variable coefficients, which describes the propagation of an optical beam inside the two-dimensional graded-index waveguide amplifier with the polarization effects. According to the similarity transformation, we derive the type-I and type-II rogue-wave solutions. We graphically present two types of the rouge wave and discuss the influence of the diffraction parameter on the rogue waves. When the diffraction parameters are exponentially-growing-periodic, exponential, linear and quadratic parameters, we obtain the periodic rogue wave and composite rogue waves respectively. Supported by the National Natural Science Foundation of China under Grant Nos. 11772017, 11272023, and 11471050, by the Fund of State Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications), China (IPOC: 2017ZZ05) and by the Fundamental Research Funds for the Central Universities of China under Grant No. 2011BUPTYB02.

Extremely broadband, on-chip optical nonreciprocity enabled by mimicking nonlinear anti-adiabatic quantum jumps near exceptional points

NASA Astrophysics Data System (ADS)

Choi, Youngsun; Hahn, Choloong; Yoon, Jae Woong; Song, Seok Ho; Berini, Pierre

2017-01-01

Time-asymmetric state-evolution properties while encircling an exceptional point are presently of great interest in search of new principles for controlling atomic and optical systems. Here, we show that encircling-an-exceptional-point interactions that are essentially reciprocal in the linear interaction regime make a plausible nonlinear integrated optical device architecture highly nonreciprocal over an extremely broad spectrum. In the proposed strategy, we describe an experimentally realizable coupled-waveguide structure that supports an encircling-an-exceptional-point parametric evolution under the influence of a gain saturation nonlinearity. Using an intuitive time-dependent Hamiltonian and rigorous numerical computations, we demonstrate strictly nonreciprocal optical transmission with a forward-to-backward transmission ratio exceeding 10 dB and high forward transmission efficiency (~100%) persisting over an extremely broad bandwidth approaching 100 THz. This predicted performance strongly encourages experimental realization of the proposed concept to establish a practical on-chip optical nonreciprocal element for ultra-short laser pulses and broadband high-density optical signal processing.

THz-wave generation via difference frequency mixing in strained silicon based waveguide utilizing its second order susceptibility χ((2)).

PubMed

Saito, Kyosuke; Tanabe, Tadao; Oyama, Yutaka

2014-07-14

Terahertz (THz) wave generation via difference frequency mixing (DFM) process in strain silicon membrane waveguides by introducing the straining layer is theoretically investigated. The Si(3)N(4) straining layer induces anisotropic compressive strain in the silicon core and results in the appearance of the bulk second order nonlinear susceptibility χ((2)) by breaking the crystal symmetry. We have proposed waveguide structures for THz wave generation under the DFM process by .using the modal birefringence in the waveguide core. Our simulations show that an output power of up to 0.95 mW can be achieved at 9.09 THz. The strained silicon optical device may open a widow in the field of the silicon-based active THz photonic device applications.

The Longwave Silicon Chip - Integrated Plasma-Photonics in Group IV And III-V Semiconductors

DTIC Science & Technology

2013-10-01

infrared applications; SiGeSn heterostructure photonics; group IV plasmonics with silicides , germanicides, doped Si, Ge or GeSn; Franz-Keldysh...SPP waveguide in which localized silicide or germanicide “conductors” are introduced to give local plasmonic confinement. Therefore, guided-wave...reconfigurable integrated optoelectronics, electro-optical logic in silicon, silicides for group IV plasmonics, reviews of third-order nonlinear optical

Analog optical computing primitives in silicon photonics

DOE PAGES

Jiang, Yunshan; DeVore, Peter T. S.; Jalali, Bahram

2016-03-15

Optical computing accelerators help alleviate bandwidth and power consumption bottlenecks in electronics. In this paper, we show an approach to implementing logarithmic-type analog co-processors in silicon photonics and use it to perform the exponentiation operation and the recovery of a signal in the presence of multiplicative distortion. Finally, the function is realized by exploiting nonlinear-absorption-enhanced Raman amplification saturation in a silicon waveguide.

Plasmonic waveguide with folded stubs for highly confined terahertz propagation and concentration.

PubMed

Ye, Longfang; Xiao, Yifan; Liu, Na; Song, Zhengyong; Zhang, Wei; Liu, Qing Huo

2017-01-23

We proposed a novel planar terahertz (THz) plasmonic waveguide with folded stub arrays to achieve excellent terahertz propagation performance with tight field confinement and compact size based on the concept of spoof surface plasmon polaritons (spoof SPPs). It is found that the waveguide propagation characteristics can be directly manipulated by increasing the length of the folded stubs without increasing its lateral dimension, which exhibits much lower asymptotic frequency of the dispersion relation and even tighter terahertz field confinement than conventional plasmonic waveguides with rectangular stub arrays. Based on this waveguiding scheme, a terahertz concentrator with gradual step-length folded stubs is proposed to achieve high terahertz field enhancement, and an enhancement factor greater than 20 is demonstrated. This work offers a new perspective on very confined terahertz propagation and concentration, which may have promising potential applications in various integrated terahertz plasmonic circuits and devices, terahertz sensing and terahertz nonlinear optics.

Optomechanically induced spontaneous symmetry breaking

NASA Astrophysics Data System (ADS)

Miri, Mohammad-Ali; Verhagen, Ewold; Alú, Andrea

2017-05-01

We explore the dynamics of spontaneous breakdown of mirror symmetry in a pair of identical optomechanical cavities symmetrically coupled to a waveguide. Large optical intensities enable optomechanically induced nonlinear detuning of the optical resonators, resulting in a pitchfork bifurcation. We investigate the stability of this regime and explore the possibility of inducing multistability. By injecting proper trigger pulses, the proposed structure can toggle between two asymmetric stable states, thus serving as a low-noise nanophotonic all-optical switch or memory element.

Successive approximation-like 4-bit full-optical analog-to-digital converter based on Kerr-like nonlinear photonic crystal ring resonators

NASA Astrophysics Data System (ADS)

Tavousi, Alireza; Mansouri-Birjandi, Mohammad Ali; Saffari, Mehdi

2016-09-01

Implementing of photonic sampling and quantizing analog-to-digital converters (ADCs) enable us to extract a single binary word from optical signals without need for extra electronic assisting parts. This would enormously increase the sampling and quantizing time as well as decreasing the consumed power. To this end, based on the concept of successive approximation method, a 4-bit full-optical ADC that operates using the intensity-dependent Kerr-like nonlinearity in a two dimensional photonic crystal (2DPhC) platform is proposed. The Silicon (Si) nanocrystal is chosen because of the suitable nonlinear material characteristic. An optical limiter is used for the clamping and quantization of each successive levels that represent the ADC bits. In the proposal, an energy efficient optical ADC circuit is implemented by controlling the system parameters such as ring-to-waveguide coupling coefficients, the ring's nonlinear refractive index, and the ring's length. The performance of the ADC structure is verified by the simulation using finite difference time domain (FDTD) method.

Ponderomotive electron acceleration in a silicon-based nanoplasmonic waveguide.

PubMed

Sederberg, S; Elezzabi, A Y

2014-10-17

Ponderomotive electron acceleration is demonstrated in a semiconductor-loaded nanoplasmonic waveguide. Photogenerated free carriers are accelerated by the tightly confined nanoplasmonic fields and reach energies exceeding the threshold for impact ionization. Broadband (375 nm ≤ λ ≤ 650  nm) white light emission is observed from the nanoplasmonic waveguides. Exponential growth of visible light emission confirms the exponential growth of the electron population, demonstrating the presence of an optical-field-driven electron avalanche. Electron sweeping dynamics are visualized using pump-probe measurements, and a sweeping time of 1.98 ± 0.40 ps is measured. These findings offer a means to harness the potential of the emerging field of ultrafast nonlinear nanoplasmonics.

Femtosecond laser inscription of optical circuits in the cladding of optical fibers

NASA Astrophysics Data System (ADS)

Grenier, Jason R.

The aim of this dissertation was to address the question of whether the cladding of single-mode fibers (SMFs) could be modified to enable optical fibers to serve as a more integrated, highly functional platform for optical circuit devices that can efficiently interconnect with the pre-existing fiber core waveguide. The approach adopted in this dissertation was to employ femtosecond laser direct writing (FLDW), an inherently 3D fabrication technique that harnesses non-linear laser-material interactions to modify the fused silica fiber cladding. A fiber mounting and alignment technique was developed along with oil-immersion focusing to address the strong aberrations caused by the cylindrical fiber shape. The development of real-time device monitoring during the FLDW was instrumental to overcome the acute coupling sensitivity to laser alignment errors of +/-1 ?m positional uncertainty, and thereby opened a new practical direction for the precise fabrication of optical devices inside optical fibers. These powerful and flexible laser fabrication and characterization techniques were successfully employed to optimize optical waveguiding devices positioned within the core and cladding of optical fibers. X-, S-Bend, and directional couplers were developed to enable efficient coupling between the laser-formed cladding devices and the pre-existing core waveguide, enabling up to 62% power transfer over bandwidths up to 300 nm at telecommunication wavelengths. Precise alignment of femtosecond laser modification tracks were positioned inside or near the core waveguide of SMFs was further shown to enable a flexible reshaping of the optical properties to create multimode guiding sections arbitrarily along the fiber length. This core waveguide modification facilitated the precise formation of multimode interferometers along the core waveguide to precisely tailor the modal profiles, and control the spectral and polarization response. In-fiber multimode interference (MMI) splitters and couplers were fabricated with coupling ratios from 2% to 50% over a broad 350 nm bandwidth across the telecommunication band. Laser-induced birefringence was harnessed to generate polarization dependent MMI devices for strong polarization filtering (24 dB isolation), or polarization selective taps with up to 50% tapping efficiency over a 25 nm bandwidth. This dissertation is therefore the first demonstration of femtosecond laser direct writing as a flexible and monolithic means of embedding and integrating highly functional optical circuit devices within the cladding of optical fibers that can interconnect efficiently with the pre-existing fiber core waveguide. These developments represent a significant technological advancement for creating new 3D photonic integrated microsystems within the cladding of optical fibers and underpins a new technological platform of fiber cladding photonics.

Coherent ultra-violet to near-infrared generation in silica ridge waveguides

PubMed Central

Yoon Oh, Dong; Yang, Ki Youl; Fredrick, Connor; Ycas, Gabriel; Diddams, Scott A.; Vahala, Kerry J.

2017-01-01

Short duration, intense pulses of light can experience dramatic spectral broadening when propagating through lengths of optical fibre. This continuum generation process is caused by a combination of nonlinear optical effects including the formation of dispersive waves. Optical analogues of Cherenkov radiation, these waves allow a pulse to radiate power into a distant spectral region. In this work, efficient and coherent dispersive wave generation of visible to ultraviolet light is demonstrated in silica waveguides on a silicon chip. Unlike fibre broadeners, the arrays provide a wide range of emission wavelength choices on a single, compact chip. This new capability is used to simplify offset frequency measurements of a mode-locked frequency comb. The arrays can also enable mode-locked lasers to attain unprecedented tunable spectral reach for spectroscopy, bioimaging, tomography and metrology. PMID:28067233

Waveguide coupling in the few-cycle regime

NASA Astrophysics Data System (ADS)

Leblond, Hervé; Terniche, Said

2016-04-01

We consider the coupling of two optical waveguides in the few-cycle regime. The analysis is performed in the frame of a generalized Kadomtsev-Petviashvili model. A set of two coupled modified Korteweg-de Vries equations is derived, and it is shown that three types of coupling can occur, involving the linear index, the dispersion, or the nonlinearity. The linear nondispersive coupling is investigated numerically, showing the formation of vector solitons. Separate pulses may be trapped together if they have not initially the same location, size, or phase, and even if their initial frequencies differ.

Nonlinear Optical Properties of Organic and Polymeric Thin Film Materials of Potential for Microgravity Processing Studies

NASA Technical Reports Server (NTRS)

Abdeldayem, Hossin; Frazier, Donald O.; Paley, Mark S.; Penn, Benjamin; Witherow, William K.; Bank, Curtis; Shields, Angela; Hicks, Rosline; Ashley, Paul R.

1996-01-01

In this paper, we will take a closer look at the state of the art of polydiacetylene, and metal-free phthalocyanine films, in view of the microgravity impact on their optical properties, their nonlinear optical properties and their potential advantages for integrated optics. These materials have many attractive features with regard to their use in integrated optical circuits and optical switching. Thin films of these materials processed in microgravity environment show enhanced optical quality and better molecular alignment than those processed in unit gravity. Our studies of these materials indicate that microgravity can play a major role in integrated optics technology. Polydiacetylene films are produced by UV irradiation of monomer solution through an optical window. This novel technique of forming polydiacetylene thin films has been modified for constructing sophisticated micro-structure integrated optical patterns using a pre-programmed UV-Laser beam. Wave guiding through these thin films by the prism coupler technique has been demonstrated. The third order nonlinear parameters of these films have been evaluated. Metal-free phthalocyanine films of good optical quality are processed in our laboratories by vapor deposition technique. Initial studies on these films indicate that they have excellent chemical, laser, and environmental stability. They have large nonlinear optical parameters and show intrinsic optical bistability. This bistability is essential for optical logic gates and optical switching applications. Waveguiding and device making investigations of these materials are underway.

Ultra-low-power hybrid light–matter solitons

PubMed Central

Walker, P. M.; Tinkler, L.; Skryabin, D. V.; Yulin, A.; Royall, B.; Farrer, I.; Ritchie, D. A.; Skolnick, M. S.; Krizhanovskii, D. N.

2015-01-01

New functionalities in nonlinear optics will require systems with giant optical nonlinearity as well as compatibility with photonic circuit fabrication techniques. Here we introduce a platform based on strong light–matter coupling between waveguide photons and quantum-well excitons. On a sub-millimetre length scale we generate picosecond bright temporal solitons at a pulse energy of only 0.5 pJ. From this we deduce a nonlinear refractive index three orders of magnitude larger than in any other ultrafast system. We study both temporal and spatio-temporal nonlinear effects and observe dark–bright spatio-temporal polariton solitons. Theoretical modelling of soliton formation in the strongly coupled system confirms the experimental observations. These results show the promise of our system as a high speed, low power, integrated platform for physics and devices based on strong interactions between photons. PMID:26400748

Ultra-low-power hybrid light-matter solitons.

PubMed

Walker, P M; Tinkler, L; Skryabin, D V; Yulin, A; Royall, B; Farrer, I; Ritchie, D A; Skolnick, M S; Krizhanovskii, D N

2015-09-24

New functionalities in nonlinear optics will require systems with giant optical nonlinearity as well as compatibility with photonic circuit fabrication techniques. Here we introduce a platform based on strong light-matter coupling between waveguide photons and quantum-well excitons. On a sub-millimetre length scale we generate picosecond bright temporal solitons at a pulse energy of only 0.5 pJ. From this we deduce a nonlinear refractive index three orders of magnitude larger than in any other ultrafast system. We study both temporal and spatio-temporal nonlinear effects and observe dark-bright spatio-temporal polariton solitons. Theoretical modelling of soliton formation in the strongly coupled system confirms the experimental observations. These results show the promise of our system as a high speed, low power, integrated platform for physics and devices based on strong interactions between photons.

Efficient nonlinear optical conversion of 1.319-micron laser radiation

NASA Astrophysics Data System (ADS)

Byer, Robert L.; Eckardt, Robert C.

1993-01-01

The accomplishments of this program are in the development and application of periodically poled nonlinear optical materials for nonlinear frequency-conversion. We have demonstrated the use of periodically poled lithium niobate (PPLN) as a bulk material for external resonant cavity second-harmonic generation with continuous-wave (cw) output power of 1.7 W. Work that is following this investigation is showing that planar waveguides of PPLN may well be the most satisfactory method of generation of 10's of mW of the 659-nm harmonic of the 1.32-micrometer Nd:YAG laser. We encountered major obstacles obtaining multilayer dielectric coatings necessary to pursue our proposed design of monolithic bulk optical harmonic generators. Additional alternative approaches such as discrete component resonant second harmonic generation employing single domain and periodically poled bulk crystals and monolithic single domain resonators formed by total internal reflection remain under investigation.

Optical sideband generation up to room temperature with mid-infrared quantum cascade lasers.

PubMed

Houver, S; Cavalié, P; St-Jean, M Renaudat; Amanti, M I; Sirtori, C; Li, L H; Davies, A G; Linfield, E H; Pereira, T A S; Lebreton, A; Tignon, J; Dhillon, S S

2015-02-23

Mid-infrared (MIR) sideband generation on a near infrared (NIR) optical carrier is demonstrated within a quantum cascade laser (QCL). By employing an externally injected NIR beam, E(NIR), that is resonant with the interband transitions of the quantum wells in the QCL, the nonlinear susceptibility is enhanced, leading to both frequency mixing and sideband generation. A GaAs-based MIR QCL (E(QCL) = 135 meV) with an aluminum-reinforced waveguide was utilized to overlap the NIR and MIR modes with the optical nonlinearity of the active region. The resulting difference sideband (E(NIR) - E(QCL)) shows a resonant behavior as a function of NIR pump wavelength and a maximum second order nonlinear susceptibility, χ((2)), of ~1 nm/V was obtained. Further, the sideband intensity showed little dependence with the operating temperature of the QCL, allowing sideband generation to be realized at room temperature.

Waveguides with Absorbing Boundaries: Nonlinearity Controlled by an Exceptional Point and Solitons

NASA Astrophysics Data System (ADS)

Midya, Bikashkali; Konotop, Vladimir V.

2017-07-01

We reveal the existence of continuous families of guided single-mode solitons in planar waveguides with weakly nonlinear active core and absorbing boundaries. Stable propagation of TE and TM-polarized solitons is accompanied by attenuation of all other modes, i.e., the waveguide features properties of conservative and dissipative systems. If the linear spectrum of the waveguide possesses exceptional points, which occurs in the case of TM polarization, an originally focusing (defocusing) material nonlinearity may become effectively defocusing (focusing). This occurs due to the geometric phase of the carried eigenmode when the surface impedance encircles the exceptional point. In its turn, the change of the effective nonlinearity ensures the existence of dark (bright) solitons in spite of focusing (defocusing) Kerr nonlinearity of the core. The existence of an exceptional point can also result in anomalous enhancement of the effective nonlinearity. In terms of practical applications, the nonlinearity of the reported waveguide can be manipulated by controlling the properties of the absorbing cladding.

Numerical study of phase conjugation in stimulated Brillouin scattering from an optical waveguide

NASA Astrophysics Data System (ADS)

Lehmberg, R. H.

1983-05-01

Stimulated Brillouin scattering (SBS) in a multimode optical waveguide is examined, and the parameters that affect the wavefront conjugation fidelity are studied. The nonlinear propagation code is briefly described and the calculated quantities are defined. The parameter study in the low reflectivity limit is described, and the effects of pump depletion are considered. The waveguide produced significantly higher fidelities than the focused configuration, in agreement with several experimental studies. The light scattered back through the phase aberrator exhibited a farfield intenstiy profile closely matching that of the incident beam; however, the nearfield intensity exhibited large and rapid spatial inhomogeneities across the entire aberrator, even for conjugation fidelities as high as 98 percent. In the absence of pump depletion, the fidelity increased with average pump intensity for amplitude gains up to around e to the 10th and then decreased slowly and monotonically with higher intensity. For all cases, pump depletion significantly enhanced the fidelity of the wavefront conjugation by inhibiting the small-scale pulling effect.

Efficient Ti:LiNbO3 ridge waveguide lasers: investigation of Er and Yb:Er doped waveguides pumped at 980nm and 1486nm

NASA Astrophysics Data System (ADS)

Brüske, Dominik; Suntsov, Sergiy; Volk, Martin F.; Rüter, Christian E.; Kip, Detlef

2018-02-01

Erbium-ytterbium-codoped titanium in-diffused ridge waveguides optical amplifiers in x-cut congruent LiNbO3 substrates pumped at 980.5 nm and 1486 nm are reported for the first time. An internal gain of 2.8 dB/cm has been measured in 2.3 cm long Yb:Er:Ti:LiNbO3 ridge waveguides for the coupled pump power of 145 mW at 980.5 nm, which is the highest gain ever reported, to the best of our knowledge, for erbium-based LiNbO3 waveguide amplifiers under 980 nm excitation. Furthermore, we realized an internal gain of 3.2 dB/cm for the coupled pump power of 200 mW at 1486 nm, which also exceeds the best literature values for Er:Ti:LiNbO3 waveguide amplifiers pumped at this wavelength. In addition, we report on a method for local periodic poling (periods of 30 μm and 18.4 μm) of ridge waveguides in LiNbO3, which allows for future integration of waveguide lasers and nonlinear frequency converters on the same substrate.

Supermodes in Coupled Multi-Core Waveguide Structures

DTIC Science & Technology

2016-04-01

and therefore can be treated as linear polarization (LP) modes. In essence, the LP modes are scalar approximations of the vector mode fields and contain...field, including the discovery of optical discrete solitons , Bragg and vector solitons in fibers, nonlinear surface waves, and the discovery of self...increased for an isolated core, it can guide high-order modes. For optical fibers with low re- fractive index contrast, the vector modes are weakly guided

Nonlinear coupled mode approach for modeling counterpropagating solitons in the presence of disorder-induced multiple scattering in photonic crystal waveguides

NASA Astrophysics Data System (ADS)

Mann, Nishan; Hughes, Stephen

2018-02-01

We present the analytical and numerical details behind our recently published article [Phys. Rev. Lett. 118, 253901 (2017), 10.1103/PhysRevLett.118.253901], describing the impact of disorder-induced multiple scattering on counterpropagating solitons in photonic crystal waveguides. Unlike current nonlinear approaches using the coupled mode formalism, we account for the effects of intraunit cell multiple scattering. To solve the resulting system of coupled semilinear partial differential equations, we introduce a modified Crank-Nicolson-type norm-preserving implicit finite difference scheme inspired by the transfer matrix method. We provide estimates of the numerical dispersion characteristics of our scheme so that optimal step sizes can be chosen to either minimize numerical dispersion or to mimic the exact dispersion. We then show numerical results of a fundamental soliton propagating in the presence of multiple scattering to demonstrate that choosing a subunit cell spatial step size is critical in accurately capturing the effects of multiple scattering, and illustrate the stochastic nature of disorder by simulating soliton propagation in various instances of disordered photonic crystal waveguides. Our approach is easily extended to include a wide range of optical nonlinearities and is applicable to various photonic nanostructures where power propagation is bidirectional, either by choice, or as a result of multiple scattering.

All-Optical Implementation of the Ant Colony Optimization Algorithm

PubMed Central

Hu, Wenchao; Wu, Kan; Shum, Perry Ping; Zheludev, Nikolay I.; Soci, Cesare

2016-01-01

We report all-optical implementation of the optimization algorithm for the famous “ant colony” problem. Ant colonies progressively optimize pathway to food discovered by one of the ants through identifying the discovered route with volatile chemicals (pheromones) secreted on the way back from the food deposit. Mathematically this is an important example of graph optimization problem with dynamically changing parameters. Using an optical network with nonlinear waveguides to represent the graph and a feedback loop, we experimentally show that photons traveling through the network behave like ants that dynamically modify the environment to find the shortest pathway to any chosen point in the graph. This proof-of-principle demonstration illustrates how transient nonlinearity in the optical system can be exploited to tackle complex optimization problems directly, on the hardware level, which may be used for self-routing of optical signals in transparent communication networks and energy flow in photonic systems. PMID:27222098

Ge-rich graded-index Si1-xGex devices for MID-IR integrated photonics

NASA Astrophysics Data System (ADS)

Ramirez, J. M.; Vakarin, V.; Liu, Q.; Frigerio, J.; Ballabio, A.; Le Roux, X.; Benedikovic, D.; Alonso-Ramos, C.; Isella, G.; Vivien, L.; Marris-Morini, D.

2018-02-01

Mid-infrared (mid-IR) silicon photonics is becoming a prominent research with remarkable potential in several applications such as in early medical diagnosis, safe communications, imaging, food safety and many more. In the quest for the best material platform to develop new photonic systems, Si and Ge depart with a notable advantage over other materials due to the high processing maturity accomplished during the last part of the 20th century through the deployment of the CMOS technology. From an optical viewpoint, combining Si with Ge to obtain SiGe alloys with controlled stoichiometry is also of interest for the photonic community since permits to increase the effective refractive index and the nonlinear parameter, providing a fascinating playground to exploit nonlinear effects. Furthermore, using Ge-rich SiGe gives access to a range of deep mid-IR wavelengths otherwise inaccessible (λ 2-20 μm). In this paper, we explore for the first time the limits of this approach by measuring the spectral loss characteristic over a broadband wavelength range spanning from λ = 5.5 μm to 8.5 μm. Three different SiGe waveguide platforms are compared, each one showing higher compactness than the preceding through the engineering of the vertical Ge profile, giving rise to different confinement characteristics to the propagating modes. A flat propagation loss characteristic of 2-3 dB/cm over the entire wavelength span is demonstrated in Ge-rich graded-index SiGe waveguides of only 6 μm thick. Also, the role of the overlap fraction of the confined optical mode with the Si-rich area at the bottom side of the epitaxial SiGe waveguide is put in perspective, revealing a lossy characteristic compared to the other designs were the optical mode is located in the Ge-rich area at the top of the waveguide uniquely. These Ge-rich graded-index SiGe waveguides may pave the way towards a new generation of photonic integrated circuits operating at deep mid-IR wavelengths.

FIBER OPTICS: Schrödinger soliton in a fiber waveguide exhibiting both gain and losses: squeezed states and growth of noise in the linear approximation

NASA Astrophysics Data System (ADS)

Belinskiĭ, A. V.

1992-09-01

An investigation is made of the evolution of quantum fluctuations of a fundamental soliton in the course of its propagation in a nonlinear fiber waveguide characterized by losses and compensated by amplification. Simple relationships are obtained for the amplitude and phase noise, quantum uncertainty of the position and momentum, and also fluctuations of the quadrature components of the radiation field. Numerical estimates are obtained. It is shown that loss-compensating amplification is unnecessary for efficient formation of squeezed states of a soliton.

Noninvasive and Real-Time Plasmon Waveguide Resonance Thermometry

PubMed Central

Zhang, Pengfei; Liu, Le; He, Yonghong; Zhou, Yanfei; Ji, Yanhong; Ma, Hui

2015-01-01

In this paper, the noninvasive and real-time plasmon waveguide resonance (PWR) thermometry is reported theoretically and demonstrated experimentally. Owing to the enhanced evanescent field and thermal shield effect of its dielectric layer, a PWR thermometer permits accurate temperature sensing and has a wide dynamic range. A temperature measurement sensitivity of 9.4 × 10−3 °C is achieved and the thermo optic coefficient nonlinearity is measured in the experiment. The measurement of water cooling processes distributed in one dimension reveals that a PWR thermometer allows real-time temperature sensing and has potential to be applied for thermal gradient analysis. Apart from this, the PWR thermometer has the advantages of low cost and simple structure, since our transduction scheme can be constructed with conventional optical components and commercial coating techniques. PMID:25871718

Low-power, ultrafast, and dynamic all-optical tunable plasmon induced transparency in two stub resonators side-coupled with a plasmonic waveguide system

NASA Astrophysics Data System (ADS)

Wang, Boyun; Zeng, Qingdong; Xiao, Shuyuan; Xu, Chen; Xiong, Liangbin; Lv, Hao; Du, Jun; Yu, Huaqing

2017-11-01

We theoretically and numerically investigate a low-power, ultrafast, and dynamic all-optical tunable plasmon induced transparency (PIT) in two stub resonators side-coupled with a metal-dielectric-metal (MDM) plasmonic waveguide system. The optical Kerr effect is enhanced by the local electromagnetic field of surface plasmon polaritons (SPPs) and the plasmonic waveguide based on graphene-Ag composite material structures with large effective Kerr nonlinear coefficient. An ultrafast response time of the order of 1 ps is reached because of ultrafast carrier relaxation dynamics of graphene. With dynamically tuning the propagation phase of the plasmonic waveguide, π-phase shift of the transmission spectrum in the PIT system is achieved under excitation of a pump light with an intensity as low as 5.8 MW cm-2. The group delay is controlled between 0.14 and 0.67 ps. Moreover, the tunable bandwidth of about 42 nm is obtained. For the indirect coupling between two stub cavities or the phase coupling scheme, the phase shift multiplication effect of the PIT effect is found. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. This work not only paves the way towards the realization of on-chip integrated nanophotonic devices but also opens the possibility of the construction of ultrahigh-speed information processing chips based on plasmonic circuits.

Self-phase-modulation induced spectral broadening in silicon waveguides

NASA Astrophysics Data System (ADS)

Boyraz, Ozdal; Indukuri, Tejaswi; Jalali, Bahram

2004-03-01

The prospect for generating supercontinuum pulses on a silicon chip is studied. Using ~4ps optical pulses with 2.2GW/cm2 peak power, a 2 fold spectral broadening is obtained. Theoretical calculations, that include the effect of two-photon-absorption, indicate up to 5 times spectral broadening is achievable at 10x higher peak powers. Representing a nonlinear loss mechanism at high intensities, TPA limits the maximum optical bandwidth that can be generated.

Self-phase-modulation induced spectral broadening in silicon waveguides.

PubMed

Boyraz, Ozdal; Indukuri, Tejaswi; Jalali, Bahram

2004-03-08

The prospect for generating supercontinuum pulses on a silicon chip is studied. Using ~4ps optical pulses with 2.2GW/cm(2) peak power, a 2 fold spectral broadening is obtained. Theoretical calculations, that include the effect of two-photon-absorption, indicate up to 5 times spectral broadening is achievable at 10x higher peak powers. Representing a nonlinear loss mechanism at high intensities, TPA limits the maximum optical bandwidth that can be generated.

All-Union Conference on Laser Optics, 4th, Leningrad, USSR, January 13-18, 1984, Proceedings

NASA Astrophysics Data System (ADS)

Bukhenskii, M. F.

1984-08-01

The papers presented in this volume provide an overview of current theoretical and experimental research in laser optics. Topics discussed include electronically controlled tunable lasers, nonlinear phenomena in fiber-optic waveguides, holographic distributed-feedback dye lasers, and new developments in solid-state lasers. Papers are also presented on the generation of picosecond pulses through self-Q-switching in a distributed-feedback laser, temporal compression of light pulses during stimulated backscattering, and optimization of second harmonic generation in a multimode Nd:glass laser.

Direct femtosecond laser writing of buried infrared waveguides in chalcogenide glasses

NASA Astrophysics Data System (ADS)

Le Coq, D.; Bychkov, E.; Masselin, P.

2016-02-01

Direct laser writing technique is now widely used in particular in glass, to produce both passive and active photonic devices. This technique offers a real scientific opportunity to generate three-dimensional optical components and since chalcogenide glasses possess transparency properties from the visible up to mid-infrared range, they are of great interest. Moreover, they also have high optical non-linearity and high photo-sensitivity that make easy the inscription of refractive index modification. The understanding of the fundamental and physical processes induced by the laser pulses is the key to well-control the laser writing and consequently to realize integrated photonic devices. In this paper, we will focus on two different ways allowing infrared buried waveguide to be obtained. The first part will be devoted to a very original writing process based on a helical translation of the sample through the laser beam. In the second part, we will report on another original method based on both a filamentation phenomenon and a point by point technique. Finally, we will demonstrate that these two writing techniques are suitable for the design of single mode waveguide for wavelength ranging from the visible up to the infrared but also to fabricate optical components.

Compound semiconductor optical waveguide switch

DOEpatents

Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

2003-06-10

An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

SiNOI and AlGaAs-on-SOI nonlinear circuits for continuum generation in Si photonics

NASA Astrophysics Data System (ADS)

El Dirani, Houssein; Monat, Christelle; Brision, Stéphane; Olivier, Nicolas; Jany, Christophe; Letartre, Xavier; Pu, Minhao; Girouard, Peter D.; Hagedorn Frandsen, Lars; Semenova, Elizaveta; Katsuo Oxenløwe, Leif; Yvind, Kresten; Sciancalepore, Corrado

2018-02-01

In this communication, we report on the design, fabrication, and testing of Silicon Nitride on Insulator (SiNOI) and Aluminum-Gallium-Arsenide (AlGaAs) on silicon-on-insulator (SOI) nonlinear photonic circuits for continuum generation in Silicon (Si) photonics. As recently demonstrated, the generation of frequency continua and supercontinua can be used to overcome the intrinsic limitations of nowadays silicon photonics notably concerning the heterogeneous integration of III-V on SOI lasers for datacom and telecom applications. By using the Kerr nonlinearity of monolithic silicon nitride and heterointegrated GaAs-based alloys on SOI, the generation of tens or even hundreds of new optical frequencies can be obtained in dispersion tailored waveguides, thus providing an all-optical alternative to the heterointegration of hundreds of standalone III-V on Si lasers. In our work, we present paths to energy-efficient continua generation on silicon photonics circuits. Notably, we demonstrate spectral broadening covering the full C-band via Kerrbased self-phase modulation in SiNOI nanowires featuring full process compatibility with Si photonic devices. Moreover, AlGaAs waveguides are heterointegrated on SOI in order to dramatically reduce (x1/10) thresholds in optical parametric oscillation and in the power required for supercontinuum generation under pulsed pumping. The manufacturing techniques allowing the monolithic co-integration of nonlinear functionalities on existing CMOS-compatible Si photonics for both active and passive components will be shown. Experimental evidence based on self-phase modulation show SiNOI and AlGaAs nanowires capable of generating wide-spanning frequency continua in the C-Band. This will pave the way for low-threshold power-efficient Kerr-based comb- and continuum- sources featuring compatibility with Si photonic integrated circuits (Si-PICs).

Rogue waves for a system of coupled derivative nonlinear Schrödinger equations.

PubMed

Chan, H N; Malomed, B A; Chow, K W; Ding, E

2016-01-01

Rogue waves (RWs) are unexpectedly strong excitations emerging from an otherwise tranquil background. The nonlinear Schrödinger equation (NLSE), a ubiquitous model with wide applications to fluid mechanics, optics, plasmas, etc., exhibits RWs only in the regime of modulation instability (MI) of the background. For a system of multiple waveguides, the governing coupled NLSEs can produce regimes of MI and RWs, even if each component has dispersion and cubic nonlinearity of opposite signs. A similar effect is demonstrated here for a system of coupled derivative NLSEs (DNLSEs) where the special feature is the nonlinear self-steepening of narrow pulses. More precisely, these additional regimes of MI and RWs for coupled DNLSEs depend on the mismatch in group velocities between the components, and the parameters for cubic nonlinearity and self-steepening. RWs considered in this paper differ from those of the NLSEs in terms of the amplification ratio and criteria of existence. Applications to optics and plasma physics are discussed.

Spectro-spatial analysis of wave packet propagation in nonlinear acoustic metamaterials

NASA Astrophysics Data System (ADS)

Zhou, W. J.; Li, X. P.; Wang, Y. S.; Chen, W. Q.; Huang, G. L.

2018-01-01

The objective of this work is to analyze wave packet propagation in weakly nonlinear acoustic metamaterials and reveal the interior nonlinear wave mechanism through spectro-spatial analysis. The spectro-spatial analysis is based on full-scale transient analysis of the finite system, by which dispersion curves are generated from the transmitted waves and also verified by the perturbation method (the L-P method). We found that the spectro-spatial analysis can provide detailed information about the solitary wave in short-wavelength region which cannot be captured by the L-P method. It is also found that the optical wave modes in the nonlinear metamaterial are sensitive to the parameters of the nonlinear constitutive relation. Specifically, a significant frequency shift phenomenon is found in the middle-wavelength region of the optical wave branch, which makes this frequency region behave like a band gap for transient waves. This special frequency shift is then used to design a direction-biased waveguide device, and its efficiency is shown by numerical simulations.

Efficient On-chip Optical Microresonator for Optical Comb Generation: Design and Fabrication

NASA Astrophysics Data System (ADS)

Han, Kyunghun

An optical frequency comb is a series of equally spaced frequency components. It has gained much attention since Nobel physics prize was awarded John L. Hall and Theodor W. Hansch for their contribution to the optical frequency comb technique in 2005. The optical frequency comb has been extensively studied because of its precision as a tool for spectroscopy, and is now widely used in bio- and chemical sensors, optical clocks, mode-locked dark pulse generation, soliton generation, and optical communication. Recently, thanks to the developments in nanotechnology, the optical frequency comb generation is made possible at a chip-scale level with microresonators. However, because the threshold power of the optical frequency comb generation is beyond the capability of the on-chip laser source, efficient microresonator is required. Here, we demonstrate an ultra-compact and highly efficient strip-slot direct mode coupler, aiming to achieve slotted silicon microresonator cladded with nonlinear polymer Poly-DDMEBT in SOI platform. As an application of the strip-slot direct mode coupling, a double slot fiber-to-chip edge coupler is demonstrated showing 2 dB insertion loss reduction compared to the conventional single tip edge coupler. For silicon nitride platform, we investigated evanescent wave coupling of microresonator, focusing on bus waveguide geometry optimization. The optimized waveguide width offers an efficient excitation of a fundamental mode in the resonator waveguide. This investigation can benefit low threshold comb generation by enhancing the extinction ratio. We experimentally demonstrated the high Q-factor micro-ring resonator with intrinsic Q of 12.6 million as well as the single FSR comb generation with 63 mW.

Optical waveguide device with an adiabatically-varying width

DOEpatents

Watts,; Michael R. , Nielson; Gregory, N [Albuquerque, NM

2011-05-10

Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

Integrated Metamaterials and Nanophotonics in CMOS-Compatible Materials

NASA Astrophysics Data System (ADS)

Reshef, Orad

This thesis explores scalable nanophotonic devices in integrated, CMOS-compatible platforms. Our investigation focuses on two main projects: studying the material properties of integrated titanium dioxide (TiO2), and studying integrated metamaterials in silicon-on-insulator (SOI) technologies. We first describe the nanofabrication process for TiO2 photonic integrated circuits. We use this procedure to demonstrate polycrystalline anatase TiO2 ring resonators with high quality factors. We measure the thermo-optic coefficient of TiO2 and determine that it is negative, a unique property among CMOS-compatible dielectric photonic platforms. We also derive a transfer function for ring resonators in the presence of reflections and demonstrate using full-wave simulations that these reflections produce asymmetries in the resonances. For the second half of the dissertation, we design and demonstrate an SOI-based photonic-Dirac-cone metamaterial. Using a prism composed of this metamaterial, we measure its index of refraction and unambiguously determine that it is zero. Next, we take a single channel of this metamaterial to form a waveguide. Using interferometry, we independently confirm that the waveguide in this configuration preserves the dispersion profile of the aggregate medium, with a zero phase advance. We also characterize the waveguide, determining its propagation loss. Finally, we perform simulations to study nonlinear optical phenomena in zero-index media. We find that an isotropic refractive index near zero relaxes certain phase-matching constraints, allowing for more flexible configurations of nonlinear devices with dramatically reduced footprints. The outcomes of this work enable higher quality fabrication of scalable nanophotonic devices for use in nonlinear applications with passive temperature compensation. These devices are CMOS-compatible and can be integrated vertically for compact, device-dense industrial applications. It also provides access to a versatile, scalable and integrated medium with a refractive index that can be continuously engineered between n = -0.20 and n = +0.50. This opens the door to applications in high-precision interferometry, sensing, quantum information technologies and compact nonlinear applications.

Fabrication of low loss waveguide using fundamental light of Yb-based femtosecond laser (Conference Presentation)

NASA Astrophysics Data System (ADS)

Imai, Ryo; Konishi, Kuniaki; Yumoto, Junji; Gonokami, Makoto K.

2017-03-01

Laser direct writing of optical devices and circuits is attracted attention because of its ability of three-dimensional fabrication without any mask[1]. Recently, Yb-fiber or solid-state laser has been commonly used for fabrication in addition to traditional Ti:S laser. However, it is reported that waveguide cannot be fabricated in fused silica by using the fundamental light from Yb-based femtosecond laser[2]. Some groups reported on waveguide fabrication by using second-harmonic beam of such lasers[3], but wavelength conversion using nonlinear process has drawbacks such as destabilization of laser power and beam deformation by walk off. In this study, we investigated fabrication of low-loss waveguide in fused silica by using the fundamental beam (1030nm) from an Yb solid-state femtosecond laser with a pulse duration of 250 fs. The NA of focusing objective lens was 0.42. The fabricated waveguide was made to have a circular cross-section by shaping laser beam with a slit[4]. We fixed repetition rate to 150 kHz, and identified appropriate scan speed and pulse energy for fabrication of low loss waveguide. Waveguide fabricated with appropriate condition had a propagation loss of 0.2 dB/cm, and this is the first report on optical waveguides in a fused silica fabricated by femto-second laser pulses at a wavelength of 1030nm. [1]K. M. Davis, et. al., Opt. Lett 21, 1729(1996) [2]J. Canning, et. al., Opt. Mater. Express 1, 998(2011) [3]L. Shah, et. al., Opt. Express 13, 1999(2005) [4]M. Ams, et. al., Opt. Express 13, 5676(2005)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Yunshan; DeVore, Peter T. S.; Jalali, Bahram

Optical computing accelerators help alleviate bandwidth and power consumption bottlenecks in electronics. In this paper, we show an approach to implementing logarithmic-type analog co-processors in silicon photonics and use it to perform the exponentiation operation and the recovery of a signal in the presence of multiplicative distortion. Finally, the function is realized by exploiting nonlinear-absorption-enhanced Raman amplification saturation in a silicon waveguide.

A compact, all-optical, THz wave generator based on self-modulation in a slab photonic crystal waveguide with a single sub-nanometer graphene layer.

PubMed

Asadi, R; Ouyang, Z; Mohammd, M M

2015-07-14

We design a compact, all-optical THz wave generator based on self-modulation in a 1-D slab photonic crystal (PhC) waveguide with a single sub-nanometer graphene layer by using enhanced nonlinearity of graphene. It has been shown that at the bandgap edge of higher bands of a 1-D slab PhC, through only one sub-nanometer graphene layer we can obtain a compact, high modulation factor (about 0.98 percent), self-intensity modulator at a high frequency (about 0.6 THz) and low threshold intensity (about 15 MW per square centimeter), and further a compact, all-optical THz wave generator by integrating the self-modulator with a THz photodiode or photonic mixer. Such a THz source is expected to have a relatively high efficiency compared with conventional sources based on optical methods. The proposed THz source can find wide applications in THz science and technology, e.g., in THz imaging, THz sensors and detectors, THz communication systems, and THz optical integrated logic circuits.

Fast analytical model of MZI micro-opto-mechanical pressure sensor

NASA Astrophysics Data System (ADS)

Rochus, V.; Jansen, R.; Goyvaerts, J.; Neutens, P.; O’Callaghan, J.; Rottenberg, X.

2018-06-01

This paper presents a fast analytical procedure in order to design a micro-opto-mechanical pressure sensor (MOMPS) taking into account the mechanical nonlinearity and the optical losses. A realistic model of the photonic MZI is proposed, strongly coupled to a nonlinear mechanical model of the membrane. Based on the membrane dimensions, the residual stress, the position of the waveguide, the optical wavelength and the phase variation due to the opto-mechanical coupling, we derive an analytical model which allows us to predict the response of the total system. The effect of the nonlinearity and the losses on the total performance are carefully studied and measurements on fabricated devices are used to validate the model. Finally, a design procedure is proposed in order to realize fast design of this new type of pressure sensor.

Two-photon Anderson localization in a disordered quadratic waveguide array

NASA Astrophysics Data System (ADS)

Bai, Y. F.; Xu, P.; Lu, L. L.; Zhong, M. L.; Zhu, S. N.

2016-05-01

We theoretically investigate two-photon Anderson localization in a χ (2) waveguide array with off-diagonal disorder. The nonlinear parametric down-conversion process would enhance both the single-photon and the two-photon Anderson localization. In the strong disorder regime, the two-photon position correlation exhibits a bunching distribution around the pumped waveguides, which is independent of pumping conditions and geometrical structures of waveguide arrays. Quadratic nonlinearity can be supplied as a new ingredient for Anderson localization. Also, our results pave the way for engineering quantum states through nonlinear quantum walks.

Testing Born-Infeld electrodynamics in waveguides.

PubMed

Ferraro, Rafael

2007-12-07

Waveguides can be employed to test nonlinear effects in electrodynamics. We solve Born-Infeld equations for TE waves in a rectangular waveguide. We show that the energy velocity acquires a dependence on the amplitude, and harmonic components appear as a consequence of the nonlinear behavior.

Monolithically integrated all-optical gate switch using intersubband transition in InGaAs/AlAsSb coupled double quantum wells.

PubMed

Akimoto, Ryoichi; Gozu, Shin-ichiro; Mozume, Teruo; Ishikawa, Hiroshi

2011-07-04

We have developed a compact all-optical gate switch with a footprint less than 1 mm2, in which an optical nonlinear waveguide using cross-phase-modulation associated with intersubband transition in InGaAs/AlGaAs/AlAsSb coupled double quantum wells and a Michelson interferometer (MI) are monolithically integrated on an InP chip. The MI configuration allows a transverse magnetic pump light direct access to an MI arm for phase modulation while passive photonic integrated circuits serve a transverse electric signal light. Full switching of the π-rad nonlinear phase shift is achieved with a pump pulse energy of 8.6 pJ at a 10-GHz repetition rate. We also demonstrate all-optical demultiplexing of a 160-Gb/s signal to a 40-Gb/s signal.

Investigation of phase matching for third-harmonic generation in silicon slow light photonic crystal waveguides using Fourier optics.

PubMed

Monat, Christelle; Grillet, Christian; Corcoran, Bill; Moss, David J; Eggleton, Benjamin J; White, Thomas P; Krauss, Thomas F

2010-03-29

Using Fourier optics, we retrieve the wavevector dependence of the third-harmonic (green) light generated in a slow light silicon photonic crystal waveguide. We show that quasi-phase matching between the third-harmonic signal and the fundamental mode is provided in this geometry by coupling to the continuum of radiation modes above the light line. This process sustains third-harmonic generation with a relatively high efficiency and a substantial bandwidth limited only by the slow light window of the fundamental mode. The results give us insights into the physics of this nonlinear process in the presence of strong absorption and dispersion at visible wavelengths where bandstructure calculations are problematic. Since the characteristics (e.g. angular pattern) of the third-harmonic light primarily depend on the fundamental mode dispersion, they could be readily engineered.

System and method for ultrafast optical signal detecting via a synchronously coupled anamorphic light pulse encoded laterally

DOEpatents

Heebner, John E [Livermore, CA

2010-08-03

In one general embodiment, a method for ultrafast optical signal detecting is provided. In operation, a first optical input signal is propagated through a first wave guiding layer of a waveguide. Additionally, a second optical input signal is propagated through a second wave guiding layer of the waveguide. Furthermore, an optical control signal is applied to a top of the waveguide, the optical control signal being oriented diagonally relative to the top of the waveguide such that the application is used to influence at least a portion of the first optical input signal propagating through the first wave guiding layer of the waveguide. In addition, the first and the second optical input signals output from the waveguide are combined. Further, the combined optical signals output from the waveguide are detected. In another general embodiment, a system for ultrafast optical signal recording is provided comprising a waveguide including a plurality of wave guiding layers, an optical control source positioned to propagate an optical control signal towards the waveguide in a diagonal orientation relative to a top of the waveguide, at least one optical input source positioned to input an optical input signal into at least a first and a second wave guiding layer of the waveguide, and a detector for detecting at least one interference pattern output from the waveguide, where at least one of the interference patterns results from a combination of the optical input signals input into the first and the second wave guiding layer. Furthermore, propagation of the optical control signal is used to influence at least a portion of the optical input signal propagating through the first wave guiding layer of the waveguide.

Spectroscopic Study of Terahertz Generation in Mid-Infrared Quantum Cascade Lasers.

PubMed

Jiang, Yifan; Vijayraghavan, Karun; Jung, Seungyong; Jiang, Aiting; Kim, Jae Hyun; Demmerle, Frederic; Boehm, Gerhard; Amann, Markus C; Belkin, Mikhail A

2016-02-16

Terahertz quantum cascade laser sources based on intra-cavity difference-frequency generation are currently the only room-temperature mass-producible diode-laser-like emitters of coherent 1-6 THz radiation. Device performance has improved dramatically over the past few years to reach milliwatt-level power output and broad tuning from 1.2 to 5.9 THz, all at room-temperature. Terahertz output in these sources originates from intersubband optical nonlinearity in the laser active region. Here we report the first comprehensive spectroscopic study of the optical nonlinearity and investigate its dependence on the mid-infrared pump frequencies. Our work shows that the terahertz generation efficiency can vary by a factor of 2 or greater depending on the spectral position of the mid-infrared pumps for a fixed THz difference-frequency. We have also measured for the first time the linewidth for transitions between the lower quantum cascade laser states, which is critical for determining terahertz nonlinearity and predicting optical loss in quantum cascade laser waveguides.

Tunable room temperature THz sources based on nonlinear mixing in a hybrid optical and THz micro-ring resonator.

PubMed

Sinha, Raju; Karabiyik, Mustafa; Al-Amin, Chowdhury; Vabbina, Phani K; Güney, Durdu Ö; Pala, Nezih

2015-03-24

We propose and systematically investigate a novel tunable, compact room temperature terahertz (THz) source based on difference frequency generation in a hybrid optical and THz micro-ring resonator. We describe detailed design steps of the source capable of generating THz wave in 0.5-10 THz with a tunability resolution of 0.05 THz by using high second order optical susceptibility (χ((2))) in crystals and polymers. In order to enhance THz generation compared to bulk nonlinear material, we employ a nonlinear optical micro-ring resonator with high-Q resonant modes for infrared input waves. Another ring oscillator with the same outer radius underneath the nonlinear ring with an insulation of SiO2 layer supports the generated THz with resonant modes and out-couples them into a THz waveguide. The phase matching condition is satisfied by engineering both the optical and THz resonators with appropriate effective indices. We analytically estimate THz output power of the device by using practical values of susceptibility in available crystals and polymers. The proposed source can enable tunable, compact THz emitters, on-chip integrated spectrometers, inspire a broader use of THz sources and motivate many important potential THz applications in different fields.

Tunable Room Temperature THz Sources Based on Nonlinear Mixing in a Hybrid Optical and THz Micro-Ring Resonator

PubMed Central

Sinha, Raju; Karabiyik, Mustafa; Al-Amin, Chowdhury; Vabbina, Phani K.; Güney, Durdu Ö.; Pala, Nezih

2015-01-01

We propose and systematically investigate a novel tunable, compact room temperature terahertz (THz) source based on difference frequency generation in a hybrid optical and THz micro-ring resonator. We describe detailed design steps of the source capable of generating THz wave in 0.5–10 THz with a tunability resolution of 0.05 THz by using high second order optical susceptibility (χ(2)) in crystals and polymers. In order to enhance THz generation compared to bulk nonlinear material, we employ a nonlinear optical micro-ring resonator with high-Q resonant modes for infrared input waves. Another ring oscillator with the same outer radius underneath the nonlinear ring with an insulation of SiO2 layer supports the generated THz with resonant modes and out-couples them into a THz waveguide. The phase matching condition is satisfied by engineering both the optical and THz resonators with appropriate effective indices. We analytically estimate THz output power of the device by using practical values of susceptibility in available crystals and polymers. The proposed source can enable tunable, compact THz emitters, on-chip integrated spectrometers, inspire a broader use of THz sources and motivate many important potential THz applications in different fields. PMID:25800287

Periodically poled silicon

NASA Astrophysics Data System (ADS)

Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Khurgin, Jacob B.; Jalali, Bahram

2010-02-01

Bulk centrosymmetric silicon lacks second-order optical nonlinearity χ(2) - a foundational component of nonlinear optics. Here, we propose a new class of photonic device which enables χ(2) as well as quasi-phase matching based on periodic stress fields in silicon - periodically-poled silicon (PePSi). This concept adds the periodic poling capability to silicon photonics, and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on χ(2)) effects. The concept can also be simply achieved by having periodic arrangement of stressed thin films along a silicon waveguide. As an example of the utility, we present simulations showing that mid-wave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50% based on χ(2) values measurements for strained silicon reported in the literature [Jacobson et al. Nature 441, 199 (2006)]. The use of PePSi for frequency conversion can also be extended to terahertz generation. With integrated piezoelectric material, dynamically control of χ(2)nonlinearity in PePSi waveguide may also be achieved. The successful realization of PePSi based devices depends on the strength of the stress induced χ(2) in silicon. Presently, there exists a significant discrepancy in the literature between the theoretical and experimentally measured values. We present a simple theoretical model that produces result consistent with prior theoretical works and use this model to identify possible reasons for this discrepancy.

Two-octave spanning supercontinuum generation in stoichiometric silicon nitride waveguides pumped at telecom wavelengths.

PubMed

Porcel, Marco A G; Schepers, Florian; Epping, Jörn P; Hellwig, Tim; Hoekman, Marcel; Heideman, René G; van der Slot, Peter J M; Lee, Chris J; Schmidt, Robert; Bratschitsch, Rudolf; Fallnich, Carsten; Boller, Klaus-J

2017-01-23

We demonstrate supercontinuum generation in stoichiometric silicon nitride (Si₃N₄ in SiO₂) integrated optical waveguides, pumped at telecommunication wavelengths. The pump laser is a mode-locked erbium fiber laser at a wavelength of 1.56 µm with a pulse duration of 120 fs. With a waveguide-internal pulse energy of 1.4 nJ and a waveguide with 1.0 µm × 0.9 µm cross section, designed for anomalous dispersion across the 1500 nm telecommunication range, the output spectrum extends from the visible, at around 526 nm, up to the mid-infrared, at least to 2.6 µm, the instrumental limit of our detection. This output spans more than 2.2 octaves (454 THz at the -30 dB level). The measured output spectra agree well with theoretical modeling based on the generalized nonlinear Schrödinger equation. The infrared part of the supercontinuum spectra shifts progressively towards the mid-infrared, well beyond 2.6 µm, by increasing the width of the waveguides.

Bright-dark soliton solutions for the (2+1)-dimensional variable-coefficient coupled nonlinear Schrödinger system in a graded-index waveguide

NASA Astrophysics Data System (ADS)

Yuan, Yu-Qiang; Tian, Bo; Xie, Xi-Yang; Chai, Jun; Liu, Lei

2017-04-01

Under investigation in this paper is the (2+1)-dimensional coupled nonlinear Schrödinger (NLS) system with variable coefficients, which describes the propagation of an optical beam inside the two-dimensional graded-index waveguide amplifier with the polarization effects. Through a similarity transformation, we convert that system into a set of the integrable defocusing (1+1)-dimensional coupled NLS equations, and subsequently construct the bright-dark soliton solutions for the original system which are converted from the ones of the latter set. With the graphic analysis, we discuss the soliton propagation and collision with r(t), which is related to the nonlinear, profile and gain/loss coefficients. When r(t) is a constant, one soliton propagates with the amplitude, width and velocity unvaried, while velocity and width of the one soliton can be affected, and two solitons possess the elastic collision; When r(t) is a linear function, velocity and width of the one soliton varies with t increasing, and collision of the two solitons is altered. Besides, bound-state solitons are seen.

Propagating Polaritons in III-Nitride Slab Waveguides

NASA Astrophysics Data System (ADS)

Ciers, J.; Roch, J. G.; Carlin, J.-F.; Jacopin, G.; Butté, R.; Grandjean, N.

2017-03-01

We report on III-nitride waveguides with c -plane GaN /(Al ,Ga )N quantum wells in the strong light-matter coupling regime supporting propagating polaritons. They feature a normal-mode splitting as large as 60 meV at low temperatures thanks to the large overlap between the optical mode and the active region, a polariton decay length up to 100 μ m for photonlike polaritons and a lifetime of 1 to 2 ps, with the latter values being essentially limited by residual absorption occurring in the waveguide. The fully lattice-matched nature of the structure allows for very low disorder and high in-plane homogeneity, which is an important asset for the realization of polaritonic integrated circuits that could support nonlinear polariton wave packets up to room temperature thanks to the large exciton binding energy of 40 meV.

Barium Titanate Photonic Crystal Electro-Optic Modulators for Telecommunication and Data Network Applications

NASA Astrophysics Data System (ADS)

Girouard, Peter D.

The microwave, optical, and electro-optic properties of epitaxial barium titanate thin films grown on (100) MgO substrates and photonic crystal electro-optic modulators fabricated on these films were investigated to demonstrate the applicability of these devices for telecommunication and data networks. The electrical and electro-optical properties were characterized up to modulation frequencies of 50 GHz, and the optical properties of photonic crystal waveguides were determined for wavelengths spanning the optical C band between 1500 and 1580 nm. Microwave scattering parameters were measured on coplanar stripline devices with electrode gap spacings between 5 and 12 mum on barium titanate films with thicknesses between 230 and 680 nm. The microwave index and device characteristic impedance were obtained from the measurements. Larger (lower) microwave indices (impedances) were obtained for devices with narrower electrode gap spacings and on thicker films. Thinner film devices have both lower index mismatch between the co-propagating microwave and optical signals and lower impedance mismatch to a 50O system, resulting in a larger predicted electro-optical 3 dB bandwidth. This was experimentally verified with electro-optical frequency response measurements. These observations were applied to demonstrate a record high 28 GHz electro-optic bandwidth measured for a BaTiO3 conventional ridge waveguide modulator having 1mm long electrodes and 12 mum gap spacing on a 260nm thick film. The half-wave voltage and electro-optic coefficients of barium titanate modulators were measured for films having thicknesses between 260 and 500 nm. The half-wave voltage was directly measured at low frequencies using a polarizer-sample-compensator-analyzer setup by over-driving waveguide integrated modulators beyond their linear response regime. Effective in-device electro-optic coefficients were obtained from the measured half-wave voltages. The effective electro-optic coefficients were found to increase with both applied electrical dc bias and with film thickness. A record low 0.39V ˙ cm (0.45V ˙ cm) voltage-length product was measured for barium titanate modulators operating at telecommunication wavelengths on a device with 5 ?m electrode gap spacing on a 500nm thick film modulated at a frequency of 100 Hz (1 MHz). This measured voltage-length product is more than a factor of 5 lower than that reported for state-of-the-art silicon conventional waveguide modulators. The electro-optical characterization of BaTiO3 films revealed a trade-off that exists for traveling wave BaTiO3 modulators: lower voltages are obtained in thicker film devices with narrow electrode gap spacing while larger bandwidths are obtained in thinner film devices with wider electrode gap spacing. These findings were supported by calculations of the film thickness dependent half-wave voltage and electro-optic bandwidth. In order to demonstrate modulators having simultaneously low voltage operation and high electro-optic bandwidth, photonic crystal waveguide modulators with large group index were investigated through theory and experiment. The theory for slow light phase delay in linear optical materials was extended for second order nonlinear optical materials. This theory was incorporated into a detailed model for predicting photonic crystal modulator performance in terms of voltage-length product and electro-optic bandwidth. Modeling shows that barium titanate photonic crystal modulators with sub-millimeter length, sub-volt operation, and greater than 40 GHz electro-optic bandwidth are achievable in a single device. Two types of photonic crystal waveguides (PC) on BaTiO3 films were designed, fabricated, and characterized: waveguides with hexagonal lattice symmetry and waveguides with hexagonal symmetry having a line defect oriented in the direction of light propagation. Excellent agreement was obtained between the simulated and measured transmission for hexagonal lattice PC waveguides. An extinction of 20 dB was measured across a 9.9 nm stop band edge, yielding a record large band edge sharpness of 2 dB/nm for all photonic crystal waveguides on ferroelectric films. A 12-fold enhancement of the electro-optic coefficient was measured via optical spectral analysis in a line defect BaTiO3 modulator, yielding an effective electro-optic coefficient of 900 pm/V in the photonic crystal region at a modulation frequency of 10 GHz. This enhancement was demonstrated over a 48 nm range, demonstrating the wideband operation of these devices.

Travelling-wave resonant four-wave mixing breaks the limits of cavity-enhanced all-optical wavelength conversion.

PubMed

Morichetti, Francesco; Canciamilla, Antonio; Ferrari, Carlo; Samarelli, Antonio; Sorel, Marc; Melloni, Andrea

2011-01-01

Wave mixing inside optical resonators, while experiencing a large enhancement of the nonlinear interaction efficiency, suffers from strong bandwidth constraints, preventing its practical exploitation for processing broad-band signals. Here we show that such limits are overcome by the new concept of travelling-wave resonant four-wave mixing (FWM). This approach combines the efficiency enhancement provided by resonant propagation with a wide-band conversion process. Compared with conventional FWM in bare waveguides, it exhibits higher robustness against chromatic dispersion and propagation loss, while preserving transparency to modulation formats. Travelling-wave resonant FWM has been demonstrated in silicon-coupled ring resonators and was exploited to realize a 630-μm-long wavelength converter operating over a wavelength range wider than 60 nm and with 28-dB gain with respect to a bare waveguide of the same physical length. Full compatibility of the travelling-wave resonant FWM with optical signal processing applications has been demonstrated through signal retiming and reshaping at 10 Gb s(-1).

Travelling-wave resonant four-wave mixing breaks the limits of cavity-enhanced all-optical wavelength conversion

PubMed Central

Morichetti, Francesco; Canciamilla, Antonio; Ferrari, Carlo; Samarelli, Antonio; Sorel, Marc; Melloni, Andrea

2011-01-01

Wave mixing inside optical resonators, while experiencing a large enhancement of the nonlinear interaction efficiency, suffers from strong bandwidth constraints, preventing its practical exploitation for processing broad-band signals. Here we show that such limits are overcome by the new concept of travelling-wave resonant four-wave mixing (FWM). This approach combines the efficiency enhancement provided by resonant propagation with a wide-band conversion process. Compared with conventional FWM in bare waveguides, it exhibits higher robustness against chromatic dispersion and propagation loss, while preserving transparency to modulation formats. Travelling-wave resonant FWM has been demonstrated in silicon-coupled ring resonators and was exploited to realize a 630-μm-long wavelength converter operating over a wavelength range wider than 60 nm and with 28-dB gain with respect to a bare waveguide of the same physical length. Full compatibility of the travelling-wave resonant FWM with optical signal processing applications has been demonstrated through signal retiming and reshaping at 10 Gb s−1 PMID:21540838

Ultrafast all-optical flip-flop based on passive micro Sagnac waveguide ring with photonic crystal fiber.

PubMed

Xu, Ming; Yang, Wan; Hong, Tao; Kang, TangZhen; Ji, JianHua; Wang, Ke

2017-06-01

Ultrafast all-optical flip-flop based on a passive micro Sagnac waveguide ring is studied through theoretical analysis and numerical simulation in this paper. The types of D, R-S, J-K, and T flip-flop are designed by controlling the cross-phase modulation effect of lights in this special microring. The high nonlinearity of the hollow-core photonic crystal fiber is implanted on a chip to shorten the length of the ring and reduce input power. By sensible management, the pulse width ratio of the input and the control signal, problems of pulse narrowing, and residual pedestal at the out port are solved. The parameters affecting the performance of flip-flops are optimized. The results show that the all-optical flip-flops have stable performance, low power consumption, high transmission rate (up to 100  Gb/s), and response time in picosecond order. The small size microwaveguide structure is suitable for photonic integration.

Optical solitons, explicit solutions and modulation instability analysis with second-order spatio-temporal dispersion

NASA Astrophysics Data System (ADS)

Inc, Mustafa; Isa Aliyu, Aliyu; Yusuf, Abdullahi; Baleanu, Dumitru

2017-12-01

This paper obtains the dark, bright, dark-bright or combined optical and singular solitons to the nonlinear Schrödinger equation (NLSE) with group velocity dispersion coefficient and second-order spatio-temporal dispersion coefficient, which arises in photonics and waveguide optics and in optical fibers. The integration algorithm is the sine-Gordon equation method (SGEM). Furthermore, the explicit solutions of the equation are derived by considering the power series solutions (PSS) theory and the convergence of the solutions is guaranteed. Lastly, the modulation instability analysis (MI) is studied based on the standard linear-stability analysis and the MI gain spectrum is obtained.

Quantum information processing with a travelling wave of light

NASA Astrophysics Data System (ADS)

Serikawa, Takahiro; Shiozawa, Yu; Ogawa, Hisashi; Takanashi, Naoto; Takeda, Shuntaro; Yoshikawa, Jun-ichi; Furusawa, Akira

2018-02-01

We exploit quantum information processing on a traveling wave of light, expecting emancipation from thermal noise, easy coupling to fiber communication, and potentially high operation speed. Although optical memories are technically challenging, we have an alternative approach to apply multi-step operations on traveling light, that is, continuous-variable one-way computation. So far our achievement includes generation of a one-million-mode entangled chain in time-domain, mode engineering of nonlinear resource states, and real-time nonlinear feedforward. Although they are implemented with free space optics, we are also investigating photonic integration and performed quantum teleportation with a passive liner waveguide chip as a demonstration of entangling, measurement, and feedforward. We also suggest a loop-based architecture as another model of continuous-variable computing.

1.5-μm high-average power laser amplifier using a Er,Yb:glass planar waveguide for coherent Doppler lidar

NASA Astrophysics Data System (ADS)

Sakimura, Takeshi; Watanabe, Yojiro; Ando, Toshiyuki; Kameyama, Shumpei; Asaka, Kimio; Tanaka, Hisamichi; Yanagisawa, Takayuki; Hirano, Yoshihito; Inokuchi, Hamaki

2012-11-01

We have developed a 1.5-μm eye-safe wavelength high average power laser amplifier using an Er,Yb:glass planar waveguide for coherent Doppler LIDAR. Large cooling surface of the planar waveguide enabled high average power pumping for Er,Yb:glass which has low thermal fracture limit. Nonlinear effects are suppressed by the large beam size which is designed by the waveguide thickness and the beam width of the planar direction. Multi-bounce optical path configuration and high-intensity pumping provide high-gain and high-efficient operation using three-level laser material. With pulsed operation, the maximum pulse energy of 1.9 mJ was achieved at the repetition rate of 4 kHz. Output average power of the amplified signal was 7.6W with the amplified gain of more than 20dB. This amplifier is suitable for coherent Doppler LIDAR to enhance the measurable range.

Plasmon-assisted optical vias for photonic ASICS

DOEpatents

Skogen, Erik J.; Vawter, Gregory A.; Tauke-Pedretti, Anna

2017-03-21

The present invention relates to optical vias to optically connect multilevel optical circuits. In one example, the optical via includes a surface plasmon polariton waveguide, and a first optical waveguide formed on a first substrate is coupled to a second optical waveguide formed on a second substrate by the surface plasmon polariton waveguide. In some embodiments, the first optical waveguide includes a transition region configured to convert light from an optical mode to a surface plasmon polariton mode or from a surface plasmon polariton mode to an optical mode.

Method for ultrafast optical deflection enabling optical recording via serrated or graded light illumination

DOEpatents

Heebner, John E [Livermore, CA

2009-09-08

In one general embodiment, a method for deflecting an optical signal input into a waveguide is provided. In operation, an optical input signal is propagated through a waveguide. Additionally, an optical control signal is applied to a mask positioned relative to the waveguide such that the application of the optical control signal to the mask is used to influence the optical input signal propagating in the waveguide. Furthermore, the deflected optical input signal output from the waveguide is detected in parallel on an array of detectors. In another general embodiment, a beam deflecting structure is provided for deflecting an optical signal input into a waveguide, the structure comprising at least one wave guiding layer for guiding an optical input signal and at least one masking layer including a pattern configured to influence characteristics of a material of the guiding layer when an optical control signal is passed through the masking layer in a direction of the guiding layer. In another general embodiment, a system is provided including a waveguide, an attenuating mask positioned on the waveguide, and an optical control source positioned to propagate pulsed laser light towards the attenuating mask and the waveguide such that a pattern of the attenuating mask is applied to the waveguide and material properties of at least a portion of the waveguide are influenced.

Vertically-tapered optical waveguide and optical spot transformer formed therefrom

DOEpatents

Bakke, Thor; Sullivan, Charles T.

2004-07-27

An optical waveguide is disclosed in which a section of the waveguide core is vertically tapered during formation by spin coating by controlling the width of an underlying mesa structure. The optical waveguide can be formed from spin-coatable materials such as polymers, sol-gels and spin-on glasses. The vertically-tapered waveguide section can be used to provide a vertical expansion of an optical mode of light within the optical waveguide. A laterally-tapered section can be added adjacent to the vertically-tapered section to provide for a lateral expansion of the optical mode, thereby forming an optical spot-size transformer for efficient coupling of light between the optical waveguide and a single-mode optical fiber. Such a spot-size transformer can also be added to a III-V semiconductor device by post processing.

Synthetic Engineering of Spider Silk Fiber as Implantable Optical Waveguides for Low-Loss Light Guiding.

PubMed

Qiao, Xin; Qian, Zhigang; Li, Junjie; Sun, Hongji; Han, Yao; Xia, Xiaoxia; Zhou, Jin; Wang, Chunlan; Wang, Yan; Wang, Changyong

2017-05-03

A variety of devices used for biomedical engineering have been fabricated using protein polymer because of their excellent properties, such as strength, toughness, biocompatibility, and biodegradability. In this study, we fabricated an optical waveguide using genetically engineered spider silk protein. This method has two significant advantages: (1) recombinant spider silk optical waveguide exhibits excellent optical and biological properties and (2) biosynthesis of spider silk protein can overcome the limitation to the research on spider silk optical waveguide due to the low yield of natural spider silk. In detail, two kinds of protein-based optical waveguides made from recombinant spider silk protein and regenerative silkworm silk protein were successfully prepared. Results suggested that the recombinant spider silk optical waveguide showed a smoother surface and a higher refractive index when compared with regenerative silkworm silk protein. The optical loss of recombinant spider silk optical waveguide was 0.8 ± 0.1 dB/cm in air and 1.9 ± 0.3 dB/cm in mouse muscles, which were significantly lower than those of regenerative silkworm silk optical waveguide. Moreover, recombinant spider silk optical waveguide can meet the demand to guide and efficiently deliver light through biological tissue. In addition, recombinant spider silk optical waveguide showed low toxicity to cells in vitro and low-level inflammatory reaction with surrounding tissue in vivo. Therefore, recombinant spider silk optical waveguide is a promising implantable device to guide and deliver light with low loss.

Tailorable stimulated Brillouin scattering in nanoscale silicon waveguides.

PubMed

Shin, Heedeuk; Qiu, Wenjun; Jarecki, Robert; Cox, Jonathan A; Olsson, Roy H; Starbuck, Andrew; Wang, Zheng; Rakich, Peter T

2013-01-01

Nanoscale modal confinement is known to radically enhance the effect of intrinsic Kerr and Raman nonlinearities within nanophotonic silicon waveguides. By contrast, stimulated Brillouin-scattering nonlinearities, which involve coherent coupling between guided photon and phonon modes, are stifled in conventional nanophotonics, preventing the realization of a host of Brillouin-based signal-processing technologies in silicon. Here we demonstrate stimulated Brillouin scattering in silicon waveguides, for the first time, through a new class of hybrid photonic-phononic waveguides. Tailorable travelling-wave forward-stimulated Brillouin scattering is realized-with over 1,000 times larger nonlinearity than reported in previous systems-yielding strong Brillouin coupling to phonons from 1 to 18 GHz. Experiments show that radiation pressures, produced by subwavelength modal confinement, yield enhancement of Brillouin nonlinearity beyond those of material nonlinearity alone. In addition, such enhanced and wideband coherent phonon emission paves the way towards the hybridization of silicon photonics, microelectromechanical systems and CMOS signal-processing technologies on chip.

Low-loss adiabatically-tapered high-contrast gratings for slow-wave modulators on SOI

NASA Astrophysics Data System (ADS)

Sciancalepore, Corrado; Hassan, Karim; Ferrotti, Thomas; Harduin, Julie; Duprez, Hélène; Menezo, Sylvie; Ben Bakir, Badhise

2015-02-01

In this communication, we report about the design, fabrication, and testing of Silicon-based photonic integrated circuits (Si-PICs) including low-loss flat-band slow-light high-contrast-gratings (HCGs) waveguides at 1.31 μm. The light slowdown is achieved in 300-nm-thick silicon-on-insulator (SOI) rib waveguides by patterning adiabatically-tapered highcontrast gratings, capable of providing slow-light propagation with extremely low optical losses, back-scattering, and Fabry-Pérot noise. In detail, the one-dimensional (1-D) grating architecture is capable to provide band-edge group indices ng ~ 25, characterized by overall propagation losses equivalent to those of the index-like propagation regime (~ 1-2 dB/cm). Such photonic band-edge slow-light regime at low propagation losses is made possible by the adiabatic apodization of such 1-D HCGs, thus resulting in a win-win approach where light slow-down regime is reached without additional optical losses penalty. As well as that, a tailored apodization optimized via genetic algorithms allows the flattening of slow-light regime over the wavelength window of interest, therefore suiting well needs for group index stability for modulation purposes and non-linear effects generation. In conclusion, such architectures provide key features suitable for power-efficient high-speed modulators in silicon as well as an extremely low-loss building block for non-linear optics (NLO) which is now available in the Si photonics toolbox.

Integrated optical refractometer based on bend waveguide with air trench structure

NASA Astrophysics Data System (ADS)

Ryu, Jin Hwa; Park, Jaehoon; Kang, Chan-mo; Son, Youngdal; Do, Lee-Mi; Baek, Kyu-Ha

2015-07-01

This study proposed a novel optical sensor based on a refractometer integrating a bend waveguide and a trench structure. The optical sensor is a planar lightwave circuit (PLC) device involving a bend waveguide with maximum optical loss. A trench structure was aligned with the partially exposed core layer's sidewall of the bend waveguide, providing a quantitative measurement condition. The insertion losses of the proposed 1 x 2 single-mode optical splitter-type sensor were 4.38 dB and 8.67 dB for the reference waveguide and sensing waveguide, respectively, at a wavelength of 1,550 nm. The optical loss of the sensing waveguide depends on the change in the refractive index of the material in contact with the trench, but the reference waveguide had stable optical propagating characteristic regardless of the variations of the refractive index.

Direct Wafer Bonding and Its Application to Waveguide Optical Isolators

PubMed Central

Mizumoto, Tetsuya; Shoji, Yuya; Takei, Ryohei

2012-01-01

This paper reviews the direct bonding technique focusing on the waveguide optical isolator application. A surface activated direct bonding technique is a powerful tool to realize a tight contact between dissimilar materials. This technique has the potential advantage that dissimilar materials are bonded at low temperature, which enables one to avoid the issue associated with the difference in thermal expansion. Using this technique, a magneto-optic garnet is successfully bonded on silicon, III-V compound semiconductors and LiNbO3. As an application of this technique, waveguide optical isolators are investigated including an interferometric waveguide optical isolator and a semileaky waveguide optical isolator. The interferometric waveguide optical isolator that uses nonreciprocal phase shift is applicable to a variety of waveguide platforms. The low refractive index of buried oxide layer in a silicon-on-insulator (SOI) waveguide enhances the magneto-optic phase shift, which contributes to the size reduction of the isolator. A semileaky waveguide optical isolator has the advantage of large fabrication-tolerance as well as a wide operation wavelength range. PMID:28817020

Collisions and Trapping of Time Delayed Solitons in Optical Waveguides with Orthogonally Polarized Modes

NASA Astrophysics Data System (ADS)

Zhou, Huan; Li, Jin-Hua; Chow, Kwok-Wing; Xiao, Shao-Rong; Sun, Ting-Ting

2017-04-01

The interactions and collisions of time delayed solitons in optical waveguides with orthogonally polarized modes are studied. Direct numerical simulations of the coherently coupled nonlinear Schrödinger equations are performed, and neither the high birefringence nor the low birefringence approximations are invoked. Trapping of solitary pulses occurs when the birefringence parameter is small or the four-wave mixing parameter is large. The distance before the first collision depends strongly on the initial separation of the two solitary pulses. Variational techniques are employed to calculate this distance, and results agree with those from the full simulations very well. Supported by the National Natural Science Foundation of China under Grant Nos. 11605090 and 11447113, Natural Science Foundation of Jiangsu Provincial Universities under Grant No. 14KJB140009 and the startup Foundation for Introducing Talent of Nanjing University of Information Science and Technology under Grant No. 2241131301064

Synthesis and Characterization of Germanium Dioxide - Dioxide Waveguides

NASA Astrophysics Data System (ADS)

Chen, Din-Guo

The increasing use of single mode fibers in local -area networks (LAN) and customer premises networks (CPN) will increase the need for passive optical components, such as branching devices, mixers, etc. Integrated optical devices are potentially ideal for these applications, provided that they can be made compatible with single mode fibers. The use of GeO_2 as the core dopant and SiO_2 as the substrate ensures that these waveguides will have virtually identical characteristics to single mode fibers. Additionally, glasses in the form of waveguides have recently been used to study various nonlinear optical phenomena, which provide great potential applications such as data storage and information processing. The present study has for the first time demonstrated the feasibility of employing both sol-gel multiple dip -coating and low pressure chemical vapor deposition (LPCVD) in the production of GeO_2-SiO _2 waveguiding films with various germania contents. The thin film characteristics were studied by various analytical techniques (e.g. ellipsometry, waveguiding Raman spectroscopy, FTIR, XPS, SEM/TEM, etc.). The composition dependence of the linear refractive index of GeO _2-SiO_2 films follows that predicted by the Lorenz-Lorenz model. Vibrational spectroscopy revealed the existence of Si-O-Ge linkages in GeO_2-SiO_2 glass network. The addition of GeO_2 in SiO_2 caused a decrease in the size of both the D1 and D2 defect bands in the SiO _2 Raman spectra. The structure of the LPCVD film appears to be dominated by D1 and D2 defect bands. Using a three-prism loss measurement technique, the propagation losses were found to be 3.31 dB/cm and 2.59dB/cm for sol-gel and LPCVD films, respectively. These losses are attributed to various scattering processes in the films. The mode indices of the waveguide were measured using a prism coupling technique. The measured mode indices were found to agree with the calculated value based upon a step-index profile assumption. The theoretical electromagnetic field distribution profiles for a step-index planar waveguide has been calculated and compared to the experimentally measured mode profiles using a near field technique. The nonlinear refractive indices of the sol-gel films (GeO_2-SiO_2 and GeO_2-TiO_2 ) were measured using a THG interferometry fringe technique. The relation between n_{ rm 2THG} and n_1 was found to follow that predicted by the empirical BGO model. An additive model was used to calculate the linear refractive indices, Abbe numbers, and n_1 dispersion curves of the films.

Photonic integrated circuits based on novel glass waveguides and devices

NASA Astrophysics Data System (ADS)

Zhang, Yaping; Zhang, Deng; Pan, Weijian; Rowe, Helen; Benson, Trevor; Loni, Armando; Sewell, Phillip; Furniss, David; Seddon, Angela B.

2006-04-01

Novel materials, micro-, nano-scale photonic devices, and 'photonic systems on a chip' have become important focuses for global photonics research and development. This interest is driven by the rapidly growing demand for broader bandwidth in optical communication networks, and higher connection density in the interconnection area, as well as a wider range of application areas in, for example, health care, environment monitoring and security. Taken together, chalcogenide, heavy metal fluoride and fluorotellurite glasses offer transmission from ultraviolet to mid-infrared, high optical non-linearity and the ability to include active dopants, offering the potential for developing optical components with a wide range of functionality. Moreover, using single-mode large cross-section glass-based waveguides as an optical integration platform is an elegant solution for the monolithic integration of optical components, in which the glass-based structures act both as waveguides and as an optical bench for integration. We have previously developed a array of techniques for making photonic integrated circuits and devices based on novel glasses. One is fibre-on-glass (FOG), in which the fibres can be doped with different active dopants and pressed onto a glass substrate with a different composition using low-temperature thermal bonding under mechanical compression. Another is hot-embossing, in which a silicon mould is placed on top of a glass sample, and hot-embossing is carried out by applying heat and pressure. In this paper the development of a fabrication technique that combines the FOG and hot-embossing procedures to good advantage is described. Simulation and experimental results are presented.

Numerical studies of nonlinear ultrasonic guided waves in uniform waveguides with arbitrary cross sections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zuo, Peng; Fan, Zheng, E-mail: ZFAN@ntu.edu.sg; Zhou, Yu

2016-07-15

Nonlinear guided waves have been investigated widely in simple geometries, such as plates, pipe and shells, where analytical solutions have been developed. This paper extends the application of nonlinear guided waves to waveguides with arbitrary cross sections. The criteria for the existence of nonlinear guided waves were summarized based on the finite deformation theory and nonlinear material properties. Numerical models were developed for the analysis of nonlinear guided waves in complex geometries, including nonlinear Semi-Analytical Finite Element (SAFE) method to identify internal resonant modes in complex waveguides, and Finite Element (FE) models to simulate the nonlinear wave propagation at resonantmore » frequencies. Two examples, an aluminum plate and a steel rectangular bar, were studied using the proposed numerical model, demonstrating the existence of nonlinear guided waves in such structures and the energy transfer from primary to secondary modes.« less

Ultrashort soliton switching based on coherent energy hiding.

PubMed

Romagnoli, M; Wabnitz, S; Zoccolotti, L

1991-08-15

Coherent coupling between light and atoms may be exploited for conceiving a novel class of all-optical signalprocessing devices without a direct counterpart in the continuous-wave regime. We show that the self-switching of ultrashort soliton pulses on resonance with a transition of doping centers in a slab waveguide directional coupler is based on nonlinear group-velocity (instead of the usual phase-velocity) changes.

Power-controlled transition from standard to negative refraction in reorientational soft matter.

PubMed

Piccardi, Armando; Alberucci, Alessandro; Kravets, Nina; Buchnev, Oleksandr; Assanto, Gaetano

2014-11-25

Refraction at a dielectric interface can take an anomalous character in anisotropic crystals, when light is negatively refracted with incident and refracted beams emerging on the same side of the interface normal. In soft matter subject to reorientation, such as nematic liquid crystals, the nonlinear interaction with light allows tuning of the optical properties. We demonstrate that in such material a beam of light can experience either positive or negative refraction depending on input power, as it can alter the spatial distribution of the optic axis and, in turn, the direction of the energy flow when traveling across an interface. Moreover, the nonlinear optical response yields beam self-focusing and spatial localization into a self-confined solitary wave through the formation of a graded-index waveguide, linking the refractive transition to power-driven readdressing of copolarized guided-wave signals, with a number of output ports not limited by diffraction.

Sensing nitrous oxide with QCL-coupled silicon-on-sapphire ring resonators.

PubMed

Smith, Clinton J; Shankar, Raji; Laderer, Matthew; Frish, Michael B; Loncar, Marko; Allen, Mark G

2015-03-09

We report the initial evaluation of a mid-infrared QCL-coupled silicon-on-sapphire ring resonator gas sensor. The device probes the N(2)O 2241.79 cm(-1) optical transition (R23 line) in the ν(3) vibrational band. N(2)O concentration is deduced using a non-linear least squares fit, based on coupled-mode theory, of the change in ring resonator Q due to gas absorption losses in the evanescent portion of the waveguide optical mode. These early experiments demonstrated response to 5000 ppmv N(2)O.

Silicon photonics thermal phase shifter with reduced temperature range

DOEpatents

Lentine, Anthony L; Kekatpure, Rohan D; DeRose, Christopher; Davids, Paul; Watts, Michael R

2013-12-17

Optical devices, phased array systems and methods of phase-shifting an input signal are provided. An optical device includes a microresonator and a waveguide for receiving an input optical signal. The waveguide includes a segment coupled to the microresonator with a coupling coefficient such that the waveguide is overcoupled to the microresonator. The microresonator received the input optical signal via the waveguide and phase-shifts the input optical signal to form an output optical signal. The output optical signal is coupled into the waveguide via the microresonator and transmitted by the waveguide. At an operating point of the optical device, the coupling coefficient is selected to reduce a change in an amplitude of the output optical signal and to increase a change in a phase of the output optical signal, relative to the input optical signal.

Effets optiques et structurels de l'implantation ionique dans des couches minces polymeres

NASA Astrophysics Data System (ADS)

Cottin, Pierre

The main goal of this work is to highlight the effect of ion implantation---a widely spread technique to modify chemical, electrical or optical properties of materials---on the third order nonlinear optical properties (chi (3)) of polymers. This study was limited to four polymers (PMMA, PVK, PVA, CA) for which we developed a fabrication process to obtain high optical quality thin films and controlled thickness compatible with ion implantation depth. Moreover, these polymers show different chemical structures and have in common to have very low nonlinear optical properties. Two faces of the problem were studied. First, the chemical structure of these polymers was characterized using ultraviolet and infrared spectroscopy before and after ion implantation and then was compared with which of intrinsic nonlinear optical polymers. These analysis have clearly shown that from one hand, ion implantation leads to a great number of bond breaks but from the other hand, it creates a high concentration of conjugated bonds characteristic of nonlinear optical polymers. Second, the third order nonlinear optical properties of ion implanted polymers were measured by nonlinear waveguide coupling and by third harmonic generation. For the first method, the coupling function was performed by a diffraction grating etched in a glass substrate whose fabrication process was developed in this particular case. In both cases, the used laser wave-length was 1064 nm with pulse duration of 30 ps and 5 ns respectively. The corresponding modelization for each of these techniques was established and numerically implemented. Both techniques have shown an increase of chi(3) for these polymers after ion implantation but however, they can not reach the performance of chemically designed nonlinear optical polymers. The best results were obtained for 50 keV helium implanted PMMA given |chi(3)(-3o; o, o, o)| = 7.2 x 10-21 m2.V-2 which is six time greater than the pristine material.

FIBER AND INTEGRATED OPTICS: New type of heterogeneous nanophotonic silicon-on-insulator optical waveguides

NASA Astrophysics Data System (ADS)

Tsarev, Andrei V.

2007-08-01

A new type of optical waveguides in silicon-on-insulator nanostructures is proposed and studied. Their optical properties are simulated by the beam propagation method and discussed. A new design in the form of heterogeneous waveguide structures is based on the production of additionally heavily doped p+-regions on the sides of a multimode stripe waveguide (the silicon core cross section is ~200 nm × 16 μm). Such doping provides the 'single-mode' behaviour of the heterogeneous waveguide due to the decrease in the optical losses for the fundamental mode and increase in losses for higher-order modes. Single-mode heterogeneous waveguides can be used as base waveguides in photonic and integrated optical elements.

Theoretical description and design of nanomaterial slab waveguides: application to compensation of optical diffraction.

PubMed

Kivijärvi, Ville; Nyman, Markus; Shevchenko, Andriy; Kaivola, Matti

2018-04-02

Planar optical waveguides made of designable spatially dispersive nanomaterials can offer new capabilities for nanophotonic components. As an example, a thin slab waveguide can be designed to compensate for optical diffraction and provide divergence-free propagation for strongly focused optical beams. Optical signals in such waveguides can be transferred in narrow channels formed by the light itself. We introduce here a theoretical method for characterization and design of nanostructured waveguides taking into account their inherent spatial dispersion and anisotropy. Using the method, we design a diffraction-compensating slab waveguide that contains only a single layer of silver nanorods. The waveguide shows low propagation loss and broadband diffraction compensation, potentially allowing transfer of optical information at a THz rate.

Nonlinear defect localized modes and composite gray and anti-gray solitons in one-dimensional waveguide arrays with dual-flip defects

NASA Astrophysics Data System (ADS)

Liu, Yan; Guan, Yefeng; Li, Hai; Luo, Zhihuan; Mai, Zhijie

2017-08-01

We study families of stationary nonlinear localized modes and composite gray and anti-gray solitons in a one-dimensional linear waveguide array with dual phase-flip nonlinear point defects. Unstaggered fundamental and dipole bright modes are studied when the defect nonlinearity is self-focusing. For the fundamental modes, symmetric and asymmetric nonlinear modes are found. Their stable areas are studied using different defect coefficients and their total power. For the nonlinear dipole modes, the stability conditions of this type of mode are also identified by different defect coefficients and the total power. When the defect nonlinearity is replaced by the self-defocusing one, staggered fundamental and dipole bright modes are created. Finally, if we replace the linear waveguide with a full nonlinear waveguide, a new type of gray and anti-gray solitons, which are constructed by a kink and anti-kink pair, can be supported by such dual phase-flip defects. In contrast to the usual gray and anti-gray solitons formed by a single kink, their backgrounds on either side of the gray hole or bright hump have the same phase.

Chirped self-similar waves for quadratic-cubic nonlinear Schrödinger equation

NASA Astrophysics Data System (ADS)

Pal, Ritu; Loomba, Shally; Kumar, C. N.

2017-12-01

We have constructed analytical self-similar wave solutions for quadratic-cubic Nonlinear Schrödinger equation (QC-NLSE) by means of similarity transformation method. Then, we have investigated the role of chirping on these self-similar waves as they propagate through the tapered graded index waveguide. We have revealed that the chirping leads to interesting features and allows us to control the propagation of self-similar waves. This has been demonstrated for two cases (i) periodically distributed system and (ii) constant choice of system parameters. We expect our results to be useful in designing high performance optical devices.

Ultralow power continuous-wave frequency conversion in hydrogenated amorphous silicon waveguides.

PubMed

Wang, Ke-Yao; Foster, Amy C

2012-04-15

We demonstrate wavelength conversion through nonlinear parametric processes in hydrogenated amorphous silicon (a-Si:H) with maximum conversion efficiency of -13 dB at telecommunication data rates (10 GHz) using only 15 mW of pump peak power. Conversion bandwidths as large as 150 nm (20 THz) are measured in continuous-wave regime at telecommunication wavelengths. The nonlinear refractive index of the material is determined by four-wave mixing (FWM) to be n(2)=7.43×10(-13) cm(2)/W, approximately an order of magnitude larger than that of single crystal silicon. © 2012 Optical Society of America

A novel optical fibre doped with the nano-material as InP

NASA Astrophysics Data System (ADS)

Chen, Xi; Lee, Ly Guat; Zhang, Ru

2007-11-01

As the key of these optical devices which are widely used in the communication system, high nonlinear optical fibre will play an important role in the future optical fibre communication. With recent growth of nano-technology, researchers are hoping to obtain some kinds of optical fibre by combining the optical fibre with the nanotechnology. According to this current situation, the optical fibre doped with nano-material as InP (indium phosphide) is manufactured by using the MCVD (modified chemical vapor deposition) technology after our comprehensive consideration of many relative factors. Proved by experiments, this novel optical fibre has an excellent waveguide characteristic. After a consideration of the model of this novel optical fibre, its propagation constant β has been simulated by using the FEM (finite element method), and the graphs of presentation of magnetic field of the core are also obtained. In accordance with the results, the effective refractive index n eff = 1.401 has be calculated. Both the calculated result and the simulated graphs are matching well with the test, and this result is a step-stone bridge for future research of nonlinear parameter on this novel optical fiber.

Dielectric waveguide gas-filled stark shift modulator

DOEpatents

Hutchinson, Donald P.; Richards, Roger K.

2003-07-22

An optical modulator includes a dielectric waveguide for receiving an optical beam and coupling energy of the optical beam into the waveguide. At least one Stark material is provided in the waveguide. A bias circuit generates a bias signal to produce an electrical field across the Stark material to shift at least one of the Stark absorption frequencies towards the frequency of the optical beam. A circuit for producing a time varying electric field across the Stark material modulates the optical beam. At least a portion of the bias field can be generated by an alternating bias signal, such as a square wave. A method of modulating optical signals includes the steps of providing a dielectric waveguide for receiving an optical beam and coupling energy of the optical beam into the waveguide, the waveguide having at least one Stark material disposed therein, and varying an electric field imposed across the Stark material.

Nonlinear ball chain waveguides for acoustic emission and ultrasound sensing of ablation

NASA Astrophysics Data System (ADS)

Pearson, Stephen H.

Harsh environment acoustic emission and ultrasonic wave sensing applications often benefit from placing the sensor in a remote and more benign physical location by using waveguides to transmit elastic waves between the structural location under test and the transducer. Waveguides are normally designed to have high fidelity over broad frequency ranges to minimize distortion -- often difficult to achieve in practice. This thesis reports on an examination of using nonlinear ball chain waveguides for the transmission of acoustic emission and ultrasonic waves for the monitoring of thermal protection systems undergoing severe heat loading, leading to ablation and similar processes. Experiments test the nonlinear propagation of solitary, harmonic and mixed harmonic elastic waves through a copper tube filled with steel and elastomer balls and various other waveguides. Triangulation of pencil lead breaks occurs on a steel plate. Data are collected concerning the usage of linear waveguides and a water-cooled linear waveguide. Data are collected from a second water-cooled waveguide monitoring Atmospheric Reentry Materials in UVM's Inductively-Coupled Plasma Torch Facility. The motion of the particles in the dimer waveguides is linearly modeled with a three ball and spring chain model and the results are compared per particle. A theoretical nonlinear model is presented which is capable of exactly modeling the motion of the dimer chains. The shape of the waveform propagating through the dimer chain is modeled in a sonic vacuum. Mechanical pulses of varying time widths and amplitudes are launched into one end of the ball chain waveguide and observed at the other end in both time and frequency domains. Similarly, harmonic and mixed harmonic mechanical loads are applied to one end of the waveguide. Balls of different materials are analyzed and discriminated into categories. A copper tube packed with six steel particles, nine steel or marble particles and a longer copper tube packed with 17 steel particles are studied with a frequency sweep. The deformation experienced by a single steel particle in the dimer chain is approximated. Steel ball waveguides and steel rods are fitted with piezoelectric sensors to monitor the force at different points inside the waveguide during testing. The corresponding frequency responses, including intermodulation products, are compared based on amplitude and preloads. A nonlinear mechanical model describes the motion of the dimer chains in a vacuum. Based on the results of these studies it is anticipated that a nonlinear waveguide will be designed, built, and tested as a possible replacement for the high-fidelity waveguides presently being used in an Inductively Coupled Plasma Torch facility for high heat flux thermal protection system testing. The design is intended to accentuate acoustic emission signals of interest, while suppressing other forms of elastic wave noise.

A waveguide frequency converter connecting rubidium-based quantum memories to the telecom C-band.

PubMed

Albrecht, Boris; Farrera, Pau; Fernandez-Gonzalvo, Xavier; Cristiani, Matteo; de Riedmatten, Hugues

2014-02-27

Coherently converting the frequency and temporal waveform of single and entangled photons will be crucial to interconnect the various elements of future quantum information networks. Of particular importance is the quantum frequency conversion of photons emitted by material systems able to store quantum information, so-called quantum memories. There have been significant efforts to implement quantum frequency conversion using nonlinear crystals, with non-classical light from broadband photon-pair sources and solid-state emitters. However, solid state quantum frequency conversion has not yet been achieved with long-lived optical quantum memories. Here we demonstrate an ultra-low-noise solid state photonic quantum interface suitable for connecting quantum memories based on atomic ensembles to the telecommunication fibre network. The interface is based on an integrated-waveguide nonlinear device. We convert heralded single photons at 780 nm from a rubidium-based quantum memory to the telecommunication wavelength of 1,552 nm, showing significant non-classical correlations between the converted photon and the heralding signal.

Theory of absorption integrated optical sensor of gaseous materials

NASA Astrophysics Data System (ADS)

Egorov, A. A.

2010-10-01

The eigen and noneigen (leaky) modes of a three-layer planar integrated optical waveguide are described. The dispersion relation of a three-layer planar waveguide and other dependences are derived, and the cutoff conditions are analyzed. The diagram of propagation constants of the guided and radiation modes of an irregular asymmetric three-layer waveguide and the dependence of the electric field amplitudes of radiation modes of substrate on vertical coordinate in a tantalum integrated optical waveguide are presented. The operating principles of an absorption integrated optical waveguide sensor are investigated. The dependences of sensitivity of an integrated optical waveguide sensor on the sensory cell length, the coupling efficiency of the laser radiation into the waveguide, the absorption cross-section of the studied material, and the level of additive statistical noise are investigated. Some of the prospective areas of application of integrated-optical waveguide sensors are outlined.

Optical panel system including stackable waveguides

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeSanto, Leonard; Veligdan, James T.

An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, whereinmore » each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.« less

Optical panel system including stackable waveguides

DOEpatents

DeSanto, Leonard; Veligdan, James T.

2007-03-06

An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

Tailorable stimulated Brillouin scattering in nanoscale silicon waveguides

PubMed Central

Shin, Heedeuk; Qiu, Wenjun; Jarecki, Robert; Cox, Jonathan A.; Olsson, Roy H.; Starbuck, Andrew; Wang, Zheng; Rakich, Peter T.

2013-01-01

Nanoscale modal confinement is known to radically enhance the effect of intrinsic Kerr and Raman nonlinearities within nanophotonic silicon waveguides. By contrast, stimulated Brillouin-scattering nonlinearities, which involve coherent coupling between guided photon and phonon modes, are stifled in conventional nanophotonics, preventing the realization of a host of Brillouin-based signal-processing technologies in silicon. Here we demonstrate stimulated Brillouin scattering in silicon waveguides, for the first time, through a new class of hybrid photonic–phononic waveguides. Tailorable travelling-wave forward-stimulated Brillouin scattering is realized—with over 1,000 times larger nonlinearity than reported in previous systems—yielding strong Brillouin coupling to phonons from 1 to 18 GHz. Experiments show that radiation pressures, produced by subwavelength modal confinement, yield enhancement of Brillouin nonlinearity beyond those of material nonlinearity alone. In addition, such enhanced and wideband coherent phonon emission paves the way towards the hybridization of silicon photonics, microelectromechanical systems and CMOS signal-processing technologies on chip. PMID:23739586

Polymer electro-optic waveguide devices: Low-loss etchless fabrication techniques and passive-to-active integration

NASA Astrophysics Data System (ADS)

Geary, Kevin

The development of high-frequency polymer electro-optic modulators has seen steady and significant progress in recent years, yet applications of these promising materials to more complicated integrated optic structures and arrays of devices have been limited primarily due to high optical waveguide loss characteristics. This is unfortunate since a major advantage of polymers as photonic materials is their compatibility with photolithographic processing of large components. In this Dissertation, etchless waveguide writing techniques are presented in order to improve the overall optical insertion loss of electro-optic polymer waveguide devices. These techniques include poling-induced writing, stress-induced waveguide writing, and photobleaching. Using these waveguide writing mechanisms, we have demonstrated straight waveguides, phase modulators, Mach-Zehnder intensity modulators, variable optical attenuators, and multimode interference (MMI) power splitters, all with improved loss characteristics over their etched rib waveguide counterparts. Ultimately, the insertion loss of an integrated optic device is limited by the actual material loss of the core waveguide material. In this Dissertation, passive-to-active polymer waveguide transitions are proposed to circumvent this problem. These transitions are compact, in-plane, self-aligned, and require no tapering of any physical dimensions of the waveguides. By utilizing both the time-dependent and intensity-dependent photobleaching characteristics of electro-optic polymer materials, adiabatic refractive index tapers can be seamlessly coupled to in-plane butt couple transitions, resulting in losses as low as 0.1 dB per interface. By integrating passive polymer planar lightwave circuits with the high-speed phase shifting capability of electro-optic polymers, active wideband photonic devices of increased size and complexity can be realized. Optical fiber-to-device coupling can also result in significant contributions to the overall insertion loss of an integrated electro-optic polymer device. In this Dissertation, we leverage the photobleached refractive index taper component of our proposed passive-to-active polymer waveguide transitions in order to realize a two-dimensional optical mode transformer for improved overall fiber-to-device coupling of electro-optic polymer waveguide devices.

Room-temperature subnanosecond waveguide lasers in Nd:YVO4 Q-switched by phase-change VO2: A comparison with 2D materials

NASA Astrophysics Data System (ADS)

Nie, Weijie; Li, Rang; Cheng, Chen; Chen, Yanxue; Lu, Qingming; Romero, Carolina; Vázquez de Aldana, Javier R.; Hao, Xiaotao; Chen, Feng

2017-04-01

We report on room-temperature subnanosecond waveguide laser operation at 1064 nm in a Nd:YVO4 crystal waveguide through Q-switching of phase-change nanomaterial vanadium dioxide (VO2). The unique feature of VO2 nanomaterial from the insulating to metallic phases offers low-saturation-intensity nonlinear absorptions of light for subnanosecond pulse generation. The low-loss waveguide is fabricated by using the femtosecond laser writing with depressed cladding geometry. Under optical pump at 808 nm, efficient pulsed laser has been achieved in the Nd:YVO4 waveguide, reaching minimum pulse duration of 690 ps and maximum output average power of 66.7 mW. To compare the Q-switched laser performances by VO2 saturable absorber with those based on two-dimensional materials, the 1064-nm laser pulses have been realized in the same waveguide platform with either graphene or transition metal dichalcogenide (in this work, WS2) coated mirror. The results on 2D material Q-switched waveguide lasers have shown that the shortest pulses are with 22-ns duration, whilst the maximum output average powers reach ~161.9 mW. This work shows the obvious difference on the lasing properties based on phase-change material and 2D materials, and suggests potential applications of VO2 as low-cost saturable absorber for subnanosecond laser generation.

Room-temperature subnanosecond waveguide lasers in Nd:YVO4 Q-switched by phase-change VO2: A comparison with 2D materials.

PubMed

Nie, Weijie; Li, Rang; Cheng, Chen; Chen, Yanxue; Lu, Qingming; Romero, Carolina; Vázquez de Aldana, Javier R; Hao, Xiaotao; Chen, Feng

2017-04-06

We report on room-temperature subnanosecond waveguide laser operation at 1064 nm in a Nd:YVO 4 crystal waveguide through Q-switching of phase-change nanomaterial vanadium dioxide (VO 2 ). The unique feature of VO 2 nanomaterial from the insulating to metallic phases offers low-saturation-intensity nonlinear absorptions of light for subnanosecond pulse generation. The low-loss waveguide is fabricated by using the femtosecond laser writing with depressed cladding geometry. Under optical pump at 808 nm, efficient pulsed laser has been achieved in the Nd:YVO 4 waveguide, reaching minimum pulse duration of 690 ps and maximum output average power of 66.7 mW. To compare the Q-switched laser performances by VO 2 saturable absorber with those based on two-dimensional materials, the 1064-nm laser pulses have been realized in the same waveguide platform with either graphene or transition metal dichalcogenide (in this work, WS 2 ) coated mirror. The results on 2D material Q-switched waveguide lasers have shown that the shortest pulses are with 22-ns duration, whilst the maximum output average powers reach ~161.9 mW. This work shows the obvious difference on the lasing properties based on phase-change material and 2D materials, and suggests potential applications of VO 2 as low-cost saturable absorber for subnanosecond laser generation.

Monolithically integrated solid state laser and waveguide using spin-on glass

DOEpatents

Ashby, C.I.H.; Hohimer, J.P.; Neal, D.R.; Vawter, G.A.

1995-10-31

A monolithically integrated photonic circuit is disclosed combining a semiconductor source of excitation light with an optically active waveguide formed on the substrate. The optically active waveguide is preferably formed of a spin-on glass to which are added optically active materials which can enable lasing action, optical amplification, optical loss, or frequency conversion in the waveguide, depending upon the added material. 4 figs.

Theory of coupled resonator optical waveguides exhibiting high-order exceptional points of degeneracy

NASA Astrophysics Data System (ADS)

Nada, Mohamed Y.; Othman, Mohamed A. K.; Capolino, Filippo

2017-11-01

We present an approach and a theoretical framework for generating high-order exceptional points of degeneracy (EPDs) in photonic structures based on periodic coupled resonator optical waveguides (CROWs). Such EPDs involve the coalescence of Floquet-Bloch eigenwaves in CROWs, without the presence of gain and loss, which contrasts with the parity-time symmetry required to develop exceptional points based on gain and loss balance. The EPDs arise here by introducing symmetry breaking in a conventional chain of coupled resonators through periodic coupling to an adjacent uniform optical waveguide, which leads to unique modal characteristics that cannot be realized in conventional CROWs. Such remarkable characteristics include high quality factors (Q factors) and strong field enhancement, even without any mirrors at the two ends of a cavity. We show for the first time the capability of CROWs to exhibit EPDs of various orders, including the degenerate band edge (DBE) and the stationary inflection point. The proposed CROW of finite length shows an enhanced quality factor when operating near the DBE, and the Q factor exhibits an unconventional scaling with the CROW's length. We develop the theory of EPDs in such unconventional CROW using coupled-wave equations, and we derive an analytical expression for the dispersion relation. The proposed unconventional CROW concepts have various potential applications including Q switching, nonlinear devices, lasers, and extremely sensitive sensors.

Optical properties of an atomic ensemble coupled to a band edge of a photonic crystal waveguide

NASA Astrophysics Data System (ADS)

Munro, Ewan; Kwek, Leong Chuan; Chang, Darrick E.

2017-08-01

We study the optical properties of an ensemble of two-level atoms coupled to a 1D photonic crystal waveguide (PCW), which mediates long-range coherent dipole-dipole interactions between the atoms. We show that the long-range interactions can dramatically alter the linear and nonlinear optical behavior, as compared to a typical atomic ensemble. In particular, in the linear regime, we find that the transmission spectrum contains multiple transmission dips, whose properties we characterize. Moreover, we show how the linear spectrum may be used to infer the number of atoms present in the system, constituting an important experimental tool in a regime where techniques for conventional ensembles break down. We also show that some of the transmission dips are associated with an effective ‘two-level’ resonance that forms due to the long-range interactions. In particular, under strong global driving and appropriate conditions, we find that the atomic ensemble is only capable of absorbing and emitting single collective excitations at a time. Our results are of direct relevance to atom-PCW experiments that should soon be realizable.

Effectively Single-Mode Self-Recovering Ultrafast Nonlinear Nanowire Surface Plasmons

NASA Astrophysics Data System (ADS)

Tuniz, Alessandro; Weidlich, Stefan; Schmidt, Markus A.

2018-04-01

We report on a regime for surface-plasmon propagation, which is robust to defects and effectively single mode, and we exploit it for accessing the ultrafast nonlinear response of gold on centimeter-long subwavelength-diameter cylindrical nanowires. The hybrid plasmonic-photonic platform is formed by a gold nanowire, monolithically integrated into the core of an optical fiber. We show that, despite the dual-waveguide nature of this structure, the long-range surface plasmon is the only effectively propagating mode in the near infrared, which self-recovers in the presence of gaps via a light-recapturing effect. This self-recovery overcomes detrimental effects of wire discontinuities and enables measurements of the ultrafast nonlinearity of gold, which we perform for a 28-fs pulse duration.

Quantum Optics with Near-Lifetime-Limited Quantum-Dot Transitions in a Nanophotonic Waveguide.

PubMed

Thyrrestrup, Henri; Kiršanskė, Gabija; Le Jeannic, Hanna; Pregnolato, Tommaso; Zhai, Liang; Raahauge, Laust; Midolo, Leonardo; Rotenberg, Nir; Javadi, Alisa; Schott, Rüdiger; Wieck, Andreas D; Ludwig, Arne; Löbl, Matthias C; Söllner, Immo; Warburton, Richard J; Lodahl, Peter

2018-03-14

Establishing a highly efficient photon-emitter interface where the intrinsic linewidth broadening is limited solely by spontaneous emission is a key step in quantum optics. It opens a pathway to coherent light-matter interaction for, e.g., the generation of highly indistinguishable photons, few-photon optical nonlinearities, and photon-emitter quantum gates. However, residual broadening mechanisms are ubiquitous and need to be combated. For solid-state emitters charge and nuclear spin noise are of importance, and the influence of photonic nanostructures on the broadening has not been clarified. We present near-lifetime-limited linewidths for quantum dots embedded in nanophotonic waveguides through a resonant transmission experiment. It is found that the scattering of single photons from the quantum dot can be obtained with an extinction of 66 ± 4%, which is limited by the coupling of the quantum dot to the nanostructure rather than the linewidth broadening. This is obtained by embedding the quantum dot in an electrically contacted nanophotonic membrane. A clear pathway to obtaining even larger single-photon extinction is laid out; i.e., the approach enables a fully deterministic and coherent photon-emitter interface in the solid state that is operated at optical frequencies.

Si-rich SiNx based Kerr switch enables optical data conversion up to 12 Gbit/s

PubMed Central

Lin, Gong-Ru; Su, Sheng-Pin; Wu, Chung-Lun; Lin, Yung-Hsiang; Huang, Bo-Ji; Wang, Huai-Yung; Tsai, Cheng-Ting; Wu, Chih-I; Chi, Yu-Chieh

2015-01-01

Silicon photonic interconnection on chip is the emerging issue for next-generation integrated circuits. With the Si-rich SiNx micro-ring based optical Kerr switch, we demonstrate for the first time the wavelength and format conversion of optical on-off-keying data with a bit-rate of 12 Gbit/s. The field-resonant nonlinear Kerr effect enhances the transient refractive index change when coupling the optical data-stream into the micro-ring through the bus waveguide. This effectively red-shifts the notched dip wavelength to cause the format preserved or inversed conversion of data carried by the on-resonant or off-resonant probe, respectively. The Si quantum dots doped Si-rich SiNx strengthens its nonlinear Kerr coefficient by two-orders of magnitude higher than that of bulk Si or Si3N4. The wavelength-converted and cross-amplitude-modulated probe data-stream at up to 12-Gbit/s through the Si-rich SiNx micro-ring with penalty of −7 dB on transmission has shown very promising applicability to all-optical communication networks. PMID:25923653

Si-rich SiNx based Kerr switch enables optical data conversion up to 12 Gbit/s.

PubMed

Lin, Gong-Ru; Su, Sheng-Pin; Wu, Chung-Lun; Lin, Yung-Hsiang; Huang, Bo-Ji; Wang, Huai-Yung; Tsai, Cheng-Ting; Wu, Chih-I; Chi, Yu-Chieh

2015-04-29

Silicon photonic interconnection on chip is the emerging issue for next-generation integrated circuits. With the Si-rich SiNx micro-ring based optical Kerr switch, we demonstrate for the first time the wavelength and format conversion of optical on-off-keying data with a bit-rate of 12 Gbit/s. The field-resonant nonlinear Kerr effect enhances the transient refractive index change when coupling the optical data-stream into the micro-ring through the bus waveguide. This effectively red-shifts the notched dip wavelength to cause the format preserved or inversed conversion of data carried by the on-resonant or off-resonant probe, respectively. The Si quantum dots doped Si-rich SiNx strengthens its nonlinear Kerr coefficient by two-orders of magnitude higher than that of bulk Si or Si3N4. The wavelength-converted and cross-amplitude-modulated probe data-stream at up to 12-Gbit/s through the Si-rich SiNx micro-ring with penalty of -7 dB on transmission has shown very promising applicability to all-optical communication networks.

Integrated optical gyroscope using active Long-range surface plasmon-polariton waveguide resonator

PubMed Central

Zhang, Tong; Qian, Guang; Wang, Yang-Yang; Xue, Xiao-Jun; Shan, Feng; Li, Ruo-Zhou; Wu, Jing-Yuan; Zhang, Xiao-Yang

2014-01-01

Optical gyroscopes with high sensitivity are important rotation sensors for inertial navigation systems. Here, we present the concept of integrated resonant optical gyroscope constructed by active long-range surface plasmon-polariton (LRSPP) waveguide resonator. In this gyroscope, LRSPP waveguide doped gain medium is pumped to compensate the propagation loss, which has lower pump noise than that of conventional optical waveguide. Peculiar properties of single-polarization of LRSPP waveguide have been found to significantly reduce the polarization error. The metal layer of LRSPP waveguide is electro-optical multiplexed for suppression of reciprocal noises. It shows a limited sensitivity of ~10−4 deg/h, and a maximum zero drift which is 4 orders of magnitude lower than that constructed by conventional single-mode waveguide. PMID:24458281

Observation of soliton compression in silicon photonic crystals

PubMed Central

Blanco-Redondo, A.; Husko, C.; Eades, D.; Zhang, Y.; Li, J.; Krauss, T.F.; Eggleton, B.J.

2014-01-01

Solitons are nonlinear waves present in diverse physical systems including plasmas, water surfaces and optics. In silicon, the presence of two photon absorption and accompanying free carriers strongly perturb the canonical dynamics of optical solitons. Here we report the first experimental demonstration of soliton-effect pulse compression of picosecond pulses in silicon, despite two photon absorption and free carriers. Here we achieve compression of 3.7 ps pulses to 1.6 ps with <10 pJ energy. We demonstrate a ~1-ps free-carrier-induced pulse acceleration and show that picosecond input pulses are critical to these observations. These experiments are enabled by a dispersion-engineered slow-light photonic crystal waveguide and an ultra-sensitive frequency-resolved electrical gating technique to detect the ultralow energies in the nanostructured device. Strong agreement with a nonlinear Schrödinger model confirms the measurements. These results further our understanding of nonlinear waves in silicon and open the way to soliton-based functionalities in complementary metal-oxide-semiconductor-compatible platforms. PMID:24423977

Field analysis of the Cerenkov doubling of infrared coherent radiation utilizing an organic crystal core bounded by a glass capillary

NASA Astrophysics Data System (ADS)

Hayata, K.; Yanagawa, K.; Koshiba, M.

1990-12-01

A mode field analysis is presented of the second-harmonic electromagnetic wave that radiates from a nonlinear core bounded by a dielectric cladding. With this analysis the ultimate performance of the organic crystal-cored single-mode optical fiber waveguide as a guided-wave frequency doubler is evaluated through the solution of nonlinear parametric equations derived from Maxwell's equations under some assumptions. As a phase-matching scheme, a Cerenkov approach is considered because of advantages in actual device applications, in which the phase matching is achievable between the fundamental guided LP01 mode and the second-harmonic radiation (leaky) mode. Calculated results for organic cores made of benzil, 4-(N,N-dimethyl-amino)-3-acetamidonitrobenzen, 2-methyl-4-nitroaniline, and 4'-nitrobenzilidene-3-acetoamino-4-metxianiline provide useful data for designing an efficient fiber-optic wavelength converter utilizing nonlinear parametric processes. A detailed comparison is made between results for infinite and finite cladding thicknesses.

Squeezed-light generation in a nonlinear planar waveguide with a periodic corrugation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perina, Jan Jr.; Haderka, Ondrej; Sibilia, Concita

Two-mode nonlinear interaction (second-harmonic and second-subharmonic generation) in a planar waveguide with a small periodic corrugation at the surface is studied. Scattering of the interacting fields on the corrugation leads to constructive interference that enhances the nonlinear process provided that all the interactions are phase matched. Conditions for the overall phase matching are found. Compared with a perfectly quasi-phase-matched waveguide, better values of squeezing as well as higher intensities are reached under these conditions. Procedure for finding optimum values of parameters for squeezed-light generation is described.

Hong-Ou-Mandel Interference with a Single Atom.

PubMed

Ralley, K A; Lerner, I V; Yurkevich, I V

2015-09-14

The Hong-Ou-Mandel (HOM) effect is widely regarded as the quintessential quantum interference phenomenon in optics. In this work we examine how nonlinearity can smear statistical photon bunching in the HOM interferometer. We model both the nonlinearity and a balanced beam splitter with a single two-level system and calculate a finite probability of anti-bunching arising in this geometry. We thus argue that the presence of such nonlinearity would reduce the visibility in the standard HOM setup, offering some explanation for the diminution of the HOM visibility observed in many experiments. We use the same model to show that the nonlinearity affects a resonant two-photon propagation through a two-level impurity in a waveguide due to a "weak photon blockade" caused by the impossibility of double-occupancy and argue that this effect might be stronger for multi-photon propagation.

Nonlinear response of silicon photonic crystal microresonators excited via an integrated waveguide and fiber taper.

PubMed

Barclay, Paul; Srinivasan, Kartik; Painter, Oskar

2005-02-07

A technique is demonstrated which efficiently transfers light between a tapered standard single-mode optical fiber and a high-Q, ultra-small mode volume, silicon photonic crystal resonant cavity. Cavity mode quality factors of 4.7x10(4) are measured, and a total fiber-to-cavity coupling efficiency of 44% is demonstrated. Using this efficient cavity input and output channel, the steady-state nonlinear absorption and dispersion of the photonic crystal cavity is studied. Optical bistability is observed for fiber input powers as low as 250 microW, corresponding to a dropped power of 100 microW and 3 fJ of stored cavity energy. A high-density effective free-carrier lifetime for these silicon photonic crystal resonators of ~ 0.5 ns is also estimated from power dependent loss and dispersion measurements.

Optical keyboard

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veligdan, James T.; Feichtner, John D.; Phillips, Thomas E.

2001-01-01

An optical keyboard includes an optical panel having optical waveguides stacked together. First ends of the waveguides define an inlet face, and opposite ends thereof define a screen. A projector transmits a light beam outbound through the waveguides for display on the screen as a keyboard image. A light sensor is optically aligned with the inlet face for sensing an inbound light beam channeled through the waveguides from the screen upon covering one key of the keyboard image.

Fabrication of raised and inverted SU8 polymer waveguides

NASA Astrophysics Data System (ADS)

Holland, Anthony S.; Mitchell, Arnan; Balkunje, Vishal S.; Austin, Mike W.; Raghunathan, Mukund K.

2005-01-01

Polymer films with high optical transmission have been investigated for making optical devices for several years. SU8 photoresist and optical adhesives have been investigated for use as thin films for optical devices, not what they were originally designed for. Optical adhesives are typically a one component thermoset polymer and are convenient to use for making thin film optical devices such as waveguides. They are prepared in minutes as thin films unlike SU8, which has to be carefully thermally cured over several hours for optimum results. However SU8 can be accurately patterned to form the geometry of structures required for single mode optical waveguides. SU8 in combination with the lower refractive index optical adhesive films such as UV15 from Master Bond are used to form single and multi mode waveguides. SU8 is photopatternable but we have also used dry etching of the SU8 layer or the other polymer layers e.g. UV15 to form the ribs, ridges or trenches required to guide single modes of light. Optical waveguides were also fabricated using only optical adhesives of different refractive indices. The resolution obtainable is poorer than with SU8 and hence multi mode waveguides are obtained. Loss measurements have been obtained for waveguides of different geometries and material combinations. The process for making polymer waveguides is demonstrated for making large multi mode waveguides and microfluidic channels by scaling the process up in size.

Laser-induced nonlinear crystalline waveguide on glass fiber format and diode-pumped second harmonic generation

NASA Astrophysics Data System (ADS)

Shi, Jindan; Feng, Xian

2018-03-01

We report a diode pumped self-frequency-doubled nonlinear crystalline waveguide on glass fiber. A ribbon fiber has been drawn on the glass composition of 50GeO2-25B2O3-25(La,Yb)2O3. Surface channel waveguides have been written on the surface of the ribbon fiber, using space-selective laser heating method with the assistance of a 244 nm CW UV laser. The Raman spectrum of the written area indicates that the waveguide is composed of structure-deformed nonlinear (La,Yb)BGeO5 crystal. The laser-induced surface wavy cracks have also been observed and the forming mechanism of the wavy cracks has been discussed. Efficient second harmonic generation has been observed from the laser-induced crystalline waveguide, using a 976 nm diode pump. 13 μW of 488 nm output has been observed from a 17 mm long waveguide with 26.0 mW of launched diode pump power, corresponding to a normalized conversion efficiency of 4.4%W-1.

Nonlinear evolution equations for surface plasmons for nano-focusing at a Kerr/metallic interface and tapered waveguide

NASA Astrophysics Data System (ADS)

Crutcher, Sihon H.; Osei, Albert; Biswas, Anjan

2012-06-01

Maxwell's equations for a metallic and nonlinear Kerr interface waveguide at the nanoscale can be approximated to a (1+1) D Nonlinear Schrodinger type model equation (NLSE) with appropriate assumptions and approximations. Theoretically, without losses or perturbations spatial plasmon solitons profiles are easily produced. However, with losses, the amplitude or beam profile is no longer stationary and adiabatic parameters have to be considered to understand propagation. For this model, adiabatic parameters are calculated considering losses resulting in linear differential coupled integral equations with constant definite integral coefficients not dependent on the transverse and longitudinal coordinates. Furthermore, by considering another configuration, a waveguide that is an M-NL-M (metal-nonlinear Kerr-metal) that tapers, the tapering can balance the loss experienced at a non-tapered metal/nonlinear Kerr interface causing attenuation of the beam profile, so these spatial plasmon solitons can be produced. In this paper taking into consideration the (1+1)D NLSE model for a tapered waveguide, we derive a one soliton solution based on He's Semi-Inverse Variational Principle (HPV).

Propagation length enhancement of surface plasmon polaritons in gold nano-/micro-waveguides by the interference with photonic modes in the surrounding active dielectrics

NASA Astrophysics Data System (ADS)

Suárez, Isaac; Ferrando, Albert; Marques-Hueso, Jose; Díez, Antonio; Abargues, Rafael; Rodríguez-Cantó, Pedro J.; Martínez-Pastor, Juan P.

2017-02-01

In this work, the unique optical properties of surface plasmon polaritons (SPPs), i.e. subwavelength confinement or strong electric field concentration, are exploited to demonstrate the propagation of light signal at 600 nm along distances in the range from 17 to 150 μm for Au nanostripes 500 nm down to 100 nm wide (30 nm of height), respectively, both theoretically and experimentally. A low power laser is coupled into an optical fiber tip that is used to locally excite the photoluminescence of colloidal quantum dots (QDs) dispersed in their surroundings. Emitted light from these QDs is generating the SPPs that propagate along the metal waveguides. Then, the above-referred propagation lengths were directly extracted from this novel experimental technique by studying the intensity of light decoupled at the output edge of the waveguide. Furthermore, an enhancement of the propagation length up to 0.4 mm is measured for the 500-nm-wide metal nanostripe, for which this effect is maximum. For this purpose, a simultaneous excitation of the same QDs dispersed in poly(methyl methacrylate) waveguides integrated with the metal nanostructures is performed by end-fire coupling an excitation laser energy as low as 1 KW/cm2. The proposed mechanism to explain such enhancement is a non-linear interference effect between dielectric and plasmonic (super)modes propagating in the metal-dielectric structure, which can be apparently seen as an effective amplification or compensation effect of the gain material (QDs) over the SPPs, as previously reported in literature. The proposed system and the method to create propagating SPPs in metal waveguides can be of interest for the application field of sensors and optical communications at visible wavelengths, among other applications, using plasmonic interconnects to reduce the dimensions of photonic chips.

Few-cycle solitons and supercontinuum generation with cascaded quadratic nonlinearities in unpoled lithium niobate ridge waveguides.

PubMed

Guo, Hairun; Zeng, Xianglong; Zhou, Binbin; Bache, Morten

2014-03-01

Formation and interaction of few-cycle solitons in a lithium niobate ridge waveguide are numerically investigated. The solitons are created through a cascaded phase-mismatched second-harmonic generation process, which induces a dominant self-defocusing Kerr-like nonlinearity on the pump pulse. The inherent material self-focusing Kerr nonlinearity is overcome over a wide wavelength range, and self-defocusing solitons are supported from 1100 to 1900 nm, covering the whole communication band. Single cycle self-compressed solitons and supercontinuum generation spanning 1.3 octaves are observed when pumped with femtosecond nanojoule pulses at 1550 nm. The waveguide is not periodically poled, as quasi-phase-matching would lead to detrimental nonlinear effects impeding few-cycle soliton formation.

Magneto-optical non-reciprocal devices in silicon photonics

PubMed Central

Shoji, Yuya; Mizumoto, Tetsuya

2014-01-01

Silicon waveguide optical non-reciprocal devices based on the magneto-optical effect are reviewed. The non-reciprocal phase shift caused by the first-order magneto-optical effect is effective in realizing optical non-reciprocal devices in silicon waveguide platforms. In a silicon-on-insulator waveguide, the low refractive index of the buried oxide layer enhances the magneto-optical phase shift, which reduces the device footprints. A surface activated direct bonding technique was developed to integrate a magneto-optical garnet crystal on the silicon waveguides. A silicon waveguide optical isolator based on the magneto-optical phase shift was demonstrated with an optical isolation of 30 dB and insertion loss of 13 dB at a wavelength of 1548 nm. Furthermore, a four port optical circulator was demonstrated with maximum isolations of 15.3 and 9.3 dB in cross and bar ports, respectively, at a wavelength of 1531 nm. PMID:27877640

Nonlinear surface waves at ferrite-metamaterial waveguide structure

NASA Astrophysics Data System (ADS)

Hissi, Nour El Houda; Mokhtari, Bouchra; Eddeqaqi, Noureddine Cherkaoui; Shabat, Mohammed Musa; Atangana, Jacques

2016-09-01

A new ferrite slab made of a metamaterial (MTM), surrounded by a nonlinear cover cladding and a ferrite substrate, was shown to support unusual types of electromagnetic surface waves. We impose the boundary conditions to derive the dispersion relation and others necessary to formulate the proposed structure. We analyse the dispersion properties of the nonlinear surface waves and we calculate the associated propagation index and the film-cover interface nonlinearity. In the calculation, several sets of the permeability of the MTM are considered. Results show that the waves behaviour depends on the values of the permeability of the MTM, the thickness of the waveguide and the film-cover interface nonlinearity. It is also shown that the use of the singular solutions to the electric field equation allows to identify several new properties of surface waves which do not exist in conventional waveguide.

Offset-Free Gigahertz Midinfrared Frequency Comb Based on Optical Parametric Amplification in a Periodically Poled Lithium Niobate Waveguide

NASA Astrophysics Data System (ADS)

Mayer, A. S.; Phillips, C. R.; Langrock, C.; Klenner, A.; Johnson, A. R.; Luke, K.; Okawachi, Y.; Lipson, M.; Gaeta, A. L.; Fejer, M. M.; Keller, U.

2016-11-01

We report the generation of an optical-frequency comb in the midinfrared region with 1-GHz comb-line spacing and no offset with respect to absolute-zero frequency. This comb is tunable from 2.5 to 4.2 μ m and covers a critical spectral region for important environmental and industrial applications, such as molecular spectroscopy of trace gases. We obtain such a comb using a highly efficient frequency conversion of a near-infrared frequency comb. The latter is based on a compact diode-pumped semiconductor saturable absorber mirror-mode-locked ytterbium-doped calcium-aluminum gadolynate (Yb:CALGO) laser operating at 1 μ m . The frequency-conversion process is based on optical parametric amplification (OPA) in a periodically poled lithium niobate (PPLN) chip containing buried waveguides fabricated by reverse proton exchange. The laser with a repetition rate of 1 GHz is the only active element of the system. It provides the pump pulses for the OPA process as well as seed photons in the range of 1.4 - 1.8 μ m via supercontinuum generation in a silicon-nitride (Si3 N4 ) waveguide. Both the PPLN and Si3 N4 waveguides represent particularly suitable platforms for low-energy nonlinear interactions; they allow for mid-IR comb powers per comb line at the microwatt level and signal amplification levels up to 35 dB, with 2 orders of magnitude less pulse energy than reported in OPA systems using bulk devices. Based on numerical simulations, we explain how high amplification can be achieved at low energy using the interplay between mode confinement and a favorable group-velocity mismatch configuration where the mid-IR pulse moves at the same velocity as the pump.

Background-free balanced optical cross correlator

DOEpatents

Nejadmalayeri, Amir Hossein; Kaertner, Franz X

2014-12-23

A balanced optical cross correlator includes an optical waveguide, a first photodiode including a first n-type semiconductor and a first p-type semiconductor positioned about the optical waveguide on a first side of the optical waveguide's point of symmetry, and a second photodiode including a second n-type semiconductor and a second p-type semiconductor positioned about the optical waveguide on a second side of the optical waveguide's point of symmetry. A balanced receiver including first and second inputs is configured to produce an output current or voltage that reflects a difference in currents or voltages, originating from the first and the second photodiodes of the balanced cross correlator and fed to the first input and to the second input of the balanced receiver.

Elliptic-type soliton combs in optical ring microresonators

NASA Astrophysics Data System (ADS)

Dikandé Bitha, Rodrigues D.; Dikandé, Alain M.

2018-03-01

Soliton crystals are periodic patterns of multispot optical fields formed from either time or space entanglements of equally separated identical high-intensity pulses. These specific nonlinear optical structures have gained interest in recent years with the advent and progress in nonlinear optical fibers and fiber lasers, photonic crystals, wave-guided wave systems, and most recently optical ring microresonator devices. In this work an extensive analysis of characteristic features of soliton crystals is carried out, with an emphasis on their one-to-one correspondence with elliptic solitons. With this purpose in mind, we examine their formation, their stability, and their dynamics in ring-shaped nonlinear optical media within the framework of the Lugiato-Lefever equation. The stability analysis deals with internal modes of the system via a 2 ×2 -matrix Lamé-type eigenvalue problem, the spectrum of which is shown to possess a rich set of bound states consisting of stable zero-fequency modes and unstable decaying as well as growing modes. Turning towards the dynamics of elliptic solitons in ring-shaped fiber resonators with Kerr nonlinearity, we first propose a collective-coordinate approach, based on a Lagrangian formalism suitable for elliptic-soliton solutions to the nonlinear Schrödinger equation with an arbitrary perturbation. Next we derive time evolutions of elliptic-soliton parameters in the specific context of ring-shaped optical fiber resonators, where the optical field evolution is thought to be governed by the Lugiato-Lefever equation. By solving numerically the collective-coordinate equations an analysis of the amplitude, the position, the phase of internal oscillations, the phase velocity, the energy, and phase portraits of the amplitude is carried out and reveals a complex dynamics of the elliptic soliton in ring-shaped optical microresonators. Direct numerical simulations of the Lugiato-Lefever equation are also carried out seeking for stationary-wave solutions, and the numerical results are in very good agreement with the collective-coordinate approach.

Room-temperature subnanosecond waveguide lasers in Nd:YVO4 Q-switched by phase-change VO2: A comparison with 2D materials

PubMed Central

Nie, Weijie; Li, Rang; Cheng, Chen; Chen, Yanxue; Lu, Qingming; Romero, Carolina; Vázquez de Aldana, Javier R.; Hao, Xiaotao; Chen, Feng

2017-01-01

We report on room-temperature subnanosecond waveguide laser operation at 1064 nm in a Nd:YVO4 crystal waveguide through Q-switching of phase-change nanomaterial vanadium dioxide (VO2). The unique feature of VO2 nanomaterial from the insulating to metallic phases offers low-saturation-intensity nonlinear absorptions of light for subnanosecond pulse generation. The low-loss waveguide is fabricated by using the femtosecond laser writing with depressed cladding geometry. Under optical pump at 808 nm, efficient pulsed laser has been achieved in the Nd:YVO4 waveguide, reaching minimum pulse duration of 690 ps and maximum output average power of 66.7 mW. To compare the Q-switched laser performances by VO2 saturable absorber with those based on two-dimensional materials, the 1064-nm laser pulses have been realized in the same waveguide platform with either graphene or transition metal dichalcogenide (in this work, WS2) coated mirror. The results on 2D material Q-switched waveguide lasers have shown that the shortest pulses are with 22-ns duration, whilst the maximum output average powers reach ~161.9 mW. This work shows the obvious difference on the lasing properties based on phase-change material and 2D materials, and suggests potential applications of VO2 as low-cost saturable absorber for subnanosecond laser generation. PMID:28383017

Multistage Polymeric Lens Structures Integrated into Silica Waveguides

NASA Astrophysics Data System (ADS)

Tate, Atsushi; Suzuki, Takanori; Tsuda, Hiroyuki

2006-08-01

A waveguide lens, composed of multistage polymer-filled thin grooves in a silica planar lightwave circuit (PLC) is proposed and a low-loss structure has been designed. A waveguide lens in a silica slab waveguide has been fabricated using reactive ion etching (RIE) and formed by filling with polymer. Both an imagding optical system and a Fourier-transform optical system can be configured in a PLC using a waveguide lens. It renders the PLC functional and its design flexible. To obtain a shorter focal length with a low insertion loss, it is more effective to use a multistage lens structure. An imaging optical system and a Fourier-transform optical system with a focal length of less than 1000 μm were fabricated in silica waveguides using a multistage lens structure. The lens imaging waveguides incorporate a 16-24-stage lens, with insertion losses of 4-7 dB. A 4 × 4 optical coupler, using a Fourier-transform optical system, utilizes a 6-stage lens with losses of 2-4 dB.

Design of a wideband tunable AWG using electro-optic polymers and push-pull electrode configuration for ultrafast photonic switching applications

NASA Astrophysics Data System (ADS)

Asquini, Rita; d'Alessandro, Antonio; Salusti, Andrea; Gizzi, Claudio

2003-08-01

A tunable waveguide grating router (WGR) design is reported, where a subpicosecond phase shift is obtained by means of the electro-optically induced refractive index change in the arms of an arrayed-waveguide grating (AWG) made of highly nonlinear poled polymer CLD-75/APC. The polymer consists of a guest-host system, formed by a ring-locked phenyltetraene bridged cromophore dispersed in an amorphous polycarbonate, with coefficient r33=55pm/V and propagation losses of 1.7dB/cm. We propose a multilayer structure on Si substrate, where segments of each waveguide of the AWG are sandwiched between a ground gold electrode and electrodes whose length varies over the AWG. Numerical simulations of a device with electrode length difference of 250μm show a tuning range of 11nm centered at 1550nm by varying the applied voltage from -90V to +90V. From the optimized AWG, a WGR operating with 16 channels spaced by 100GHz has been designed. The WGR is made of single-mode rib waveguides and buffers whose thicknesses are respectively 1.8μm and 1.7μm. A broader tunability range is obtained using the push-pull technique, which induces a refractive index change of opposite sign in two halves of the AWG. A crosstalk of -40dB with tuning range of 22nm over the C-band was figured out.

Induced high-order resonance linewidth shrinking with multiple coupled resonators in silicon-organic hybrid slotted two-dimensional photonic crystals for reduced optical switching power in bistable devices

NASA Astrophysics Data System (ADS)

Hoang, Thu Trang; Ngo, Quang Minh; Vu, Dinh Lam; Le, Khai Q.; Nguyen, Truong Khang; Nguyen, Hieu P. T.

2018-01-01

Shrinking the linewidth of resonances induced by multiple coupled resonators is comprehensively analyzed using the coupled-mode theory (CMT) in time. Two types of coupled resonators under investigation are coupled resonator optical waveguides (CROWs) and side-coupled resonators with waveguide (SCREW). We examine the main parameters influencing on the spectral response such as the number of resonators (n) and the phase shift (φ) between two adjacent resonators. For the CROWs geometry consisting of n coupled resonators, we observe the quality (Q) factor of the right- and left-most resonant lineshapes increases n times larger than that of a single resonator. For the SCREW geometry, relying on the phase shift, sharp, and asymmetric resonant lineshape of the high Q factor a narrow linewidth of the spectral response could be achieved. We employ the finite-difference time-domain (FDTD) method to design and simulate two proposed resonators for practical applications. The proposed coupled resonators in silicon-on-insulator (SOI) slotted two-dimensional (2-D) photonic crystals (PhCs) filled and covered with a low refractive index organic material. Slotted PhC waveguides and cavities are designed to enhance the electromagnetic intensity and to confine the light into small cross-sectional area with low refractive index so that efficient optical devices could be achieved. A good agreement between the theoretical CMT analysis and the FDTD simulation is shown as an evidence for our accurate investigation. All-optical switches based on the CROWs in the SOI slotted 2-D PhC waveguide that are filled and covered by a nonlinear organic cladding to overcome the limitations of its well-known intrinsic properties are also presented. From the calculations, we introduce a dependency of the normalized linewidth of the right-most resonance and its switching power of the all-optical switches on number of resonator, n. This result might provide a guideline for all-optical signal processing on a silicon PhC chip design.

FIBER AND INTEGRATED OPTICS: Optimization of optical film waveguides

NASA Astrophysics Data System (ADS)

Adamson, P. V.

1990-10-01

Theoretical investigations were made of the possibility of optimization of the effective thickness, of the optical confinement factor Γ1, and of the birefringence of a planar dielectric waveguide as a function of the waveguide parameter V and the waveguide asymmetry. For a given value of V it is possible to ensure higher values of Γ1, for an asymmetric waveguide than for a symmetric one. An approximate expression is proposed for the factor Γ1, of an asymmetric waveguide directly in terms of its thickness and the refractive indices of the layers.

Deoxyribonucleic acid (DNA)-based optical materials

NASA Astrophysics Data System (ADS)

Grote, James G.; Heckman, Emily M.; Hagen, Joshua A.; Yaney, Perry P.; Subramanyam, Guru; Clarson, Stephen J.; Diggs, Darnell E.; Nelson, Robert L.; Zetts, John S.; Hopkins, F. Kenneth; Ogata, Naoya

2004-12-01

Optical materials for waveguiding applications must possess the desired optical and electromagnetic properties for optimal device performance. Purified deoxyribonucleic acid (DNA), derived from salmon sperm, has been investigated for use as an optical waveguide material. In this paper we present the materials processing and optical and electromagnetic characterization of this purified DNA to render a high quality, low loss optical waveguide material.

Ytterbium-doped fiber laser passively mode locked by few-layer Molybdenum Disulfide (MoS2) saturable absorber functioned with evanescent field interaction

PubMed Central

Du, Juan; Wang, Qingkai; Jiang, Guobao; Xu, Changwen; Zhao, Chujun; Xiang, Yuanjiang; Chen, Yu; Wen, Shuangchun; Zhang, Han

2014-01-01

By coupling few-layer Molybdenum Disulfide (MoS2) with fiber-taper evanescent light field, a new type of MoS2 based nonlinear optical modulating element had been successfully fabricated as a two-dimensional layered saturable absorber with strong light-matter interaction. This MoS2-taper-fiber device is not only capable of passively mode-locking an all-normal-dispersion ytterbium-doped fiber laser and enduring high power laser excitation (up to 1 W), but also functions as a polarization sensitive optical modulating component (that is, different polarized light can induce different nonlinear optical response). Thanks to the combined advantages from the strong nonlinear optical response in MoS2 together with the sufficiently-long-range interaction between light and MoS2, this device allows for the generation of high power stable dissipative solitons at 1042.6 nm with pulse duration of 656 ps and a repetition rate of 6.74 MHz at a pump power of 210 mW. Our work may also constitute the first example of MoS2-enabled wave-guiding photonic device, and potentially give some new insights into two-dimensional layered materials related photonics. PMID:25213108

Microgravity Processing and Photonic Applications of Organic and Polymeric Materials

NASA Technical Reports Server (NTRS)

Frazier, Donald O.; Penn, Benjamin G.; Smith, David D.; Witherow, William K.; Paley, Mark S.; Abdeldayem, Hossin A.

1997-01-01

In recent years, a great deal of interest has been directed toward the use of organic materials in the development of high-efficiency optoelectronic and photonic devices. There is a myriad of possibilities among organics which allow flexibility in the design of unique structures with a variety of functional groups. The use of nonlinear optical (NLO) organic materials such as thin-film waveguides allows full exploitation of their desirable qualities by permitting long interaction lengths and large susceptibilities allowing modest power input. There are several methods in use to prepare thin films, such as Langmuir-Blodgett (LB) and self-assembly techniques, vapor deposition, growth from sheared solution or melt, and melt growth between glass plates. Organics have many features that make them desirable for use in optical devices such as high second- and third-order nonlinearities, flexibility of molecular design, and damage resistance to optical radiation. However, their use in devices has been hindered by processing difficulties for crystals and thin films. In this chapter, we discuss photonic and optoelectronic applications of a few organic materials and the potential role of microgravity on processing these materials. It is of interest to note how materials with second- and third-order nonlinear optical behavior may be improved in a diffusion-limited environment and ways in which convection may be detrimental to these materials.

Electro-optical line cards with multimode polymer waveguides for chip-to-chip interconnects

NASA Astrophysics Data System (ADS)

Zhu, Long Xiu; Immonen, Marika; Wu, Jinhua; Yan, Hui Juan; Shi, Ruizhi; Chen, Peifeng; Rapala-Virtanen, Tarja

2014-10-01

In this paper, we report developments of electro-optical PCBs (EO-PCB) with low-loss (<0.05dB/cm) polymer waveguides. Our results shows successful fabrication of complex waveguide structures part of hybrid EO-PCBs utilizing production scale process on standard board panels. Test patterns include 90° bends of varying radii (40mm - 2mm), waveguide crossing with varied crossing angles (90°-20°), cascaded bends with varying radii, splitters and tapered waveguides. Full ranges of geometric configurations are required to meet practical optical routing functions and layouts. Moreover, we report results obtained to realize structures to integrate optical connectors with waveguides. Experimental results are shown for MT in-plane and 90° out-of-plane optical connectors realized with coupling loss < 2dB and < 2.5 dB, respectively. These connectors are crucial to realize efficient light coupling from/to TX/RX chip-to-waveguide and within waveguide-to-fiber connections in practical optical PCBs. Furthermore, we show results for fabricating electrical interconnect structures e.g. tracing layers, vias, plated vias top/bottom and through optical layers. Process compatibility with accepted practices and production scale up for high volumes are key concerns to meet the yield target and cost efficiency. Results include waveguide characterization, transmission loss, misalignment tolerance, and effect of lamination. Critical link metrics are reported.

FIBER AND INTEGRATED OPTICS: Waveguide characteristics of real optical strip waveguides

NASA Astrophysics Data System (ADS)

Shmal'ko, A. V.; Frolov, V. V.

1990-01-01

A study is reported of the influence of the parameters of real thin-film optical strip waveguides on their waveguide characteristics (propagation constants, localization of the mode field, etc.) allowing for the presence of transition layers in a transverse cross section of the base planar waveguide, for the real geometry of this section (which is nearly trapezoidal), and for the thickness of the guiding strip. Analytic expressions are obtained for the optical confinement coefficient and the effective mode format of a weakly guiding symmetric strip waveguide. It is shown that the coefficient representing the fundamental E11x(y) mode is practically independent of the relative thickness t /h (h is the thickness of the base planar waveguide) of the guiding strip provided t /h>=0.5. The corrections to the normalized effective refractive indices of the base planar and strip waveguides are found in order to allow for the real geometry and for the refractive index profile in the strip waveguide.

Integrated Optical Dipole Trap for Cold Neutral Atoms with an Optical Waveguide Coupler

NASA Astrophysics Data System (ADS)

Lee, J.; Park, D. H.; Mittal, S.; Meng, Y.; Dagenais, M.; Rolston, S. L.

2013-05-01

Using an optical waveguide, an integrated optical dipole trap uses two-color (red and blue-detuned) traveling evanescent wave fields for trapping cold neutral atoms. To achieve longitudinal confinement, we propose using an integrated optical waveguide coupler, which provides a potential gradient along the beam propagation direction sufficient to confine atoms. This integrated optical dipole trap can support an atomic ensemble with a large optical depth due to its small mode area. Its quasi-TE0 waveguide mode has an advantage over the HE11 mode of a nanofiber, with little inhomogeneous Zeeman broadening at the trapping region. The longitudinal confinement eliminates the need for a 1D optical lattice, reducing collisional blockaded atomic loading, potentially producing larger ensembles. The waveguide trap allows for scalability and integrability with nano-fabrication technology. We analyze the potential performance of such integrated atom traps and present current research progress towards a fiber-coupled silicon nitride optical waveguide integrable with atom chips. Work is supported by the ARO Atomtronics MURI. Work is supported by the ARO Atomtronics MURI.

Characterization of Si3N4/SiO2 optical channel waveguides by photon scanning tunneling microscopy

NASA Technical Reports Server (NTRS)

Wang, Yan; Chudgar, Mona H.; Jackson, Howard E.; Miller, Jeffrey S.; De Brabander, Gregory N.; Boyd, Joseph T.

1993-01-01

Photon scanning tunneling microscopy (PSTM) is used to characterize Si3N4/Si02 optical channel waveguides being used for integrated optical-micromechanical sensors. PSTM utilizes an optical fiber tapered to a fine point which is piezoelectrically positioned to measure the decay of the evanescent field intensity associated with the waveguide propagating mode. Evanescent field decays are recorded for both ridge channel waveguides and planar waveguide regions. Values for the local effective refractive index are calculated from the data for both polarizations and compared to model calculations.

Vapor deposition and characterization of supramolecular assemblies for integrated nonlinear optics

NASA Astrophysics Data System (ADS)

Esembeson, Bweh

Very recently, some organic molecules have been developed that are very compact and have exceptionally high molecular polarizabilities which approach the fundamental quantum limit. Supramolecular assemblies created from such highly nonlinear molecules could find applications in integrated nonlinear optics such as all-optical signal processing, electro-optic modulators and frequency conversion. In this work, we have constructed a versatile vacuum deposition system for the creation of organic thin films from these molecules that can be sublimated without decomposition. We have used deposition temperatures of the order of 100--200°C in a high vacuum of 10-6--10 -7 Torrs. While some molecules showed a tendency to form polycrystalline films, others led to very high optical quality films, with a roughness of less than 10 nm over tens of micrometers and no grains detected down to a size of 2 nm, as seen in Atomic Force and Scanning Electron Microscopy studies. The best material we developed has a linear refractive index of 1.8 +/- 0.1 at 1.5 mum and an off-resonant third order susceptibility, chi (3), measured through Degenerate Four Wave Mixing, of 2 +/- 1 x 10-19 m2V-2 at 1.5 mum, a value three orders of magnitude larger than fused silica. This vapor deposited thin film may represent one of the best materials demonstrated to date whereby a large third order susceptibility, high optical quality, and simplicity of fabrication and integration are in perfect harmony for integrated nonlinear optical applications. We have used this novel organic material to create a hybrid organic/silicon-on-insulator waveguide that showed a record high nonlinearity coefficient of 10 5 W-1m-1 and has been used as an all-optical switch for demultiplexing a 120 Gbit/s data stream to 10 Gbit/s on a 6 mm long device.

A Resonator for Low-Threshold Frequency Conversion

NASA Technical Reports Server (NTRS)

Iltchenko, Vladimir; Matsko, Andrey; Savchenkov, Anatoliy; Maleki, Lute

2004-01-01

A proposed toroidal or disklike dielectric optical resonator (dielectric optical cavity) would be made of an optically nonlinear material and would be optimized for use in parametric frequency conversion by imposition of a spatially periodic permanent electric polarization. The poling (see figure) would suppress dispersions caused by both the material and the geometry of the optical cavity, thereby effecting quasi-matching of the phases of high-resonance-quality (high-Q) whispering-gallery electromagnetic modes. The quasi-phase-matching of the modes would serve to maximize the interactions among them. Such a resonator might be a prototype of a family of compact, efficient nonlinear devices for operation over a broad range of optical wavelengths. A little background information is prerequisite to a meaningful description of this proposal: (1) Described in several prior NASA Tech Briefs articles, the whispering-gallery modes in a component of spheroidal, disklike, or toroidal shape are waveguide modes that propagate circumferentially and are concentrated in a narrow toroidal region centered on the equatorial plane and located near the outermost edge. (2) For the sake of completeness, it must be stated that even though optical resonators of the type considered here are solid dielectric objects and light is confined within them by total internal reflection at dielectric interfaces without need for mirrors, such components are sometimes traditionally called cavities because their effects upon the light propagating within them are similar to those of true cavities bounded by mirrors. (3) For a given set of electromagnetic modes interacting with each other in an optically nonlinear material (e.g., modes associated with the frequencies involved in a frequency-conversion scheme), the threshold power for oscillation depends on the mode volumes and the mode-overlap integral. (4) Whispering-gallery modes are attractive in nonlinear optics because they maximize the effects of nonlinearities by occupying small volumes and affording high Q values

Experimental Demonstration of a Hybrid-Quantum-Emitter Producing Individual Entangled Photon Pairs in the Telecom Band

PubMed Central

Chen, Geng; Zou, Yang; Zhang, Wen-Hao; Zhang, Zi-Huai; Zhou, Zong-Quan; He, De-Yong; Tang, Jian-Shun; Liu, Bi-Heng; Yu, Ying; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Han, Yong-Jian; Li, Chuan-Feng; Guo, Guang-Can

2016-01-01

Quantum emitters generating individual entangled photon pairs (IEPP) have significant fundamental advantages over schemes that suffer from multiple photon emission, or schemes that require post-selection techniques or the use of photon-number discriminating detectors. Quantum dots embedded within nanowires (QD-NWs) represent one of the most promising candidate for quantum emitters that provide a high collection efficiency of photons. However, a quantum emitter that generates IEPP in the telecom band is still an issue demanding a prompt solution. Here, we demonstrate in principle that IEPPs in the telecom band can be created by combining a single QD-NW and a nonlinear crystal waveguide. The QD-NW system serves as the single photon source, and the emitted visible single photons are split into IEPPs at approximately 1.55 μm through the process of spontaneous parametric down conversion (SPDC) in a periodically poled lithium niobate (PPLN) waveguide. The compatibility of the QD-PPLN interface is the determinant factor in constructing this novel hybrid-quantum-emitter (HQE). Benefiting from the desirable optical properties of QD-NWs and the extremely high nonlinear conversion efficiency of PPLN waveguides, we successfully generate IEPPs in the telecom band with the polarization degree of freedom. The entanglement of the generated photon pairs is confirmed by the entanglement witness. Our experiment paves the way to producing HQEs inheriting the advantages of multiple systems. PMID:27225881

Experimental Demonstration of a Hybrid-Quantum-Emitter Producing Individual Entangled Photon Pairs in the Telecom Band.

PubMed

Chen, Geng; Zou, Yang; Zhang, Wen-Hao; Zhang, Zi-Huai; Zhou, Zong-Quan; He, De-Yong; Tang, Jian-Shun; Liu, Bi-Heng; Yu, Ying; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Han, Yong-Jian; Li, Chuan-Feng; Guo, Guang-Can

2016-05-26

Quantum emitters generating individual entangled photon pairs (IEPP) have significant fundamental advantages over schemes that suffer from multiple photon emission, or schemes that require post-selection techniques or the use of photon-number discriminating detectors. Quantum dots embedded within nanowires (QD-NWs) represent one of the most promising candidate for quantum emitters that provide a high collection efficiency of photons. However, a quantum emitter that generates IEPP in the telecom band is still an issue demanding a prompt solution. Here, we demonstrate in principle that IEPPs in the telecom band can be created by combining a single QD-NW and a nonlinear crystal waveguide. The QD-NW system serves as the single photon source, and the emitted visible single photons are split into IEPPs at approximately 1.55 μm through the process of spontaneous parametric down conversion (SPDC) in a periodically poled lithium niobate (PPLN) waveguide. The compatibility of the QD-PPLN interface is the determinant factor in constructing this novel hybrid-quantum-emitter (HQE). Benefiting from the desirable optical properties of QD-NWs and the extremely high nonlinear conversion efficiency of PPLN waveguides, we successfully generate IEPPs in the telecom band with the polarization degree of freedom. The entanglement of the generated photon pairs is confirmed by the entanglement witness. Our experiment paves the way to producing HQEs inheriting the advantages of multiple systems.

Method and apparatus of wide-angle optical beamsteering from a nanoantenna phased array

DOEpatents

Davids, Paul; DeRose, Christopher; Rakich, Peter Thomas

2015-08-11

An optical beam-steering apparatus is provided. The apparatus includes one or more optical waveguides and at least one row of metallic nanoantenna elements overlying and electromagnetically coupled to a respective waveguide. In each such row, individual nanoantenna elements are spaced apart along an optical propagation axis of the waveguide so that there is an optical propagation phase delay between successive pairs of nanoantenna elements along the row. The apparatus also includes a respective single electric heating element in thermal contact with each of the waveguides. Each heating element is arranged to heat, substantially uniformly, at least that portion of its waveguide that directly underlies the corresponding row of nanoantenna elements.

Wavelength selective switch array employing silica-based waveguide frontend with integrated polarization diversity optics.

PubMed

Sakamaki, Yohei; Shikama, Kota; Ikuma, Yuichiro; Suzuki, Kenya

2017-08-21

We propose a waveguide frontend with integrated polarization diversity optics for a wavelength selective switch (WSS) array with a liquid crystal on silicon switching engine to simplify the free space optics configuration and the alignment process in optical modules. The polarization diversity function is realized by the integration of a waveguide-type polarization beam splitter and a polarization rotating half-wave plate in a beam launcher using silica-based planar lightwave circuit technology. We confirmed experimentally the feasibility of using our proposed waveguide frontend in a two-in-one 1 × 20 WSS. The experimental results show that the fabricated waveguide frontend provides a polarization diversity function without any degradation in optical performance.

NONLINEAR AND FIBER OPTICS: Analysis of the mode noise in interference fiber channels used for the distribution of microwave signals

NASA Astrophysics Data System (ADS)

Bratchikov, A. N.; Glukhov, I. P.

1991-03-01

The results are given of a statistical theory of the speckle generalized to interference channels used for the distribution of microwave signals using multimode fiber waveguides with step and graded refractive-index profiles. A method is described for estimating the mode noise level in the open and closed regimes with one longitudinal speckle. The influence of the degree of mode filtering, losses at microbends, and spectral properties of a laser source on the statistical properties and the mode noise level is demonstrated. Numerical estimates are obtained of the ratio of the powers of the signal and mode noise for interference channels with typical parameters of fiber waveguides and a qualitative description is given of the effect of the mode noise.

Spatially Modulated Gain Waveguide Electro-Optic Laser

DTIC Science & Technology

2013-08-09

1997, pp 1223-1226. 5. Y. Li, S. M. Goldwasser, P. Herczfeld, L.M. Narducci, "Dynamics of an electro-optically tunable microchip laser ", IEEE...TYPE Final 3. DATES COVERED (From 7/2/2010-5-10-2013 To) 4. TITLE AND SUBTITLE Spatially modulated gain waveguide electro-optic laser 5a...optical waveguides laser on LiNb03 substrate. The main goal of this work is to implement an active LiNb03 waveguide with the desired spatially modulated

Nanowires and nanoribbons as subwavelength optical waveguides and their use as components in photonic circuits and devices

DOEpatents

Yang, Peidong; Law, Matt; Sirbuly, Donald J.; Johnson, Justin C.; Saykally, Richard; Fan, Rong; Tao, Andrea

2012-10-02

Nanoribbons and nanowires having diameters less than the wavelength of light are used in the formation and operation of optical circuits and devices. Such nanostructures function as subwavelength optical waveguides which form a fundamental building block for optical integration. The extraordinary length, flexibility and strength of these structures enable their manipulation on surfaces, including the precise positioning and optical linking of nanoribbon/wire waveguides and other nanoribbon/wire elements to form optical networks and devices. In addition, such structures provide for waveguiding in liquids, enabling them to further be used in other applications such as optical probes and sensors.

Optical trapping and propulsion of red blood cells on waveguide surfaces.

PubMed

Ahluwalia, Balpreet Singh; McCourt, Peter; Huser, Thomas; Hellesø, Olav Gaute

2010-09-27

We have studied optical trapping and propulsion of red blood cells in the evanescent field of optical waveguides. Cell propulsion is found to be highly dependent on the biological medium and serum proteins the cells are submerged in. Waveguides made of tantalum pentoxide are shown to be efficient for cell propulsion. An optical propulsion velocity of up to 
6 µm/s on a waveguide with a width of ~6 µm is reported. Stable optical trapping and propulsion of cells during transverse flow is also reported.

Optical NAND gate

DOEpatents

Skogen, Erik J [Albuquerque, NM; Raring, James [Goleta, CA; Tauke-Pedretti, Anna [Albuquerque, NM

2011-08-09

An optical NAND gate is formed from two pair of optical waveguide devices on a substrate, with each pair of the optical waveguide devices consisting of an electroabsorption modulator and a photodetector. One pair of the optical waveguide devices is electrically connected in parallel to operate as an optical AND gate; and the other pair of the optical waveguide devices is connected in series to operate as an optical NOT gate (i.e. an optical inverter). The optical NAND gate utilizes two digital optical inputs and a continuous light input to provide a NAND function output. The optical NAND gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 .mu.m.

Far infrared pump injection using an alumina waveguide

NASA Astrophysics Data System (ADS)

Nedvidek, F. J.; Kucerovsky, Z.; Brannen, Eric

1987-01-01

An alumina waveguide extension is employed to channel infrared radiation from a CO2 waveguide laser into an optically pumped far IR waveguide laser resonator in order to obtain far IR lasing with methyl alcohol and other media. Low pump transmission losses and efficient free space coupling are possible with proper choice of waveguide bore. The technique compares favorably with other injection schemes using refractive optics, and it offers greater flexibility, easier alignment, and less expense than optical arrangements using lenses.

Extraction film for optical waveguide and method of producing same

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tarsa, Eric J.; Durkee, John W.

2017-05-16

An optical waveguide includes a waveguide body and a film disposed on a surface of the waveguide body. The film includes a base and a plurality of undercut light extraction elements disposed between the base and the surface.

Integrated resonant micro-optical gyroscope and method of fabrication

DOEpatents

Vawter, G Allen [Albuquerque, NM; Zubrzycki, Walter J [Sandia Park, NM; Guo, Junpeng [Albuquerque, NM; Sullivan, Charles T [Albuquerque, NM

2006-09-12

An integrated optic gyroscope is disclosed which is based on a photonic integrated circuit (PIC) having a bidirectional laser source, a pair of optical waveguide phase modulators and a pair of waveguide photodetectors. The PIC can be connected to a passive ring resonator formed either as a coil of optical fiber or as a coiled optical waveguide. The lasing output from each end of the bidirectional laser source is phase modulated and directed around the passive ring resonator in two counterpropagating directions, with a portion of the lasing output then being detected to determine a rotation rate for the integrated optical gyroscope. The coiled optical waveguide can be formed on a silicon, glass or quartz substrate with a silicon nitride core and a silica cladding, while the PIC includes a plurality of III V compound semiconductor layers including one or more quantum well layers which are disordered in the phase modulators and to form passive optical waveguides.

Acrylic and metal based Y-branch plastic optical fiber splitter with optical NOA63 polymer waveguide taper region

NASA Astrophysics Data System (ADS)

Ehsan, Abang Annuar; Shaari, Sahbudin; Rahman, Mohd Kamil Abd.

2011-01-01

We proposed a simple low-cost acrylic and metal-based Y-branch plastic optical fiber (POF) splitter which utilizes a low cost optical polymer glue NOA63 as the main waveguiding medium at the waveguide taper region. The device is composed of three sections: an input POF waveguide, a middle waveguide taper region and output POF waveguides. A desktop high speed CNC engraver is utilized to produce the mold inserts used for the optical devices. Short POF fibers are inserted into the engraved slots at the input and output ports. UV curable optical polymer glue NOA63 is injected into the waveguide taper region and cured. The assembling is completed when the top plate is positioned to enclose the device structure and connecting screws are secured. Both POF splitters have an average insertion loss of 7.8 dB, coupling ratio of 55: 45 and 57: 43 for the acrylic and metal-based splitters respectively. The devices have excess loss of 4.82 and 4.73 dB for the acrylic and metal-based splitters respectively.

Demonstration of an all-optical feed-forward delay line buffer using the quadratic Stark effect and two-photon absorption in an SOA.

PubMed

Soto, Horacio; Tong, Miriam A; Domínguez, Juan C; Muraoka, Ramón

2017-09-04

We have inserted into an unbiased semiconductor optical amplifier (SOA) a powerful control beam, with photon energy slightly smaller than that of the band-gap of its active region, for exciting two-photon absorption and the quadratic Stark effect. For the available SOA, we estimated these phenomena generated a nonlinear absorption coefficient β= -865 cm/GW and induced an appreciable birefringence inside the amplifier waveguide, which significantly modified the polarization-state of a probe beam. Based on these effects, we have experimentally demonstrated the operation of an all-optical buffer, using an 80 Gb/s optical pulse comb, as well as an unbiased SOA, which was therefore, devoid of amplified spontaneous emission and pattern effects.

Optical pumping in a whispering mode optical waveguide

DOEpatents

Kurnit, Norman A.

1984-01-01

A device and method for optical pumping in a whispering mode optical waveguide. Both a helical ribbon and cylinder are disclosed which incorporate an additional curvature for confining the beam to increase intensity. An optical pumping medium is disposed in the optical path of the beam as it propagates along the waveguide. Optical pumping is enhanced by the high intensities of the beam and long interaction pathlengths which are achieved in a small volume.

Single-mode glass waveguide technology for optical interchip communication on board level

NASA Astrophysics Data System (ADS)

Brusberg, Lars; Neitz, Marcel; Schröder, Henning

2012-01-01

The large bandwidth demand in long-distance telecom networks lead to single-mode fiber interconnects as result of low dispersion, low loss and dense wavelength multiplexing possibilities. In contrast, multi-mode interconnects are suitable for much shorter lengths up to 300 meters and are promising for optical links between racks and on board level. Active optical cables based on multi-mode fiber links are at the market and research in multi-mode waveguide integration on board level is still going on. Compared to multi-mode, a single-mode waveguide has much more integration potential because of core diameters of around 20% of a multi-mode waveguide by a much larger bandwidth. But light coupling in single-mode waveguides is much more challenging because of lower coupling tolerances. Together with the silicon photonics technology, a single-mode waveguide technology on board-level will be the straight forward development goal for chip-to-chip optical interconnects integration. Such a hybrid packaging platform providing 3D optical single-mode links bridges the gap between novel photonic integrated circuits and the glass fiber based long-distance telecom networks. Following we introduce our 3D photonic packaging approach based on thin glass substrates with planar integrated optical single-mode waveguides for fiber-to-chip and chip-to-chip interconnects. This novel packaging approach merges micro-system packaging and glass integrated optics. It consists of a thin glass substrate with planar integrated singlemode waveguide circuits, optical mirrors and lenses providing an integration platform for photonic IC assembly and optical fiber interconnect. Thin glass is commercially available in panel and wafer formats and characterizes excellent optical and high-frequency properties. That makes it perfect for microsystem packaging. The paper presents recent results in single-mode waveguide technology on wafer level and waveguide characterization. Furthermore the integration in a hybrid packaging process and design issues are discussed.

Board-to-board optical interconnection using novel optical plug and slot

NASA Astrophysics Data System (ADS)

Cho, In K.; Yoon, Keun Byoung; Ahn, Seong H.; Kim, Jin Tae; Lee, Woo Jin; Shin, Kyoung Up; Heo, Young Un; Park, Hyo Hoon

2004-10-01

A novel optical PCB with transmitter/receiver system boards and optical bakcplane was prepared, which is board-to-board interconnection by optical plug and slot. We report an 8Gb/s PRBS NRZ data transmission between transmitter system board and optical backplane embedded multimode polymeric waveguide arrays. The basic concept of ETRI's optical PCB is as follows; 1) Metal optical bench is integrated with optoelectronic devices, driver and receiver circuits, polymeric waveguide and access line PCB module. 2) Multimode polymeric waveguide inside an optical backplane, which is embedded into PCB. 3) Optical slot and plug for high-density(channel pitch : 500um) board-to-board interconnection. The polymeric waveguide technology can be used for transmission of data on transmitter/ receiver system boards and for backplane interconnections. The main components are low-loss tapered polymeric waveguides and a novel optical plug and slot for board-to-board interconnections, respectively. The optical PCB is characteristic of low coupling loss, easy insertion/extraction of the boards and, especially, reliable optical coupling unaffected from external environment after board insertion.

Shaping plasmon beams via the controlled illumination of finite-size plasmonic crystals

PubMed Central

Bouillard, J.-S.; Segovia, P.; Dickson, W.; Wurtz, G. A.; Zayats, A. V.

2014-01-01

Plasmonic crystals provide many passive and active optical functionalities, including enhanced sensing, optical nonlinearities, light extraction from LEDs and coupling to and from subwavelength waveguides. Here we study, both experimentally and numerically, the coherent control of SPP beam excitation in finite size plasmonic crystals under focussed illumination. The correct combination of the illuminating spot size, its position relative to the plasmonic crystal, wavelength and polarisation enables the efficient shaping and directionality of SPP beam launching. We show that under strongly focussed illumination, the illuminated part of the crystal acts as an antenna, launching surface plasmon waves which are subsequently filtered by the surrounding periodic lattice. Changing the illumination conditions provides rich opportunities to engineer the SPP emission pattern. This offers an alternative technique to actively modulate and control plasmonic signals, either via micro- and nano-electromechanical switches or with electro- and all-optical beam steering which have direct implications for the development of new integrated nanophotonic devices, such as plasmonic couplers and switches and on-chip signal demultiplexing. This approach can be generalised to all kinds of surface waves, either for the coupling and discrimination of light in planar dielectric waveguides or the generation and control of non-diffractive SPP beams. PMID:25429786

Analysis of Nonlinear Periodic and Aperiodic Media: Application to Optical Logic Gates

NASA Astrophysics Data System (ADS)

Yu, Yisheng

This dissertation is about the analysis of nonlinear periodic and aperiodic media and their application to the design of intensity controlled all optical logic gates: AND, OR, and NOT. A coupled nonlinear differential equation that characterizes the electromagnetic wave propagation in a nonlinear periodic (and aperiodic) medium has been derived from the first principle. The equations are general enough that it reflects the effect of transverse modal fields and can be used to analyze both co-propagating and counter propagating waves. A numerical technique based on the finite differences method and absorbing boundary condition has been developed to solve the coupled differential equations here. The numerical method is simple and accurate. Unlike the method based on characteristics that has been reported in the literature, this method does not involve integration and step sizes of time and space coordinates are decoupled. The decoupling provides independent choice for time and space step sizes. The concept of "gap soliton" has also been re-examined. The dissertation consists of four manuscripts. Manuscript I reports on the design of all optical logic gates: AND, OR, and NOT based on the bistability property of nonlinear periodic and aperiodic waveguiding structures. The functioning of the logic gates has been shown by analysis. The numerical technique that has been developed to solve the nonlinear differential equations are addressed in manuscript II. The effect of transverse modal fields on the bistable property of nonlinear periodic medium is reported in manuscript III. The concept of "gap soliton" that are generated in a nonlinear periodic medium has been re-examined. The details on the finding of the re-examination are discussed in manuscript IV.

Application of microstructural optical waveguides with hollow core for enzyme immunoassay

NASA Astrophysics Data System (ADS)

Pidenko, Pavel S.; Pidenko, Sergei A.; Burmistrova, Natalia A.; Shuvalov, Andrei A.; Chibrova, Anastasiya A.; Skibina, Yulia S.; Goryacheva, Irina Y.

2018-04-01

Microstructural optical waveguides with the hollow core are actively studied as a promising support for heterogeneous immunoassay in development of new optical biosensor elements for medicine and biology. Overcoming of the limitations associated with the low sorption capacity of glass used for the waveguides production is a crucial step for this assay format. In this work the possibility of silanization of microstructural optical waveguides with the hollow core using (3-glycidyloxypropyl) trimethoxysilane and their further application to enzymatic immunoassay was studied.

Fluorescent fluid interface position sensor

DOEpatents

Weiss, Jonathan D.

2004-02-17

A new fluid interface position sensor has been developed, which is capable of optically determining the location of an interface between an upper fluid and a lower fluid, the upper fluid having a larger refractive index than a lower fluid. The sensor functions by measurement, of fluorescence excited by an optical pump beam which is confined within a fluorescent waveguide where that waveguide is in optical contact with the lower fluid, but escapes from the fluorescent waveguide where that waveguide is in optical contact with the upper fluid.

Rapid assessment of nonlinear optical propagation effects in dielectrics

PubMed Central

Hoyo, J. del; de la Cruz, A. Ruiz; Grace, E.; Ferrer, A.; Siegel, J.; Pasquazi, A.; Assanto, G.; Solis, J.

2015-01-01

Ultrafast laser processing applications need fast approaches to assess the nonlinear propagation of the laser beam in order to predict the optimal range of processing parameters in a wide variety of cases. We develop here a method based on the simple monitoring of the nonlinear beam shaping against numerical prediction. The numerical code solves the nonlinear Schrödinger equation with nonlinear absorption under simplified conditions by employing a state-of-the art computationally efficient approach. By comparing with experimental results we can rapidly estimate the nonlinear refractive index and nonlinear absorption coefficients of the material. The validity of this approach has been tested in a variety of experiments where nonlinearities play a key role, like spatial soliton shaping or fs-laser waveguide writing. The approach provides excellent results for propagated power densities for which free carrier generation effects can be neglected. Above such a threshold, the peculiarities of the nonlinear propagation of elliptical beams enable acquiring an instantaneous picture of the deposition of energy inside the material realistic enough to estimate the effective nonlinear refractive index and nonlinear absorption coefficients that can be used for predicting the spatial distribution of energy deposition inside the material and controlling the beam in the writing process. PMID:25564243

Rapid assessment of nonlinear optical propagation effects in dielectrics.

PubMed

del Hoyo, J; de la Cruz, A Ruiz; Grace, E; Ferrer, A; Siegel, J; Pasquazi, A; Assanto, G; Solis, J

2015-01-07

Ultrafast laser processing applications need fast approaches to assess the nonlinear propagation of the laser beam in order to predict the optimal range of processing parameters in a wide variety of cases. We develop here a method based on the simple monitoring of the nonlinear beam shaping against numerical prediction. The numerical code solves the nonlinear Schrödinger equation with nonlinear absorption under simplified conditions by employing a state-of-the art computationally efficient approach. By comparing with experimental results we can rapidly estimate the nonlinear refractive index and nonlinear absorption coefficients of the material. The validity of this approach has been tested in a variety of experiments where nonlinearities play a key role, like spatial soliton shaping or fs-laser waveguide writing. The approach provides excellent results for propagated power densities for which free carrier generation effects can be neglected. Above such a threshold, the peculiarities of the nonlinear propagation of elliptical beams enable acquiring an instantaneous picture of the deposition of energy inside the material realistic enough to estimate the effective nonlinear refractive index and nonlinear absorption coefficients that can be used for predicting the spatial distribution of energy deposition inside the material and controlling the beam in the writing process.

Rapid assessment of nonlinear optical propagation effects in dielectrics

NASA Astrophysics Data System (ADS)

Hoyo, J. Del; de La Cruz, A. Ruiz; Grace, E.; Ferrer, A.; Siegel, J.; Pasquazi, A.; Assanto, G.; Solis, J.

2015-01-01

Ultrafast laser processing applications need fast approaches to assess the nonlinear propagation of the laser beam in order to predict the optimal range of processing parameters in a wide variety of cases. We develop here a method based on the simple monitoring of the nonlinear beam shaping against numerical prediction. The numerical code solves the nonlinear Schrödinger equation with nonlinear absorption under simplified conditions by employing a state-of-the art computationally efficient approach. By comparing with experimental results we can rapidly estimate the nonlinear refractive index and nonlinear absorption coefficients of the material. The validity of this approach has been tested in a variety of experiments where nonlinearities play a key role, like spatial soliton shaping or fs-laser waveguide writing. The approach provides excellent results for propagated power densities for which free carrier generation effects can be neglected. Above such a threshold, the peculiarities of the nonlinear propagation of elliptical beams enable acquiring an instantaneous picture of the deposition of energy inside the material realistic enough to estimate the effective nonlinear refractive index and nonlinear absorption coefficients that can be used for predicting the spatial distribution of energy deposition inside the material and controlling the beam in the writing process.

Fabrication of Metallic Quantum Dot Arrays For Nanoscale Nonlinear Optics

NASA Astrophysics Data System (ADS)

McMahon, M. D.; Hmelo, A. B.; Lopez Magruder, R., III; Weller Haglund, R. A., Jr.; Feldman, L. C.

2003-03-01

Ordered arrays of metal nanocrystals embedded in or sequestered on dielectric hosts have potential applications as elements of nonlinear or near-field optical circuits, as sensitizers for fluorescence emitters and photo detectors, and as anchor points for arrays of biological molecules. Metal nanocrystals are strongly confined electronic systems with size-, shape and spatial orientation-dependent optical responses. At the smallest scales (below about 15 nm diameter), their band structure is drastically altered by the small size of the system, and the reduced population of conduction-band electrons. Here we report on the fabrication of two-dimensional ordered metallic nanocrystal arrays, and one-dimensional nanocrystal-loaded waveguides for optical investigations. We have employed strategies for synthesizing metal nanocrystal composites that capitalize on the best features of focused ion beam (FIB) machining and pulsed laser deposition (PLD). The FIB generates arrays of specialized sites; PLD vapor deposition results in the directed self-assembly of Ag nanoparticles nucleated at the FIB generated sites on silicon substrates. We present results based on the SEM, AFM and optical characterization of prototype composites. This research has been supported by the U.S. Department of Energy under grant DE-FG02-01ER45916.

Polymer waveguide grating sensor integrated with a thin-film photodetector

PubMed Central

Song, Fuchuan; Xiao, Jing; Xie, Antonio Jou; Seo, Sang-Woo

2014-01-01

This paper presents a planar waveguide grating sensor integrated with a photodetector (PD) for on-chip optical sensing systems which are suitable for diagnostics in the field and in-situ measurements. III–V semiconductor-based thin-film PD is integrated with a polymer based waveguide grating device on a silicon platform. The fabricated optical sensor successfully discriminates optical spectral characteristics of the polymer waveguide grating from the on-chip PD. In addition, its potential use as a refractive index sensor is demonstrated. Based on a planar waveguide structure, the demonstrated sensor chip may incorporate multiple grating waveguide sensing regions with their own optical detection PDs. In addition, the demonstrated processing is based on a post-integration process which is compatible with silicon complementary metal-oxide semiconductor (CMOS) electronics. Potentially, this leads a compact, chip-scale optical sensing system which can monitor multiple physical parameters simultaneously without need for external signal processing. PMID:24466407

Fabrication of planar optical waveguides by 6.0 MeV silicon ion implantation in Nd-doped phosphate glasses

NASA Astrophysics Data System (ADS)

Shen, Xiao-Liang; Dai, Han-Qing; Zhang, Liao-Lin; Wang, Yue; Zhu, Qi-Feng; Guo, Hai-Tao; Li, Wei-Nan; Liu, Chun-Xiao

2018-04-01

We report the fabrication of a planar optical waveguide by silicon ion implantation into Nd-doped phosphate glass at an energy of 6.0 MeV and a dose of 5.0 × 1014 ions/cm2. The change in the surface morphology of the glass after the implantation can be clearly observed by scanning electron microscopy. The measurement of the dark mode spectrum of the waveguide is conducted using a prism coupler at 632.8 nm. The refractive index distribution of the waveguide is reconstructed by the reflectivity calculation method. The near-field optical intensity profile of the waveguide is measured using an end-face coupling system. The waveguide with good optical properties on the glass matrix may be valuable for the application of the Nd-doped phosphate glass in integrated optical devices.

International Conference on Integrated Optical Circuit Engineering, 1st, Cambridge, MA, October 23-25, 1984, Proceedings

NASA Astrophysics Data System (ADS)

Ostrowsky, D. B.; Sriram, S.

Aspects of waveguide technology are explored, taking into account waveguide fabrication techniques in GaAs/GaAlAs, the design and fabrication of AlGaAs/GaAs phase couplers for optical integrated circuit applications, ion implanted GaAs integrated optics fabrication technology, a direct writing electron beam lithography based process for the realization of optoelectronic integrated circuits, and advances in the development of semiconductor integrated optical circuits for telecommunications. Other subjects examined are related to optical signal processing, optical switching, and questions of optical bistability and logic. Attention is given to acousto-optic techniques in integrated optics, acousto-optic Bragg diffraction in proton exchanged waveguides, optical threshold logic architectures for hybrid binary/residue processors, integrated optical modulation and switching, all-optic logic devices for waveguide optics, optoelectronic switching, high-speed photodetector switching, and a mechanical optical switch.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prakash, S. Arun; Malathi, V.; Mani Rajan, M. S., E-mail: senthilmanirajanofc@gmail.com

We obtain the bright similariton solutions for generalized inhomogeneous nonlinear Schrödinger equation (GINLSE) which governs the pulse propagation in a tapered graded index diffraction decreasing waveguide (DDW). The exact solutions have been worked out by employing similarity transformations which involve the mapping of the GINLSE to standard NLSE for the certain conditions of the parameters. By making use of the exact analytical solutions, we have investigated the dynamical behavior of optical similariton pairs and have suggested the methods to control them as they propagate through DDW. Moreover, pulse width of similariton is controlled through various profiles. These results are helpfulmore » to understand the similaritons in DDW and can be potentially useful for future experiments in optical communications which involve optical amplifiers and long-haul telecommunication networks.« less

[Optical Design of Miniature Infrared Gratings Spectrometer Based on Planar Waveguide].

PubMed

Li, Yang-yu; Fang, Yong-hua; Li, Da-cheng; Liu, Yang

2015-03-01

In order to miniaturize an infrared spectrometer, we analyze the current optical design of miniature spectrometers and propose a method for designing a miniature infrared gratings spectrometer based on planar waveguide. Common miniature spectrometer uses miniature optical elements to reduce the size of system, which also shrinks the effective aperture. So the performance of spectrometer has dropped. Miniaturization principle of planar waveguide spectrometer is different from the principle of common miniature spectrometer. In planar waveguide spectrometer, the propagation of light is limited in a thin planar waveguide, which looks like the whole optical system is squashed flat. In the direction parallel to the planar waveguide, the light through the slit is collimated, dispersed and focused. And a spectral image is formed in the detector plane. This propagation of light is similar to the light in common miniature spectrometer. In the direction perpendicular to the planar waveguide, light is multiple reflected by the upper and lower surfaces of the planar waveguide and propagates in the waveguide. So the size of corresponding optical element could be very small in the vertical direction, which can reduce the size of the optical system. And the performance of the spectrometer is still good. The design method of the planar waveguide spectrometer can be separated into two parts, Czerny-Turner structure design and planar waveguide structure design. First, by using aberration theory an aberration-corrected (spherical aberration, coma, focal curve) Czerny-Turner structure is obtained. The operation wavelength range and spectral resolution are also fixed. Then, by using geometrical optics theory a planar waveguide structure is designed for reducing the system size and correcting the astigmatism. The planar waveguide structure includes a planar waveguide and two cylindrical lenses. Finally, they are modeled together in optical design software and are optimized as a whole. An infrared planar waveguide spectrometer is designed using this method. The operation wavelength range is 8 - 12 μm, the numerical aperture is 0.22, and the linear array detector contains 64 elements. By using Zemax software, the design is optimized and analyzed. The results indicate that the size of the optical system is 130 mm x 125 mm x 20 mm and the spectral resolution of spectrometer is 80 nm, which satisfy the requirements of design index. Thus it is this method that can be used for designing a miniature spectrometer without movable parts and sizes in the range of several cubic centimeters.

Planar polymer and glass graded index waveguides for data center applications

NASA Astrophysics Data System (ADS)

Pitwon, Richard; Yamauchi, Akira; Brusberg, Lars; Wang, Kai; Ishigure, Takaaki; Schröder, Henning; Neitz, Marcel; Worrall, Alex

2016-03-01

Embedded optical waveguide technology for optical printed circuit boards (OPCBs) has advanced considerably over the past decade both in terms of materials and achievable waveguide structures. Two distinct classes of planar graded index multimode waveguide have recently emerged based on polymer and glass materials. We report on the suitability of graded index polymer waveguides, fabricated using the Mosquito method, and graded index glass waveguides, fabricated using ion diffusion on thin glass foils, for deployment within future data center environments as part of an optically disaggregated architecture. To this end, we first characterize the wavelength dependent performance of different waveguide types to assess their suitability with respect to two dominant emerging multimode transceiver classes based on directly modulated 850 nm VCSELs and 1310 silicon photonics devices. Furthermore we connect the different waveguide types into an optically disaggregated data storage system and characterize their performance with respect to different common high speed data protocols used at the intra and inter rack level including 10 Gb Ethernet and Serial Attached SCSI.

Broadband and scalable optical coupling for silicon photonics using polymer waveguides

NASA Astrophysics Data System (ADS)

La Porta, Antonio; Weiss, Jonas; Dangel, Roger; Jubin, Daniel; Meier, Norbert; Horst, Folkert; Offrein, Bert Jan

2018-04-01

We present optical coupling schemes for silicon integrated photonics circuits that account for the challenges in large-scale data processing systems such as those used for emerging big data workloads. Our waveguide based approach allows to optimally exploit the on-chip optical feature size, and chip- and package real-estate. It further scales well to high numbers of channels and is compatible with state-of-the-art flip-chip die packaging. We demonstrate silicon waveguide to polymer waveguide coupling losses below 1.5 dB for both the O- and C-bands with a polarisation dependent loss of <1 dB. Over 100 optical silicon waveguide to polymer waveguide interfaces were assembled within a single alignment step, resulting in a physical I/O channel density of up to 13 waveguides per millimetre along the chip-edge, with an average coupling loss of below 3.4 dB measured at 1310 nm.

Microgravity Processing and Photonic Applications of Organic and Polymeric Materials

NASA Technical Reports Server (NTRS)

Frazier, Donald 0; Penn, Benjamin G.; Smith, David; Witherow, William K.; Paley, M. S.; Abdeldayem, Hossin A.

1998-01-01

In recent years, a great deal of interest has been directed toward the use of organic materials in the development of high-efficiency optoelectronic and photonic devices. There is a myriad of possibilities among organic which allow flexibility in the design of unique structures with a variety of functional groups. The use of nonlinear optical (NLO) organic materials such as thin-film waveguides allows full exploitation of their desirable qualities by permitting long interaction lengths and large susceptibilities allowing modest power input. There are several methods in use to prepare thin films, such as Langmuir-Blodgett (LB) and self-assembly techniques, vapor deposition, growth from sheared solution or melt, and melt growth between glass plates. Organics have many features that make Abstract: them desirable for use in optical devices such as high second- and third-order nonlinearities, flexibility of molecular design, and damage resistance to optical radiation. However, their use in devices has been hindered by processing difficulties for crystals and thin films. In this chapter, we discuss photonic and optoelectronic applications of a few organic materials and the potential role of microgravity on processing these materials. It is of interest to note how materials with second- and third-order nonlinear optical behavior may be improved in a diffusion-limited environment and ways in which convection may be detrimental to these materials. We focus our discussion on third-order materials for all-optical switching, and second-order materials for all-optical switching, and second-order materials for frequency conversion and electrooptics.

Optical pumping in a whispering-mode optical waveguide

DOEpatents

Kurnit, N.A.

1981-08-11

A device and method for optical pumping in a whispering mode optical waveguide are described. Both a helical ribbon and cylinder are disclosed which incorporate an additional curvature for confining the beam to increase intensity. An optical pumping medium is disposed in the optical path of the beam as it propagates along the waveguide. Optical pumping is enhanced by the high intensities of the beam and long interaction path lengths which are achieved in a small volume.

Optical-fiber-to-waveguide coupling using carbon-dioxide-laser-induced long-period fiber gratings.

PubMed

Bachim, Brent L; Ogunsola, Oluwafemi O; Gaylord, Thomas K

2005-08-15

Optical fibers are expected to play a role in chip-level and board-level optical interconnects because of limitations on the bandwidth and level of integration of electrical interconnects. Therefore, methods are needed to couple optical fibers directly to waveguides on chips and on boards. We demonstrate optical-fiber-to-waveguide coupling using carbon-dioxide laser-induced long-period fiber gratings (LPFGs). Such gratings can be written in standard fiber and offer wavelength multiplexing-demultiplexing performance. The coupler fabrication process and the characterization apparatus are presented. The operation and the wavelength response of a LPFG-based optical-fiber-to-waveguide directional coupler are demonstrated.

Wavelength-addressed intra-board optical interconnection by plug-in alignment with a micro hole array

NASA Astrophysics Data System (ADS)

Nakama, Kenichi; Tokiwa, Yuu; Mikami, Osamu

2010-09-01

Intra-board interconnection between optical waveguide channels is suitable for assembling high-speed optoelectronic printed wiring boards (OE-PWB). Here, we propose a novel optical interconnection method combining techniques for both wavelength-based optical waveguide addressing and plug-in optical waveguide alignment with a micro-hole array (MHA). This array was fabricated by the mask transfer method. For waveguide addressing, we used a micro passive wavelength selector (MPWS) module, which is a type of Littrow mount monochromator consisting of an optical diffraction grating, a focusing lens, and the MHA. From the experimental results, we found that the wavelength addressing operation of the MPWS module was effective for intra-board optical interconnection.

Characterization and Power Scaling of Beam-Combinable Ytterbium-Doped Microstructured Fiber Amplifier

NASA Astrophysics Data System (ADS)

Mart, Cody W.

In this dissertation, high-power ytterbium-doped fiber amplifiers designed with advanced waveguide concepts are characterized and power scaled. Fiber waveguides utilizing cladding microstructures to achieve wave guidance via the photonic bandgap (PBG) effect and a combination of PBG and modified total internal reflection (MTIR) have been proposed as viable single-mode waveguides. Such novel structures allow larger core diameters (>35 ?m diameters) than conventional step-index fibers while still maintaining near-diffraction limited beam quality. These microstructured fibers are demonstrated as robust single-mode waveguides at low powers and are power scaled to realize the thermal power limits of the structure. Here above a certain power threshold, these coiled few-mode fibers have been shown to be limited by modal instability (MI); where energy is dynamically transferred between the fundamental mode and higher-order modes. Nonlinear effects such as stimulated Brillouin scattering (SBS) are also studied in these fiber waveguides as part of this dissertation. Suppressing SBS is critical towards achieving narrow optical bandwidths (linewidths) necessary for efficient fiber amplifier beam combining. Towards that end, new effects that favorably reduce acoustic wave dispersion to increase the SBS threshold are discovered and reported. The first advanced waveguide examined is a Yb-doped 50/400 mum diameter core/clad PBGF. The PBGF is power scaled with a single-frequency 1064 nm seed to an MI-limited 410 W with 79% optical-to-optical efficiency and near-diffraction limited beam quality (M-Squared < 1.25) before MI onset. To this author's knowledge, this represents 2.4x improvement in power output from a PBGF amplifier without consideration for linewidth and a 16x improvement in single-frequency power output from a PBGF amplifier. During power scaling of the PBGF, a remarkably low Brillouin response was elicited from the fiber even when the ultra large diameter 50 mum core is accounted for in the SBS threshold equation. Subsequent interrogation of the Brillouin response in a pump probe Brillouin gain spectrum diagnostic estimated a Brillouin gain coefficient, gB, of 0.62E-11 m/W; which is 4x reduced from standard silica-based fiber. A finite element numerical model that solves the inhomogenous Helmholtz equation that governs the acoustic and optical coupling in SBS is utilized to verify experimental results with an estimated gB = 0.68E-11 m/W. Consequently, a novel SBS-suppression mechanism based on inclusion of sub-optical wavelength acoustic features in the core is proposed. The second advanced waveguide analyzed is a 35/350 mum diameter core/clad fiber that achieved wave guidance via both PBG and MTIR, and is referred to as a hybrid fiber. The waveguide benefits mutually from the amenable properties of PBG and MTIR wave guidance because robust single-mode propagation with minimal confinement loss is assured due to MTIR effects, and the waveguide spectrally filters unwanted wavelengths via the PBG effect. The waveguide employs annular Yb-doped gain tailoring to reduce thermal effects and mitigate MI. Moreover, it is designed to suppress Raman processes for a 1064 nm signal by attenuating wavelengths > 1110 nm via the PBG effect. When seeded with a 1064 nm signal deterministically broadened to ˜1 GHz, the hybrid fiber was power scaled to a MI-limited 820 W with 78% optical-to-optical efficiency and near diffraction limited beam quality of M_Squared ˜1.2 before MI onset. This represents a 14x improvement in power output from a hybrid fiber, and demonstrates that this type of fiber amplifier is a quality candidate for further power scaling for beam combining.

FIBER AND INTEGRATED OPTICS: Detection of the optical anisotropy in KTP:Rb waveguides

NASA Astrophysics Data System (ADS)

Buritskiĭ, K. S.; Dianov, Evgenii M.; Maslov, Vladislav A.; Chernykh, V. A.; Shcherbakov, E. A.

1990-10-01

The optical characteristics of channel waveguides made of rubidium-activated potassium titanyl phosphate (KTP:Rb) were determined. The refractive index increment of such waveguides was found to exhibit a considerable anisotropy: Δnx / Δnz approx 2. A deviation of the distribution of the refractive index in a channel waveguide from the model distribution was observed for ion-exchange times in excess of 1 h.

Rogue wave modes for a derivative nonlinear Schrödinger model.

PubMed

Chan, Hiu Ning; Chow, Kwok Wing; Kedziora, David Jacob; Grimshaw, Roger Hamilton James; Ding, Edwin

2014-03-01

Rogue waves in fluid dynamics and optical waveguides are unexpectedly large displacements from a background state, and occur in the nonlinear Schrödinger equation with positive linear dispersion in the regime of positive cubic nonlinearity. Rogue waves of a derivative nonlinear Schrödinger equation are calculated in this work as a long-wave limit of a breather (a pulsating mode), and can occur in the regime of negative cubic nonlinearity if a sufficiently strong self-steepening nonlinearity is also present. This critical magnitude is shown to be precisely the threshold for the onset of modulation instabilities of the background plane wave, providing a strong piece of evidence regarding the connection between a rogue wave and modulation instability. The maximum amplitude of the rogue wave is three times that of the background plane wave, a result identical to that of the Peregrine breather in the classical nonlinear Schrödinger equation model. This amplification ratio and the resulting spectral broadening arising from modulation instability correlate with recent experimental results of water waves. Numerical simulations in the regime of marginal stability are described.

Optical waveguides in magneto-optical glasses fabricated by proton implantation

NASA Astrophysics Data System (ADS)

Liu, Chun-Xiao; Li, Yu-Wen; Zheng, Rui-Lin; Fu, Li-Li; Zhang, Liao-Lin; Guo, Hai-Tao; Zhou, Zhi-Guang; Li, Wei-Nan; Lin, She-Bao; Wei, Wei

2016-11-01

Planar waveguides in magneto-optical glasses (Tb3+-doped aluminum borosilicate glasses) have been produced by a 550-keV proton implantation at a dose of 4.0×1016 ions/cm2 for the first time to our knowledge. After annealing at 260 °C for 1.0 h, the dark-mode spectra and near-field intensity distributions are measured by the prism-coupling and end-face coupling methods. The damage profile, refractive index distribution and light propagation mode of the planar waveguide are numerically calculated by SRIM 2010, RCM and FD-BPM, respectively. The effects of implantation on the structural and optical properties are investigated by Raman and absorption spectra. It suggests that the proton-implanted Tb3+-doped aluminum borosilicate glass waveguide is a good candidate for a waveguide isolator in optical fiber communication and all-optical communication.

Optical waveguides with memory effect using photochromic material for neural network

NASA Astrophysics Data System (ADS)

Tanimoto, Keisuke; Amemiya, Yoshiteru; Yokoyama, Shin

2018-04-01

An optical neural network using a waveguide with a memory effect, a photodiode, CMOS circuits and LEDs was proposed. To realize the neural network, optical waveguides with a memory effect were fabricated using a cladding layer containing the photochromic material “diarylethene”. The transmittance of green light was decreased by UV light irradiation and recovered by the passage of green light through the waveguide. It was confirmed that the transmittance versus total energy of the green light that passed through the waveguide well fit the universal exponential curve.

Integrated optical gyroscopes offering low cost, small size and vibration immunity

NASA Astrophysics Data System (ADS)

Monovoukas, Christos; Swiecki, Andrew; Maseeh, Fariborz

2000-03-01

IntelliSense has developed an integrated optic gyro technology that provides the sensitivity of fiber optic gyros while utilizing batch microfabrication techniques to achieve the low cost of mechanical MEMS gyros. The base technology consists of an optical resonating waveguide chip, sensor electronics and an optical bench. The sensing element is based on an integrated optic waveguide chip in which counter-propagating optical fields are used to sense rotation in the plane of the waveguide through the Sagnac effect. It is powered by a semiconductor laser light source, which is coupled into a waveguide and split into two waveguide arms. Both signals are probed through the out coupled light at each waveguide arm, and rate information is derived from the difference in phase between these two signals. Measuring angular rotation is important for proper operation of a variety of systems such as: missile guidance systems, satellites, energy exploration, camera stabilization, robotics positioning, platform stabilization and space craft guidance to mention a few. This technology overcomes the limitations that previous commercially available gyros for this purpose have had including limitations in size, sensitivity, durability, and premium price.

Optical continuum generation on a silicon chip

NASA Astrophysics Data System (ADS)

Jalali, Bahram; Boyraz, Ozdal; Koonath, Prakash; Raghunathan, Varun; Indukuri, Tejaswi; Dimitropoulos, Dimitri

2005-08-01

Although the Raman effect is nearly two orders of magnitude stronger than the electronic Kerr nonlinearity in silicon, under pulsed operation regime where the pulse width is shorter than the phonon response time, Raman effect is suppressed and Kerr nonlinearity dominates. Continuum generation, made possible by the non-resonant Kerr nonlinearity, offers a technologically and economically appealing path to WDM communication at the inter-chip or intra-chip levels. We have studied this phenomenon experimentally and theoretically. Experimentally, a 2 fold spectral broadening is obtained by launching ~4ps optical pulses with 2.2GW/cm2 peak power into a conventional silicon waveguide. Theoretical calculations, that include the effect of two-photon-absorption, free carrier absorption and refractive index change indicate that up to >30 times spectral broadening is achievable in an optimized device. The broadening is due to self phase modulation and saturates due to two photon absorption. Additionally, we find that free carrier dynamics also contributes to the spectral broadening and cause the overall spectrum to be asymmetric with respect to the pump wavelength.

Femtosecond writing of near-surface waveguides in lithium niobate for low-loss electro-optical modulators of broadband emission

NASA Astrophysics Data System (ADS)

Bukharin, Mikhail A.; Skryabin, Nikolay N.; Khudyakov, Dmitriy V.; Vartapetov, Sergey K.

2016-05-01

In the investigation we demonstrated technique of direct femtosecond laser writing of tracks with induced refractive index at record low depth under surface of lithium niobate (3-15 μm). It was shown that with the help of proposed technique one can be written claddings of near surface optical waveguides that plays a key role in fabrication of fast electro-optical modulators with low operating voltage. Fundamental problem resolved in the investigation consists in suppression of negative factors impeding femtosecond inscription of waveguides at low depths. To prevent optical breakdown of crystal surface we used high numerical aperture objectives for focusing of light. It was shown, that advanced heat accumulation regime of femtosecond inscription is inapplicable for writing of near-surface waveguides, and near the surface waveguides should be written in non-thermal regime in contrast to widespread femtosecond writing at depths of tens micrometers. Inscribed waveguides were examined for optical losses and polarization properties. It was experimentally shown, that femtosecond written near surface waveguides have such advantages over widely used proton exchanged and Ti-diffusion waveguides as lower optical losses (down to 0.3 dB/cm) and maintaining of all polarization states of propagation light, which is crucial for development of electro-optical modulators for broadband and ultrashort laser emission. Novelty of the results consists in technique of femtosecond inscription of waveguides at record low depths under the surface of crystals. As compared to previous investigations in the field (structures at depths near 50 um with buried electrodes), the obtained waveguides could be used with simple closely adjacent on-surface electrodes.

Integrated optical isolators using magnetic surface plasmon (Presentation Recording)

NASA Astrophysics Data System (ADS)

Shimizu, Hiromasa; Kaihara, Terunori; Umetsu, Saori; Hosoda, Masashi

2015-09-01

Optical isolators are one of the essential components to protect semiconductor laser diodes (LDs) from backward reflected light in integrated optics. In order to realize optical isolators, nonreciprocal propagation of light is necessary, which can be realized by magnetic materials. Semiconductor optical isolators have been strongly desired on Si and III/V waveguides. We have developed semiconductor optical isolators based on nonreciprocal loss owing to transverse magneto-optic Kerr effect, where the ferromagnetic metals are deposited on semiconductor optical waveguides1). Use of surface plasmon polariton at the interface of ferromagnetic metal and insulator leads to stronger optical confinement and magneto-optic effect. It is possible to modulate the optical confinement by changing the magnetic field direction, thus optical isolator operation is proposed2, 3). We have investigated surface plasmons at the interfaces between ferrimagnetic garnet/gold film, and applications to waveguide optical isolators. We assumed waveguides composed of Au/Si(38.63nm)/Ce:YIG(1700nm)/Si(220nm)/Si , and calculated the coupling lengths between Au/Si(38.63nm)/Ce:YIG plasmonic waveguide and Ce:YIG/Si(220nm)/Si waveguide for transversely magnetized Ce:YIG with forward and backward directions. The coupling length was calculated to 232.1um for backward propagating light. On the other hand, the coupling was not complete, and the length was calculated to 175.5um. The optical isolation by using the nonreciprocal coupling and propagation loss was calculated to be 43.7dB when the length of plasmonic waveguide is 700um. 1) H. Shimizu et al., J. Lightwave Technol. 24, 38 (2006). 2) V. Zayets et al., Materials, 5, 857-871 (2012). 3) J. Montoya, et al, J. Appl. Phys. 106, 023108, (2009).

Electro-optical backplane demonstrator with integrated multimode gradient-index thin glass waveguide panel

NASA Astrophysics Data System (ADS)

Schröder, Henning; Brusberg, Lars; Pitwon, Richard; Whalley, Simon; Wang, Kai; Miller, Allen; Herbst, Christian; Weber, Daniel; Lang, Klaus-Dieter

2015-03-01

Optical interconnects for data transmission at board level offer increased energy efficiency, system density, and bandwidth scalability compared to purely copper driven systems. We present recent results on manufacturing of electrooptical printed circuit board (PCB) with integrated planar glass waveguides. The graded index multi-mode waveguides are patterned inside commercially available thin-glass panels by performing a specific ion-exchange process. The glass waveguide panel is embedded within the layer stack-up of a PCB using proven industrial processes. This paper describes the design, manufacture, assembly and characterization of the first electro-optical backplane demonstrator based on integrated planar glass waveguides. The electro-optical backplane in question is created by laminating the glass waveguide panel into a conventional multi-layer electronic printed circuit board stack-up. High precision ferrule mounts are automatically assembled, which will enable MT compliant connectors to be plugged accurately to the embedded waveguide interfaces on the glass panel edges. The demonstration platform comprises a standardized sub-rack chassis and five pluggable test cards each housing optical engines and pluggable optical connectors. The test cards support a variety of different data interfaces and can support data rates of up to 32 Gb/s per channel.

Optical ridge waveguides preserving the thermo-optic features in LiNbO3 crystals fabricated by combination of proton implantation and selective wet etching.

PubMed

Tan, Yang; Chen, Feng

2010-05-24

We report on a new, simple method to fabricate optical ridge waveguides in a z-cut LiNbO3 wafer by using proton implantation and selective wet etching. The measured modal field is well confined in the ridge waveguide region, which is also confirmed by the numerical simulation. With thermal annealing treatment at 400 degrees C, the propagation loss of the ridge waveguides is determined to be as low as approximately 0.9 dB/cm. In addition, the measured thermo-optic coefficients of the waveguides are in good agreement with those of the bulk, suggesting potential applications in integrated photonics.

Continuously tunable optical buffer with a dual silicon waveguide design.

PubMed

Horak, Peter; Stewart, Will; Loh, Wei H

2011-06-20

We propose a design for an optical buffer that comprises two coupled silicon waveguides, which is capable of generating a large continuously tunable change in the propagation delay time. The optical delay can be varied by more than 100% through varying the spacing between the waveguides.

Planar optical waveguides for optical panel having gradient refractive index core

DOEpatents

Veligdan, James T.

2001-01-01

An optical panel is disclosed. A plurality of stacked planar optical waveguides are used to guide light from an inlet face to an outlet face of an optical panel. Each of the optical waveguides comprises a planar sheet of core material having a central plane. The core material has an index of refraction which decreases as the distance from the central plane increases. The decrease in the index of refraction occurs gradually and continuously.

Planar optical waveguides for optical panel having gradient refractive index core

DOEpatents

Veligdan, James T.

2004-08-24

An optical panel is disclosed. A plurality of stacked planar optical waveguides are used to guide light from an inlet face to an outlet face of an optical panel. Each of the optical waveguides comprises a planar sheet of core material having a central plane. The core material has an index of refraction which decreases as the distance from the central plane increases. The decrease in the index of refraction occurs gradually and continuously.

Incorporating an optical waveguide into a neural interface

DOEpatents

Tolosa, Vanessa; Delima, Terri L.; Felix, Sarah H.; Pannu, Satinderpall S.; Shah, Kedar G.; Sheth, Heeral; Tooker, Angela C.

2016-11-08

An optical waveguide integrated into a multielectrode array (MEA) neural interface includes a device body, at least one electrode in the device body, at least one electrically conducting lead coupled to the at least one electrode, at least one optical channel in the device body, and waveguide material in the at least one optical channel. The fabrication of a neural interface device includes the steps of providing a device body, providing at least one electrode in the device body, providing at least one electrically conducting lead coupled to the at least one electrode, providing at least one optical channel in the device body, and providing a waveguide material in the at least one optical channel.

High Bandwidth Optical Links for Micro-Satellite Support

NASA Technical Reports Server (NTRS)

Chao, Tien-Hsin (Inventor); Wilson, Keith E. (Inventor); Coste, Keith (Inventor)

2016-01-01

A method, systems, apparatus and device enable high bandwidth satellite communications. An onboard tracking detector, installed in a low-earth orbit satellite, detects a position of an incoming optical beam received/transmitted from a first ground station of one or more ground stations. Tracker electronics determine orientation information of the incoming optical beam based on the position. Control electronics receive the orientation information from the tracker electronics, and control a waveguide drive electronics. The waveguide drive electronics control a voltage that is provided to an electro-optic waveguide beam steering device. The electro-optic waveguide beam steering device steers an outgoing optical beam to one of the one or more ground stations based on the voltage.

Optical XOR gate

DOEpatents

Vawter, G. Allen

2013-11-12

An optical XOR gate is formed as a photonic integrated circuit (PIC) from two sets of optical waveguide devices on a substrate, with each set of the optical waveguide devices including an electroabsorption modulator electrically connected in series with a waveguide photodetector. The optical XOR gate utilizes two digital optical inputs to generate an XOR function digital optical output. The optical XOR gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 .mu.m.

Optical NOR gate

DOEpatents

Skogen, Erik J [Albuquerque, NM; Tauke-Pedretti, Anna [Albuquerque, NM

2011-09-06

An optical NOR gate is formed from two pair of optical waveguide devices on a substrate, with each pair of the optical waveguide devices consisting of an electroabsorption modulator electrically connected in series with a waveguide photodetector. The optical NOR gate utilizes two digital optical inputs and a continuous light input to provide a NOR function digital optical output. The optical NOR gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 .mu.m.

Method and apparatus for use of III-nitride wide bandgap semiconductors in optical communications

DOEpatents

Hui, Rongqing [Lenexa, KS; Jiang, Hong-Xing [Manhattan, KS; Lin, Jing-Yu [Manhattan, KS

2008-03-18

The present disclosure relates to the use of III-nitride wide bandgap semiconductor materials for optical communications. In one embodiment, an optical device includes an optical waveguide device fabricated using a III-nitride semiconductor material. The III-nitride semiconductor material provides for an electrically controllable refractive index. The optical waveguide device provides for high speed optical communications in an infrared wavelength region. In one embodiment, an optical amplifier is provided using optical coatings at the facet ends of a waveguide formed of erbium-doped III-nitride semiconductor materials.

The hybrid photonic planar integrated receiver with a polymer optical waveguide

NASA Astrophysics Data System (ADS)

Busek, Karel; Jerábek, Vitezslav; Armas Arciniega, Julio; Prajzler, Václav

2008-11-01

This article describes design of the photonic receiver composed of the system polymer planar waveguides, InGaAs p-i-n photodiode and integrated HBT amplifier on a low loss composite substrate. The photonic receiver was the main part of the hybrid integrated microwave optoelectronic transceiver TRx (transciever TRx) for the optical networks PON (passive optical networks) with FTTH (fiber-to-the-home) topology. In this article are presented the research results of threedimensional field between output facet of a optical waveguide and p-i-n photodiode. In terms of our research, there was optimized the optical coupling among the facet waveguide and pi-n photodiode and the electrical coupling among p-i-n photodiode and input of HBT amplifier. The hybrid planar lightwave circuit (PLC) of the transceiver TRx will be composed from a two parts - polymer optical waveguide including VHGT filter section and a optoelectronic microwave section.

Optical waveguide circuit board with a surface-mounted optical receiver array

NASA Astrophysics Data System (ADS)

Thomson, J. E.; Levesque, Harold; Savov, Emil; Horwitz, Fred; Booth, Bruce L.; Marchegiano, Joseph E.

1994-03-01

A photonic circuit board is fabricated for potential application to interchip and interboard parallel optical links. The board comprises photolithographically patterned polymer optical waveguides on a conventional glass-epoxy electrical circuit board and a surface-mounted integrated circuit (IC) package that optically and electrically couples to an optoelectronic IC. The waveguide circuits include eight-channel arrays of straights, cross-throughs, curves, self- aligning interconnects to multi-fiber ribbon, and out-of-plane turning mirrors. A coherent, fused bundle of optical fibers couples light between 45-deg waveguide mirrors and a GaAs receiver array in the IC package. The fiber bundle is easily aligned to the mirrors and the receivers and is amenable to surface mounting and hermetic sealing. The waveguide-receiver- array board achieved error-free data rates up to 1.25 Gbits/s per channel, and modal noise was shown to be negligible.

Numerical model of the polymer electro-optic waveguide

NASA Astrophysics Data System (ADS)

Fan, Guofang; Li, Yuan; Han, Bing; Wang, Qi; Liu, Xinhou; Zhen, Zhen

2012-09-01

A numerical design model is presented for the polymer waveguide in an electro-optic modulator. The effective index method is used to analyze the height of the core waveguide and rib waveguide, an improved Marcatili method is presented to design the rib waveguide width in order to keep the strong single mode operation and have a good match with the standard fiber. Also, the thickness of the upper cladding layer is discussed through calculating the effective index of the multilayer planar waveguide structure has been obtained by setting the optical loss due to the metallic absorption to an acceptable value (<0.1 dB/cm). As a consequence, we take the EO polymer waveguide structure of UV15:CLD/APC:UFC170 as an example, an optimized design is reported.

On-chip generation of heralded photon-number states

NASA Astrophysics Data System (ADS)

Vergyris, Panagiotis; Meany, Thomas; Lunghi, Tommaso; Sauder, Gregory; Downes, James; Steel, M. J.; Withford, Michael J.; Alibart, Olivier; Tanzilli, Sébastien

2016-10-01

Beyond the use of genuine monolithic integrated optical platforms, we report here a hybrid strategy enabling on-chip generation of configurable heralded two-photon states. More specifically, we combine two different fabrication techniques, i.e., non-linear waveguides on lithium niobate for efficient photon-pair generation and femtosecond-laser-direct-written waveguides on glass for photon manipulation. Through real-time device manipulation capabilities, a variety of path-coded heralded two-photon states can be produced, ranging from product to entangled states. Those states are engineered with high levels of purity, assessed by fidelities of 99.5 ± 8% and 95.0 ± 8%, respectively, obtained via quantum interferometric measurements. Our strategy therefore stands as a milestone for further exploiting entanglement-based protocols, relying on engineered quantum states, and enabled by scalable and compatible photonic circuits.

On-chip generation of heralded photon-number states

PubMed Central

Vergyris, Panagiotis; Meany, Thomas; Lunghi, Tommaso; Sauder, Gregory; Downes, James; Steel, M. J.; Withford, Michael J.; Alibart, Olivier; Tanzilli, Sébastien

2016-01-01

Beyond the use of genuine monolithic integrated optical platforms, we report here a hybrid strategy enabling on-chip generation of configurable heralded two-photon states. More specifically, we combine two different fabrication techniques, i.e., non-linear waveguides on lithium niobate for efficient photon-pair generation and femtosecond-laser-direct-written waveguides on glass for photon manipulation. Through real-time device manipulation capabilities, a variety of path-coded heralded two-photon states can be produced, ranging from product to entangled states. Those states are engineered with high levels of purity, assessed by fidelities of 99.5 ± 8% and 95.0 ± 8%, respectively, obtained via quantum interferometric measurements. Our strategy therefore stands as a milestone for further exploiting entanglement-based protocols, relying on engineered quantum states, and enabled by scalable and compatible photonic circuits. PMID:27775062

Traveling-wave photodetector

DOEpatents

Hietala, V.M.; Vawter, G.A.

1993-12-14

The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size. 4 figures.

Traveling-wave photodetector

DOEpatents

Hietala, Vincent M.; Vawter, Gregory A.

1993-01-01

The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.

Anti resonant reflecting optical waveguide structure based on oxidized porous silicon for label free bio sensing applications

NASA Astrophysics Data System (ADS)

Haji, L.; Hiraoui, M.; Lorrain, N.; Guendouz, M.

2012-03-01

In this letter we report on the use of an electrochemical process for the fabrication of anti resonant reflecting optical waveguide based on oxidized porous silicon. This method is known to allow the formation of various photonic structures (Bragg mirror, microcavity), thanks to the easy and in situ modulation of the porosity and thus of the refractive index. Planar anti resonant reflecting optical waveguide structure made from porous silicon is demonstrated to be very effective for low losses as compared to conventional resonant waveguide. Optical measurements carried out for TE and TM polarizations are reported and related to optical sensing.

Optical properties of new wide heterogeneous waveguides with thermo optical shifters.

PubMed

De Leonardis, Francesco; Tsarev, Andrei V; Passaro, Vittorio M

2008-12-22

We present analysis and simulation of novel silicon-on-insulator (SOI) heterogeneous waveguides with thermo-optic phase shifters. New structure design contains a p-n junction on both sides of SOI ridge waveguide with 220 nm x 35 microm silicon core. Strongly mode-dependent optical losses (by additional free charge absorption) provide quasi-singe-mode behavior of wide waveguide with mode size approximately 10 microm. Local heater produces an efficient phase shifting by small temperature increase (DeltaT approximately 2K), switching power (< 40 mW) and switching time (< 10 micros). Mode optical losses are significantly decreased at high heating (DeltaT approximately 120 K).

Distributed meandering waveguides (DMWs) for novel photonic circuits (Conference Presentation)

NASA Astrophysics Data System (ADS)

Dag, Ceren B.; Anil, Mehmet Ali; Serpengüzel, Ali

2017-05-01

Meandering waveguide distributed feedback structures are novel integrated photonic lightwave and microwave circuit elements. Meandering waveguide distributed feedback structures with a variety of spectral responses can be designed for a variety of lightwave and microwave circuit element functions. Distributed meandering waveguide (DMW) structures [1] show a variety of spectral behaviors with respect to the number of meandering loop mirrors (MLMs) [2] used in their composition as well as their internal coupling constants (Cs). DMW spectral behaviors include Fano resonances, coupled resonator induced transparency (CRIT), notch, add-drop, comb, and hitless filters. What makes the DMW special is the self-coupling property intrinsic to the DMW's nature. The basic example of DMW's nature is motivated through the analogy between the so-called symmetric meandering resonator (SMR), which consists of two coupled MLMs, and the resonator enhanced Mach-Zehnder interferometer (REMZI) [3]. A SMR shows the same spectral characteristics of Fano resonances with its self-coupling property, similar to the single, distributed and binary self coupled optical waveguide (SCOW) resonators [4]. So far DMWs have been studied for their electric field intensity, phase [5] and phasor responses [6]. The spectral analysis is performed using the coupled electric field analysis and the generalization of single meandering loop mirrors to multiple meandering distributed feedback structures is performed with the transfer matrix method. The building block of the meandering waveguide structures, the meandering loop mirror (MLM), is the integrated analogue of the fiber optic loop mirrors. The meandering resonator (MR) is composed of two uncoupled MLM's. The meandering distributed feedback (MDFB) structure is the DFB of the MLM. The symmetric MR (SMR) is composed of two coupled MLM's, and has the characteristics of a Fano resonator in the general case, and tunable power divider or tunable hitless filter in special cases. The antisymmetric MR (AMR) is composed of two coupled MLM's. The AMR has the characteristics of an add-drop filter in the general case, and coupled resonator induced transparency (CRIT) filter in a special case. The symmetric MDFB (SMDFB) is composed of multiple coupled MLM's. The antisymmetric MDFB (AMDFB) is composed of multiple coupled MLM's. The SMDFB and AMDFB can be utilized as band-pass, Fano, or Lorentzian filters, or Rabi splitters. Distributed meandering waveguide elements with extremely rich spectral and phase responses can be designed with creative combinations of distributed meandering waveguides structures for various novel photonic circuits. References [1 ] C. B. Dağ, M. A. Anıl, and A. Serpengüzel, "Meandering Waveguide Distributed Feedback Lightwave Circuits," J. Lightwave Technol, vol. 33, no. 9, pp. 1691-1702, May 2015. [2] N. J. Doran and D. Wood, "Nonlinear-optical loop mirror," Opt. Lett. vol. 13, no. 1, pp. 56-58, Jan. 1988. [3] L. Zhou and A. W. Poon, "Fano resonance-based electrically reconfigurable add-drop filters in silicon microring resonator-coupled Mach-Zehnder interferometers," Opt. Lett. vol. 32, no. 7, pp. 781-783, Apr. 2007. [4] Z. Zou, L. Zhou, X. Sun, J. Xie, H. Zhu, L. Lu, X. Li, and J. Chen, "Tunable two-stage self-coupled optical waveguide resonators," Opt. Lett. vol. 38, no. 8, pp. 1215-1217, Apr. 2013. [5] C. B. Dağ, M. A. Anıl, and A. Serpengüzel, "Novel distributed feedback lightwave circuit elements," in Proc. SPIE, San Francisco, 2015, vol. 9366, p. 93660A. [6] C. B. Dağ, M. A. Anıl, and A. Serpengüzel, "Meandering Waveguide Distributed Feedback Lightwave Elements: Phasor Diagram Analysis," in Proc. PIERS, Prague, 1986-1990 (2015).

Periodic domain inversion in x-cut single-crystal lithium niobate thin film

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mackwitz, P., E-mail: peterm@mail.upb.de; Rüsing, M.; Berth, G.

2016-04-11

We report the fabrication of periodically poled domain patterns in x-cut lithium niobate thin-film. Here, thin films on insulator have drawn particular attention due to their intrinsic waveguiding properties offering high mode confinement and smaller devices compared to in-diffused waveguides in bulk material. In contrast to z-cut thin film lithium niobate, the x-cut geometry does not require back electrodes for poling. Further, the x-cut geometry grants direct access to the largest nonlinear and electro-optical tensor element, which overall promises smaller devices. The domain inversion was realized via electric field poling utilizing deposited aluminum top electrodes on a stack of LNmore » thin film/SiO{sub 2} layer/Bulk LN, which were patterned by optical lithography. The periodic domain inversion was verified by non-invasive confocal second harmonic microscopy. Our results show domain patterns in accordance to the electrode mask layout. The second harmonic signatures can be interpreted in terms of spatially, overlapping domain filaments which start their growth on the +z side.« less

Strong field localization in subwavelength metal-dielectric optical waveguides

NASA Astrophysics Data System (ADS)

Kozina, O. N.; Mel'Nikov, L. A.; Nefedov, I. S.

2011-08-01

Detailed calculations of eigenmodes of waveguiding structures made of silver and glass and containing coaxial cables with a nanoscale cross section of different configurations are conducted. In particular, the study focuses on optical coaxial waveguides with the core made in the form of a thin metallic cylinder filled with a dielectric. We show that these waveguides support relatively low-loss propagation of radiation that is strongly localized in the central region, has phase velocity approaching the speed of light and predominant electric-field orientation (dipole type). Optical characteristics of such waveguides are compared with those of coaxial-type waveguides containing a continuous central filament made of metal and with a multilayer structure. Using numeric modeling, we established that the proposed type of the waveguide enables the transmission of an optical image with relatively low losses with a submicron resolution over a distance considerably longer than its cross section. A typical propagation length in the waveguides based on silver and glass with the refractive index of about 1.5 at a wavelength of 500 nm is about 1700 nm.

Optofluidic waveguides: I. Concepts and implementations

PubMed Central

Schmidt, Holger; Hawkins, Aaron R.

2011-01-01

We review recent developments and current status of liquid-core optical waveguides in optofluidics with emphasis on suitability for creating fully planar optofluidic labs-on-a-chip. In this first of two contributions, we give an overview of the different waveguide types that are being considered for effectively combining micro and nanofluidics with integrated optics. The large number of approaches is separated into conventional index-guided waveguides and more recent implementations using wave interference. The underlying principle for waveguiding and the current status are described for each type. We then focus on reviewing recent work on microfabricated liquid-core antiresonant reflecting optical (ARROW) waveguides, including the development of intersecting 2D waveguide networks and optical fluorescence and Raman detection with planar beam geometry. Single molecule detection capability and addition of electrical control for electrokinetic manipulation and analysis of single bioparticles are demonstrated. The demonstrated performance of liquid-core ARROWs is representative of the potential of integrated waveguides for on-chip detection with ultrahigh sensitivity, and points the way towards the next generation of high-performance, low-cost and portable biomedical instruments. PMID:21442048

Optical pulling force and conveyor belt effect in resonator-waveguide system.

PubMed

Intaraprasonk, Varat; Fan, Shanhui

2013-09-01

We present the theoretical condition and actual numerical design that achieves an optical pulling force in resonator-waveguide systems, where the direction of the force on the resonator is in the opposite direction to the input light in the waveguide. We also show that this pulling force can occur in conjunction with the lateral optical equilibrium effect, such that the resonator is maintained at the fixed distance from the waveguide while experiencing the pulling force.

InGaAsP/InP optical waveguide switch operated by a carrier-induced change in the refractive index

NASA Astrophysics Data System (ADS)

Mikami, O.; Nakagome, H.

1985-11-01

Waveguided semiconductor optical switches operated by a carrier-induced change in the refractive-index associated with the plasma dispersion are proposed. InGaAsP/InP four-port switches having two intersecting single-mode channel waveguides are fabricated by selective liquid-phase epitaxy and investigated at 1.5 microns wavelength. Optical switching is observed as a result of mode interference in the waveguide intersection region.

Characterization of passive polymer optical waveguides

NASA Astrophysics Data System (ADS)

Joehnck, Matthias; Kalveram, Stefan; Lehmacher, Stefan; Pompe, Guido; Rudolph, Stefan; Neyer, Andreas; Hofstraat, Johannes W.

1999-05-01

The characterization of monomode passive polymer optical devices fabricated according to the POPCORN technology by methods originated from electron, ion and optical spectroscopy is summarized. Impacts of observed waveguide perturbations on the optical characteristics of the waveguide are evaluated. In the POPCORN approach optical components for telecommunication applications are fabricated by photo-curing of liquid halogenated (meth)acrylates which have been applied on moulded thermoplastic substrates. For tuning of waveguide material refractive indices with respect to the substrate refractive index frequently comonomer mixtures are used. The polymerization characteristics, especially the polymerization kinetics of individual monomers, determine the formation of copolymers. Therefore the unsaturation as function of UV-illumination time in the formation of halogenated homo- and copolymers has been examined. From different suitable copolymer system, after characterization of their glass transition temperatures, their curing behavior and their refractive indices as function of the monomer ratios, monomode waveguides applying PMMA substrates have been fabricated. To examine the materials composition also in the 6 X 6 micrometers 2 waveguides they have been visualized by transmission electron microscopy. With this method e.g. segregation phenomena could be observed in the waveguide cross section characterization as well. The optical losses in monomode waveguides caused by segregation and other materials induce defects like micro bubbles formed as a result of shrinkage have been quantized by return loss measurements. Defects causing scattering could be observed by convocal laser scanning microscopy and by conventional light microscopy.

INTEGRATED AND FIBER OPTICS: Threshold of photoinduced conversion of the polarization of radiation in lithium niobate optical waveguides

NASA Astrophysics Data System (ADS)

Kazanskiĭ, P. G.

1989-02-01

A threshold of photoinduced conversion of an ordinary wave into an extraordinary one was discovered for lithium niobate optical waveguides. The threshold intensity of the radiation was determined for waveguides prepared under different conditions. The experimental results were compared with theoretical estimates.

Photo-induced reduction of graphene oxide coating on optical waveguide and consequent optical intermodulation

PubMed Central

Chong, W. Y.; Lim, W. H.; Yap, Y. K.; Lai, C. K.; De La Rue, R. M.; Ahmad, H.

2016-01-01

Increased absorption of transverse-magnetic (TM) - polarised light by a graphene-oxide (GO) coated polymer waveguide has been observed in the presence of transverse-electric (TE) - polarised light. The GO-coated waveguide exhibits very strong photo-absorption of TE-polarised light - and acts as a TM-pass waveguide polariser. The absorbed TE-polarised light causes a significant temperature increase in the GO film and induces thermal reduction of the GO, resulting in an increase in optical-frequency conductivity and consequently increased optical propagation loss. This behaviour in a GO-coated waveguide gives the action of an inverted optical switch/modulator. By varying the incident TE-polarised light power, a maximum modulation efficiency of 72% was measured, with application of an incident optical power level of 57 mW. The GO-coated waveguide was able to respond clearly to modulated TE-polarised light with a pulse duration of as little as 100 μs. In addition, no wavelength dependence was observed in the response of either the modulation (TE-polarised light) or the signal (TM-polarised light). PMID:27034015

Linear integrated optics in 3C silicon carbide.

PubMed

Martini, Francesco; Politi, Alberto

2017-05-15

The development of new photonic materials that combine diverse optical capabilities is needed to boost the integration of different quantum and classical components within the same chip. Amongst all candidates, the superior optical properties of cubic silicon carbide (3C SiC) could be merged with its crystalline point defects, enabling single photon generation, manipulation and light-matter interaction on a single device. The development of photonics devices in SiC has been limited by the presence of the silicon substrate, over which thin crystalline films are heteroepitaxially grown. By employing a novel approach in the material fabrication, we demonstrate grating couplers with coupling efficiency reaching -6 dB, sub-µm waveguides and high intrinsic quality factor (up to 24,000) ring resonators. These components are the basis for linear optical networks and essential for developing a wide range of photonics component for non-linear and quantum optics.

Temporal waveguides for optical pulses

DOE PAGES

Plansinis, Brent W.; Donaldson, William R.; Agrawal, Govind P.

2016-05-12

Here we discuss, temporal total internal reflection (TIR), in analogy to the conventional TIR of an optical beam at a dielectric interface, is the total reflection of an optical pulse inside a dispersive medium at a temporal boundary across which the refractive index changes. A pair of such boundaries separated in time acts as the temporal analog of planar dielectric waveguides. We study the propagation of optical pulses inside such temporal waveguides, both analytically and numerically, and show that the waveguide supports a finite number of temporal modes. We also discuss how a single-mode temporal waveguide can be created inmore » practice. In contrast with the spatial case, the confinement can occur even when the central region has a lower refractive index.« less

WGM resonators for studying orbital angular momentum of a photon, and methods

NASA Technical Reports Server (NTRS)

Matsko, Andrey B. (Inventor); Savchenkov, Anatoliy A. (Inventor); Maleki, Lute (Inventor); Strekalov, Dmitry V. (Inventor)

2009-01-01

An optical system, device, and method that are capable of generating high-order Bessel beams and determining the orbital angular momentum of at least one of the photons of a Bessel beam are provided. The optical system and device include a tapered waveguide having an outer surface defined by a diameter that varies along a longitudinal axis of the waveguide from a first end to an opposing second end. The optical system and device include a resonator that is arranged in optical communication with the first end of the tapered waveguide such that an evanescent field emitted from (i) the waveguide can be coupled with the resonator, or (ii) the resonator can be coupled with the waveguide.

Proposal of ultra-compact NAND/NOR/XNOR all-optical logic gates based on a nonlinear 3x1 multimode interference

NASA Astrophysics Data System (ADS)

Tajaldini, Mehdi; Mat Jafri, M. Z.

2014-05-01

We present a highly miniaturized multimode interference (MMI) coupler based on nonlinear modal propagation analysis (NMPA) method as a novel design method and potential application for optical NAND, NOR and XNOR logic gates for Boolean logic signal processing devices. Crystalline polydiacetylene is used to allow the appearances of nonlinear effects in low input intensities and ultra- short length to control the MMI coupler as an active device to access light switching due to its high nonlinear susceptibility. We consider a 10x33 μm2 MMI structure with three inputs and one output. Notably, the access facets are single-mode waveguides with sub-micron width. The center input contributes to control the induced light propagation in MMI by intensity variation whereas others could be launched by particular intensity when they are ON and 0 in OFF. Output intensity is analyzed in various sets of inputs to show the capability of Boolean logic gates, the contrast between ON and OFF is calculated on mentioned gates to present the efficiency. Good operation in low intensity and highly miniaturized MMI coupler is observed. Furthermore, nonlinear effects could be realized through the modal interferences. The issue of high insertion loss is addressed with a 3×3 upgraded coupler. Furthermore, the main significant aspect of this paper is simulating an MMI coupler that is launched by three nonlinear inputs, simultaneously, whereas last presents have never studied more than one input in nonlinear regimes.

Transmission and correlation of a two-photon pulse in a one-dimensional waveguide coupled with quantum emitters

NASA Astrophysics Data System (ADS)

Hu, Qingmei; Zou, Bingsuo; Zhang, Yongyou

2018-03-01

Transmission and correlation properties of a two-photon pulse are studied in a one-dimensional waveguide (1DW) in the presence of three types of quantum emitters: two-level atom (TLA), side optical cavity (SOC), and Jaynes-Cummings model (JCM). Since there are many plane-wave components for a two-photon pulse, a nonlinear waveguide dispersion is used instead of the linearized one. The two-photon transmission spectra become flatter with decreasing the pulse width. With respect to the δ coupling between the 1DW and quantum emitter the transmission dips show a blueshift for the non-δ one and the blueshift first increases and then decreases with increasing the width of the coupling. The TLA and JCM can induce an effective photon-photon interaction that depends on the distance between the two photons, while the SOC cannot. We show that the 1DW coupled with the TLA or JCM is able to evaluate the overlap of the two photons and that the non-δ coupling has potential for controlling the two-photon correlation.

Nanocrystal waveguide (NOW) laser

DOEpatents

Simpson, John T.; Simpson, Marcus L.; Withrow, Stephen P.; White, Clark W.; Jaiswal, Supriya L.

2005-02-08

A solid state laser includes an optical waveguide and a laser cavity including at least one subwavelength mirror disposed in or on the optical waveguide. A plurality of photoluminescent nanocrystals are disposed in the laser cavity. The reflective subwavelength mirror can be a pair of subwavelength resonant gratings (SWG), a pair of photonic crystal structures (PC), or a distributed feedback structure. In the case of a pair of mirrors, a PC which is substantially transmissive at an operating wavelength of the laser can be disposed in the laser cavity between the subwavelength mirrors to improve the mode structure, coherence and overall efficiency of the laser. A method for forming a solid state laser includes the steps of providing an optical waveguide, creating a laser cavity in the optical waveguide by disposing at least one subwavelength mirror on or in the waveguide, and positioning a plurality of photoluminescent nanocrystals in the laser cavity.

Observation and investigation of narrow optical transitions of 167Er3+ ions in femtosecond laser printed waveguides in 7LiYF4 crystal

NASA Astrophysics Data System (ADS)

Minnegaliev, M. M.; Dyakonov, I. V.; Gerasimov, K. I.; Kalinkin, A. A.; Kulik, S. P.; Moiseev, S. A.; Saygin, M. Yu; Urmancheev, R. V.

2018-04-01

We produced optical waveguides in the 167Er3+:7 LiYF4 crystal with diameters ranging from 30 to 100 μm by using the depressed-cladding approach with femtosecond laser. Stationary and coherent spectroscopy was performed on the 809 nm optical transitions between the hyperfine sublevels of 4I15/2 and 4I9/2 multiplets of 167Er3+ ions both inside and outside of waveguides. It was found that the spectra of 167Er3+ were slightly broadened and shifted inside the waveguides compared to the bulk crystal spectra. We managed to observe a two-pulse photon echo on this transition and determined phase relaxation times for each waveguide. The experimental results show that the created crystal waveguides doped by rare-earth ions can be used in optical quantum memory and integrated quantum schemes.

Silicon-on-insulator multimode-interference waveguide-based arrayed optical tweezers (SMART) for two-dimensional microparticle trapping and manipulation.

PubMed

Lei, Ting; Poon, Andrew W

2013-01-28

We demonstrate two-dimensional optical trapping and manipulation of 1 μm and 2.2 μm polystyrene particles in an 18 μm-thick fluidic cell at a wavelength of 1565 nm using the recently proposed Silicon-on-insulator Multimode-interference (MMI) waveguide-based ARrayed optical Tweezers (SMART) technique. The key component is a 100 μm square-core silicon waveguide with mm length. By tuning the fiber-coupling position at the MMI waveguide input facet, we demonstrate various patterns of arrayed optical tweezers that enable optical trapping and manipulation of particles. We numerically simulate the physical mechanisms involved in the arrayed trap, including the optical force, the heat transfer and the thermal-induced microfluidic flow.

Stokes solitons in optical microcavities

NASA Astrophysics Data System (ADS)

Yang, Qi-Fan; Yi, Xu; Yang, Ki Youl; Vahala, Kerry

2017-01-01

Solitons are wave packets that resist dispersion through a self-induced potential well. They are studied in many fields, but are especially well known in optics on account of the relative ease of their formation and control in optical fibre waveguides. Besides their many interesting properties, solitons are important to optical continuum generation, in mode-locked lasers, and have been considered as a natural way to convey data over great distances. Recently, solitons have been realized in microcavities, thereby bringing the power of microfabrication methods to future applications. This work reports a soliton not previously observed in optical systems, the Stokes soliton. The Stokes soliton forms and regenerates by optimizing its Raman interaction in space and time within an optical potential well shared with another soliton. The Stokes and the initial soliton belong to distinct transverse mode families and benefit from a form of soliton trapping that is new to microcavities and soliton lasers in general. The discovery of a new optical soliton can impact work in other areas of photonics, including nonlinear optics and spectroscopy.

FIBER AND INTEGRATED OPTICS: New method for determination of the parameters of a channel waveguide

NASA Astrophysics Data System (ADS)

Galechyan, M. G.; Dianov, Evgenii M.; Lyndin, N. M.; Sychugov, V. A.; Tishchenko, A. V.; Usievich, B. A.

1992-02-01

A new method for the determination of the parameters of channel integrated optical waveguides is proposed. This method is based on measuring the spectral transmission of a system comprising the investigated waveguide and single-mode fiber waveguides, which are brought into contact with the channel waveguide. The results are reported of an investigation of two channel waveguides formed in glass by a variety of methods and characterized by different refractive index profiles. The proposed method is found to be suitable for determination of the parameters of the refractive index profile of the investigated channel waveguides.

Optical-analog-to-digital conversion based on successive-like approximations in octagonal-shape photonic crystal ring resonators

NASA Astrophysics Data System (ADS)

Tavousi, A.; Mansouri-Birjandi, M. A.

2018-02-01

Implementing intensity-dependent Kerr-like nonlinearity in octagonal-shape photonic crystal ring resonators (OSPCRRs), a new class of optical analog-to-digital converters (ADCs) with low power consumption is presented. Due to its size dependent refractive index, Silicon (Si) nanocrystal is used as nonlinear medium in the proposed ADC. Coding system of optical ADC is based on successive-like approximations which requires only one quantization level to represent each single bit, despite of conventional ADCs that require at least two distinct levels for each bit. Each is representing bit of optical ADC is formed by vertically alignment of double rings of OSPCRRs (DR-OSPCRR) and cascading m number of DR-OSPCRR, forms an m bit ADC. Investigating different parameters of DR-OSPCRR such as refractive indices of rings, lattice refractive index, and coupling coefficients of waveguide-to-ring and ring-to-ring, the ADC's threshold power is tuned. Increasing the number of bits of ADC, increases the overall power consumption of ADC. One can arrange to have any number of bits for this ADC, as long as the power levels are treated carefully. Finite difference time domain (FDTD) in-house codes were used to evaluate the ADC's effectiveness.

Waveguide device and method for making same

DOEpatents

Forman, Michael A [San Francisco, CA

2007-08-14

A monolithic micromachined waveguide device or devices with low-loss, high-power handling, and near-optical frequency ranges is set forth. The waveguide and integrated devices are capable of transmitting near-optical frequencies due to optical-quality sidewall roughness. The device or devices are fabricated in parallel, may be mass produced using a LIGA manufacturing process, and may include a passive component such as a diplexer and/or an active capping layer capable of particularized signal processing of the waveforms propagated by the waveguide.

Transverse writing of three-dimensional tubular optical waveguides in glass with a slit-shaped femtosecond laser beam

PubMed Central

Liao, Yang; Qi, Jia; Wang, Peng; Chu, Wei; Wang, Zhaohui; Qiao, Lingling; Cheng, Ya

2016-01-01

We report on fabrication of tubular optical waveguides buried in ZBLAN glass based on transverse femtosecond laser direct writing. Irradiation in ZBLAN with focused femtosecond laser pulses leads to decrease of refractive index in the modified region. Tubular optical waveguides of variable mode areas are fabricated by forming the four sides of the cladding with slit-shaped femtosecond laser pulses, ensuring single mode waveguiding with a mode field dimension as small as ~4 μm. PMID:27346285

Low-cost integrated-optic fiber couplers

NASA Astrophysics Data System (ADS)

Sheem, Sang K.; Zhang, Feng; Choi, Jong-Ho; Lee, Yong-Woo; Low, Sarah; Lu, Shih-Yau

1997-04-01

In an effort to lower the cost of fiber optic couplers, integrated optic channel waveguide circuits are made of a UV-curable polymer using a molding technique, and then a novel fiber-to-channel connecting approach is employed in which UV light radiating from an optical fiber core cures the polymer in the channel, thus accomplishing a 'touchdown' of the core-extension waveguide onto the walls of the channel waveguide.

Raman Amplification and Tunable Pulse Delays in Silicon Waveguides

NASA Astrophysics Data System (ADS)

Rukhlenko, Ivan D.; Garanovich, Ivan L.; Premaratne, Malin; Sukhorukov, Andrey A.; Agrawal, Govind P.

2010-10-01

The nonlinear process of stimulated Raman scattering is important for silicon photonics as it enables optical amplification and lasing. However, generally employed numerical approaches provide very little insight into the contribution of different silicon Raman amplifier (SRA) parameters. In this paper, we solve the coupled pump-signal equations analytically and derive an exact formula for the envelope of a signal pulse when picosecond optical pulses are amplified inside a SRA pumped by a continuous-wave laser beam. Our solution is valid for an arbitrary pulse shape and fully accounts for the Raman gain-dispersion effects, including temporal broadening and group-velocity reduction. Our results are useful for optimizing the performance of SRAs and for engineering controllable signal delays.

Roughness measurements on coupling structures for optical interconnections integrated on a printed circuit board

NASA Astrophysics Data System (ADS)

Hendrickx, Nina; Van Erps, Jürgen; Suyal, Himanshu; Taghizadeh, Mohammad; Thienpont, Hugo; Van Daele, Peter

2006-04-01

In this paper, laser ablation (at UGent), deep proton writing (at VUB) and laser direct writing (at HWU) are presented as versatile technologies that can be used for the fabrication of coupling structures for optical interconnections integrated on a printed circuit board (PCB). The optical layer, a highly cross-linked acrylate based polymer, is applied on an FR4 substrate. Both laser ablation and laser direct writing are used for the definition of arrays of multimode optical waveguides, which guide the light in the plane of the optical layer. In order to couple light vertically in/out of the plane of the optical waveguides, coupling structures have to be integrated into the optical layer. Out-of-plane turning mirrors, that deflect the light beam over 90°, are used for this purpose. The surface roughness and angle of three mirror configurations are evaluated: a laser ablated one that is integrated into the optical waveguide, a laser direct written one that is also directly written onto the waveguide and a DPW insert that is plugged into a cavity into the waveguiding layer.

Polymer multimode waveguide optical and electronic PCB manufacturing

NASA Astrophysics Data System (ADS)

Selviah, David R.

2009-02-01

The paper describes the research in the Â#1.3 million IeMRC Integrated Optical and Electronic Interconnect PCB Manufacturing (OPCB) Flagship Project in which 8 companies and 3 universities carry out collaborative research and which was formed and is technically led by the author. The consortium's research is aimed at investigating a range of fabrication techniques, some established and some novel, for fabricating polymer multimode waveguides from several polymers, some formulations of which are being developed within the project. The challenge is to develop low cost waveguide manufacturing techniques compatible with commercial PCB manufacturing and to reduce their alignment cost. The project aims to take the first steps in making this hybrid optical waveguide and electrical copper track printed circuit board disruptive technology widely available by establishing and incorporating waveguide design rules into commercial PCB layout software and transferring the technology for fabricating such boards to a commercial PCB manufacturer. To focus the research the project is designing an optical waveguide backplane to tight realistic constraints, using commercial layout software with the new optical design rules, for a demonstrator into which 4 daughter cards are plugged, each carrying an aggregate of 80 Gb/s data so that each waveguide carries 10 Gb/s.

Optical Waveguides Written in Silicon with Femtosecond Laser

NASA Astrophysics Data System (ADS)

Pavlov, Ihor; Tokel, Onur; Pavlova, Svitlana; Kadan, Viktor; Makey, Ghaith; Turnali, Ahmed; Ilday, Omer

Silicon is one of the most widely used materials in modern technology, ranging from electronics and Si-photonics to microfluidic and sensor applications. Despite the long history of Si-based devices, and the strong demand for opto-electronical integration, 3D Si laser processing technology is still challenging. Recently, nanosecond-pulsed laser was used to fabricate embedded holographic elements in Si. However, until now, there was no demonstration of femtosecond-laser-written optical elements inside Si. In this paper, we present optical waveguides written deep inside Si with 1.5 um femtosecond laser. The laser beam, with 2 uJ pulse energy and 350 fs pulse duration focused inside Si sample, produces permanent modification of Si. By moving the lens along the beam direction we were able to produce optical waveguides up to 5 mm long. The diameter of the waveguide is measured to be 10 um. The waveguides were characterized with both optical shadowgraphy and far field imaging after CW light coupling. We observed nearly single mode propagation of light inside of the waveguide. The obtained difference of refractive index inside of the waveguide, is 2.5*10-4. TUBITAK Grant 113M930, TUBITAK Grant 114F256.

Exact semi-separation of variables in waveguides with non-planar boundaries

NASA Astrophysics Data System (ADS)

Athanassoulis, G. A.; Papoutsellis, Ch. E.

2017-05-01

Series expansions of unknown fields Φ =∑φn Zn in elongated waveguides are commonly used in acoustics, optics, geophysics, water waves and other applications, in the context of coupled-mode theories (CMTs). The transverse functions Zn are determined by solving local Sturm-Liouville problems (reference waveguides). In most cases, the boundary conditions assigned to Zn cannot be compatible with the physical boundary conditions of Φ, leading to slowly convergent series, and rendering CMTs mild-slope approximations. In the present paper, the heuristic approach introduced in Athanassoulis & Belibassakis (Athanassoulis & Belibassakis 1999 J. Fluid Mech. 389, 275-301) is generalized and justified. It is proved that an appropriately enhanced series expansion becomes an exact, rapidly convergent representation of the field Φ, valid for any smooth, non-planar boundaries and any smooth enough Φ. This series expansion can be differentiated termwise everywhere in the domain, including the boundaries, implementing an exact semi-separation of variables for non-separable domains. The efficiency of the method is illustrated by solving a boundary value problem for the Laplace equation, and computing the corresponding Dirichlet-to-Neumann operator, involved in Hamiltonian equations for nonlinear water waves. The present method provides accurate results with only a few modes for quite general domains. Extensions to general waveguides are also discussed.

Nonlinear equation of the modes in circular slab waveguides and its application.

PubMed

Zhu, Jianxin; Zheng, Jia

2013-11-20

In this paper, circularly curved inhomogeneous waveguides are transformed into straight inhomogeneous waveguides first by a conformal mapping. Then, the differential transfer matrix method is introduced and adopted to deduce the exact dispersion relation for modes. This relation itself is complex and difficult to solve, but it can be approximated by a simpler nonlinear equation in practical applications, which is close to the exact relation and quite easy to analyze. Afterward, optimized asymptotic solutions are obtained and act as initial guesses for the following Newton's iteration. Finally, very accurate solutions are achieved in the numerical experiment.

Directional emissivity from two-dimensional infrared waveguide arrays

NASA Astrophysics Data System (ADS)

Burckel, D. Bruce; Davids, Paul S.; Finnegan, Patrick S.; Figueiredo, Pedro N.; Ginn, James C.

2015-09-01

Fabrication and optical characterization of surfaces covered with open-ended metallic waveguides are presented along with numerical modeling of these structures. Both modeling and measurement of the structures indicate that the 2-D array of 3D metallic waveguides modify both the direction and spectral content of the emissivity, resulting in directionality normal to the surface due to the optical axis of the waveguides and spectrally narrow emissivity due to the lateral dimensions of the waveguides. Furthermore, the optical behavior of these structures is placed in the broader context of other structured emission/absorption surfaces such as organ pipe modes, surface plasmon modes, and coherent thermal emission from gratings.

Electro-Optic Analog/Digital Converter.

DTIC Science & Technology

electro - optic material and a source of linearly polarized light is arranged to transmit its light energy along each of the optical waveguides. Electrodes are disposed contiguous to the optical waveguides for impressing electric fields thereacross. An input signal potential is applied to the electrodes to produce electric fields of intensity relative to each of the waveguides such that causes phase shift and resultant change of polarization which can be detected as representative of a binary ’one’ or binary ’zero’ for each of the channel optical

Resonant optical device with a microheater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lentine, Anthony L.; DeRose, Christopher

2017-04-04

A resonant photonic device is provided. The device comprises an optical waveguiding element, such as an optical resonator, that includes a diode junction region, two signal terminals configured to apply a bias voltage across the junction region, and a heater laterally separated from the optical waveguiding element. A semiconductor electrical barrier element is juxtaposed to the heater. A metallic strip is electrically and thermally connected at one end to a signal terminal of the optical waveguiding element and thermally connected at another end to the barrier element.

FIBER AND INTEGRATED OPTICS: Matching of fiber and strip optical waveguides by graded-index optical matching components

NASA Astrophysics Data System (ADS)

Shmal'ko, A. V.; Gordova, M. R.; Lamekin, V. F.; Nikolaev, I. V.; Sakharov, V. V.; Smirnov, V. L.; Polyantsev, A. S.

1990-01-01

A method for selection and calculation of the parameters of axisymmetric and anamorphic graded-index lenses for optical matching devices is developed and tested. These devices are intended for detachable connectors joining single-mode fibers to strip optical waveguides and are characterized by a greater tolerance to a mismatch between these waveguides. An experimental study is reported of a prototype of an optical matching device based on graded-index lenses characterized by insertion losses from 1-3 dB.

Polymer taper bridge for silicon waveguide to single mode waveguide coupling

NASA Astrophysics Data System (ADS)

Kruse, Kevin; Middlebrook, Christopher T.

2016-03-01

Coupling of optical power from high-density silicon waveguides to silica optical fibers for signal routing can incur high losses and often requires complex end-face preparation/processing. Novel coupling device taper structures are proposed for low coupling loss between silicon photonic waveguides and single mode fibers are proposed and devices are fabricated and measured in terms of performance. Theoretical mode conversion models for waveguide tapers are derived for optimal device structure design and performance. Commercially viable vertical and multi-layer taper designs using polymer waveguide materials are proposed as innovative, cost-efficient, and mass-manufacturable optical coupling devices. The coupling efficiency for both designs is determined to evaluate optimal device dimensions and alignment tolerances with both silicon rib waveguides and silicon nanowire waveguides. Propagation loss as a function of waveguide roughness and metallic loss are determined and correlated to waveguide dimensions to obtain total insertion loss for the proposed taper designs. Multi-layer tapers on gold-sputtered substrates are fabricated through photolithography as proof-of-concept devices and evaluated for device loss optimization. Tapered waveguide coupling loss with Si WGs (2.74 dB) was experimentally measured with high correlation to theoretical results.

Chemical Sensors Based on Optical Ring Resonators

NASA Technical Reports Server (NTRS)

Homer, Margie; Manfreda, Allison; Mansour, Kamjou; Lin, Ying; Ksendzov, Alexander

2005-01-01

Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong evanescent-wave coupling between the outer polymer layer and the electromagnetic field propagating along the waveguide core. By virtue of this coupling, the chemically induced change in index of refraction of the polymer causes a measurable shift in the resonance peaks of the ring. In a prototype that has been used to demonstrate the feasibility of this sensor concept, the ring resonator is a dielectric optical waveguide laid out along a closed path resembling a racetrack (see Figure 1). The prototype was fabricated on a silicon substrate by use of standard techniques of thermal oxidation, chemical vapor deposition, photolithography, etching, and spin coating. The prototype resonator waveguide features an inner cladding of SiO2, a core of SixNy, and a chemical-sensing outer cladding of ethyl cellulose. In addition to the ring Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong evanescent-wave coupling between the outer polymer layer and the electromagnetic field propagating along the waveguide core. By virtue of this coupling, the chemically induced change in index of refraction of the polymer causes a measurable shift in the resonance peaks of the ring. In a prototype that has been used to demonstrate the feasibility of this sensor concept, the ring resonator is a dielectric optical waveguide laid out along a closed path resembling a racetrack (see Figure 1). The prototype was fabricated on a silicon substrate by use of standard techniques of thermal oxidation, chemical vapor deposition, photolithography, etching, and spin coating. The prototype resonator waveguide features an inner cladding of SiO2, a core of SixNy, and a chemical-sensing outer cladding of ethyl cellulose. In addition to the ring res

Long-period fiber phase grating devices

NASA Astrophysics Data System (ADS)

Stegall, David Brian

In recent years, the explosive growth of the internet has virtually surpassed the limits of the global communications infrastructure. As a result, the fiber- optic communications industry is spearheading research and development to transmit information at ever increasing rates and over longer distances. The industry faces several obstacles to improving the performance of these systems. One problem is dispersion, which manifests at faster transmission rates when pulse spreading and distortion scramble the signal. Furthermore, high transmission powers needed for longer distances introduce deleterious optical nonlinearity phenomenon. Several waveguide and bulk devices have been implemented to address these issues, but each have shortcomings. Many of these problems and challenges have also impacted other fiber-optic industries, such as sensor systems. Long- period optical fiber gratings pose simple solutions to these problems and offer novel applications previously impractical through any other means. In this dissertation, research is presented in which modeling and fabrication of long-period gratings is improved over existing techniques by incorporating the effects of waveguide dispersion. An arbitrary dispersion also can be introduced into a long-period grating intentionally and a theoretical examination is made relating the chirp of a long-period grating and the resulting dispersion. In addition, several device applications such as a biological sensor and the concept of an actively controlled transmission spectrum of a long-period grating are explored. Finally, multiple in-series Bragg and long- period gratings are investigated for novel device configurations.

FIBER AND INTEGRATED OPTICS: Integrated optical passive ring resonator for optical gyroscopes

NASA Astrophysics Data System (ADS)

Baĭborodin, Yu V.; Dyadin, S. S.; Lyadenko, A. F.; Mashchenko, A. I.; Ul'yanov, I. A.; Fatin, Yu L.

1992-02-01

A passive ring resonator based on channel waveguides, formed in a K8 glass substrate by diffusion ion exchange in molten potassium nitrate, was made and investigated. The waveguide structure of the resonator included a ring waveguide as well as two Y-type couplers, whose symmetric arms were coupled to the ring waveguide, whereas homogeneous arms were coupled to an external laser and a photodetector. The coupling of the external devices to the channel waveguides was implemented by prisms and butt (end face) contacts. The transfer function of the ring resonator was determined experimentally in order to illustrate its resonant properties and sharpness. Estimates were obtained of the ultimate sensitivity of an optical gyroscope utilizing a ring resonator with the properties described above and ways of improving this sensitivity were analyzed.

Dynamics of nonlinear Schrödinger breathers in a potential trap

NASA Astrophysics Data System (ADS)

Malomed, B. A.; Rosanov, N. N.; Fedorov, S. V.

2018-05-01

We consider the evolution of the 2-soliton (breather) of the nonlinear Schrödinger equation on a semi-infinite line with the zero boundary condition and a linear potential, which corresponds to the gravity field in the presence of a hard floor. This setting can be implemented in atomic Bose-Einstein condensates, and in a nonlinear planar waveguide in optics. In the absence of the gravity, repulsion of the breather from the floor leads to its splitting into constituent fundamental solitons, if the initial distance from the floor is smaller than a critical value; otherwise, the moving breather persists. In the presence of gravity, the breather always splits into a pair of "co-hopping" fundamental solitons, which may be frequency locked in the form of a quasi-breather, or unlocked, forming an incoherent pseudo-breather. Some essential results are obtained in an analytical form, in addition to the systematic numerical investigation.

Surface transport and stable trapping of particles and cells by an optical waveguide loop.

PubMed

Hellesø, Olav Gaute; Løvhaugen, Pål; Subramanian, Ananth Z; Wilkinson, James S; Ahluwalia, Balpreet Singh

2012-09-21

Waveguide trapping has emerged as a useful technique for parallel and planar transport of particles and biological cells and can be integrated with lab-on-a-chip applications. However, particles trapped on waveguides are continuously propelled forward along the surface of the waveguide. This limits the practical usability of the waveguide trapping technique with other functions (e.g. analysis, imaging) that require particles to be stationary during diagnosis. In this paper, an optical waveguide loop with an intentional gap at the centre is proposed to hold propelled particles and cells. The waveguide acts as a conveyor belt to transport and deliver the particles/cells towards the gap. At the gap, the diverging light fields hold the particles at a fixed position. The proposed waveguide design is numerically studied and experimentally implemented. The optical forces on the particle at the gap are calculated using the finite element method. Experimentally, the method is used to transport and trap micro-particles and red blood cells at the gap with varying separations. The waveguides are only 180 nm thick and thus could be integrated with other functions on the chip, e.g. microfluidics or optical detection, to make an on-chip system for single cell analysis and to study the interaction between cells.

Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities

PubMed Central

Reardon, Christopher Paul; Rey, Isabella H.; Welna, Karl; O'Faolain, Liam; Krauss, Thomas F.

2012-01-01

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view and for its considerable potential for practical applications. Slow light photonic crystal waveguides, in particular, have played a major part and have been successfully employed for delaying optical signals1-4 and the enhancement of both linear5-7 and nonlinear devices.8-11 Photonic crystal cavities achieve similar effects to that of slow light waveguides, but over a reduced band-width. These cavities offer high Q-factor/volume ratio, for the realization of optically12 and electrically13 pumped ultra-low threshold lasers and the enhancement of nonlinear effects.14-16 Furthermore, passive filters17 and modulators18-19 have been demonstrated, exhibiting ultra-narrow line-width, high free-spectral range and record values of low energy consumption. To attain these exciting results, a robust repeatable fabrication protocol must be developed. In this paper we take an in-depth look at our fabrication protocol which employs electron-beam lithography for the definition of photonic crystal patterns and uses wet and dry etching techniques. Our optimised fabrication recipe results in photonic crystals that do not suffer from vertical asymmetry and exhibit very good edge-wall roughness. We discuss the results of varying the etching parameters and the detrimental effects that they can have on a device, leading to a diagnostic route that can be taken to identify and eliminate similar issues. The key to evaluating slow light waveguides is the passive characterization of transmission and group index spectra. Various methods have been reported, most notably resolving the Fabry-Perot fringes of the transmission spectrum20-21 and interferometric techniques.22-25 Here, we describe a direct, broadband measurement technique combining spectral interferometry with Fourier transform analysis.26 Our method stands out for its simplicity and power, as we can characterise a bare photonic crystal with access waveguides, without need for on-chip interference components, and the setup only consists of a Mach-Zehnder interferometer, with no need for moving parts and delay scans. When characterising photonic crystal cavities, techniques involving internal sources21 or external waveguides directly coupled to the cavity27 impact on the performance of the cavity itself, thereby distorting the measurement. Here, we describe a novel and non-intrusive technique that makes use of a cross-polarised probe beam and is known as resonant scattering (RS), where the probe is coupled out-of plane into the cavity through an objective. The technique was first demonstrated by McCutcheon et al.28 and further developed by Galli et al.29 PMID:23222804

Investigation of semiconductor clad optical waveguides

NASA Technical Reports Server (NTRS)

Batchman, T. E.; Carson, R. F.

1985-01-01

A variety of techniques have been proposed for fabricating integrated optical devices using semiconductors, lithium niobate, and glasses as waveguides and substrates. The use of glass waveguides and their interaction with thin semiconductor cladding layers was studied. Though the interactions of these multilayer waveguide structures have been analyzed here using glass, they may be applicable to other types of materials as well. The primary reason for using glass is that it provides a simple, inexpensive way to construct waveguides and devices.

Integrated optical dipole trap for cold neutral atoms with an optical waveguide coupler

NASA Astrophysics Data System (ADS)

Lee, J.; Park, D. H.; Mittal, S.; Dagenais, M.; Rolston, S. L.

2013-04-01

An integrated optical dipole trap uses two-color (red and blue-detuned) traveling evanescent wave fields for trapping cold neutral atoms. To achieve longitudinal confinement, we propose using an integrated optical waveguide coupler, which provides a potential gradient along the beam propagation direction sufficient to confine atoms. This integrated optical dipole trap can support an atomic ensemble with a large optical depth due to its small mode area. Its quasi-TE0 waveguide mode has an advantage over the HE11 mode of a nanofiber, with little inhomogeneous Zeeman broadening at the trapping region. The longitudinal confinement eliminates the need for a one dimensional optical lattice, reducing collisional blockaded atomic loading, potentially producing larger ensembles. The waveguide trap allows for scalability and integrability with nano-fabrication technology. We analyze the potential performance of such integrated atom traps.

Quantum correlations in microwave frequency combs

NASA Astrophysics Data System (ADS)

Weissl, Thomas; Jolin, Shan W.; Haviland, David B.; Department of Applied Physics Team

Non-linear superconducting resonators are used as parametric amplifiers in circuit quantum electrodynamics experiments. When a strong pump is applied to a non-linear microwave oscillator, it correlates vacuum fluctuations at signal and idler frequencies symmetrically located around the pump, resulting in two-mode squeezed vacuum. When the non-linear oscillator is pumped with a frequency comb, complex multipartite entangled states can be created as demonstrated with experiments in the optical domain. Such cluster states are considered to be a universal resource for one-way quantum computing. With our microwave measurement setup it is possible to pump and measure response at as many as 42 frequencies in parallel, with independent control over all pump amplitudes and phases. We show results of two-mode squeezing for of pairs of tones in a microwave frequency comb. The squeezing is created by four-wave mixing of a pump tone applied to a non-linear coplanar-waveguide resonator. We acknowledge financial support from the Knut and Alice Wallenberg foundation.

Integrated optical tamper sensor with planar waveguide

DOEpatents

Carson, Richard F.; Casalnuovo, Stephen A.

1993-01-01

A monolithic optical tamper sensor, comprising an optical emitter and detector, connected by an optical waveguide and placed into the critical entry plane of an enclosed sensitive region, the tamper sensor having a myriad of scraps of a material optically absorbent at the wavelength of interest, such that when the absorbent material is in place on the waveguide, an unique optical signature can be recorded, but when entry is attempted into the enclosed sensitive region, the scraps of absorbent material will be displaced and the optical/electrical signature of the tamper sensor will change and that change can be recorded.

Integrated optical tamper sensor with planar waveguide

DOEpatents

Carson, R.F.; Casalnuovo, S.A.

1993-01-05

A monolithic optical tamper sensor, comprising an optical emitter and detector, connected by an optical waveguide and placed into the critical entry plane of an enclosed sensitive region, the tamper sensor having a myriad of scraps of a material optically absorbent at the wavelength of interest, such that when the absorbent material is in place on the waveguide, an unique optical signature can be recorded, but when entry is attempted into the enclosed sensitive region, the scraps of absorbent material will be displaced and the optical/electrical signature of the tamper sensor will change and that change can be recorded.

Polymer waveguides for electro-optical integration in data centers and high-performance computers.

PubMed

Dangel, Roger; Hofrichter, Jens; Horst, Folkert; Jubin, Daniel; La Porta, Antonio; Meier, Norbert; Soganci, Ibrahim Murat; Weiss, Jonas; Offrein, Bert Jan

2015-02-23

To satisfy the intra- and inter-system bandwidth requirements of future data centers and high-performance computers, low-cost low-power high-throughput optical interconnects will become a key enabling technology. To tightly integrate optics with the computing hardware, particularly in the context of CMOS-compatible silicon photonics, optical printed circuit boards using polymer waveguides are considered as a formidable platform. IBM Research has already demonstrated the essential silicon photonics and interconnection building blocks. A remaining challenge is electro-optical packaging, i.e., the connection of the silicon photonics chips with the system. In this paper, we present a new single-mode polymer waveguide technology and a scalable method for building the optical interface between silicon photonics chips and single-mode polymer waveguides.

Theory and design of nonlinear metamaterials

NASA Astrophysics Data System (ADS)

Rose, Alec Daniel

If electronics are ever to be completely replaced by optics, a significant possibility in the wake of the fiber revolution, it is likely that nonlinear materials will play a central and enabling role. Indeed, nonlinear optics is the study of the mechanisms through which light can change the nature and properties of matter and, as a corollary, how one beam or color of light can manipulate another or even itself within such a material. However, of the many barriers preventing such a lofty goal, the narrow and limited range of properties supported by nonlinear materials, and natural materials in general, stands at the forefront. Many industries have turned instead to artificial and composite materials, with homogenizable metamaterials representing a recent extension of such composites into the electromagnetic domain. In particular, the inclusion of nonlinear elements has caused metamaterials research to spill over into the field of nonlinear optics. Through careful design of their constituent elements, nonlinear metamaterials are capable of supporting an unprecedented range of interactions, promising nonlinear devices of novel design and scale. In this context, I cast the basic properties of nonlinear metamaterials in the conventional formalism of nonlinear optics. Using alternately transfer matrices and coupled mode theory, I develop two complementary methods for characterizing and designing metamaterials with arbitrary nonlinear properties. Subsequently, I apply these methods in numerical studies of several canonical metamaterials, demonstrating enhanced electric and magnetic nonlinearities, as well as predicting the existence of nonlinear magnetoelectric and off-diagonal nonlinear tensors. I then introduce simultaneous design of the linear and nonlinear properties in the context of phase matching, outlining five different metamaterial phase matching methods, with special emphasis on the phase matching of counter propagating waves in mirrorless parametric amplifiers and oscillators. By applying this set of tools and knowledge to microwave metamaterials, I experimentally confirm several novel nonlinear phenomena. Most notably, I construct a backward wave nonlinear medium from varactor-loaded split ring resonators loaded in a rectangular waveguide, capable of generating second-harmonic opposite to conventional nonlinear materials with a conversion efficiency as high as 1.5%. In addition, I confirm nonlinear magnetoelectric coupling in two dual gap varactor-loaded split ring resonator metamaterials through measurement of the amplitude and phase of the second-harmonic generated in the forward and backward directions from a thin slab. I then use the presence of simultaneous nonlinearities in such metamaterials to observe nonlinear interference, manifest as unidirectional difference frequency generation with contrasts of 6 and 12 dB in the forward and backward directions, respectively. Finally, I apply these principles and intuition to several plasmonic platforms with the goal of achieving similar enhancements and configurations at optical frequencies. Using the example of fluorescence enhancement in optical patch antennas, I develop a semi-classical numerical model for the calculation of field-induced enhancements to both excitation and spontaneous emission rates of an embedded fluorophore, showing qualitative agreement with experimental results, with enhancement factors of more than 30,000. Throughout these series of works, I emphasize the indispensability of effective design and retrieval tools in understanding and optimizing both metamaterials and plasmonic systems. Ultimately, when weighed against the disadvantages in fabrication and optical losses, the results presented here provide a context for the application of nonlinear metamaterials within three distinct areas where a competitive advantage over conventional materials might be obtained: fundamental science demonstrations, linear and nonlinear anisotropy engineering, and extremely compact resonant all-optical devices.

On-chip optical mode conversion based on dynamic grating in photonic-phononic hybrid waveguide

PubMed Central

Chen, Guodong; Zhang, Ruiwen; Sun, Junqiang

2015-01-01

We present a scheme for reversible and tunable on-chip optical mode conversion based on dynamic grating in a hybrid photonic-phononic waveguide. The dynamic grating is built up through the acousto-optic effect and the theoretical model of the optical mode conversion is developed by considering the geometrical deformation and refractive index change. Three kinds of mode conversions are able to be realized using the same hybrid waveguide structure in a large bandwidth by only changing the launched acoustic frequency. The complete mode conversion can be achieved by choosing a proper acoustic power under a given waveguide length. PMID:25996236

Optofluidic waveguide as a transformation optics device for lightwave bending and manipulation.

PubMed

Yang, Y; Liu, A Q; Chin, L K; Zhang, X M; Tsai, D P; Lin, C L; Lu, C; Wang, G P; Zheludev, N I

2012-01-31

Transformation optics represents a new paradigm for designing light-manipulating devices, such as cloaks and field concentrators, through the engineering of electromagnetic space using materials with spatially variable parameters. Here we analyse liquid flowing in an optofluidic waveguide as a new type of controllable transformation optics medium. We show that a laminar liquid flow in an optofluidic channel exhibits spatially variable dielectric properties that support novel wave-focussing and interference phenomena, which are distinctively different from the discrete diffraction observed in solid waveguide arrays. Our work provides new insight into the unique optical properties of optofluidic waveguides and their potential applications.

Interactive optical panel

DOEpatents

Veligdan, J.T.

1995-10-03

An interactive optical panel assembly includes an optical panel having a plurality of ribbon optical waveguides stacked together with opposite ends thereof defining panel first and second faces. A light source provides an image beam to the panel first face for being channeled through the waveguides and emitted from the panel second face in the form of a viewable light image. A remote device produces a response beam over a discrete selection area of the panel second face for being channeled through at least one of the waveguides toward the panel first face. A light sensor is disposed across a plurality of the waveguides for detecting the response beam therein for providing interactive capability. 10 figs.

Optimized Wavelength-Tuned Nonlinear Frequency Conversion Using a Liquid Crystal Clad Waveguide

NASA Technical Reports Server (NTRS)

Stephen, Mark A. (Inventor)

2018-01-01

An optimized wavelength-tuned nonlinear frequency conversion process using a liquid crystal clad waveguide. The process includes implanting ions on a top surface of a lithium niobate crystal to form an ion implanted lithium niobate layer. The process also includes utilizing a tunable refractive index of a liquid crystal to rapidly change an effective index of the lithium niobate crystal.

Three-Dimensional Waveguide Arrays for Coupling Between Fiber-Optic Connectors and Surface-Mounted Optoelectronic Devices

NASA Astrophysics Data System (ADS)

Hiramatsu, Seiki; Kinoshita, Masao

2005-09-01

This paper describes the fabrication of novel surface-mountable waveguide connectors and presents test results for them. To ensure more highly integrated and low-cost fabrication, we propose new three-dimensional (3-D) waveguide arrays that feature two-dimensionally integrated optical inputs/outputs and optical path redirection. A wafer-level stack and lamination process was used to fabricate the waveguide arrays. Vertical-cavity surface-emitting lasers (VCSELs) and photodiodes were directly mounted on the arrays and combined with mechanical transferable ferrule using active alignment. With the help of a flip-chip bonder, the waveguide connectors were mounted on a printed circuit board by solder bumps. Using mechanical transferable connectors, which can easily plug into the waveguide connectors, we obtained multi-gigabits-per-second transmission performance.

Nano-optical conveyor belt with waveguide-coupled excitation.

PubMed

Wang, Guanghui; Ying, Zhoufeng; Ho, Ho-pui; Huang, Ying; Zou, Ningmu; Zhang, Xuping

2016-02-01

We propose a plasmonic nano-optical conveyor belt for peristaltic transport of nano-particles. Instead of illumination from the top, waveguide-coupled excitation is used for trapping particles with a higher degree of precision and flexibility. Graded nano-rods with individual dimensions coded to have resonance at specific wavelengths are incorporated along the waveguide in order to produce spatially addressable hot spots. Consequently, by switching the excitation wavelength sequentially, particles can be transported to adjacent optical traps along the waveguide. The feasibility of this design is analyzed using three-dimensional finite-difference time-domain and Maxwell stress tensor methods. Simulation results show that this system is capable of exciting addressable traps and moving particles in a peristaltic fashion with tens of nanometers resolution. It is the first, to the best of our knowledge, report about a nano-optical conveyor belt with waveguide-coupled excitation, which is very important for scalability and on-chip integration. The proposed approach offers a new design direction for integrated waveguide-based optical manipulation devices and its application in large scale lab-on-a-chip integration.

Optical waveguide loop for planar trapping of blood cells and microspheres

NASA Astrophysics Data System (ADS)

Ahluwalia, Balpreet S.; Hellesø, Olav G.

2013-09-01

The evanescent field from a waveguide can be used to trap and propel a particle. An optical waveguide loop with an intentional gap at the center is used for planar transport and stable trapping of particles. The waveguide acts as a conveyor belt to trap and deliver spheres towards the gap. At the gap, the counter-diverging light fields hold the sphere at a fixed position. Numerical simulation based on the finite element method was performed in three dimensions using a computer cluster. The field distribution and optical forces for rib and strip waveguide designs are compared and discussed. The optical force on a single particle was computed for various positions of the particle in the gap. Simulation predicted stable trapping of particles in the gap. Depending on the gap separation (2-50 μm) a single or multiple spheres and red blood cells were trapped at the gap. Waveguides were made of tantalum pentaoxide material. The waveguides are only 180 nm thick and thus could be integrated with other functions on the chip.

Femtosecond-laser inscribed double-cladding waveguides in Nd:YAG crystal: a promising prototype for integrated lasers.

PubMed

Liu, Hongliang; Chen, Feng; Vázquez de Aldana, Javier R; Jaque, D

2013-09-01

We report on the design and implementation of a prototype of optical waveguides fabricated in Nd:YAG crystals by using femtosecond-laser irradiation. In this prototype, two concentric tubular structures with nearly circular cross sections of different diameters have been inscribed in the Nd:YAG crystals, generating double-cladding waveguides. Under 808 nm optical pumping, waveguide lasers have been realized in the double-cladding structures. Compared with single-cladding waveguides, the concentric tubular structures, benefiting from the large pump area of the outermost cladding, possess both superior laser performance and nearly single-mode beam profile in the inner cladding. Double-cladding waveguides of the same size were fabricated and coated by a thin optical film, and a maximum output power of 384 mW and a slope efficiency of 46.1% were obtained. Since the large diameters of the outer claddings are comparable with those of the optical fibers, this prototype paves a way to construct an integrated single-mode laser system with a direct fiber-waveguide configuration.

Investigation of giant Kerr nonlinearity in quantum cascade lasers using mid-infrared femtosecond pulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Hong; Liu, Sheng; Department of Physics, University of Maryland, Baltimore County

2015-02-02

We study the Kerr nonlinearity of quantum cascade lasers (QCLs) by coupling resonant and off-resonant mid-infrared (mid-IR) femtosecond (fs) pulses into an active QCL waveguide. We observe an increase in the spectral width of the transmitted fs pulses as the coupled mid-infrared (mid-IR) pulse power increases. This is explained by the self-phase modulation effect due to the large Kerr nonlinearity of QCL waveguides. We further confirm this effect by observing the intensity dependent far-field profile of the transmitted mid-IR pulses, showing the pulses undergo self-focusing as they propagate through the active QCL due to the intensity dependent refractive index. Wemore » experimentally estimate the nonlinear refractive index n{sub 2} of a QCL to be ∼8 × 10{sup −9 }cm{sup 2}/W using the far-field beam profile of the transmitted pulses. The finite-difference time-domain simulations of QCL waveguides with Kerr nonlinearity incorporated show similar behavior to the experimental results.« less

Chirped pulse Raman amplification in warm plasma: towards controlling saturation

PubMed Central

Yang, X.; Vieux, G.; Brunetti, E.; Ersfeld, B.; Farmer, J. P.; Hur, M. S.; Issac, R. C.; Raj, G.; Wiggins, S. M.; Welsh, G. H.; Yoffe, S. R.; Jaroszynski, D. A.

2015-01-01

Stimulated Raman backscattering in plasma is potentially an efficient method of amplifying laser pulses to reach exawatt powers because plasma is fully broken down and withstands extremely high electric fields. Plasma also has unique nonlinear optical properties that allow simultaneous compression of optical pulses to ultra-short durations. However, current measured efficiencies are limited to several percent. Here we investigate Raman amplification of short duration seed pulses with different chirp rates using a chirped pump pulse in a preformed plasma waveguide. We identify electron trapping and wavebreaking as the main saturation mechanisms, which lead to spectral broadening and gain saturation when the seed reaches several millijoules for durations of 10’s – 100’s fs for 250 ps, 800 nm chirped pump pulses. We show that this prevents access to the nonlinear regime and limits the efficiency, and interpret the experimental results using slowly-varying-amplitude, current-averaged particle-in-cell simulations. We also propose methods for achieving higher efficiencies. PMID:26290153

Correlation between optical return loss and transmission fringe noise in high-index contrast waveguides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, Chi; Martin, Yves; Khater, Marwan

2017-05-15

We present a phenomenological model correlating optical return loss and amplitude of fringes in transmission spectrum due to distributed backscattering in high-index-contrast waveguides. The model is validated experimentally using four different waveguide cross sections.

Device-packaging method and apparatus for optoelectronic circuits

DOEpatents

Zortman, William A.; Henry, Michael David; Jarecki, Jr., Robert L.

2017-04-25

An optoelectronic device package and a method for its fabrication are provided. The device package includes a lid die and an active die that is sealed or sealable to the lid die and in which one or more optical waveguides are integrally defined. The active die includes one or more active device regions, i.e. integral optoelectronic devices or etched cavities for placement of discrete optoelectronic devices. Optical waveguides terminate at active device regions so that they can be coupled to them. Slots are defined in peripheral parts of the active dies. At least some of the slots are aligned with the ends of integral optical waveguides so that optical fibers or optoelectronic devices inserted in the slots can optically couple to the waveguides.

Realization of non-linear coherent states by photonic lattices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dehdashti, Shahram, E-mail: shdehdashti@zju.edu.cn; Li, Rujiang; Chen, Hongsheng, E-mail: hansomchen@zju.edu.cn

2015-06-15

In this paper, first, by introducing Holstein-Primakoff representation of α-deformed algebra, we achieve the associated non-linear coherent states, including su(2) and su(1, 1) coherent states. Second, by using waveguide lattices with specific coupling coefficients between neighbouring channels, we generate these non-linear coherent states. In the case of positive values of α, we indicate that the Hilbert size space is finite; therefore, we construct this coherent state with finite channels of waveguide lattices. Finally, we study the field distribution behaviours of these coherent states, by using Mandel Q parameter.

Two different ways for waveguides and optoelectronics components on top of C-MOS

NASA Astrophysics Data System (ADS)

Fedeli, J. M.; Jeannot, S.; Kostrzewa, M.; Di Cioccio, L.; Jousseaume, V.; Orobtchouk, R.; Maury, P.; Zussy, M.

2006-02-01

While fabrication of photonic components at the wafer level is a long standing goal of integrated optics, new applications such as optical interconnects are introducing new challenges for waveguides and optoelectronic component fabrication. Indeed, global interconnects are expected to face severe limitations in the near future. To face this problem, optical links on top of a CMOS circuits could be an alternative. The critical points to perform an optical link on a chip are firstly the realization of compact passive optical distribution and secondly the report of optoelectronic components for the sources and detectors. This paper presents two different approaches for the integration of both waveguides and optoelectronic components. In a first "total bonding" approach, waveguides have been elaborated using classical "Silicon On Insulators" technology and then reported using molecular bonding on top off Si wafers. The S0I substrate was then chemically etched, after what InP dies were moleculary bonded on top of the waveguides. With this approach, optical components with low loses and a good equilibrium are demonsrated. Using molecular bonding, InP dies were reported with no degradation of the optoelectronic properties of the films. In a second approach, using PECVD silicon nitride or amorphous silicon coupled to PECVD silicon oxide, basic optical components are demonstrated. This low temperature technology is compatible with a microelectronic Back End process, allowing an integration of the waveguides directly on top of CMOS circuits. InP dies can then be bonded on top of the waveguides.

Direct write fabrication of waveguides and interconnects for optical printed wiring boards

NASA Astrophysics Data System (ADS)

Dingeldein, Joseph C.

Current copper based circuit technology is becoming a limiting factor in high speed data transfer applications as processors are improving at a faster rate than are developments to increase on board data transfer. One solution is to utilize optical waveguide technology to overcome these bandwidth and loss restrictions. The use of this technology virtually eliminates the heat and cross-talk loss seen in copper circuitry, while also operating at a higher bandwidth. Transitioning current fabrication techniques from small scale laboratory environments to large scale manufacturing presents significant challenges. Optical-to-electrical connections and out-of-plane coupling are significant hurdles in the advancement of optical interconnects. The main goals of this research are the development of direct write material deposition and patterning tools for the fabrication of waveguide systems on large substrates, and the development of out-of-plane coupler components compatible with standard fiber optic cabling. Combining these elements with standard printed circuit boards allows for the fabrication of fully functional optical-electrical-printed-wiring-boards (OEPWBs). A direct dispense tool was designed, assembled, and characterized for the repeatable dispensing of blanket waveguide layers over a range of thicknesses (25-225 μm), eliminating waste material and affording the ability to utilize large substrates. This tool was used to directly dispense multimode waveguide cores which required no UV definition or development. These cores had circular cross sections and were comparable in optical performance to lithographically fabricated square waveguides. Laser direct writing is a non-contact process that allows for the dynamic UV patterning of waveguide material on large substrates, eliminating the need for high resolution masks. A laser direct write tool was designed, assembled, and characterized for direct write patterning waveguides that were comparable in quality to those produced using standard lithographic practices (0.047 dB/cm loss for laser written waveguides compared to 0.043 dB/cm for lithographic waveguides). Straight waveguides, and waveguide turns were patterned at multimode and single mode sizes, and the process was characterized and documented. Support structures such as angled reflectors and vertical posts were produced, showing the versatility of the laser direct write tool. Commercially available components were implanted into the optical layer for out-of-plane routing of the optical signals. These devices featured spherical lenses on the input and output sides of a total internal reflection (TIR) mirror, as well as alignment pins compatible with standard MT design. Fully functional OEPWBs were fabricated featuring input and output out-of-plane optical signal routing with total optical losses not exceeding 10 dB. These prototypes survived thermal cycling (-40°C to 85°C) and humidity exposure (95±4% humidity), showing minimal degradation in optical performance. Operational failure occurred after environmental aging life testing at 110°C for 216 hours.

Room-temperature-deposited dielectrics and superconductors for integrated photonics.

PubMed

Shainline, Jeffrey M; Buckley, Sonia M; Nader, Nima; Gentry, Cale M; Cossel, Kevin C; Cleary, Justin W; Popović, Miloš; Newbury, Nathan R; Nam, Sae Woo; Mirin, Richard P

2017-05-01

We present an approach to fabrication and packaging of integrated photonic devices that utilizes waveguide and detector layers deposited at near-ambient temperature. All lithography is performed with a 365 nm i-line stepper, facilitating low cost and high scalability. We have shown low-loss SiN waveguides, high-Q ring resonators, critically coupled ring resonators, 50/50 beam splitters, Mach-Zehnder interferometers (MZIs) and a process-agnostic fiber packaging scheme. We have further explored the utility of this process for applications in nonlinear optics and quantum photonics. We demonstrate spectral tailoring and octave-spanning supercontinuum generation as well as the integration of superconducting nanowire single photon detectors with MZIs and channel-dropping filters. The packaging approach is suitable for operation up to 160 ^°C as well as below 1 K. The process is well suited for augmentation of existing foundry capabilities or as a stand-alone process.

Optically Controlled Distributed Quantum Computing Using Atomic Ensembles As Qubits

DTIC Science & Technology

2016-02-23

Second, the lithium niobate material has a large nonlinear coefficient (>20 pm V–1) for efficient QFC and a wide transparent window (∼ 350 –5200 nm...for the 1550 nm + 1570 nm 780 nm process. Finally, to implement QFC for the 637 and 780 nm light, one would use a pump at 350 nm and a waveguide QPM...for the 637 nm + 780 nm 350 nm process. Again, the 350 nm laser can be produced adopting successive SHG and SFG processes using a 1050 nm laser

Electrical and Nonlinear Optical Studies of Specific Organic Molecular and Nonconjugated Conductive Polymeric Systems

NASA Astrophysics Data System (ADS)

Narayanan, Ananthakrishnan

In this research, structural, electrical and nonlinear optical characteristics of: (a) single crystal films involving a noncentrosymmetric molecule DAST and a laser dye IR125 and (b) specific nonconjugated conducting polymers including poly(beta-pinene) and polynorbornene have been studied. 4'-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) is a well known second order nonlinear optical material. This material has exceptionally high electro-optic coefficients, high thermal stability and ultrafast response time. In this work single crystal films involving a combination of DAST and IR125 have been prepared using modified shear method and the films have been characterized using polarized optical microscopy, X-ray diffraction, polarization dependent optical absorption and photoluminescence spectroscopy. The electro-optic coefficient of these films measured at 633nm was found to be 300pm/V. Since IR-125 has a strong absorption band from 500nm to 800nm, these films are promising for various applications in nonlinear optics at longer wavelength and for light emission. Nonconjugated conducting polymers are a class of polymers that have at least one double bond in their repeat units. 1,4-cis polyisoprene, polyalloocimene, styrene butadiene rubber, poly(ethylenepyrrolediyl) derivatives, and poly(beta-pinene) are some of the well known examples of nonconjugated conducting polymers. In this work, polynorborne, a new addition to the class of nonconjugated conducting polymers is discussed. Like other polymers in this class, polynorbornene exhibits increase in electrical conductivity by many orders of magnitude upon doping with iodine. The maximum electrical conductivity of this material is 0.01 S/cm. As shown by using FTIR microscopy, the C=C bonds are transformed into cation radicals when polynorborne is doped. This is due to the charge-transfer from the double bond to the dopant (iodine). These materials like other nonconjugated conducting polymers have significant applications in electro-optics and photonics. Electron paramagnetic resonance measurements on poly(beta-pinene) before and after doping with iodine are reported in this work. The EPR signal of this polymer increases proportionally with the iodine concentration due to the formation of cation radicals upon doping and charge-transfer. The results agree well with the doping mechanism of nonconjugated conducting polymers discussed earlier in literature. Hyperfine splitting in heavily doped polymers is observed due to the reduced distance between the cation radical and the iodine anion. Off-resonant electro-optic measurements in doped poly(beta-pinene) at 790nm, 800nm, 810nm and 1.55microm using field-induced birefringence technique have been studied. The results show that this material exhibits the highest cubic nonlinearities of all known materials. The Kerr coefficient measured at 1.55microm is 1.6x10-10 m/V2 which is about 30 times higher than that of conjugated polymers. Results of two photon measurements in this doped polymer using pump-probe technique with a pulsed, mode-locked (150 fs pulses) beam from a Ti-Sapphire laser are reported. The measured value of alpha2 at 790 nm and 795 nm were found to be 2.28+/-0.1 cm/MW and 2.5+/-0.1 cm/MW respectively. The data confirms that the nonlinearity in this material is ultrafast and electronic in nature. Such large nonlinearities in these materials are attributed the charge confinement in these materials in a sub-nanometer domain (upon doping) resulting in a metal-like quantum dot structure. Photovoltaic measurements in a composite involving poly(beta-pinene) and C60 are discussed. This is the first time a nonconjugated conducting polymer based photovoltaic cell has been fabricated. A composite involving 4% C60 by weight produced a photovoltage of 280mV for an incident light intensity of 6mW/sq.cm. These low cost devices have applications in solar cells, photodetectors etc. A nonlinear optical waveguide was prepared by casting a thin film of poly(beta-pinene) on bare multi-mode optical fiber and doping it with iodine. The doped fibers were of excellent optical quality. Two-photon absorption experiments were conducted using these waveguides and large changes in transmission upto 28% was observed in 15cm long fiber. More work needs to be done to confirm this result. This is a significant step in the direction of making these materials a viable choice for ultrafast (femtosecond time-scale) optical devices. To summarize, these works included detailed investigations of structural, electrical and nonlinear optical characteristics of specific molecular crystal films and nonconjugated conducting polymers.

Study of Third-Order Optical Nonlinearities of Se-Sn (Bi,Te) Quaternary Chalcogenide Thin Films Using Ti: Sapphire Laser in Femtosecond Regime

NASA Astrophysics Data System (ADS)

Yadav, Preeti; Sharma, Ambika

2017-01-01

The objective of the present research work is to study the nonlinear optical properties of quaternary Se-Sn (Bi,Te) chalcogenide thin films. A Z-scan technique utilizing 800 nm femtosecond laser source has been used for the determination of the nonlinear refractive index ( n 2), two-photon absorption coefficient ( β 2) and third-order susceptibility ( χ (3)). In the measurement of n 2, an aperture is placed in the far field before the detector (closed aperture), while for the measurement of β 2, entire transmitted light is collected by the detector without an aperture (open aperture). Self-focusing has been observed in closed aperture transmission spectra. The appearance of the peak after the valley in this spectrum reflects the positive nonlinear refractive index. The calculated value of n 2 of the studied thin films varies from 1.06 × 10-12 cm2/W to 0.88 × 10-12 cm2/W. The compound-dependent behavior of n 2 is explained in this paper. We have also compared the experimental values of n 2 with the theoretically determined values, other compounds of chalcogenide glass and pure silica. The n 2 of the investigated thin films is found to be 3200 times higher than pure silica. The results of the open aperture Z-scan revealed that the value of β 2 of the studied compound is in the order of 10-8 cm/W. The behavior of two-photon absorption is described by means of the optical band gap ( E g) of the studied compound. The variation in the figure-of-merit from 0.32 to 1.4 with varying Sn content is also reported in this paper. The higher value of nonlinearity makes this material advantageous for optical fibers, waveguides and optical limiting devices.

Integrated Miniature Arrays of Optical Biomolecule Detectors

NASA Technical Reports Server (NTRS)

Iltchenko, Vladimir; Maleki, Lute; Lin, Ying; Le, Thanh

2009-01-01

Integrated miniature planar arrays of optical sensors for detecting specific biochemicals in extremely small quantities have been proposed. An array of this type would have an area of about 1 cm2. Each element of the array would include an optical microresonator that would have a high value of the resonance quality factor (Q . 107). The surface of each microresonator would be derivatized to make it bind molecules of a species of interest, and such binding would introduce a measurable change in the optical properties of the microresonator. Because each microresonator could be derivatized for detection of a specific biochemical different from those of the other microresonators, it would be possible to detect multiple specific biochemicals by simultaneous or sequential interrogation of all the elements in the array. Moreover, the derivatization would make it unnecessary to prepare samples by chemical tagging. Such interrogation would be effected by means of a grid of row and column polymer-based optical waveguides that would be integral parts of a chip on which the array would be fabricated. The row and column polymer-based optical waveguides would intersect at the elements of the array (see figure). At each intersection, the row and column waveguides would be optically coupled to one of the microresonators. The polymer-based waveguides would be connected via optical fibers to external light sources and photodetectors. One set of waveguides and fibers (e.g., the row waveguides and fibers) would couple light from the sources to the resonators; the other set of waveguides and fibers (e.g., the column waveguides and fibers) would couple light from the microresonators to the photodetectors. Each microresonator could be addressed individually by row and column for measurement of its optical transmission. Optionally, the chip could be fabricated so that each microresonator would lie inside a microwell, into which a microscopic liquid sample could be dispensed.

Theory and simulent design of a type of auto-self-protecting optical switches

NASA Astrophysics Data System (ADS)

Li, Binhong; Peng, Songcun

1990-06-01

As the use of lasers in the military and in the civilian economy increases with each passing day, it is often necessary for the human eye or sensitive instruments to observe weak lasers, such as the return waves of laser radar and laser communications signals; but it is also necessary to provide protection against damage to the eye from the strong lasers of enemy laser weapons. For this reason, it is necessary to have a kind of automatic optical self-protecting switch. Based upon a study of the transmitting and scattering characteristics of multilayer dielectric optical waveguides, a practical computer program is set up for designing a type of auto-self-protecting optical switch with a computer model by using the nonlinear property of dielectric layers and the plasma behavior of metal substrates. This technique can be used to protect the human eye and sensitive detectors from damage caused by strong laser beams.

Manipulation of a two-photon state in a χ(2)-modulated nonlinear waveguide array

NASA Astrophysics Data System (ADS)

Yang, Y.; Xu, P.; Lu, L. L.; Zhu, S. N.

2014-10-01

We propose to engineer the quantum state in a high-dimensional Hilbert space by taking advantage of a χ(2)-modulated nonlinear waveguide array. By varying the pump condition and the waveguide array length, the momentum correlation between the signal and idler photons can be manipulated, exhibiting bunching, antibunching, and the evolution between these two states, which are characterized by the Schmidt number. We find the Schmidt number is dependent on a structure parameter, namely the ratio of the array length and the number of channels pumped. By designing the linear profile waveguide array, the degree of spatial entanglement shows a periodic relationship with the slope of linear profile, during which a high degree of position-bunching state is suggested. The two-photon self-focusing effect is disclosed when the χ(2) modulation in the waveguide array contains a parabolic profile, which can be designed for efficient coupling between a waveguide array and fibers. These results shed light on a feasible way to achieve desirable quantum state on a single waveguide chip by a compact engineering of χ(2) and also suggest a degree of freedom for quantum walk and other related applications.

Integrated optical transceiver with electronically controlled optical beamsteering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davids, Paul; DeRose, Christopher; Tauke-Pedretti, Anna

A beam-steering optical transceiver is provided. The transceiver includes one or more modules, each comprising an antenna chip and a control chip bonded to the antenna chip. Each antenna chip has a feeder waveguide, a plurality of row waveguides that tap off from the feeder waveguide, and a plurality of metallic nanoantenna elements arranged in a two-dimensional array of rows and columns such that each row overlies one of the row waveguides. Each antenna chip also includes a plurality of independently addressable thermo-optical phase shifters, each configured to produce a thermo-optical phase shift in a respective row. Each antenna chipmore » also has, for each row, a row-wise heating circuit configured to produce a respective thermo-optic phase shift at each nanoantenna element along its row. The control chip includes controllable current sources for the independently addressable thermo-optical phase shifters and the row-wise heating circuits.« less

Wavelength-division multiplexed optical integrated circuit with vertical diffraction grating

NASA Technical Reports Server (NTRS)

Lang, Robert J. (Inventor); Forouhar, Siamak (Inventor)

1994-01-01

A semiconductor optical integrated circuit for wave division multiplexing has a semiconductor waveguide layer, a succession of diffraction grating points in the waveguide layer along a predetermined diffraction grating contour, a semiconductor diode array in the waveguide layer having plural optical ports facing the succession of diffraction grating points along a first direction, respective semiconductor diodes in the array corresponding to respective ones of a predetermined succession of wavelengths, an optical fiber having one end thereof terminated at the waveguide layer, the one end of the optical fiber facing the succession of diffraction grating points along a second direction, wherein the diffraction grating points are spatially distributed along the predetermined contour in such a manner that the succession of diffraction grating points diffracts light of respective ones of the succession of wavelengths between the one end of the optical fiber and corresponding ones of the optical ports.

Optical modulator including grapene

DOEpatents

Liu, Ming; Yin, Xiaobo; Zhang, Xiang

2016-06-07

The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

Novel optical interconnect devices applying mask-transfer self-written method

NASA Astrophysics Data System (ADS)

Ishizawa, Nobuhiko; Matsuzawa, Yusuke; Tokiwa, Yu; Nakama, Kenichi; Mikami, Osamu

2012-01-01

The introduction of optical interconnect technology is expected to solve problems of conventional electric wiring. One of the promising technologies realizing optical interconnect is the self-written waveguide (SWW) technology with lightcurable resin. We have developed a new technology of the "Mask-Transfer Self-Written (MTSW)" method. This new method enables fabrication of arrayed M x N optical channels at one shot of UV-light. Using this technology, several new optical interconnect devices and connection technologies have been proposed and investigated. In this paper, first, we introduce MTSW method briefly. Next, we show plug-in alignment approach using optical waveguide plugs (OWP) and a micro-hole array (MHA) which are made of the light-curable resin. Easy and high efficiency plug-in alignment between fibers and an optoelectronic-printed wiring board (OE-PWB), between a fiber and a VCSEL, so on will be feasible. Then, we propose a new three-dimensional (3D) branch waveguide. By controlling the irradiating angle through the photomask aperture, it will be possible to fabricate 2-branch and 4-branch waveguides with a certain branch angle. The 3D branch waveguide will be very promising in the future optical interconnects and coupler devices of the multicore optical fiber.

Ultrafast direct laser writing of cladding waveguides in the 0.8CaSiO3-0.2Ca3(PO4)2 eutectic glass doped with Nd3+ ions

NASA Astrophysics Data System (ADS)

Martínez de Mendívil, J.; Sola, D.; Vázquez de Aldana, J. R.; Lifante, G.; de Aza, A. H.; Pena, P.; Peña, J. I.

2015-01-01

We report on tubular cladding optical waveguides fabricated in Neodymium doped Wollastonite-Tricalcium Phosphate glass in the eutectic composition. The glass samples were prepared by melting the eutectic powder mixture in a Pt-Rh crucible at 1600 °C and pouring it in a preheated brass mould. Afterwards, the glass was annealed to relieve the inner stresses. Cladding waveguides were fabricated by focusing beneath the sample surface using a pulsed Ti:sapphire laser with a pulsewidth of 120 fs working at 1 kHz. The optical properties of these waveguides have been assessed in terms of near-field intensity distribution and transmitted power, and these results have been compared to previously reported waveguides with double-line configuration. Optical properties have also been studied as function of the temperature. Heat treatments up to 700 °C were carried out to diminish colour centre losses where waveguide's modes and transmitted power were compared in order to establish the annealing temperature at which the optimal optical properties were reached. Laser experiments are in progress to evaluate the ability of the waveguides for 1064 nm laser light generation under 800 nm optical pumping.

Integrating cell on chip—Novel waveguide platform employing ultra-long optical paths

NASA Astrophysics Data System (ADS)

Fohrmann, Lena Simone; Sommer, Gerrit; Pitruzzello, Giampaolo; Krauss, Thomas F.; Petrov, Alexander Yu.; Eich, Manfred

2017-09-01

Optical waveguides are the most fundamental building blocks of integrated optical circuits. They are extremely well understood, yet there is still room for surprises. Here, we introduce a novel 2D waveguide platform which affords a strong interaction of the evanescent tail of a guided optical wave with an external medium while only employing a very small geometrical footprint. The key feature of the platform is its ability to integrate the ultra-long path lengths by combining low propagation losses in a silicon slab with multiple reflections of the guided wave from photonic crystal (PhC) mirrors. With a reflectivity of 99.1% of our tailored PhC-mirrors, we achieve interaction paths of 25 cm within an area of less than 10 mm2. This corresponds to 0.17 dB/cm effective propagation which is much lower than the state-of-the-art loss of approximately 1 dB/cm of single mode silicon channel waveguides. In contrast to conventional waveguides, our 2D-approach leads to a decay of the guided wave power only inversely proportional to the optical path length. This entirely different characteristic is the major advantage of the 2D integrating cell waveguide platform over the conventional channel waveguide concepts that obey the Beer-Lambert law.

Realization of optical multimode TSV waveguides for Si-Interposer in 3D-chip-stacks

NASA Astrophysics Data System (ADS)

Killge, S.; Charania, S.; Richter, K.; Neumann, N.; Al-Husseini, Z.; Plettemeier, D.; Bartha, J. W.

2017-05-01

Optical connectivity has the potential to outperform copper-based TSVs in terms of bandwidth at the cost of more complexity due to the required electro-optical and opto-electrical conversion. The continuously increasing demand for higher bandwidth pushes the breakeven point for a profitable operation to shorter distances. To integrate an optical communication network in a 3D-chip-stack optical through-silicon vertical VIAs (TSV) are required. While the necessary effort for the electrical/optical and vice versa conversion makes it hard to envision an on-chip optical interconnect, a chip-to-chip optical link appears practicable. In general, the interposer offers the potential advantage to realize electro-optical transceivers on affordable expense by specific, but not necessarily CMOS technology. We investigated the realization and characterization of optical interconnects as a polymer based waveguide in high aspect ratio (HAR) TSVs proved on waferlevel. To guide the optical field inside a TSV as optical-waveguide or fiber, its core has to have a higher refractive index than the surrounding material. Comparing different material / technology options it turned out that thermal grown silicon dioxide (SiO2) is a perfect candidate for the cladding (nSiO2 = 1.4525 at 850 nm). In combination with SiO2 as the adjacent polymer layer, the negative resist SU-8 is very well suited as waveguide material (nSU-8 = 1.56) for the core. Here, we present the fabrication of an optical polymer based multimode waveguide in TSVs proved on waferlevel using SU-8 as core and SiO2 as cladding. The process resulted in a defect-free filling of waveguide TSVs with SU-8 core and SiO2 cladding up to aspect ratio (AR) 20:1 and losses less than 3 dB.

Highly coherent mid-IR supercontinuum by self-defocusing solitons in lithium niobate waveguides with all-normal dispersion.

PubMed

Guo, Hairun; Zhou, Binbin; Zeng, Xianglong; Bache, Morten

2014-05-19

We numerically investigate self-defocusing solitons in a lithium niobate (LN) waveguide designed to have a large refractive index (RI) change. The waveguide evokes strong waveguide dispersion and all-normal dispersion is found in the entire guiding band spanning the near-IR and the beginning of the mid-IR. Meanwhile, a self-defocusing nonlinearity is invoked by the cascaded (phase-mismatched) second-harmonic generation under a quasi-phase-matching pitch. Combining this with the all-normal dispersion, mid-IR solitons can form and the waveguide presents the first all-nonlinear and solitonic device where no linear dispersion (i.e. non-solitonic) regimes exist within the guiding band. Soliton compressions at 2 μm and 3 μm are investigated, with nano-joule single cycle pulse formations and highly coherent octave-spanning supercontinuum generations. With an alternative design on the waveguide dispersion, the soliton spectral tunneling effect is also investigated, with which few-cycle pico-joule pulses at 2 μm are formed by a near-IR pump.

Classical and low-light-level detection and pulse characterization using optical-frequency mixers

NASA Astrophysics Data System (ADS)

Langrock, Carsten

2007-12-01

Classical all-optical signal processing for telecommunication applications greatly benefits from the availability of highly efficient optical frequency (OF) mixers, the optical analogue of radio-frequency mixers used in RF signal processing. The OF mixers presented in this dissertation are based on reverse-proton-exchange (RPE) periodically-poled lithium niobate (PPLN) waveguides, one of the most efficient and versatile material systems in the field of nonlinear optics to date. Taking advantage of fabrication technologies developed in Prof. Martin Fejer's group over the past two decades, we expand the range of applications for these OF mixers to low-light-level signal detection and pulse characterization. We demonstrate high-speed high-efficiency single-photon counting at telecommunication wavelengths, used for the implementation of record-breaking quantum-key distribution systems, which allow unconditionally secure data transfer. In collaboration with researchers at the MIT Lincoln Laboratory, we also show that the very same technology can be used to achieve an order of magnitude improvement in the sensitivity of classical few-photon free-space communication links based on pulse-position modulation. These extremely sensitive receivers (1 photon/bit) are being developed to facilitate deep-space communication over several hundred million kilometers between Mars and Earth. OF mixers can also be used to fully characterize, potentially weak, ultrashort pulses, as well as time-magnify segments of ultra-high-speed data streams to be detected in real time by conventional streak cameras and oscilloscopes. We will present a novel implementation of both collinear autocorrelation as well as parametric temporal imaging (in collaboration with the Lawrence Livermore National Laboratory) based on mode-multiplexing in integrated asymmetric Y-junctions in combination with linearly-chirped apodized quasi-phasematching gratings. For the first time, background-free autocorrelation, frequency-resolved optical gating, and temporal imaging can be realized in single-polarization-guiding collinear waveguide structures at sub-60-aJ (400 photons/pulse) levels. Recently, guided-wave OF mixers have also become important for precision metrology applications based on frequency-comb generation (FCG) (i.e. optical ruler) using ultrashort pulses. The most compact and energy efficient FCG systems use fiber lasers. In collaboration with IMRA America, Inc., we demonstrate that RPE PPLN waveguides can be used to implement fully integrated fiber-laser-based FCG systems taking advantage of unprecedented octave-spanning spectral broadening of the input pulses in combination with simultaneous phase sensing inside the same waveguide.

Photo-Detectors Integrated with Resonant Tunneling Diodes

PubMed Central

Romeira, Bruno; Pessoa, Luis M.; Salgado, Henrique M.; Ironside, Charles N.; Figueiredo, José M. L.

2013-01-01

We report on photo-detectors consisting of an optical waveguide that incorporates a resonant tunneling diode (RTD). Operating at wavelengths around 1.55 μm in the optical communications C band we achieve maximum sensitivities of around 0.29 A/W which is dependent on the bias voltage. This is due to the nature of RTD nonlinear current-voltage characteristic that has a negative differential resistance (NDR) region. The resonant tunneling diode photo-detector (RTD-PD) can be operated in either non-oscillating or oscillating regimes depending on the bias voltage quiescent point. The oscillating regime is apparent when the RTD-PD is biased in the NDR region giving rise to electrical gain and microwave self-sustained oscillations Taking advantage of the RTD's NDR distinctive characteristics, we demonstrate efficient detection of gigahertz (GHz) modulated optical carriers and optical control of a RTD GHz oscillator. RTD-PD based devices can have applications in generation and optical control of GHz low-phase noise oscillators, clock recovery systems, and fiber optic enabled radio frequency communication systems. PMID:23881142

Photo-detectors integrated with resonant tunneling diodes.

PubMed

Romeira, Bruno; Pessoa, Luis M; Salgado, Henrique M; Ironside, Charles N; Figueiredo, José M L

2013-07-22

We report on photo-detectors consisting of an optical waveguide that incorporates a resonant tunneling diode (RTD). Operating at wavelengths around 1.55 μm in the optical communications C band we achieve maximum sensitivities of around 0.29 A/W which is dependent on the bias voltage. This is due to the nature of RTD nonlinear current-voltage characteristic that has a negative differential resistance (NDR) region. The resonant tunneling diode photo-detector (RTD-PD) can be operated in either non-oscillating or oscillating regimes depending on the bias voltage quiescent point. The oscillating regime is apparent when the RTD-PD is biased in the NDR region giving rise to electrical gain and microwave self-sustained oscillations Taking advantage of the RTD's NDR distinctive characteristics, we demonstrate efficient detection of gigahertz (GHz) modulated optical carriers and optical control of a RTD GHz oscillator. RTD-PD based devices can have applications in generation and optical control of GHz low-phase noise oscillators, clock recovery systems, and fiber optic enabled radio frequency communication systems.

Micropore and nanopore fabrication in hollow antiresonant reflecting optical waveguides

PubMed Central

Holmes, Matthew R.; Shang, Tao; Hawkins, Aaron R.; Rudenko, Mikhail; Measor, Philip; Schmidt, Holger

2011-01-01

We demonstrate the fabrication of micropore and nanopore features in hollow antiresonant reflecting optical waveguides to create an electrical and optical analysis platform that can size select and detect a single nanoparticle. Micropores (4 μm diameter) are reactive-ion etched through the top SiO2 and SiN layers of the waveguides, leaving a thin SiN membrane above the hollow core. Nanopores are formed in the SiN membranes using a focused ion-beam etch process that provides control over the pore size. Openings as small as 20 nm in diameter are created. Optical loss measurements indicate that micropores did not significantly alter the loss along the waveguide. PMID:21922035

Micropore and nanopore fabrication in hollow antiresonant reflecting optical waveguides.

PubMed

Holmes, Matthew R; Shang, Tao; Hawkins, Aaron R; Rudenko, Mikhail; Measor, Philip; Schmidt, Holger

2010-01-01

We demonstrate the fabrication of micropore and nanopore features in hollow antiresonant reflecting optical waveguides to create an electrical and optical analysis platform that can size select and detect a single nanoparticle. Micropores (4 μm diameter) are reactive-ion etched through the top SiO(2) and SiN layers of the waveguides, leaving a thin SiN membrane above the hollow core. Nanopores are formed in the SiN membranes using a focused ion-beam etch process that provides control over the pore size. Openings as small as 20 nm in diameter are created. Optical loss measurements indicate that micropores did not significantly alter the loss along the waveguide.

ZnO nanotube waveguide arrays on graphene films for local optical excitation on biological cells

NASA Astrophysics Data System (ADS)

Baek, Hyeonjun; Kwak, Hankyul; Song, Minho S.; Ha, Go Eun; Park, Jongwoo; Tchoe, Youngbin; Hyun, Jerome K.; Park, Hye Yoon; Cheong, Eunji; Yi, Gyu-Chul

2017-04-01

We report on scalable and position-controlled optical nanoprobe arrays using ZnO nanotube waveguides on graphene films for use in local optical excitation. For the waveguide fabrication, position-controlled and well-ordered ZnO nanotube arrays were grown on chemical vapor deposited graphene films with a submicron patterned mask layer and Au prepared between the interspace of nanotubes. Mammalian cells were cultured on the nanotube waveguide arrays and were locally excited by light illuminated through the nanotubes. Fluorescence and optogenetic signals could be excited through the optical nanoprobes. This method offers the ability to investigate cellular behavior with a high spatial resolution that surpasses the current limitation.

Classical and quantum non-linear optical applications using the Mach-Zehnder interferometer

NASA Astrophysics Data System (ADS)

Prescod, Andru

Mach Zehnder (MZ) modulators are widely employed in a variety of applications, such as optical communications, optical imaging, metrology and encryption. In this dissertation, we explore two non-linear MZ applications; one classified as classical and one as quantum, in which the Mach Zehnder interferometer is used. In the first application, a classical non-linear application, we introduce and study a new electro-optic highly linear (e.g., >130 dB) modulator configuration. This modulator makes use of a phase modulator (PM) in one arm of the MZ interferometer (MZI) and a ring resonator (RR) located on the other arm. The modulator performance is obtained through the control of a combination of internal and external parameters. These parameters include the RR-coupling ratio (internal parameter); the RF power split ratio and the RF phase bias (external parameters). Results show the unique and superior features, such as high linearity (SFDR˜133 dB), modulation bandwidth extension (as much as 70%) over the previously proposed and demonstrated Resonator-Assisted Mach Zehnder (RAMZ) design. Furthermore the proposed electro-optic modulator of this dissertation also provides an inherent SFDR compensation capability, even in cases where a significant waveguide optical loss exists. This design also shows potential for increased flexibility, practicality and ease of use. In the second application, a quantum non-linear application, we experimentally demonstrate quantum optical coherence tomography (QOCT) using a type II non-linear crystal (periodically-poled potassium titanyl phosphate (KTiOPO4) or PPKTP). There have been several publications discussing the merits and disadvantages of QOCT compared to OCT and other imaging techniques. First, we discuss the issues and solutions for increasing the efficiency of the quantum entangled photons. Second, we use a free space QOCT experiment to generate a high flux of these quantum entangled photons in two orthogonal polarizations, by parametric down-conversion. Third, by ensuring that these down-converted photons have the same frequency, spatial-temporal mode, and the same polarization when they interfere at a beam splitter, quantum interference should occur. Quantum interference of these entangled photons enables high resolution probing of dispersive samples.

Process technologies of MPACVD planar waveguide devices and fiber attachment

NASA Astrophysics Data System (ADS)

Li, Cheng-Chung; Qian, Fan; Boudreau, Robert A.; Rowlette, John R., Sr.; Bowen, Terry P.

1999-03-01

Optical circuits based on low-loss glass waveguide on silicon are a practical and promising approach to integrate different functional components. Fiber attachment to planar waveguide provides a practical application for optical communications. Microwave Plasma Assisted Chemical Vapor Deposition (MPACVD) produces superior quality, low birefringence, low-loss, planar waveguides for integrated optical devices. Microwave plasma initiates the chemical vapor of SiCl4, GeCl4 and oxygen. A Ge-doped silica layer is thus deposited with a compatible high growth rate (i.e. 0.4 - 0.5 micrometer/min). Film properties are based on various parameters, such as chemical flow rates, chamber pressure and temperature, power level and injector design. The resultant refractive index can be varied between 1.46 (i.e. pure silica) and 1.60 (i.e. pure germania). Waveguides can be fabricated with any desired refractive index profile. Standard photolithography defines the waveguide pattern on a mask layer. The core layer is removed by plasma dry etch which has been investigated by both reactive ion etch (RIE) and inductively coupled plasma (ICP) etch. Etch rates of 3000 - 4000 angstrom/min have been achieved using ICP compared to typical etch rates of 200 - 300 angstrom/min using conventional RIE. Planar waveguides offer good mode matching to optical fiber. A polished fiber end can be glued to the end facet of waveguide with a very low optical coupling loss. In addition, anisotropic etching of silicon V- grooves provides a passive alignment capability. Epoxy and solder were used to fix the fiber within the guiding groove. Several designs of waveguide-fiber attachment will be discussed.

Polydimethylsiloxane-based optical waveguides for tetherless powering of floating microstimulators

NASA Astrophysics Data System (ADS)

Ersen, Ali; Sahin, Mesut

2017-05-01

Neural electrodes and associated electronics are powered either through percutaneous wires or transcutaneous powering schemes with energy harvesting devices implanted underneath the skin. For electrodes implanted in the spinal cord and the brain stem that experience large displacements, wireless powering may be an option to eliminate device failure by the breakage of wires and the tethering of forces on the electrodes. We tested the feasibility of using optically clear polydimethylsiloxane (PDMS) as a waveguide to collect the light in a subcutaneous location and deliver to deeper regions inside the body, thereby replacing brittle metal wires tethered to the electrodes with PDMS-based optical waveguides that can transmit energy without being attached to the targeted electrode. We determined the attenuation of light along the PDMS waveguides as 0.36±0.03 dB/cm and the transcutaneous light collection efficiency of cylindrical waveguides as 44%±11% by transmitting a laser beam through the thenar skin of human hands. We then implanted the waveguides in rats for a month to demonstrate the feasibility of optical transmission. The collection efficiency and longitudinal attenuation values reported here can help others design their own waveguides and make estimations of the waveguide cross-sectional area required to deliver sufficient power to a certain depth in tissue.

Application de la technologie des materiaux sol-gel et polymere a l'optique integree

NASA Astrophysics Data System (ADS)

Saddiki, Zakaria

2002-01-01

With the advancement of optical telecommunication systems, "integrated optics" and "optical interconnect" technology are becoming more and more important. The major components of these two technologies are photonic integrated circuits (PICs), optoelectronic integrated circuits (OEICs), and optoelectronic multichip modules ( OE-MCMs). Optical signals are transmitted through optical waveguides that interconnect such components. The principle of optical transmission in waveguides is the same as that in optical fibres. To implement these technologies, both passive and active optical devices are needed. A wide variety of optical materials has been studied, e.g., glasses, lithium niobate, III-V semiconductors, sol-gel and polymers. In particular, passive optical components have been fabricated using glass optical waveguides by ion-exchange, or by flame hydrolysis deposition and reactive ion etching (FHD and RIE ). When using FHD and RIE, a very high temperatures (up to 1300°C) are needed to consolidate silica. This work reports on the fabrication and characterization of a new photo-patternable hybrid organic-inorganic glass sol-gel and polymer materials for the realisation of integrated optic and opto-electronic devices. They exhibit low losses in the NIR range, especially at the most important wavelengths windows for optical communications (1320 nm and 1550 nm). The sol-gel and polymer process is based on photo polymerization and thermo polymerization effects to create the wave-guide. The single-layer film is at low temperature and deep UV-light is employed to make the wave-guide by means of the well-known photolithography process. Like any photo-imaging process, the UV energy should exceed the threshold energy of chemical bonds in the photoactive component of hybrid glass material to form the expected integrated optic pattern with excellent line width control and vertical sidewalls. To achieve optical wave-guide, a refractive index difference Delta n occurred between the isolated (guiding layer) and the surrounding region (buffer and cladding). Accordingly, the refractive index emerges as a fundamental device performance material parameter and it is investigated using slab wave-guide. (Abstract shortened by UMI.)

Silicone polymer waveguide bridge for Si to glass optical fibers

NASA Astrophysics Data System (ADS)

Kruse, Kevin L.; Riegel, Nicholas J.; Middlebrook, Christopher T.

2015-03-01

Multimode step index polymer waveguides achieve high-speed, (<10 Gb/s) low bit-error-rates for onboard and embedded circuit applications. Using several multimode waveguides in parallel enables overall capacity to reach beyond 100 Gb/s, but the intrinsic bandwidth limitations due to intermodal dispersion limit the data transmission rates within multimode waveguides. Single mode waveguides, where intermodal dispersion is not present, have the potential to further improve data transmission rates. Single mode waveguide size is significantly less than their multimode counterparts allowing for greater density of channels leading to higher bandwidth capacity per layer. Challenges in implementation of embedded single mode waveguides within printed circuit boards involves mass production fabrication techniques to create precision dimensional waveguides, precision alignment tolerances necessary to launch a mode, and effective coupling between adjoining waveguides and devices. An emerging need in which single mode waveguides can be utilized is providing low loss fan out techniques and coupling between on-chip transceiver devices containing Si waveguide structures to traditional single mode optical fiber. A polymer waveguide bridge for Si to glass optical fibers can be implemented using silicone polymers at 1310 nm. Fabricated and measured prototype devices with modeling and simulation analysis are reported for a 12 member 1-D tapered PWG. Recommendations and designs are generated with performance factors such as numerical aperture and alignment tolerances.

Optical sensor in planar configuration based on multimode interference

NASA Astrophysics Data System (ADS)

Blahut, Marek

2017-08-01

In the paper a numerical analysis of optical sensors based on multimode interference in planar one-dimensional step-index configuration is presented. The structure consists in single-mode input and output waveguides and multimode waveguide which guide only few modes. Material parameters discussed refer to a SU8 polymer waveguide on SiO2 substrate. The optical system described will be designed to the analysis of biological substances.

Capillary waveguide optrodes: an approach to optical sensing in medical diagnostics

NASA Astrophysics Data System (ADS)

Lippitsch, Max E.; Draxler, Sonja; Kieslinger, Dietmar; Lehmann, Hartmut; Weigl, Bernhard H.

1996-07-01

Glass capillaries with a chemically sensitive coating on the inner surface are used as optical sensors for medical diagnostics. A capillary simultaneously serves as a sample compartment, a sensor element, and an inhomogeneous optical waveguide. Various detection schemes based on absorption, fluorescence intensity, or fluorescence lifetime are described. In absorption-based capillary waveguide optrodes the absorption in the sensor layer is analyte dependent; hence light transmission along the inhomogeneous waveguiding structure formed by the capillary wall and the sensing layer is a function of the analyte concentration. Similarly, in fluorescence-based capillary optrodes the fluorescence intensity or the fluorescence lifetime of an indicator dye fixed in the sensing layer is analyte dependent; thus the specific property of fluorescent light excited in the sensing layer and thereafter guided along the inhomogeneous waveguiding structure is a function of the analyte concentration. Both schemes are experimentally demonstrated, one with carbon dioxide as the analyte and the other one with oxygen. The device combines optical sensors with the standard glass capillaries usually applied to gather blood drops from fingertips, to yield a versatile diagnostic instrument, integrating the sample compartment, the optical sensor, and the light-collecting optics into a single piece. This ensures enhanced sensor performance as well as improved handling compared with other sensors. waveguide, blood gases, medical diagnostics.

FIBER AND INTEGRATED OPTICS: Influence of diffraction-induced emission of light on resonant conversion of surface waves in diffraction-coupled optical waveguides

NASA Astrophysics Data System (ADS)

Kiselev, V. A.; Shaposhnikov, S. N.

1989-09-01

An investigation is reported of diffraction-induced emission of surface waves under conditions of resonant transfer of light between different regular and corrugated waveguides. It is shown that the part of the emitted light flux carried by surface waves along diffraction-coupled waveguides depends strongly on the ratio of the effective refractive indices of the guides. The dependences of the optical coupling length and of the corresponding emitted light flux on the distance between the waveguides and on the difference between their refractive indices are given.

Subwavelength core/shell cylindrical nanostructures for novel plasmonic and metamaterial devices

NASA Astrophysics Data System (ADS)

Kim, Kyoung-Ho; No, You-Shin

2017-12-01

In this review, we introduce novel plasmonic and metamaterial devices based on one-dimensional subwavelength nanostructures with cylindrical symmetry. Individual single devices with semiconductor/metal core/shell or dielectric/metal core/multi-shell structures experience strong light-matter interaction and yield unique optical properties with a variety of functions, e.g., invisibility cloaking, super-scattering/super-absorption, enhanced luminescence and nonlinear optical activities, and deep subwavelength-scale optical waveguiding. We describe the rational design of core/shell cylindrical nanostructures and the proper choice of appropriate constituent materials, which allow the efficient manipulation of electromagnetic waves and help to overcome the limitations of conventional homogeneous nanostructures. The recent developments of bottom-up synthesis combined with the top-down fabrication technologies for the practical applications and the experimental realizations of 1D subwavelength core/shell nanostructure devices are briefly discussed.

CMOS compatible on-chip telecom-band to mid-infrared supercontinuum generation in dispersion-engineered reverse strip/slot hybrid Si3N4 waveguide

NASA Astrophysics Data System (ADS)

Hui, Zhanqiang; Zhang, Lingxuan; Zhang, Wenfu

2018-01-01

A silicon nitride (Si3N4)-based reverse strip/slot hybrid waveguide with single vertical silica slot is proposed to acquire extremely low and flat chromatic dispersion profile. This is achieved by design and optimization of the geometrical structural parameters of the reverse hybrid waveguide. The flat dispersion varying between ±10 ps/(nm.km) is obtained over 610 nm bandwidth. Both the effective area and nonlinear coefficient of the waveguide across the entire spectral range of interest are investigated. This led to design of an on-chip supercontinuum (SC) source with -30 dB bandwidth of 2996 nm covering from 1.209 to 4.205 μm. Furthermore, we discuss the output signal spectral and temporal characteristic as a function of the pump power. Our waveguide design offers a CMOS compatible, low-cost/high yield (no photolithography or lift-off processes are necessary) on-chip SC source for near- and mid-infrared nonlinear applications.

Optical clock signal distribution and packaging optimization

NASA Astrophysics Data System (ADS)

Wu, Linghui

Polymer-based waveguides for optoelectronic interconnects and packagings were fabricated by a fabrication process that is compatible with the Si CMOS packaging process. An optoelectronic interconnection layer (OIL) for the high-speed massive clock signal distribution for the Cray T-90 supercomputer board employing optical multimode channel waveguides in conjunction with surface-normal waveguide grating couplers and a 1-to-2 3 dB splitter was constructed. Equalized optical paths were realized using an optical H-tree structure having 48 optical fanouts. This device could be increased to 64 without introducing any additional complications. A 1-to-48 fanout H-tree structure using Ultradel 9000D series polyimide was fabricated. The propagation loss and splitting loss have been measured as 0.21 dB/cm and 0.4 dB/splitter at 850 nm. The power budget was discussed, and the H-tree waveguide fully satisfies the power budget requirement. A tapered waveguide coupler was employed to match the mode profile between the single-mode fiber and the multimode channel waveguides of the OIL. A thermo-optical based multimode switch was designed, fabricated, and tested. The finite difference method was used to simulate the thermal distribution in the polymer waveguide. Both stable and transient conditions have been calculated. The thermo-optical switch was fabricated and tested. The switching speed of 1 ms was experimentally confirmed, fitting well with the simulation results. Thermo-optic switching for randomly polarized light at wavelengths of 850 nm was experimental confirmed, as was a stable attenuation of 25 dB. The details of tapered waveguide fabrication were investigated. Compression-molded 3-D tapered waveguides were demonstrated for the first time. Not only the vertical depth variation but also the linear dimensions of the molded waveguides were well beyond the limits of what any other conventional waveguide fabrication method is capable of providing. Molded waveguides with vertical depths of 100 mum at one end and 5 mum at the other end and lengths of 1.0 cm were fabricated using a photolime gel polymer. A propagation loss of 0.5 dB/cm was achieved when light was coupled from the 5 mum x 5 mum end to the 100 mum x 100 mum end and that of 1.1 dB/cm was observed when light was coupled from the 100 mum x 100 mum end to the 5 mum x 5 mum. By confining the energy to the fundamental mode when coupling from the large end to the small end, low-loss packaging can be achieved bi-directionally. 3-D compression-molded polymeric waveguides present a promising solution to bridging the huge dynamic range of different optoelectronic device-depths varying from a few microns to several hundred microns.

Microfabricated ommatidia using a laser induced self-writing process for high resolution artificial compound eye optical systems.

PubMed

Jung, Hyukjin; Jeong, Ki-Hun

2009-08-17

A microfabricated compound eye, comparable to a natural compound eye shows a spherical arrangement of integrated optical units called artificial ommatidia. Each consists of a self-aligned microlens and waveguide. The increase of waveguide length is imperative to obtain high resolution images through an artificial compound eye for wide field-of - view imaging as well as fast motion detection. This work presents an effective method for increasing the waveguide length of artificial ommatidium using a laser induced self-writing process in a photosensitive polymer resin. The numerical and experimental results show the uniform formation of waveguides and the increment of waveguide length over 850 microm. (c) 2009 Optical Society of America

Telecom to mid-infrared spanning supercontinuum generation in hydrogenated amorphous silicon waveguides using a Thulium doped fiber laser pump source.

PubMed

Dave, Utsav D; Uvin, Sarah; Kuyken, Bart; Selvaraja, Shankar; Leo, Francois; Roelkens, Gunther

2013-12-30

A 1,000 nm wide supercontinuum, spanning from 1470 nm in the telecom band to 2470 nm in the mid-infrared is demonstrated in a 800 nm x 220 nm 1 cm long hydrogenated amorphous silicon strip waveguide. The pump source was a picosecond Thulium doped fiber laser centered at 1950 nm. The real part of the nonlinear parameter of this waveguide at 1950 nm is measured to be 100 ± 10 W -1m-1, while the imaginary part of the nonlinear parameter is measured to be 1.2 ± 0.2 W-1m-1. The supercontinuum is stable over a period of at least several hours, as the hydrogenated amorphous silicon waveguides do not degrade when exposed to the high power picosecond pulse train.

Improved nonlinear plasmonic slot waveguide: a full study

NASA Astrophysics Data System (ADS)

Elsawy, Mahmoud M. R.; Nazabal, Virginie; Chauvet, Mathieu; Renversez, Gilles

2016-04-01

We present a full study of an improved nonlinear plasmonic slot waveguides (NPSWs) in which buffer linear dielectric layers are added between the Kerr type nonlinear dielectric core and the two semi-infinite metal regions. Our approach computes the stationary solutions using the fixed power algorithm, in which for a given structure the wave power is an input parameter and the outputs are the propagation constant and the corresponding field components. For TM polarized waves, the inclusion of these supplementary layers have two consequences. First, they reduced the overall losses. Secondly, they modify the types of solutions that propagate in the NPSWs adding new profiles enlarging the possibilities offered by these nonlinear waveguides. In addition to the symmetric linear plasmonic profile obtained in the simple plasmonic structure with linear core such that its effective index is above the linear core refractive index, we obtained a new field profile which is more localized in the core with an effective index below the core linear refractive index. In the nonlinear case, if the effective index of the symmetric linear mode is above the core linear refractive index, the mode field profiles now exhibit a spatial transition from a plasmonic type profile to a solitonic type one. Our structure also provides longer propagation length due to the decrease of the losses compared to the simple nonlinear slot waveguide and exhibits, for well-chosen refractive index or thickness of the buffer layer, a spatial transition of its main modes that can be controlled by the power. We provide a full phase diagram of the TM wave operating regimes of these improved NPSWs. The stability of the main TM modes is then demonstrated numerically using the FDTD. We also demonstrate the existence of TE waves for both linear and nonlinear cases (for some configurations) in which the maximum intensity is located in the middle of the waveguide. We indicate the bifurcation of the nonlinear asymmetric TE mode from the symmetric nonlinear one through the Hopf bifurcation. This kind of bifurcation is similar to the ones already obtained in TM case for our improved structure, and also for the simple NPSWs. At high power, above the bifurcation threshold, the fundamental symmetric nonlinear TE mode moves gradually to new nonlinear mode in which the soliton peak displays two peaks in the core. The losses of the TE modes decrease with the power for all the cases. This kind of structures could be fabricated and characterized experimentally due to the realistic parameters chosen to model them.

Electro-optics laboratory evaluation: Deutsch optical waveguide connectors

NASA Technical Reports Server (NTRS)

1980-01-01

A description of a test program evaluating the performance of an optical waveguide connector system is presented. Both quality and effectiveness of connections made in an optical fiber, performance of the equipment used and applicability of equipment and components to field conditions are reviewed.

Optical interconnection using polyimide waveguide for multichip module

NASA Astrophysics Data System (ADS)

Koyanagi, Mitsumasa

1996-01-01

We have developed a parallel processor system with 152 RISC processor chips specific for Monte-Carlo analysis. This system has the ring-bus architecture. The performance of several Gflops is expected in this system according to the computer simulation. However, it was revealed that the data transfer speed of the bus has to be increased more dramatically in order to further increase the performance. Then, we propose to introduce the optical interconnection into the parallel processor system to increase the data transfer speed of the buses. The double ringbus architecture is employed in this new parallel processor system with optical interconnection. The free-space optical interconnection arid the optical waveguide are used for the optical ring-bus. Thin polyimide film was used to form the optical waveguide. A relatively low propagation loss was achieved in the polyimide optical waveguide. In addition, it was confirmed that the propagation direction of signal light can be easily changed by using a micro-mirror.

Optical interconnection using polyimide waveguide for multichip module

NASA Astrophysics Data System (ADS)

Koyanagi, Mitsumasa

1996-01-01

We have developed a parallel processor system with 152 RISC processor chips specific for Monte-Carlo analysis. This system has the ring-bus architecture. The performance of several Gflops is expected in this system according to the computer simulation. However, it was revealed that the data transfer speed of the bus has to be increased more dramatically in order to further increase the performance. Then, we propose to introduce the optical interconnection into the parallel processor system to increase the data transfer speed of the buses. The double ring-bus architecture is employed in this new parallel processor system with optical interconnection. The free-space optical interconnection and the optical waveguide are used for the optical ring-bus. Thin polyimide film was used to form the optical waveguide. A relatively low propagation loss was achieved in the polyimide optical waveguide. In addition, it was confirmed that the propagation direction of signal light can be easily changed by using a micro-mirror.

Optical coupling of bare optoelectronic components and flexographically printed polymer waveguides in planar optronic systems

NASA Astrophysics Data System (ADS)

Wang, Yixiao; Wolfer, Tim; Lange, Alex; Overmeyer, Ludger

2016-05-01

Large scale, planar optronic systems allowing spatially distributed functionalities can be well used in diverse sensor networks, such as for monitoring the environment by measuring various physical quantities in medicine or aeronautics. In these systems, mechanically flexible and optically transparent polymeric foils, e.g. polymethyl methacrylate (PMMA) and polyethylene terephthalate (PET), are employed as carrier materials. A benefit of using these materials is their low cost. The optical interconnections from light sources to light transmission structures in planar optronic systems occupy a pivotal position for the sensing functions. As light sources, we employ the optoelectronic components, such as edgeemitting laser diodes, in form of bare chips, since their extremely small structures facilitate a high integration compactness and ensure sufficient system flexibility. Flexographically printed polymer optical waveguides are deployed as light guiding structures for short-distance communication in planar optronic systems. Printing processes are utilized for this generation of waveguides to achieve a cost-efficient large scale and high-throughput production. In order to attain a high-functional optronic system for sensing applications, one of the most essential prerequisites is the high coupling efficiency between the light sources and the waveguides. Therefore, in this work, we focus on the multimode polymer waveguide with a parabolic cross-section and investigate its optical coupling with the bare laser diode. We establish the geometrical model of the alignment based on the previous works on the optodic bonding of bare laser diodes and the fabrication process of polymer waveguides with consideration of various parameters, such as the beam profile of the laser diode, the employed polymer properties of the waveguides as well as the carrier substrates etc. Accordingly, the optical coupling of the bare laser diodes and the polymer waveguides was simulated. Additionally, we demonstrate optical links by adopting the aforementioned processes used for defining the simulation. We verify the feasibility of the developed processes for planar optronic systems by using an active alignment and conduct discussions for further improvements of optical alignment.

Photonic crystal Fano resonances for realizing optical switches, lasers, and non-reciprocal elements

NASA Astrophysics Data System (ADS)

Bekele, Dagmawi A.; Yu, Yi; Hu, Hao; Ding, Yunhong; Sakanas, Aurimas; Ottaviano, Luisa; Semenova, Elizaveta; Oxenløwe, Leif K.; Yvind, Kresten; Mork, Jesper

2017-08-01

We present our work on photonic crystal membrane devices exploiting Fano resonance between a line-defect waveguide and a side coupled nanocavity. Experimental demonstration of fast and compact all-optical switches for wavelength-conversion is reported. It is shown how the use of an asymmetric structure in combination with cavity-enhanced nonlinearity can be used to realize non-reciprocal transmission at ultra-low power and with large bandwidth. A novel type of laser structure, denoted a Fano laser, is discussed in which one of the mirrors is based on a Fano resonance. Finally, the design, fabrication and characterization of grating couplers for efficient light coupling in and out of the indium phosphide photonic crystal platform is discussed.

Fully optical backplane system using novel optical plug and slot

NASA Astrophysics Data System (ADS)

Cho, In-Kui; Ahn, Seung-Ho; Lee, Woo-Jin; Han, Sang-Pil; Kim, Jin-Tae; Choi, Chun-Ki; Shin, Kyung-Up; Yoon, Keun Byoung; Jeong, Myung-Yung; Park, Hyo Hoon

2005-10-01

A fully optical PCB with transmitter/receiver system boards and optical bakcplane was prepared, which is board-to-board interconnection by an optical slot. We report a 10 Gb/s PRBS NRZ data transmission between transmitter system board and optical backplane embedded multimode polymeric waveguide arrays. The basic concept of the optical PCB is as follows; 1) Metal optical bench is integrated with optoelectronic devices, driver and receiver circuits, polymeric waveguide and access line PCB module. 2) Multimode polymeric waveguide inside an optical backplane, which is embedded into PCB, 3) Optical slot and plug for high-density (channel pitch : 500 um) board-to-board interconnection. The polymeric waveguide technology can be used for transmission of data between transmitter/receiver processing boards and backplane boards. The main components are low-loss tapered polymeric waveguides and a novel optical plug and slot for board-to-board interconnections, respectively. The transmitter/receiver processing boards are designed as plug types, and can be easily plugged-in and -out at an optical backplane board. The optical backplane boards are prepared by employing the lamination processes for conventional electrical PCBs. A practical optical backplane system was implemented with two processing boards and an optical backplane. As connection components between the transmitter/receiver processing boards and backplane board, optical slots made of a 90°-bending structure-embedded optical plug was used. A 10 Gb/s data link was successfully demonstrated. The bit error rate (BER) was determined and is 5.6×10 -9(@10Gb/s) and the BER of 8 Gb/s is < 10 -12.

The formation and optical properties of planar waveguide in laser crystal Nd:YGG by carbon ion implantation

NASA Astrophysics Data System (ADS)

Zhao, Jin-Hua; Qin, Xi-Feng; Wang, Feng-Xiang; Jiao, Yang; Guan, Jing; Fu, Gang

2017-10-01

As one kind of prominent laser crystal, Nd:Y3Ga5O12 (Nd:YGG) crystal has outstanding performance on laser excitation at multi-wavelength which have shown promising applications in optical communication field. In addition, Nd:YGG crystal has potential applications in medical field due to its ability of emit the laser at 1110 nm. Optical waveguide structure with high quality could improve the efficiency of laser emission. In this work, we fabricated the optical planar waveguide on Nd:YGG crystal by medium mass ion implantation which was convinced an effective method to realize a waveguide structure with superior optical properties. The sample is implanted by C ions at energy of 5.0 MeV with the fluence of 1 × 1015 ions/cm2. We researched the optical propagation properties in the Nd:YGG waveguide by end-face coupling and prism coupling method. The Nd ions fluorescent properties are obtained by a confocal micro-luminescence measurement. The fluorescent properties of Nd ions obtained good reservation after C ion implantation. Our work has reference value for the application of Nd:YGG crystal in the field of optical communication.

Waveguide metatronics: Lumped circuitry based on structural dispersion.

PubMed

Li, Yue; Liberal, Iñigo; Della Giovampaola, Cristian; Engheta, Nader

2016-06-01

Engineering optical nanocircuits by exploiting modularization concepts and methods inherited from electronics may lead to multiple innovations in optical information processing at the nanoscale. We introduce the concept of "waveguide metatronics," an advanced form of optical metatronics that uses structural dispersion in waveguides to obtain the materials and structures required to construct this class of circuitry. Using numerical simulations, we demonstrate that the design of a metatronic circuit can be carried out by using a waveguide filled with materials with positive permittivity. This includes the implementation of all "lumped" circuit elements and their assembly in a single circuit board. In doing so, we extend the concepts of optical metatronics to frequency ranges where there are no natural plasmonic materials available. The proposed methodology could be exploited as a platform to experimentally validate optical metatronic circuits in other frequency regimes, such as microwave frequency setups, and/or to provide a new route to design optical nanocircuitry.

Assembly of optical fibers for the connection of polymer-based waveguide

NASA Astrophysics Data System (ADS)

Ansel, Yannick; Grau, Daniel; Holzki, Markus; Kraus, Silvio; Neumann, Frank; Reinhard, Carsten; Schmitz, Felix

2003-03-01

This paper describes the realization of polymer-based optical structures and the assembly and packaging strategy to connect optical fiber ribbons to the waveguides. For that a low cost fabrication process using the SU-8TM thick photo-resist is presented. This process consists in the deposition of two photo-structurized resist layers filled up with epoxy glue realising the core waveguide. For the assembly, a new modular vacuum gripper was realised and installed on an automatic pick and place assembly robot to mount precisely and efficiently the optical fibers in the optical structures. First results have shown acceptable optical propagation loss for the complete test structure.

Forecast analysis of optical waveguide bus performance

NASA Technical Reports Server (NTRS)

Ledesma, R.; Rourke, M. D.

1979-01-01

Elements to be considered in the design of a data bus include: architecture; data rate; modulation, encoding, detection; power distribution requirements; protocol, work structure; bus reliability, maintainability; interterminal transmission medium; cost; and others specific to application. Fiber- optic data bus considerations for a 32 port transmissive star architecture, are discussed in a tutorial format. General optical-waveguide bus concepts, are reviewed. The electrical and optical performance of a 32 port transmissive star bus, and the effects of temperature on the performance of optical-waveguide buses are examined. A bibliography of pertinent references and the bus receiver test results are included.

High voltage photo switch package module

DOEpatents

Sullivan, James S; Sanders, David M; Hawkins, Steven A; Sampayan, Stephen E

2014-02-18

A photo-conductive switch package module having a photo-conductive substrate or wafer with opposing electrode-interface surfaces, and at least one light-input surface. First metallic layers are formed on the electrode-interface surfaces, and one or more optical waveguides having input and output ends are bonded to the substrate so that the output end of each waveguide is bonded to a corresponding one of the light-input surfaces of the photo-conductive substrate. This forms a waveguide-substrate interface for coupling light into the photo-conductive wafer. A dielectric material such as epoxy is then used to encapsulate the photo-conductive substrate and optical waveguide so that only the metallic layers and the input end of the optical waveguide are exposed. Second metallic layers are then formed on the first metallic layers so that the waveguide-substrate interface is positioned under the second metallic layers.

Mid-infrared frequency comb generation via cascaded quadratic nonlinearities in quasi-phase-matched waveguides

NASA Astrophysics Data System (ADS)

Kowligy, Abijith S.; Lind, Alex; Hickstein, Daniel D.; Carlson, David R.; Timmers, Henry; Nader, Nima; Cruz, Flavio C.; Ycas, Gabriel; Papp, Scott B.; Diddams, Scott A.

2018-04-01

We experimentally demonstrate a simple configuration for mid-infrared (MIR) frequency comb generation in quasi-phase-matched lithium niobate waveguides using the cascaded-$\\chi^{(2)}$ nonlinearity. With nanojoule-scale pulses from an Er:fiber laser, we observe octave-spanning supercontinuum in the near-infrared with dispersive-wave generation in the 2.5--3 $\\text{\\mu}$m region and intra-pulse difference-frequency generation in the 4--5 $\\text{\\mu}$m region. By engineering the quasi-phase-matched grating profiles, tunable, narrow-band MIR and broadband MIR spectra are both observed in this geometry. Finally, we perform numerical modeling using a nonlinear envelope equation, which shows good quantitative agreement with the experiment---and can be used to inform waveguide designs to tailor the MIR frequency combs. Our results identify a path to a simple single-branch approach to mid-infrared frequency comb generation in a compact platform using commercial Er:fiber technology.

Mid-infrared frequency comb generation via cascaded quadratic nonlinearities in quasi-phase-matched waveguides.

PubMed

Kowligy, Abijith S; Lind, Alex; Hickstein, Daniel D; Carlson, David R; Timmers, Henry; Nader, Nima; Cruz, Flavio C; Ycas, Gabriel; Papp, Scott B; Diddams, Scott A

2018-04-15

We experimentally demonstrate a simple configuration for mid-infrared (MIR) frequency comb generation in quasi-phase-matched lithium niobate waveguides using the cascaded-χ (2) nonlinearity. With nanojoule-scale pulses from an Er:fiber laser, we observe octave-spanning supercontinuum in the near-infrared with dispersive wave generation in the 2.5-3 μm region and intrapulse difference frequency generation in the 4-5 μm region. By engineering the quasi-phase-matched grating profiles, tunable, narrowband MIR and broadband MIR spectra are both observed in this geometry. Finally, we perform numerical modeling using a nonlinear envelope equation, which shows good quantitative agreement with the experiment-and can be used to inform waveguide designs to tailor the MIR frequency combs. Our results identify a path to a simple single-branch approach to mid-infrared frequency comb generation in a compact platform using commercial Er:fiber technology.