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Sample records for finesse optical cavities

  1. Diffraction-limited high-finesse optical cavities

    SciTech Connect

    Kleckner, Dustin; Irvine, William T. M.; Oemrawsingh, Sumant S. R.; Bouwmeester, Dirk

    2010-04-15

    High-quality optical cavities with wavelength-sized end mirrors are important to the growing field of micro-optomechanical systems. We present a versatile method for calculating the modes of diffraction limited optical cavities and show that it can be used to determine the effect of a wide variety of cavity geometries and imperfections. Additionally, we show these calculations agree remarkably well with FDTD simulations for wavelength-sized optical modes, even though our method is based on the paraxial approximation.

  2. Deterministic Loading of Individual Atoms to a High-Finesse Optical Cavity

    SciTech Connect

    Fortier, Kevin M.; Kim, Soo Y.; Gibbons, Michael J.; Ahmadi, Peyman; Chapman, Michael S.

    2007-06-08

    Individual laser-cooled atoms are delivered on demand from a single atom magneto-optic trap to a high-finesse optical cavity using an atom conveyor. Strong coupling of the atom with the cavity field allows simultaneous cooling and detection of individual atoms for time scales exceeding 15 s. The single atom scatter rate is studied as a function of probe-cavity detuning and probe Rabi frequency, and the experimental results are in qualitative agreement with theoretical predictions. We demonstrate the ability to manipulate the position of a single atom relative to the cavity mode with excellent control and reproducibility.

  3. High finesse pulsed optical cavity locking by tilt-locking technique

    NASA Astrophysics Data System (ADS)

    You, Y.; Chiche, R.; Yan, L. X.; Huang, W. H.; Tang, C. X.; Zomer, F.

    2014-03-01

    We report the Tilt-Locking (TL) technique applied to lock a laser in pulsed regime to a 28 000 high finesse Fabry-Perot cavity. Preliminary experimental results show that TL technique is comparable with the well-known Pound-Drever-Hall technique. This study is the first to implement the TL technique to lock a pulsed laser to a high-finesse optical cavity. Very high and stable coupling is obtained. The coupling rate is ˜80%, and locking can last for more than 1 h. Furthermore, while previously published papers have focused on near field case, in this study we will give the error signal shape simulation for the far field case. We will show that for different types of error sources, the split photodiode transverse position can be carefully adjusted to obtain a symmetrical error signal. Our experimental results are consistent with the simulations.

  4. Electromagnetically induced transparency with Rydberg atoms inside a high-finesse optical cavity

    NASA Astrophysics Data System (ADS)

    Sheng, Jiteng; Kumar, Santosh; Sedlacek, Jonathon; Chao, Yuanxi; Fan, Haoquan; Shaffer, James

    2016-05-01

    We present experimental work on the observation of Rydberg electromagnetically induced transparency (EIT) inside a high-finesse optical cavity. We show that a cold atomic cloud with controllable number of atoms can be transported into the cavity by using a focus-tunable lens. Rydberg atoms are excited via a two-photon transition in a ladder-type EIT configuration. A three-peak structure in the cavity transmission can be observed when Rydberg EIT atoms are generated inside the cavity. The two side peaks are caused by ``bright state polaritons'', while the central peak corresponds to a ``dark-state polariton'' The cavity Rydberg EIT system can be useful for single photon generation using the Rydberg blockade effect, studying many-body physics, and generating novel quantum states amongst many other applications. This work is supported by AFOSR.

  5. Water-walled microfluidics for high-optical finesse cavities

    NASA Astrophysics Data System (ADS)

    Maayani, Shai; Martin, Leopoldo L.; Carmon, Tal

    2016-01-01

    In submerged microcavities there is a tradeoff between resonant enhancement for spatial water and light overlap. Why not transform the continuously resonating optical mode to be fully contained in a water microdroplet per se? Here we demonstrate a sustainable 30-μm-pure water device, bounded almost completely by free surfaces, enabling >1,000,000 re-circulations of light. The droplets survive for >16 h using a technique that is based on a nano-water bridge from the droplet to a distant reservoir to compensate for evaporation. More than enabling a nearly-perfect optical overlap with water, atomic-level surface smoothness that minimizes scattering loss, and ~99% coupling efficiency from a standard fibre. Surface tension in our droplet is 8,000 times stronger than gravity, suggesting a new class of devices with water-made walls, for new fields of study including opto-capillaries.

  6. Water-walled microfluidics for high-optical finesse cavities

    PubMed Central

    Maayani, Shai; Martin, Leopoldo L.; Carmon, Tal

    2016-01-01

    In submerged microcavities there is a tradeoff between resonant enhancement for spatial water and light overlap. Why not transform the continuously resonating optical mode to be fully contained in a water microdroplet per se? Here we demonstrate a sustainable 30-μm-pure water device, bounded almost completely by free surfaces, enabling >1,000,000 re-circulations of light. The droplets survive for >16 h using a technique that is based on a nano-water bridge from the droplet to a distant reservoir to compensate for evaporation. More than enabling a nearly-perfect optical overlap with water, atomic-level surface smoothness that minimizes scattering loss, and ∼99% coupling efficiency from a standard fibre. Surface tension in our droplet is 8,000 times stronger than gravity, suggesting a new class of devices with water-made walls, for new fields of study including opto-capillaries. PMID:26794271

  7. High finesse optical fiber cavities: optimal alignment and robust stabilization (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ratschbacher, Lothar; Gallego, Jose; Ghosh, Sutapa; Alavi, Seyed; Alt, Wolfgang; Martinez-Dorantes, Miguel; Meschede, Dieter

    2016-04-01

    Fiber Fabry-Perot cavities, formed by micro-machined mirrors on the end-facets of optical fibers, are used in an increasing number of technical and scientific applications. Some of the most promising areas of application of these optical micro-resonators with high finesse and small mode volume are in the field of quantum communication and information. The resonator-enhanced light-matter interaction, for instance, provide basis for the realization of efficient optical interfaces between stationary matter-based quantum nodes and flying single-photon qubits. To date fiber Fabry-Perot cavities have been successfully applied in experiments interfacing single photons with a wide range of quantum systems, including cold atoms, ions and solid state emitters as well as quantum optomechanical experiments. Here we address some important practical questions that arise during the experimental implementation of high finesse fiber Fabry-Perot cavities: How can optimal fiber cavity alignment be achieved and how can the efficiency of coupling light from the optical fibers to the cavity mode and vice versa be characterized? How should optical fiber cavities be constructed and stabilized to fulfill their potential for miniaturization and integration into robust scientific and technological devices that can operate outside of dedicated laboratory environments in the future? The first two questions we answer with an analytic mode matching calculation that relates the alignment dependent fiber-to-cavity mode-matching efficiency to the easily measurable dip in the reflected light power at the cavity resonance. Our general analysis provides a simple recipe for the optimal alignment of fiber Fabry-Perot cavities and moreover for the first time explains the asymmetry in their reflective line shapes. The latter question we explore by investigating a novel, intrinsically rigid fiber cavity design that makes use of the high passive stability of a monolithic cavity spacer and employs thermal

  8. Strong dispersive coupling between a micromechanical oscillator and a high finesse optical cavity.

    NASA Astrophysics Data System (ADS)

    Harris, Jack

    2008-03-01

    Very sensitive mechanical detectors spanning roughly seventeen orders of magnitude in size are rapidly approaching a regime in which either the mechanical device itself or its readout should demonstrate quantum behavior. One of the main technical barriers to actually reaching this regime has been the difficulty of integrating ultrasensitive micromechanical devices with high-finesse optical cavities. Recently we have developed a robust means for addressing this issue, and have integrated a 50 nm-thick membrane (with a quality factor > 1,000,000) into an optical cavity with a finesse ˜ 20,000. Although the membrane is nearly transparent, it couples to the optical cavity dispersively. This coupling is strong enough to laser-cool the membrane from room temperature to 7 mK. In addition, the dispersive nature of the optomechanical coupling allows us to realize a sensitive ``displacement squared'' readout of the membrane. Such a readout is a crucial requirement for measuring quantum jumps in a mechanical oscillator. We will describe these results, as well as our progress towards observing quantum effects in this system.

  9. High finesse optical cavity coupled with a quartz-enhanced photoacoustic spectroscopic sensor.

    PubMed

    Patimisco, Pietro; Borri, Simone; Galli, Iacopo; Mazzotti, Davide; Giusfredi, Giovanni; Akikusa, Naota; Yamanishi, Masamichi; Scamarcio, Gaetano; De Natale, Paolo; Spagnolo, Vincenzo

    2015-02-01

    An ultra-sensitive and selective quartz-enhanced photoacoustic spectroscopy (QEPAS) combined with a high-finesse cavity sensor platform is proposed as a novel method for trace gas sensing. We call this technique Intra-cavity QEPAS (I-QEPAS). In the proposed scheme, a single-mode continuous wave quantum cascade laser (QCL) is coupled into a bow-tie optical cavity. The cavity is locked to the QCL emission frequency by means of a feedback-locking loop that acts directly on a piezoelectric actuator mounted behind one of the cavity mirrors. A power enhancement factor of ∼240 was achieved, corresponding to an intracavity power of ∼0.72 W. CO2 was selected as the target gas to validate our sensor. For the P(42) CO2 absorption line, located at 2311.105 cm(-1), a minimum detection limit of 300 parts per trillion by volume at a total gas pressure of 50 mbar was achieved with a 20 s integration time. This corresponds to a normalized noise equivalent absorption of 3.2 × 10(-10) W cm(-1) Hz(-1/2), comparable with the best results reported for the QEPAS technique on much faster relaxing gases. A comparison with standard QEPAS performed under the same experimental conditions confirms that the I-QEPAS sensitivity scales with the intracavity laser power enhancement factor. PMID:25465410

  10. Very high finesse optical-feedback cavity-enhanced absorption spectrometer for low concentration water vapor isotope analyses.

    PubMed

    Landsberg, J; Romanini, D; Kerstel, E

    2014-04-01

    So far, cavity-enhanced absorption spectroscopy (CEAS) has been based on optical cavities with a high finesse F that, however, has been limited by mirror reflectivity and by cavity transmission considerations to a few times 10,000. Here, we demonstrate a compact near-infrared optical-feedback CEAS instrument for water vapor isotope ratio measurements, with F>140,000. We show that this very high finesse can be effectively exploited to improve the detection sensitivity to the full extent predicted by the increased effective path length to reach a noise equivalent absorption sensitivity of 5.7×10(-11)  cm(-1) Hz(-1/2) for a full spectrum registration (including possible effects of interference fringes and fit model inadequacies). PMID:24686607

  11. Precision measurement of single atoms strongly coupled to the higher-order transverse modes of a high-finesse optical cavity

    SciTech Connect

    Du, Jinjin; Li, Wenfang; Wen, Ruijuan; Li, Gang; Zhang, Pengfei; Zhang, Tiancai

    2013-08-19

    We have experimentally demonstrated the strong coupling between single atoms and the higher-order Hermite-Gaussian transverse modes in a high-finesse optical microcavity. Compared to the usual low-order symmetric transverse modes, multiple lobes and the asymmetric spatial pattern of the titled modes provide more information about the motion of single atoms in the cavity. The motional information can be extracted from the measured transmission spectra, which includes the velocities and the positions of the atoms in vertical and off-axis directions. The scheme has great potential in time-resolved atom-cavity microscopy and in tracking the three-dimensional single atom trajectory in real time.

  12. Birefringence-induced frequency beating in high-finesse cavities by continuous-wave cavity ring-down spectroscopy

    NASA Astrophysics Data System (ADS)

    Dupré, Patrick

    2015-11-01

    By analyzing the decaying intensity, leaking out a high-finesse cavity previously "filled" by a cw laser source (using the cavity ring-down spectroscopy technique), we observed frequency beating between what we think are two orthogonal eigenpolarization states of the intracavity electromagnetic field. The time decay (ring down) is analyzed by varying the angle of the polarization analyzer located in front of the detector. A full modeling of the observed signal is proposed. It is based on the Jones matrix formalism required for modeling the cavity behavior following a rotated phase shifter. The full transfer function is first established in the frequency domain, and then Fourier transformed to recover the temporal response. The same optical cavity, i.e., constituted of the same set of mirrors, is used at two different wavelengths (˜800 and ˜880 nm). It demonstrates the differences in behavior between a high-finesse cavity (˜400 000 ) and a lower finesse cavity (˜50 000 ). Beating frequency, characteristics time, and beat amplitude are mainly discussed versus the analyzer angle. A cavity birefringence of ˜1.6 ×10-5 rad, resulting from the mirror birefringence is suggested. If the current analysis is in agreement with pulsed CRDS experiments (polarimetry) obtained in an isotropic moderate-finesse cavity, it differs from a recent work report on a high-finesse cavity associated with a source mode locking [Phys. Rev. A 85, 013837 (2012), 10.1103/PhysRevA.85.013837].

  13. Development of a mode-locked fiber laser system for a high finesse enhancement cavity

    NASA Astrophysics Data System (ADS)

    Suzuki, R.; Kobayashi, T.; Sakaue, K.; Washio, M.; Endo, A.

    2015-05-01

    We have been studying a high finesse enhancement cavity for photon target of Laser Compton Scattering X-ray generation. It is very important to develop an extremely stable external optical cavity for laser Compton scattering. At the same time, a stable seed laser oscillator for an incident laser of an optical cavity is also very important tissue. Thus, we have been developing a stabil mode-locked Yb-doped fiber laser based on Non-Linear Polarization Rotation. We have generated laser pulses which have 102.9mW average power at repetition rate of 119MHz. Furthermore, we started accumulating lasers in the optical cavity, and we have already confirmed that our oscillator is able to accumulate in the cavity.

  14. High-finesse fiber Fabry-Perot cavities: stabilization and mode matching analysis

    NASA Astrophysics Data System (ADS)

    Gallego, J.; Ghosh, S.; Alavi, S. K.; Alt, W.; Martinez-Dorantes, M.; Meschede, D.; Ratschbacher, L.

    2016-03-01

    Fiber Fabry-Perot cavities, formed by micro-machined mirrors on the end-facets of optical fibers, are used in an increasing number of technical and scientific applications, where they typically require precise stabilization of their optical resonances. Here, we study two different approaches to construct fiber Fabry-Perot resonators and stabilize their length for experiments in cavity quantum electrodynamics with neutral atoms. A piezo-mechanically actuated cavity with feedback based on the Pound-Drever-Hall locking technique is compared to a novel rigid cavity design that makes use of the high passive stability of a monolithic cavity spacer and employs thermal self-locking and external temperature tuning. Furthermore, we present a general analysis of the mode matching problem in fiber Fabry-Perot cavities, which explains the asymmetry in their reflective line shapes and has important implications for the optimal alignment of the fiber resonators. Finally, we discuss the issue of fiber-generated background photons. We expect that our results contribute toward the integration of high-finesse fiber Fabry-Perot cavities into compact and robust quantum-enabled devices in the future.

  15. Shot-noise-limited measurement of sub-parts-per-trillion birefringence phase shift in a high-finesse cavity

    SciTech Connect

    Durand, Mathieu; Morville, Jerome; Romanini, Daniele

    2010-09-15

    We report on a promising approach to high-sensitivity anisotropy measurements using a high-finesse cavity locked by optical feedback to a diode laser. We provide a simple and effective way to decouple the weak anisotropy of interest from the inherent mirror's birefringence whose drift may be identified as the key limiting parameter in cavity-based techniques. We demonstrate a shot-noise-limited phase shift resolution previously inaccessible in an optical cavity, readily achieving the state-of-the-art level of 3x10{sup -13} rad.

  16. Frequency stabilized optical comb source with high finesse intracavity etalon

    NASA Astrophysics Data System (ADS)

    Ozdur, Ibrahim; Ozharar, Sarper; Akbulut, Mehmetcan; Mandridis, Dimitrios; Quinlan, Franklyn; Delfyett, Peter J.

    2009-05-01

    Mode-locked lasers have applications in signal processing and communications such as analog to digital conversion, arbitrary waveform generation and wavelength division multiplexing. For such applications low noise and phase coherent frequency stabilized optical combs are needed. In this work we report a low noise, Pound-Drever Hall frequency stabilized, semiconductor mode-locked laser at 10.287GHz centered at 1550nm with 1000-Finesse sealed, ultralow insertion loss intracavity etalon. The output optical power of the mode locked laser is ~5mW.

  17. Reducing the linewidth of a diode laser below 30 Hz by stabilization to a reference cavity with a finesse above 10(5).

    PubMed

    Schoof, A; Grünert, J; Ritter, S; Hemmerich, A

    2001-10-15

    An extended-cavity diode laser operating in the Littrow configuration emitting near 657 nm is stabilized through its injection current to a reference cavity with a finesse of more than 10(5) and a corresponding resonance linewidth of 14 kHz. The laser linewidth is reduced from a few megahertz to a value below 30 Hz. The compact and robust setup appears ideal as a portable optical frequency standard that uses the calcium intercombination line. PMID:18049663

  18. Compton scattering off polarized electrons with a high-finesse Fabry-Perot Cavity at Jlab

    SciTech Connect

    Nicolas Falletto; Martial Authier; Maud Baylac; M. Boyer; Francois Bugeon; Etienne Burtin; Christian Cavata; Nathalie Colombel; G. Congretel; R. Coquillard; G. Coulloux; Bertrand Couzy; P Deck; Alain Delbart; D. Desforges; A. Donati; B. Duboue; Stephanie Escoffier; F. Farci; Bernard Frois; P Girardot; J Guillotau; C Henriot; Claude Jeanney; M Juillard; J. P. Jorda; P. Legou; David Lhuillier; Y Lussignol; Phillippe Mangeot; X. Martin; Frederic Marie; Jacques Martino; M. Maurier; Bernard Mazeau; J.F. Millot; F. Molinie; J.-P. Mols; Jean-pierre Mouly; M. Mur; Damien Neyret; T. Pedrol; Stephane Platchkov; G. Pontet; Thierry Pussieux; Yannick Queinec; Philippe Rebourgeard; J. C. Sellier; Gerard Tarte; Christian Veyssiere; Andre Zakarian; Pierre Bertin; Alain Cosquer; Jian-ping Chen; Joseph Mitchell; J.-M. Mackowski; L. Pinard

    2001-03-01

    We built and commissioned a new type of Compton polarimeter to measure the electron beam polarization at the Thomas Jefferson National Accelerator Facility (Virginia, USA). The heart of this polarimeter is a high-finesse monolithic Fabry-Perot cavity. Its purpose is to amplify a primary 300 mW laser beam in order to improve the signal to noise ratio of the polarimeter. It is the first time that a high-finesse Fabry-Perot cavity is enclosed in the vacuum of a particle accelerator to monitor the beam polarization by Compton polarimetry. The measured finesse and amplification gain of the cavity are F=26000 and G=7300. The electron beam crosses this high-power photon source at an angle of 23 mrad in the middle of the cavity where the photon beam power density is estimated to be 0.85MW/cm2. We have used this facility during the HAPPEX experiment (April-July 1999) and we give a preliminary measurement of Compton scattering asymmetry.

  19. Diode laser frequency stabilization using a low cost, low finesse Fabry-Perot cavity

    NASA Astrophysics Data System (ADS)

    Hastings, Hannah; Jaber, Noura B.; Piatt, Georgia; Gregoric, Vincent C.; Carroll, Thomas J.; Noel, Michael W.

    2016-05-01

    Our lab employs low cost, low finesse Fabry-Perot cavities to stabilize the frequency of diode lasers used in ultra-cold Rydberg atom experiments. To characterize the stability of this technique, we perform a self-heterodyne linewidth measurement. For comparison, we also measure the linewidth when using a saturated absorption spectrometer to provide frequency stability. This work is supported by the National Science Foundation under Grants No. 1205895 and No. 1205897.

  20. Precision Interferometric Measurements of Mirror Birefringence in High-Finesse Optical Resonators

    PubMed Central

    Fleisher, Adam J.; Long, David A.; Liu, Qingnan; Hodges, Joseph T.

    2016-01-01

    High-finesse optical resonators found in ultrasensitive laser spectrometers utilize supermirrors ideally consisting of isotropic high-reflectivity coatings. Strictly speaking, however, the optical coatings are often non-uniformly stressed during the deposition process and therefore do possess some small amount of birefringence. When physically mounted the cavity mirrors can be additionally stressed in such a way that large optical birefringence is induced. Here we report a direct measurement of optical birefringence in a two-mirror Fabry-Pérot cavity with R = 99.99 % by observing TEM00 mode beating during cavity decays. Experiments were performed at a wavelength of 4.53 μm, with precision limited by both quantum and technical noise sources. We report a splitting of δν = 618(1) Hz, significantly less than the intrinsic cavity linewidth of δcav ≈ 3 kHz. With a cavity free spectral range of 96.9 MHz, the equivalent fractional change in mirror refractive index due to birefringence is therefore Δn/n = 6.38(1) × 10−6. PMID:27088133

  1. Precision interferometric measurements of mirror birefringence in high-finesse optical resonators

    NASA Astrophysics Data System (ADS)

    Fleisher, Adam J.; Long, David A.; Liu, Qingnan; Hodges, Joseph T.

    2016-01-01

    High-finesse optical resonators found in ultrasensitive laser spectrometers utilize supermirrors ideally consisting of isotropic high-reflectivity coatings. Strictly speaking, however, the optical coatings are often nonuniformly stressed during the deposition process and therefore do possess some small amount of birefringence. When physically mounted the cavity mirrors can be additionally stressed in such a way that large optical birefringence is induced. Here we report a direct measurement of optical birefringence in a two-mirror Fabry-Pérot cavity with R =99.99 % by observing TEM00 mode beating during cavity decays. Experiments were performed at a wavelength of 4.53 μ m , with precision limited by both quantum and technical noise sources. We report a splitting of δν=618 (1 ) Hz, significantly less than the intrinsic cavity line width of δcav≈3 kHz. With a cavity free spectral range of 96.9 MHz, the equivalent fractional change in mirror refractive index due to birefringence is therefore Δ n /n =6.38 (1 ) ×10-6 .

  2. Frequency stabilization based on high finesse glass-ceramic Fabry-Perot cavity for a 632.8-nm He-Ne laser

    NASA Astrophysics Data System (ADS)

    Fu, Tingting; Yang, Kaiyong; Tan, Zhongqi; Luo, Zhifu; Wu, Suyong

    2014-12-01

    A frequency stabilization technique for a 632.8nm He-Ne laser with a high finesse Fabry-Perot cavity is introduced in this paper. The resonant frequency of the cavity is taken as the frequency standard .In this system the Fabry-Perot cavity is composed of a glass-ceramic spacer, with thermal expansion coefficient smaller than 2×10-8/°C , which means an excellent thermal stabilization which greatly decreases the thermal impacts on the cavity length in the desired constant-temperature environment.The intra-cavity spherical mirror is specially designed, which makes the Fabry-cavity a sensor element in our subsequent experiments for a new practical optical accelerometer .Both cavity mirrors were custom made in our laboratory which have reflectivities greater than 99.995% at 632.8nm, so the Fabry-Perot cavity has a finesse of about 62830. The half-maximum transmission line width is about 55.48 KHz and the free spectral range is 3.5GHz .In the experimental setup, we adopt the frequency stabilization circuit with small dithering .With proper dithering voltage, the laser can be precisely locked to the Fabry-Perot cavity minimum reflection point. Theoretically the frequency stability can reach 10-10 order.

  3. Optical nanofiber-based photonic crystal cavity.

    PubMed

    Nayak, K P; Zhang, Pengfei; Hakuta, K

    2014-01-15

    We demonstrate the fabrication of photonic crystal (PhC) cavities on optical nanofibers using femtosecond laser ablation. PhC cavities with cavity lengths varying from 0.54 to 3.43 mm are fabricated by controlling the profile of the nanocrater array formed on the nanofiber. Such PhC cavities show high transmission of 87% for a finesse of 39. For higher finesse values from 150 to 500, the transmission can still be maintained at 20%-25%. Due to the strong confinement of the field and the efficient coupling to single-mode optical fibers, such nanofiber-based PhC cavities may become an interface between quantum and classical networks. PMID:24562114

  4. Feedback-free optical cavity with self-resonating mechanism

    NASA Astrophysics Data System (ADS)

    Uesugi, Y.; Hosaka, Y.; Honda, Y.; Kosuge, A.; Sakaue, K.; Omori, T.; Takahashi, T.; Urakawa, J.; Washio, M.

    2016-05-01

    We demonstrated the operation of a high finesse optical cavity without utilizing an active feedback system to stabilize the resonance. The effective finesse, which is a finesse including the overall system performance, of the cavity was measured to be 394 000 ± 10 000, and the laser power stored in the cavity was 2.52 ± 0.13 kW, which is approximately 187 000 times greater than the incident power to the cavity. The stored power was stabilized with a fluctuation of 1.7%, and we confirmed continuous cavity operation for more than two hours. This result has the potential to trigger an innovative evolution for applications that use optical resonant cavities such as compact photon sources with laser-Compton scattering or cavity enhanced absorption spectroscopy.

  5. Preventing and reversing vacuum-induced optical losses in high-finesse tantalum (V) oxide mirror coatings.

    PubMed

    Gangloff, Dorian; Shi, Molu; Wu, Tailin; Bylinskii, Alexei; Braverman, Boris; Gutierrez, Michael; Nichols, Rosanna; Li, Junru; Aichholz, Kai; Cetina, Marko; Karpa, Leon; Jelenković, Branislav; Chuang, Isaac; Vuletić, Vladan

    2015-07-13

    High-finesse optical cavities placed under vacuum are foundational platforms in quantum information science with photons and atoms. We study the vacuum-induced degradation of high-finesse optical cavities with mirror coatings composed of SiO₂-Ta₂O₅ dielectric stacks, and present methods to protect these coatings and to recover their initial low loss levels. For separate coatings with reflectivities centered at 370 nm and 422 nm, a vacuum-induced continuous increase in optical loss occurs if the surface-layer coating is made of Ta₂O₅, while it does not occur if it is made of SiO₂. The incurred optical loss can be reversed by filling the vacuum chamber with oxygen at atmospheric pressure, and the recovery rate can be strongly accelerated by continuous laser illumination at 422 nm. Both the degradation and the recovery processes depend strongly on temperature. We find that a 1 nm-thick layer of SiO₂ passivating the Ta₂O₅ surface layer is sufficient to reduce the degradation rate by more than a factor of 10, strongly supporting surface oxygen depletion as the primary degradation mechanism. PMID:26191861

  6. Controllable optical switch using a Bose-Einstein condensate in an optical cavity

    SciTech Connect

    Yang Shuai; Zubairy, M. Suhail; Al-Amri, M.; Evers, Joerg

    2011-05-15

    The optical bistability of an ultracold atomic ensemble located in a small-volume ultrahigh-finesse optical cavity is investigated. We find that a transverse pumping field can be used to control the bistable behavior of the intracavity photons induced by the input pumping along the cavity axis. This phenomenon can be used as a controllable optical switch.

  7. Highly stable piezoelectrically tunable optical cavities

    NASA Astrophysics Data System (ADS)

    Möhle, Katharina; Kovalchuk, Evgeny V.; Döringshoff, Klaus; Nagel, Moritz; Peters, Achim

    2013-05-01

    We have implemented highly stable and tunable frequency references using optical high finesse cavities which incorporate a piezo actuator. As piezo material we used ceramic PZT, crystalline quartz, or PZN-PT single crystals. Lasers locked to these cavities show a relative frequency stability better than 1× 10^{-14}, which is most likely not limited by the piezo actuators. The piezo cavities can be electrically tuned over more than one free spectral range (>1.5 GHz) with only a minor decrease in frequency stability. Furthermore, we present a novel cavity design, where the piezo actuator is prestressed between the cavity spacer components. This design features a hermetically sealable intra cavity volume suitable for, e.g., cavity enhanced spectroscopy.

  8. Optical single photons on-demand teleported from microwave cavities

    NASA Astrophysics Data System (ADS)

    Barzanjeh, Sh; Vitali, D.; Tombesi, P.

    2013-03-01

    We propose a scheme for entangling the optical and microwave output modes of the respective cavities by using a micro mechanical resonator. The micro mechanical resonator, on one side, is capacitively coupled to the microwave cavity and, on the other side, it is coupled to a high-finesses optical cavity. We then show how this continuous variable entanglement can be profitably used to teleport the non-Gaussian number state |1> and the superposition (|0\\rangle +|1\\rangle )/\\sqrt 2 from the microwave cavity output mode onto an output of the optical cavity mode with fidelity much larger than the no-cloning limit.

  9. Dual frequency optical cavity

    DOEpatents

    George, E.V.; Schipper, J.F.

    Method and apparatus for generating two distinct laser frequencies in an optical cavity, using a T configuration laser cavity and means for intermittently increasing or decreasing the index of refraction n of an associated transmission medium in one arm of the optical cavity to enhance laser action in one arm or the second arm of the cavity.

  10. Dual frequency optical cavity

    DOEpatents

    George, E. Victor; Schipper, John F.

    1985-01-01

    Method and apparatus for generating two distinct laser frequencies in an optical cavity, using a "T" configuration laser cavity and means for intermittently increasing or decreasing the index of refraction n of an associated transmission medium in one arm of the optical cavity to enhance laser action in one arm or the second arm of the cavity.

  11. Transmission spectrum of an optical cavity containing N atoms

    SciTech Connect

    Leslie, Sabrina; Shenvi, Neil; Brown, Kenneth R.; Whaley, K. Birgitta; Stamper-Kurn, Dan M.

    2004-04-01

    The transmission spectrum of a high-finesse optical cavity containing an arbitrary number of trapped atoms is presented in the zero-temperature, low saturation limit. We take spatial and motional effects into account and show that in the limit of strong coupling, the important spectral features can be determined for an arbitrary number of atoms, N. We also show that these results have important ramifications in limiting our ability to determine the number of atoms in the cavity.

  12. Dynamical entanglement purification using chains of atoms and optical cavities

    SciTech Connect

    Gonta, Denis; Loock, Peter van

    2011-10-15

    In the framework of cavity QED, we propose a practical scheme to purify dynamically a bipartite entangled state using short chains of atoms coupled to high-finesse optical cavities. In contrast to conventional entanglement purification protocols, we avoid controlled-not gates, thus reducing complicated pulse sequences and superfluous qubit operations. Our interaction scheme works in a deterministic way and, together with entanglement distribution and swapping, opens a route toward efficient quantum repeaters for long-distance quantum communication.

  13. A high-finesse Fabry-Perot cavity with a frequency-doubled green laser for precision Compton polarimetry at Jefferson Lab

    DOE PAGESBeta

    Rakhman, A.; Hafez, Mohamed A.; Nanda, Sirish K.; Benmokhtar, Fatiha; Camsonne, Alexandre; Cates, Gordon D.; Dalton, Mark M.; Franklin, Gregg B.; Friend, Megan L.; Michaels, Robert W.; et al

    2016-03-31

    Here, a high-finesse Fabry-Perot cavity with a frequency-doubled continuous wave green laser (532 nm) has been built and installed in Hall A of Jefferson Lab for high precision Compton polarimetry. The infrared (1064 nm) beam from a ytterbium-doped fiber amplifier seeded by a Nd:YAG nonplanar ring oscillator laser is frequency doubled in a single-pass periodically poled MgO:LiNbO3 crystal. The maximum achieved green power at 5 W infrared pump power is 1.74 W with a total conversion efficiency of 34.8%. The green beam is injected into the optical resonant cavity and enhanced up to 3.7 kW with a corresponding enhancement ofmore » 3800. The polarization transfer function has been measured in order to determine the intra-cavity circular laser polarization within a measurement uncertainty of 0.7%. The PREx experiment at Jefferson Lab used this system for the first time and achieved 1.0% precision in polarization measurements of an electron beam with energy and current of 1.0 GeV and 50 μA.« less

  14. A high-finesse Fabry-Perot cavity with a frequency-doubled green laser for precision Compton polarimetry at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Rakhman, A.; Hafez, M.; Nanda, S.; Benmokhtar, F.; Camsonne, A.; Cates, G. D.; Dalton, M. M.; Franklin, G. B.; Friend, M.; Michaels, R. W.; Nelyubin, V.; Parno, D. S.; Paschke, K. D.; Quinn, B. P.; Souder, P. A.; Tobias, W. A.

    2016-06-01

    A high-finesse Fabry-Perot cavity with a frequency-doubled continuous wave green laser (532 nm) has been built and installed in Hall A of Jefferson Lab for high precision Compton polarimetry. The infrared (1064 nm) beam from a ytterbium-doped fiber amplifier seeded by a Nd:YAG nonplanar ring oscillator laser is frequency doubled in a single-pass periodically poled MgO:LiNbO3 crystal. The maximum achieved green power at 5 W infrared pump power is 1.74 W with a total conversion efficiency of 34.8%. The green beam is injected into the optical resonant cavity and enhanced up to 3.7 kW with a corresponding enhancement of 3800. The polarization transfer function has been measured in order to determine the intra-cavity circular laser polarization within a measurement uncertainty of 0.7%. The PREx experiment at Jefferson Lab used this system for the first time and achieved 1.0% precision in polarization measurements of an electron beam with energy and current of 1.06 GeV and 50 μA.

  15. Preventing and reversing vacuum-induced optical losses in high-finesse tantalum (V) oxide mirror coatings

    NASA Astrophysics Data System (ADS)

    Gangloff, Dorian; Shi, Molu; Wu, Tailin; Bylinskii, Alexei; Braverman, Boris; Gutierrez, Michael; Nichols, Rosanna; Li, Junru; Aichholz, Kai; Cetina, Marko; Karpa, Leon; Jelenković, Branislav; Chuang, Isaac; Vuletić, Vladan

    2015-07-01

    We study the vacuum-induced degradation of high-finesse optical cavities with mirror coatings composed of SiO$_2$-Ta$_{2}$O$_{5}$ dielectric stacks, and present methods to protect these coatings and to recover their initial quality factor. For separate coatings with reflectivities centered at 370 nm and 422 nm, a vacuum-induced continuous increase in optical loss occurs if the surface-layer coating is made of Ta$_{2}$O$_{5}$, while it does not occur if it is made of SiO$_2$. The incurred optical loss can be reversed by filling the vacuum chamber with oxygen at atmospheric pressure, and the recovery rate can be strongly accelerated by continuous laser illumination at 422 nm. Both the degradation and the recovery processes depend strongly on temperature. We find that a 1 nm-thick layer of SiO$_2$ passivating the Ta$_{2}$O$_{5}$ surface layer is sufficient to reduce the degradation rate by more than a factor of 10, strongly supporting surface oxygen depletion as the primary degradation mechanism.

  16. Optically measuring interior cavities

    DOEpatents

    Stone, Gary Franklin

    2009-11-03

    A method of measuring the three-dimensional volume or perimeter shape of an interior cavity includes the steps of collecting a first optical slice of data that represents a partial volume or perimeter shape of the interior cavity, collecting additional optical slices of data that represents a partial volume or perimeter shape of the interior cavity, and combining the first optical slice of data and the additional optical slices of data to calculate of the three-dimensional volume or perimeter shape of the interior cavity.

  17. Optically measuring interior cavities

    DOEpatents

    Stone, Gary Franklin

    2008-12-21

    A method of measuring the three-dimensional volume or perimeter shape of an interior cavity includes the steps of collecting a first optical slice of data that represents a partial volume or perimeter shape of the interior cavity, collecting additional optical slices of data that represents a partial volume or perimeter shape of the interior cavity, and combining the first optical slice of data and the additional optical slices of data to calculate of the three-dimensional volume or perimeter shape of the interior cavity.

  18. Embedded coupled microrings with high-finesse and close-spaced resonances for optical signal processing.

    PubMed

    Souza, Mario C M M; Barea, Luis A M; Vallini, Felipe; Rezende, Guilherme F M; Wiederhecker, Gustavo S; Frateschi, Newton C

    2014-05-01

    Single microring resonators have been used in applications such as wavelength multicasting and microwave photonics, but the dependence of the free spectral range with ring radius imposes a trade-off between the required GHz optical channel spacing, footprint and power consumption. We demonstrate four-channel all-optical wavelength multicasting using only 1 mW of control power, with converted channel spacing of 40-60 GHz. Our device is based on a compact embedded microring design fabricated on a scalable SOI platform. The coexistence of close resonance spacing and high finesse (205) in a compact footprint is possible due to enhanced quality factors (30,000) resulting from the embedded configuration and the coupling-strength dependence of resonance spacing, instead of ring size. In addition, we discuss the possibility of achieving continuously mode splitting from a single-notch resonance up to 40 GHz. PMID:24921744

  19. Tuned optical cavity magnetometer

    DOEpatents

    Okandan, Murat; Schwindt, Peter

    2010-11-02

    An atomic magnetometer is disclosed which utilizes an optical cavity formed from a grating and a mirror, with a vapor cell containing an alkali metal vapor located inside the optical cavity. Lasers are used to magnetically polarize the alkali metal vapor and to probe the vapor and generate a diffracted laser beam which can be used to sense a magnetic field. Electrostatic actuators can be used in the magnetometer for positioning of the mirror, or for modulation thereof. Another optical cavity can also be formed from the mirror and a second grating for sensing, adjusting, or stabilizing the position of the mirror.

  20. A 23.75-GHz frequency comb with two low-finesse filtering cavities in series for high resolution spectroscopy

    NASA Astrophysics Data System (ADS)

    Lei, Hou; Hai-Nian, Han; Wei, Wang; Long, Zhang; Li-Hui, Pang; De-Hua, Li; Zhi-Yi, Wei

    2015-02-01

    A laser frequency comb with several tens GHz level is demonstrated, based on a Yb-doped femtosecond fiber laser and two low-finesse Fabry-Pérot cavities (FPCs) in series. The original 250-MHz mode-line-spacing of the source comb is filtered to 4.75 GHz and 23.75 GHz, respectively. According to the multi-beam interferences theory of FPC, the side-mode suppression rate of FPC schemes is in good agreement with our own theoretical results from 27 dB of a single FPC to 43 dB of paired FPCs. To maintain long-term stable operation and determine the absolute frequency mode number in the 23.75-GHz comb, the Pound-Drever-Hall (PDH) locking technology is utilized. Such stable tens GHz frequency combs have important applications in calibrating astronomical spectrographs with high resolution. Project supported by the National Basic Research Program of China (Grant No. 2012CB821304) and the National Natural Science Foundation of China (Grant Nos. 11078022 and 61378040).

  1. Thermalization and condensation in an incoherently pumped passive optical cavity

    NASA Astrophysics Data System (ADS)

    Michel, C.; Haelterman, M.; Suret, P.; Randoux, S.; Kaiser, R.; Picozzi, A.

    2011-09-01

    We study theoretically and numerically the condensation and the thermalization of classical optical waves in an incoherently pumped passive Kerr cavity. We show that the dynamics of the cavity exhibits a turbulent behavior that can be described by the wave turbulence theory. A mean-field kinetic equation is derived, which reveals that, in its high finesse regime, the cavity behaves essentially as a conservative Hamiltonian system. In particular, the intracavity turbulent field is shown to relax adiabatically toward a thermodynamic equilibrium state of energy equipartition. As a consequence of this effect of wave thermalization, the incoherent optical field undergoes a process of condensation, characterized by the spontaneous emergence of a plane wave from the incoherently pumped cavity. The condensation process is an equilibrium phase transition that occurs below a critical value of the (kinetic) energy of the incoherent pump. In spite of the dissipative nature of the cavity dynamics, the condensate fraction of the high-finesse cavity field is found in quantitative agreement with the theory inherited from the purely conservative (Hamiltonian) nonlinear Schrödinger equation.

  2. Crosstalk analysis of the in-line quasi-distributed low-coherence low-finesse Fabry-Pérot fiber-optic interferometric sensors

    NASA Astrophysics Data System (ADS)

    Manojlović, Lazo M.

    2016-09-01

    A crosstalk analysis of the in-line quasi-distributed low-coherence low-finesse Fabry-Pérot fiber-optic interferometric sensors is presented in this paper. The appropriate selection of the sensor cavity lengths eliminates the presence of the second-order intermodulations. Therefore, the intermodulations that can significantly influence the sensors crosstalk are the third-order intermodulations. For a typical sensor configuration by choosing the in-fiber mirror reflection coefficient lower than 0.5%, the minimum achievable signal-to-intermodulation ratio is higher than 26 dB for a maximal possible number of sensor placed along the fiber that satisfies broad range of requirements for most of the quasi-distributed measurements of typical parameters such as strain and temperature.

  3. Realistic loss estimation due to the mirror surfaces in a 10 meters-long high finesse Fabry-Perot filter-cavity.

    PubMed

    Straniero, Nicolas; Degallaix, Jérôme; Flaminio, Raffaele; Pinard, Laurent; Cagnoli, Gianpietro

    2015-08-10

    In order to benefit over the entire frequency range from the injection of squeezed vacuum light at the output of laser gravitational wave detectors, a small bandwidth high finesse cavity is required. In this paper, we investigate the light losses due to the flatness and the roughness of realistic mirrors in a 10 meters-long Fabry-Perot filter cavity. Using measurements of commercial super-polished mirrors, we were able to estimate the cavity round trip losses separating the loss contribution from low and high spatial frequencies. By careful tuning of the cavity g-factor and the incident position of the light on the mirrors, round trip losses due to imperfect mirror surfaces as low as 3 ppm can be achieved in the simulations. PMID:26367993

  4. Optical microfiber-based photonic crystal cavity

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Sun, Yi-zhi; Andrews, Steve; Li, Zhi-yuan; Ding, Wei

    2016-01-01

    Using a focused ion beam milling technique, we fabricate broad stop band (∼10% wide) photonic crystal (PhC) cavities in adiabatically-tapered silica fibers. Abrupt structural design of PhC mirrors efficiently reduces radiation loss, increasing the cavity finesse to ∼7.5. Further experiments and simulations verify that the remaining loss is mainly due to Ga ion implantation. Such a microfiber PhC cavity probably has potentials in many light-matter interaction applications.

  5. Cavity-Enhanced Optical Frequency Comb Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ye, Jun; Thorpe, Michael J.; Adler, Florian; Cossel, Kevin C.

    2009-06-01

    Cavity-enhanced optical frequency comb spectroscopy is a new technique that realizes simultaneously broad spectral coverage and high spectral resolution provided by an optical frequency comb as well as ultrahigh detection sensitivities enabled with a high-finesse optical cavity [1]. These powerful capabilities have been demonstrated in a series of experiments where real-time detection and identification of many different molecular states or species are achieved in a massively parallel fashion [2,3]. We will discuss the principle, technical requirements, and various implementations for this spectroscopic approach, as well as applications that include trace gas detections, human breath analysis, and characterization of cold and ultracold molecules [4,5,6]. References: [1] M. J. Thorpe, K. D. Moll, B. Safdi, and J. Ye, Science 311, 1595 (2006). [2] M. J. Thorpe, D. D. Hudson, K. D. Moll, J. Lasri, and J. Ye, Opt. Lett. 32, 307 (2007). [3] C. Gohle, B. Stein, A. Schliesser, T. Udem, and T. W. Hänsch, Phys. Rev. Lett. 99, 263902 (2007). [4] M. J. Thorpe, D. Balslev-Clausen, M. Kirchner, and J. Ye, Opt. Express. 16, 2387 (2008). [5] M. J. Thorpe and J. Ye, Appl. Phys. B 91, 397 (2008). [6] M. J. Thorpe, F. Adler, K. C. Cossel, M. H. G. de Miranda, and J. Ye, Chem. Phys. Lett. 468, 1 (2009).

  6. Ultra-Low Power Cross-Phase Shifts using Metastable Xenon in a High-Finesse Cavity

    NASA Astrophysics Data System (ADS)

    Hickman, Garrett; Pittman, Todd; Franson, James

    Many important applications in quantum information and quantum communications make use of weak single-photon nonlinearities. These nonlinearities have been produced using a number of methods, but they generally require a complicated experimental setup. We demonstrate a relatively simple system for producing ultra-low power cross-phase modulation, by using metastable xenon as the nonlinear medium within an optical cavity. Using metastable xenon prevents the degradation of optical surfaces which typically occurs with the use of alkali vapors such as rubidium. We produce phase shifts of up to 10 mrad using 4.5-fJ control pulses. We discuss the performance of this system and outline the planned improvements that will allow the cavity to produce single-photon phase shifts on the order of 1 mrad. This work was supported in part by DARPA DSO Grant No. W31P4Q-12-1-0015 and by NSF Grant No. PHY-1402708.

  7. Collective atomic motion and spin dynamics in a driven optical cavity

    NASA Astrophysics Data System (ADS)

    Stamper-Kurn, Dan

    2016-05-01

    Cavity quantum electrodynamics generally highlights the interchange of quantum noise and information between light and matter. I will discuss experiments in which the collective motion and spin of a trapped gas of ultracold atoms interact with and are detected by light in a single mode of a high-finesse optical cavity. I will present recent results on quantum-limited force detection, on the damping and amplification of Larmor precession through dynamical backaction, and on cavity-induced coupling between mechanical oscillators and between spin and motional degrees of freedom.

  8. Noise-Immune Cavity-Enhanced Optical Frequency Comb Spectroscopy

    NASA Astrophysics Data System (ADS)

    Rutkowski, Lucile; Khodabakhsh, Amir; Johanssson, Alexandra C.; Foltynowicz, Aleksandra

    2015-06-01

    We present noise-immune cavity-enhanced optical frequency comb spectroscopy (NICE-OFCS), a recently developed technique for sensitive, broadband, and high resolution spectroscopy. In NICE-OFCS an optical frequency comb (OFC) is locked to a high finesse cavity and phase-modulated at a frequency precisely equal to (a multiple of) the cavity free spectral range. Since each comb line and sideband is transmitted through a separate cavity mode in exactly the same way, any residual frequency noise on the OFC relative to the cavity affects each component in an identical manner. The transmitted intensity contains a beat signal at the modulation frequency that is immune to frequency-to-amplitude noise conversion by the cavity, in a way similar to continuous wave noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS). The light transmitted through the cavity is detected with a fast-scanning Fourier-transform spectrometer (FTS) and the NICE-OFCS signal is obtained by fast Fourier transform of the synchronously demodulated interferogram. Our NICE-OFCS system is based on an Er:fiber femtosecond laser locked to a cavity with a finesse of ˜9000 and a fast-scanning FTS equipped with a high-bandwidth commercial detector. We measured NICE-OFCS signals from the 3νb{1}+νb{3} overtone band of CO_2 around 1.57 μm and achieved absorption sensitivity 6.4×10-11cm-1 Hz-1/2 per spectral element, corresponding to a minimum detectable CO_2 concentration of 25 ppb after 330 s integration time. We will describe the principles of the technique and its technical implementation, and discuss the spectral lineshapes of the NICE-OFCS signals. A. Khodabakhsh, C. Abd Alrahman, and A. Foltynowicz, Opt. Lett. 39, 5034-5037 (2014). J. Ye, L. S. Ma, and J. L. Hall, J. Opt. Soc. Am. B 15, 6-15 (1998). A. Khodabakhsh, A. C. Johansson, and A. Foltynowicz, Appl. Phys. B (2015) doi:10.1007/s00340-015-6010-7.

  9. Novel laser machining of optical fibers for long cavities with low birefringence.

    PubMed

    Takahashi, Hiroki; Morphew, Jack; Oručević, Fedja; Noguchi, Atsushi; Kassa, Ezra; Keller, Matthias

    2014-12-15

    We present a novel method of machining optical fiber surfaces with a CO₂ laser for use in Fiber-based Fabry-Perot Cavities (FFPCs). Previously FFPCs were prone to large birefringence and limited to relatively short cavity lengths (≤ 200 μm). These characteristics hinder their use in some applications such as cavity quantum electrodynamics with trapped ions. We optimized the laser machining process to produce large, uniform surface structures. This enables the cavities to achieve high finesse even for long cavity lengths. By rotating the fibers around their axis during the laser machining process the asymmetry resulting from the laser's transverse mode profile is eliminated. Consequently we are able to fabricate fiber mirrors with a high degree of rotational symmetry, leading to remarkably low birefringence. Through measurements of the cavity finesse over a range of cavity lengths and the polarization dependence of the cavity linewidth, we confirmed the quality of the produced fiber mirrors for use in low-birefringence FFPCs. PMID:25607080

  10. Cavity quantum electro-optics

    SciTech Connect

    Tsang, Mankei

    2010-06-15

    The quantum dynamics of the coupling between a cavity optical field and a resonator microwave field via the electro-optic effect is studied. This coupling has the same form as the optomechanical coupling via radiation pressure, so all previously considered optomechanical effects can in principle be observed in electro-optic systems as well. In particular, I point out the possibilities of laser cooling of the microwave mode, entanglement between the optical mode and the microwave mode via electro-optic parametric amplification, and back-action-evading optical measurements of a microwave quadrature.

  11. Optical cavity furnace for semiconductor wafer processing

    DOEpatents

    Sopori, Bhushan L.

    2014-08-05

    An optical cavity furnace 10 having multiple optical energy sources 12 associated with an optical cavity 18 of the furnace. The multiple optical energy sources 12 may be lamps or other devices suitable for producing an appropriate level of optical energy. The optical cavity furnace 10 may also include one or more reflectors 14 and one or more walls 16 associated with the optical energy sources 12 such that the reflectors 14 and walls 16 define the optical cavity 18. The walls 16 may have any desired configuration or shape to enhance operation of the furnace as an optical cavity 18. The optical energy sources 12 may be positioned at any location with respect to the reflectors 14 and walls defining the optical cavity. The optical cavity furnace 10 may further include a semiconductor wafer transport system 22 for transporting one or more semiconductor wafers 20 through the optical cavity.

  12. Ultra-low-loss optical fiber cavities for applications in quantum information processing

    NASA Astrophysics Data System (ADS)

    Uphoff, Manuel; Brekenfeld, Manuel; Niemietz, Dominik; Ritter, Stephan; Rempe, Gerhard

    2016-05-01

    Single atoms strongly coupled to optical cavities are well suited as light-matter interfaces at the single photon level. The strength of the coupling is inversely proportional to the square root of the mode volume of the cavity, which depends on the radius of curvature of the mirrors. We report on the fabrication of near-spherical surfaces with small radii of curvature on the end facets of optical fibers using a CO2 laser at 9.3 μm wavelength. The surfaces are coated with a commercial, highly reflective, dielectric coating. Cavities built from two of these fibers show a finesse of up to 190000. Due to the small radii of curvature and the high finesse of these cavities, deviations from the paraxial approximation become relevant. This results in a frequency splitting of polarization eigenmodes depending on the eccentricity of the mirrors. Our analytic model that explains this effect is in excellent agreement with our measurements. This allows for the control of the frequency splitting by the geometry of the mirror surfaces. Our results confirm the great prospects of laser-machined cavities for experiments in quantum information processing. The possibility of implementing a quantum repeater node based on our cavity technologies will also be discussed.

  13. Photonic controlled-phase gates through Rydberg blockade in optical cavities

    NASA Astrophysics Data System (ADS)

    Das, Sumanta; Grankin, Andrey; Iakoupov, Ivan; Brion, Etienne; Borregaard, Johannes; Boddeda, Rajiv; Usmani, Imam; Ourjoumtsev, Alexei; Grangier, Philippe; Sørensen, Anders S.

    2016-04-01

    We propose a scheme for high-fidelity photonic controlled-phase gates using a Rydberg blockade in an ensemble of atoms in an optical cavity. The gate operation is obtained by first storing a photonic pulse in the ensemble and then scattering a second pulse from the cavity, resulting in a phase change depending on whether the first pulse contained a single photon. We show that the combination of a Rydberg blockade and optical cavities effectively enhances the optical nonlinearity created by the strong Rydberg interaction and makes the gate operation more robust. The resulting gate can be implemented with cavities of moderate finesse, allowing for highly efficient processing of quantum information encoded in photons. As an illustration, we show how the gate can be employed to increase the communication rate of quantum repeaters based on atomic ensembles.

  14. Collective state synthesis in an optical cavity using Rydberg atom dipole blockade

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh; Sheng, Jiteng; Sedlacek, Jonathon A.; Fan, Haoquan; Shaffer, James P.

    2016-03-01

    We investigate the coherent manipulation of interacting Rydberg atoms placed inside a high-finesse optical cavity for the deterministic preparation of strongly coupled light-matter systems. We consider a four-level diamond scheme with one common Rydberg level for N interacting atoms. One side of the diamond is used to excite the atoms into a collective ‘superatom’ Rydberg state using either π-pulses or stimulated Raman adiabatic passage (STIRAP) pulses. The upper transition on the other side of the diamond is used to transfer the collective state to one that is coupled to a field mode of an optical cavity. Due to the strong interaction between the atoms in the Rydberg level, the Rydberg blockade mechanism plays a key role in the deterministic quantum state synthesis of the atoms in the cavity. We use numerical simulation to show that non-classical states of light can be generated and that the state that is coupled to the cavity field is a collective one. We also investigate how different decay mechanisms affect this interacting many-body system. We also analyze our system in the case of two Rydberg excitations within the blockade volume. The simulations are carried out with parameters corresponding to realizable high-finesse optical cavities and alkali atoms like rubidium.

  15. Nanofiber Fabry-Perot microresonator for nonlinear optics and cavity quantum electrodynamics.

    PubMed

    Wuttke, C; Becker, M; Brückner, S; Rothhardt, M; Rauschenbeutel, A

    2012-06-01

    We experimentally realize a Fabry-Perot-type optical microresonator near the cesium D2 line wavelength based on a tapered optical fiber, equipped with two fiber Bragg gratings that enclose a subwavelength diameter waist. Owing to the very low taper losses, the finesse of the resonator reaches F=86 while the on-resonance transmission is T=11%. The characteristics of our resonator fulfill the requirements of nonlinear optics and cavity quantum electrodynamics in the strong coupling regime. These characteristics, combined with the demonstrated ease of use and advantageous mode geometry, open a realm of applications. PMID:22660083

  16. Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Siller, Brian; Mills, Andrew; Porambo, Michael; McCall, Benjamin

    2011-06-01

    The technique of Cavity Enhanced Velocity Modulation Spectroscopy (CEVMS) has recently been developed. By demodulating the detector signal at twice the plasma modulation frequency (2f), the velocity-modulated ionic absorption signal can be extracted. Although the concentration-modulated excited neutral molecules are also observed at 2f, the ion and neutral signals can be distinguished and separated with phase-sensitive demodulation. The optical cavity provides two major benefits. It increases both the optical path length and the intracavity laser power by a factor of 2×Finesse/π. The multipass advantage allows for much longer path length than was previously possible with unidirectional multipass White cells. The power enhancement combined with perfectly overlapped counterpropagating beams within the cavity allows for sub-Doppler spectroscopy. Although CEVMS showed much potential, its sensitivity was ultimately limited by electronic noise from the plasma interfering with the cavity-locking electronics. We have further improved upon CEVMS by combining it with Noise Immune Cavity Enhanced Optical Heterodyne Molecular Spectroscopy (NICE-OHMS). The laser is frequency modulated at precisely an integer multiple of the free spectral range of the optical cavity; this allows the heterodyne sidebands to be coupled into the optical cavity. Heterodyne detection of the cavity leak-out is immune to noise in the laser-cavity lock, and 2f demodulation further decreases electronic noise in the system and retains ion-neutral discrimination. The additional level of modulation beyond ordinary CEVMS has the added advantage of enabling the observation of both absorption and dispersion signals simultaneously by using two RF mixers, each driving its own lock-in amplifier. In a single scan, four distinct signals can be obtained: absorption and dispersion for ions and excited neutrals. The technique has been demonstrated in the near-IR for N_2^+. B. M. Siller, A. A. Mills and B. J. Mc

  17. Dicke-model phase transition in the quantum motion of a Bose-Einstein condensate in an optical cavity.

    PubMed

    Nagy, D; Kónya, G; Szirmai, G; Domokos, P

    2010-04-01

    We show that the motion of a laser-driven Bose-Einstein condensate in a high-finesse optical cavity realizes the spin-boson Dicke model. The quantum phase transition of the Dicke model from the normal to the superradiant phase corresponds to the self-organization of atoms from the homogeneous into a periodically patterned distribution above a critical driving strength. The fragility of the ground state due to photon measurement induced backaction is calculated. PMID:20481867

  18. Self-amplified lock of an ultra-narrow linewidth optical cavity.

    PubMed

    Izumi, Kiwamu; Sigg, Daniel; Barsotti, Lisa

    2014-09-15

    High finesse optical cavities are an essential tool in modern precision laser interferometry. The incident laser field is often controlled and stabilized with an active feedback system such that the field resonates in the cavity. The Pound-Drever-Hall reflection locking technique is a convenient way to derive a suitable error signal. However, it only gives a strong signal within the cavity linewidth. This poses a problem for locking an ultra-narrow linewidth cavity. We present a novel technique for acquiring lock by utilizing an additional weak control signal, but with a much larger capture range. We numerically show that this technique can be applied to the laser frequency stabilization system used in the Laser Interferometric Gravitational-wave Observatory (LIGO), which has a linewidth of 0.8 Hz. This new technique will allow us to robustly and repeatedly lock the LIGO laser frequency to the common mode of the interferometer. PMID:26466252

  19. Nonlinear spectroscopy of Sr atoms in an optical cavity for laser stabilization

    NASA Astrophysics Data System (ADS)

    Christensen, Bjarke T. R.; Henriksen, Martin R.; Schäffer, Stefan A.; Westergaard, Philip G.; Tieri, David; Ye, Jun; Holland, Murray J.; Thomsen, Jan W.

    2015-11-01

    We study the nonlinear interaction of a cold sample of 88Sr atoms coupled to a single mode of a low finesse optical cavity in the so-called bad cavity limit, and we investigate the implications for applications to laser stabilization. The atoms are probed on the weak intercombination line |5 s21S0>-|5 s 5 p 3P1> at 689 nm in a strongly saturated regime. Our measured observables include the atomic induced phase shift and absorption of the light field transmitted through the cavity represented by the complex cavity transmission coefficient. We demonstrate high signal-to-noise-ratio measurements of both quadratures—the cavity transmitted phase and absorption—by employing frequency modulation (FM) spectroscopy (noise-immune cavity-enhanced optical-heterodyne molecular spectroscopy). We also show that when FM spectroscopy is employed in connection with a cavity locked to the probe light, observables are substantially modified compared to the free-space situation in which no cavity is present. Furthermore, the nonlinear dynamics of the phase dispersion slope is experimentally investigated, and the optimal conditions for laser stabilization are established. Our experimental results are compared to state-of-the-art cavity QED theoretical calculations.

  20. Interacting Rydberg atoms in an optical cavity to synthesize coherent collective states using dipole blockade

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh; Sheng, Jiteng; Sedlacek, Jonathon; Ewel, Charlie; Fan, Haoquan; Shaffer, James

    2015-05-01

    We investigate the coherent manipulation of interacting Rydberg atoms placed inside a high-finesse optical cavity for the preparation of strongly coupled light-matter systems. We consider a four-level diamond scheme with one common Rydberg level. One side of the diamond is used to collectively excite the atoms to the Rydberg level using a pair of pulses. The other side of the diamond is used to produce a collective state that is close to resonance with a field mode of a high-finesse optical cavity. The interaction between Rydberg atoms creates a blockade which is useful for synthesizing the coherent collective state. We use numerical simulation to generate non-classical states of light and also investigate different decay mechanisms affecting this system. We also analyze our system in the case of two Rydberg excitations within the blockade volume. In this case, we show that more elaborate few excitation quantum states can be prepared in the cavity to observe interesting dynamics and analyze the correlation of the two-photon emission. This work is supported by the DARPA Quasar program by a grant through ARO, AFOSR and NSF.

  1. Quantum-Noise-Limited Sensitivity-Enhancement of a Passive Optical Cavity by a Fast-Light Medium

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Luckay, H. A.; Chang, Hongrok; Myneni, Krishna

    2016-01-01

    We demonstrate for a passive optical cavity containing an intracavity dispersive atomic medium, the increase in scale factor near the critical anomalous dispersion is not cancelled by mode broadening or attenuation, resulting in an overall increase in the predicted quantum-noiselimited sensitivity. Enhancements of over two orders of magnitude are measured in the scale factor, which translates to greater than an order-of-magnitude enhancement in the predicted quantumnoise- limited measurement precision, by temperature tuning a low-pressure vapor of noninteracting atoms in a low-finesse cavity close to the critical anomalous dispersion condition. The predicted enhancement in sensitivity is confirmed through Monte-Carlo numerical simulations.

  2. Characterization of the frequency stability of an optical frequency standard at 1.39 µm based upon noise-immune cavity-enhanced optical heterodyne molecular spectroscopy.

    PubMed

    Dinesan, H; Fasci, E; D'Addio, A; Castrillo, A; Gianfrani, L

    2015-01-26

    Frequency fluctuations of an optical frequency standard at 1.39 µm have been measured by means of a highly-sensitive optical frequency discriminator based on the fringe-side transmission of a high finesse optical resonator. Built on a Zerodur spacer, the optical resonator exhibits a finesse of 5500 and a cavity-mode width of about 120 kHz. The optical frequency standard consists of an extended-cavity diode laser that is tightly stabilized against the center of a sub-Doppler H(2) (18)O line, this latter being detected by means of noise-immune cavity-enhanced optical heterodyne molecular spectroscopy. The emission linewidth has been carefully determined from the frequency-noise power spectral density by using a rather simple approximation, known as β-line approach, as well as the exact method based on the autocorrelation function of the laser light field. It turns out that the linewidth of the optical frequency standard amounts to about 7 kHz (full width at half maximum) for an observation time of 1 ms. Compared to the free-running laser, the measured width corresponds to a line narrowing by a factor of ~220. PMID:25835931

  3. Optically coupled cavities for wavelength switching

    NASA Astrophysics Data System (ADS)

    Costazo-Caso, Pablo A.; Granieri, Sergio; Siahmakoun, Azad

    2011-01-01

    An optical bistable device which presents hysteresis behavior is proposed and experimentally demonstrated. The system finds applications in wavelength switching, pulse reshaping and optical bistability. It is based on two optically coupled cavities named master and slave. Each cavity includes a semiconductor optical amplifier (SOA), acting as the gain medium of the laser, and two pair of fiber Bragg gratings (FBG) which define the lasing wavelength (being different in each cavity). Finally, a variable optical coupler (VOC) is employed to couple both cavities. Experimental characterization of the system performance is made analyzing the effects of the coupling coefficient between the two cavities and the driving current in each SOA. The properties of the hysteretic bistable curve and switching can be controlled by adjusting these parameters and the loss in the cavities. By selecting the output wavelength (λ1 or λ2) with an external filter it is possible to choose either the invert or non-invert switched signal. Experiments were developed employing both optical discrete components and a photonic integrated circuit. They show that for 8 m-long cavities the maximum switching frequency is about 500 KHz, and for 4 m-long cavities a minimum rise-time about 21 ns was measured. The switching time can be reduced by shortening the cavity lengths and using photonic integrated circuits.

  4. Quantum memory and phase gate in Optical cavities based on EIT

    NASA Astrophysics Data System (ADS)

    Borges, Halyne; Villas-Bôas, Celso

    In this work we investigate theoretically the implementation of an optical quantum memory in a system composed by a single atom, trapped in a high finesse optical cavity. In order to analyse the feasibility of implementing a quantum memory in the atom-cavity system based on the EIT phenomenon, we investigated in detail which parameter configuration the memory efficiency is optimized considering the two different setups. Our results shows that for a asymmetric one-sided cavity, which is the experimental setup commonly used to observe the EIT effect, the memory efficiency value saturates at about 8 . 5 % . Meanwhile, for an one-sided cavity, we observe for a sufficiently high value of the coupling constant g, the efficiency has its maximum value increased considerably, close to 100 % . However, this experimental setup is not suitable to observe cavity-EIT in the transmission spectrum, being necessary another kind of experiment, such as measurements phase difference field that leaves the cavity induced by the control field. Considering this configuration we also showed the implementation of a quantum phase gate based on the same nonlinear effect, where the pulse probe can experience a phase shift on the order of π, due to the presence or absence of a control pulse. Supported by FAPESP (Proc. 2014/12740-1) and INCT-IQ.

  5. Mounting system for optical frequency reference cavities

    NASA Technical Reports Server (NTRS)

    Notcutt, Mark (Inventor); Hall, John L. (Inventor); Ma, Long-Sheng (Inventor)

    2008-01-01

    A technique for reducing the vibration sensitivity of laser-stabilizing optical reference cavities is based upon an improved design and mounting method for the cavity, wherein the cavity is mounted vertically. It is suspended at one plane, around the spacer cylinder, equidistant from the mirror ends of the cavity. The suspension element is a collar of an extremely low thermal expansion coefficient material, which surrounds the spacer cylinder and contacts it uniformly. Once the collar has been properly located, it is cemented in place so that the spacer cylinder is uniformly supported and does not have to be squeezed at all. The collar also includes a number of cavities partially bored into its lower flat surface, around the axial bore. These cavities are support points, into which mounting base pins will be inserted. Hence the collar is supported at a minimum of three points.

  6. Cavity Enhanced absorption spectroscopy with an Optical Comb: Detection of atmospheric radicals in the near UV.

    NASA Astrophysics Data System (ADS)

    Méjean, G.; Kassi, S.; Romanini, D.

    2009-04-01

    The atmospheric chemistry community suffers a lack of fast, reliable and space resolved measurement for a wide set of very reactive molecules (e.g. radicals such as OH, NO3, BrO, IO, etc.). Due to their high reactivity, these molecules largely control the lifetime and concentration of numerous key atmospheric species. The concentrations of radicals are extremely low (ppbv or less) and highly variable in time and space. Measuring their concentration is often extremely laborious, expensive and requires heavy equipment (chemical sampling and treatment followed by mass spectrometry and/or chromatography). We recently introduced an optical spectroscopy technique based on a femtosecond laser oscillator, "Mode-Locked Cavity-Enhanced Absorption Spectroscopy", that we propose to develop into an instrument for in situ measurement of local concentration of traces of reactive molecules [1-3]. We have already demonstrated the possibility of measuring part in 1E12 by volume concentrations of radicals of high atmospheric interest, such as IO or BrO [4], as needed for monitoring these species in the environment. We apply cavity-enhanced absorption spectroscopy in the near UV range using a frequency-doubled Ti:Sa modelocked femtosecond laser. Efficient broadband injection of a high finesse cavity is obtained by matching this optical frequency-comb source to the comb of cavity transmission resonances. A grating spectrograph and a detector array disperse and detect the spectrum transmitted by the cavity carrying the absorption features of intracavity molecules. IO traces were obtained by mixing together controlled flows of gaseous iodine and ozone inside a high finesse cavity (F~6000). A Chameleon Ultra II ML-Laser (gracefully lent during 1 month by Coherent Inc.) was frequency doubled to address an absorption band of IO at 436 nm. A locking scheme allowed the cavity transmission to be smooth and stable. The transmitted light was dispersed using a high resolution (0.07nm) grating

  7. Absorption line metrology by optical feedback frequency-stabilized cavity ring-down spectroscopy

    NASA Astrophysics Data System (ADS)

    Burkart, Johannes; Kassi, Samir

    2015-04-01

    Optical feedback frequency-stabilized cavity ring-down spectroscopy (OFFS-CRDS) is a near-shot-noise-limited technique combining a sensitivity of with a highly linear frequency axis and sub-kHz resolution. Here, we give an in-depth review of the key elements of the experimental setup encompassing a highly stable V-shaped reference cavity, an integrated Mach-Zehnder modulator and a tightly locked ring-down cavity with a finesse of 450,000. Carrying out a detailed analysis of the spectrometer performance and its limitations, we revisit the photo-electron shot-noise limit in CRDS and discuss the impact of optical fringes. We demonstrate different active schemes for fringe cancelation by varying the phase of parasitic reflections. The proof-of-principle experiments reported here include a broadband high-resolution spectrum of carbon dioxide at 1.6 µm and an isolated line-shape measurement with a signal-to-noise ratio of 80,000. Beyond laboratory-based absorption line metrology for fundamental research, OFFS-CRDS holds a considerable potential for field laser measurements of trace gas concentrations and isotopic ratios by virtue of its small sample volume and footprint, the robust cavity-locking scheme and supreme precision.

  8. Atom interferometry in an optical cavity.

    PubMed

    Hamilton, Paul; Jaffe, Matt; Brown, Justin M; Maisenbacher, Lothar; Estey, Brian; Müller, Holger

    2015-03-13

    We propose and demonstrate a new scheme for atom interferometry, using light pulses inside an optical cavity as matter wave beam splitters. The cavity provides power enhancement, spatial filtering, and a precise beam geometry, enabling new techniques such as low power beam splitters (<100  μW), large momentum transfer beam splitters with modest power, or new self-aligned interferometer geometries utilizing the transverse modes of the optical cavity. As a first demonstration, we obtain Ramsey-Raman fringes with >75% contrast and measure the acceleration due to gravity, g, to 60  μg/sqrt[Hz] resolution in a Mach-Zehnder geometry. We use >10(7) cesium atoms in the compact mode volume (600  μm 1/e(2) waist) of the cavity and show trapping of atoms in higher transverse modes. This work paves the way toward compact, high sensitivity, multiaxis interferometry. PMID:25815912

  9. Atom Interferometry in an Optical Cavity

    NASA Astrophysics Data System (ADS)

    Hamilton, Paul; Jaffe, Matt; Brown, Justin M.; Maisenbacher, Lothar; Estey, Brian; Müller, Holger

    2015-03-01

    We propose and demonstrate a new scheme for atom interferometry, using light pulses inside an optical cavity as matter wave beam splitters. The cavity provides power enhancement, spatial filtering, and a precise beam geometry, enabling new techniques such as low power beam splitters (<100 μ W ), large momentum transfer beam splitters with modest power, or new self-aligned interferometer geometries utilizing the transverse modes of the optical cavity. As a first demonstration, we obtain Ramsey-Raman fringes with >75 % contrast and measure the acceleration due to gravity, g , to 60 μ g /√{Hz } resolution in a Mach-Zehnder geometry. We use >107 cesium atoms in the compact mode volume (600 μ m 1 /e2 waist) of the cavity and show trapping of atoms in higher transverse modes. This work paves the way toward compact, high sensitivity, multiaxis interferometry.

  10. Optical Resonant Cavity in a Nanotaper

    SciTech Connect

    Lee, Sang Hyun; Goto, Takenari; Miyazaki, Hiroshi; Chang, Jiho; Yao, Takafumi

    2010-01-01

    The present study describes an optical resonant cavity in a nanotaper with scale reduction from micro to several nanometers. Both experimental results and a finite-difference time-domain (FDTD)-based simulation suggested that the nanometer-scale taper with a diameter similar to the wavelength of light acted as a mirror, which facilitated the formation of a laser cavity and caused lasing in ZnO nanotapers. As the light inside the nanotaper propagated toward the apex, the lateral mode was reduced and reflection occurred. This report suggests that use of the resonant optical cavities in nanotapers might result in novel active and passive optical components, which will broaden the horizons of photonic technology.

  11. Rotationally induced vortices in optical cavity modes

    NASA Astrophysics Data System (ADS)

    Habraken, Steven J. M.; Nienhuis, Gerard

    2009-09-01

    We show that vortices appear in the modes of an astigmatic optical cavity when it is put into rotation about its optical axis. We study the properties of these vortices and discuss numerical results for a specific realization of such a set-up. Our method is exact up to first order in the time-dependent paraxial approximation and involves bosonic ladder operators in the spirit of the quantum-mechanical harmonic oscillator.

  12. Cavity-enhanced parity-nonconserving optical rotation in metastable Xe and Hg.

    PubMed

    Bougas, L; Katsoprinakis, G E; von Klitzing, W; Sapirstein, J; Rakitzis, T P

    2012-05-25

    We propose the measurement of cavity-enhanced parity-nonconserving (PNC) optical rotation in several transitions of metastable Xe and Hg, including Xe (2P(3/2)(o))6s(2)[3/2](2)(o)→(2P(1/2)(o))6s(2)[1/2](1)(o) and Hg 6s6p (3)P(2)(o)→6s6p (1)P(1)(o), with calculated amplitude ratios of E(1)(PNC)/M1=11×10(-8) and 10×10(-8), respectively. We demonstrate the use of a high-finesse bow-tie cavity with counterpropagating beams and a longitudinal magnetic field, which allows the absolute measurement of chiral optical rotation, with a path length enhancement of about 10(4), necessary for PNC measurement from available column densities of 10(14) cm(-2) for metastable Xe or Hg. Rapid PNC-signal reversal, allowing robust background subtraction, is achieved by shifting the cavity resonance to an opposite polarization mode or by inverting the magnetic field. The precise measurement of isotope and nuclear-spin dependent E(1)(PNC) amplitudes provides a sensitive low-energy test of the standard model. PMID:23003234

  13. Spectroscopy of Exoplanet Atmospheres with the FINESSE Explorer

    NASA Technical Reports Server (NTRS)

    Deroo, Pieter; Swain, Mark R.; Green, Robert O.

    2012-01-01

    FINESSE (Fast INfrared Exoplanet Spectroscopic Survey Explorer) will provide uniquely detailed information on the growing number of newly discovered planets by characterizing their atmospheric composition and temperature structure. This NASA Explorer mission, selected for a competitive Phase A study, is unique in its breath and scope thanks to broad instantaneous spectroscopy from the optical to the mid-IR (0.7 - 5 micron), with a survey of exoplanets measured in a consistent, uniform way. For 200 transiting exoplanets ranging from Terrestrial to Jovians, FINESSE will measure the chemical composition and temperature structure of their atmospheres and trace changes over time with exoplanet longitude. The mission will do so by measuring the spectroscopic time series for a primary and secondary eclipse over the exoplanet orbital phase curve. With spectrophotometric precision being a key enabling aspect for combined light exoplanet characterization, FINESSE is designed to produce spectrophotometric precision of better than 100 parts-per-million per spectral channel without the need for decorrelation. The exceptional stability of FINESSE will even allow the mission to characterize non-transiting planets, potentially as part of FINESSE's Participating Scientist Program. In this paper, we discuss the flow down from the target availability to observations and scheduling to the analysis and calibration of the data and how it enables FINESSE to be the mission that will truly expand the new field of comparative exoplanetology.

  14. Optical cavity resonator in an expanding universe

    NASA Astrophysics Data System (ADS)

    Kopeikin, Sergei M.

    2015-02-01

    We study the cosmological evolution of frequency of a standing electromagnetic wave in a resonant optical cavity placed to the expanding manifold described by the Robertson-Walker metric. Because of the Einstein principle of equivalence (EEP), one can find a local coordinate system (a local freely falling frame), in which spacetime is locally Minkowskian. However, due to the conformal nature of the Robertson-Walker metric the conventional transformation to the local inertial coordinates introduces ambiguity in the physical interpretation of the local time coordinate, . Therefore, contrary to a common-sense expectation, a straightforward implementation of EEP alone does not allow us to unambiguously decide whether atomic clocks based on quantum transitions of atoms, ticks at the same rate as the clocks based on electromagnetic modes of a cavity. To resolve this ambiguity we have to analyse the cavity rigidity and the oscillation of its electromagnetic modes in an expanding universe by employing the full machinery of the Maxwell equations irrespectively of the underlying theory of gravity. We proceed in this way and found out that the size of the cavity and the electromagnetic frequency experience an adiabatic drift in conformal (unphysical) coordinates as the universe expands in accordance with the Hubble law. We set up the oscillation equation for the resonant electromagnetic modes, solve it by the WKB approximation, and reduce the coordinate-dependent quantities to their counterparts measured by a local observer who counts time with atomic clock. The solution shows that there is a perfect mutual cancellation of the adiabatic drift of cavity's frequency by space transformation to local coordinates and the time counted by the clocks based on electromagnetic modes of cavity has the same rate as that of atomic clocks. We conclude that if general relativity is correct and the local expansion of space is isotropic there should be no cosmological drift of frequency of a

  15. Hybrid ion chains inside an optical cavity

    NASA Astrophysics Data System (ADS)

    Zhou, Zichao; Siverns, James; Quraishi, Qudsia

    2016-05-01

    Trapped ions remain a leading candidate for the implementation of large-scale quantum networks. These networks require nodes that can store and process quantum information as well as communicate with each other though photonic flying qubits. We propose to use hybrid ion chains of barium, for communication, and ytterbium, for quantum information processing. We report on progress in setting up a hybrid ion chain in a versatile four-blade trap using high numerical aperture collection optics. Although the visible photons produced from barium ions are more favorable as they are not suitable for long distance fiber communication. With this in mind, we intend to implement frequency conversion to overcome this issue. Also, with the view toward increasing the flying-qubit production rate, we propose a cavity-based system to enhance interactions between the ions and photons. The cavity axis is to be placed along the axial direction of the trap allowing a chain of multiple ions to interact with the cavity at the same time. With this configuration the atom-photon coupling strength can be improved by sqrt(N), where N is the number of ions. Experiments will focus on exploring the dynamics of hybrid ion chain, dual species quantum information processing, two-colour entanglement and phase gates assisted by the ion-cavity coupling are to be explored.

  16. Specimen illumination apparatus with optical cavity for dark field illumination

    DOEpatents

    Pinkel, Daniel; Sudar, Damir; Albertson, Donna

    1999-01-01

    An illumination apparatus with a specimen slide holder, an illumination source, an optical cavity producing multiple reflection of illumination light to a specimen comprising a first and a second reflective surface arranged to achieve multiple reflections of light to a specimen is provided. The apparatus can further include additional reflective surfaces to achieve the optical cavity, a slide for mounting the specimen, a coverslip which is a reflective component of the optical cavity, one or more prisms for directing light within the optical cavity, antifading solutions for improving the viewing properties of the specimen, an array of materials for analysis, fluorescent components, curved reflective surfaces as components of the optical cavity, specimen detection apparatus, optical detection equipment, computers for analysis of optical images, a plane polarizer, fiberoptics, light transmission apertures, microscopic components, lenses for viewing the specimen, and upper and lower mirrors above and below the specimen slide as components of the optical cavity. Methods of using the apparatus are also provided.

  17. Degenerate astigmatic cavities

    NASA Astrophysics Data System (ADS)

    Courtois, Jérémie; Mohamed, Ajmal; Romanini, Daniele

    2013-10-01

    At the output of a high-finesse cavity a succession of Lissajous patterns may be observed as the cavity length is finely tuned inside a “degenerate region” around a reentrant spherical configuration. This behavior is ascribed to a small parasitic astigmatism of the cavity mirrors. Simple geometrical optics modeling confirms this hypothesis, and then a more realistic analysis using transverse Gaussian modes reveals that the Lissajous patterns correspond to an organization of the astigmatism-split modes into a finer substructure of degenerate modes relative to that of a reentrant spherical cavity. This provides a thorough understanding of the field patterns observed in the degenerate region, including an intriguing spatial symmetry of the patterns corresponding to opposite displacements with respect to a specific central cavity length. This investigation represents a generalization of the theory of reentrant spherical cavities to the astigmatic case.

  18. Optical Material Characterization Using Microdisk Cavities

    NASA Astrophysics Data System (ADS)

    Michael, Christopher P.

    Since Jack Kilby recorded his "Monolithic Idea" for integrated circuits in 1958, microelectronics companies have invested billions of dollars in developing the silicon material system to increase performance and reduce cost. For decades, the industry has made Moore's Law, concerning cost and transistor density, a self-fulfilling prophecy by integrating technical and material requirements vertically down their supply chains and horizontally across competitors in the market. At recent technology nodes, the unacceptable scaling behavior of copper interconnects has become a major design constraint by increasing latency and power consumption---more than 50% of the power consumed by high speed processors is dissipated by intrachip communications. Optical networks at the chip scale are a potential low-power high-bandwidth replacement for conventional global interconnects, but the lack of efficient on-chip optical sources has remained an outstanding problem despite significant advances in silicon optoelectronics. Many material systems are being researched, but there is no ideal candidate even though the established infrastructure strongly favors a CMOS-compatible solution. This thesis focuses on assessing the optical properties of materials using microdisk cavities with the intention to advance processing techniques and materials relevant to silicon photonics. Low-loss microdisk resonators are chosen because of their simplicity and long optical path lengths. A localized photonic probe is developed and characterized that employs a tapered optical-fiber waveguide, and it is utilized in practical demonstrations to test tightly arranged devices and to help prototype new fabrication methods. A case study in AlxGa1-xAs illustrates how the optical scattering and absorption losses can be obtained from the cavity-waveguide transmission. Finally, single-crystal Er2O3 epitaxially grown on silicon is analyzed in detail as a potential CMOS-compatable gain medium due to its high Er3

  19. [Measurement of Trace C2H6 Based on Optical-Feedback Cavity-Enhanced Absorption Spectroscopy].

    PubMed

    Wan, Fu; Chen, Wei-gen; Gu, Zhao-liang; Zou, Jing-xin; DU, Ling-Ling; Qi, Wei; Zhou, Qu

    2015-10-01

    Ethane is one of major fault characteristic gases dissolved in power transformer, the detection of Ethane with high accuracy and sensitivity is the key of dissolved gas analysis. In this paper, based on optical feedback theory and cavity-enhanced absorption spectroscopy, combined with quantum cascade laser, a detection system for dissolved gas C2 H6 in transformer oil was built up. Based on the symmetry of the individual cavity modes, the phase matching of returning light in resonance with the cavity was achieved through LabVIEW codes. The optical feedback effect that the emitted light return to the laser cavity after a small delay time and lock to the resonance frequency of cavity, even and odd modes effect that the higher modes and lower modes structure will build up alternatively, and threshold current lowering effect of about 1.2 mA were studied and achieved. By cavity ring-down spectroscopy, the effective reflectivity of 99.978% and cavity finesse of 7 138.4 is obtained respectively. The frequency selectivity is 0.005 2 cm(-1). With an acquisition time of 1s, this optical system allows detection for the PQ3 band of C2 H6 with high accuracy of 95.72% ± 0.17% and detection limit of (1.97 ± 0.06) x 10(-3) μL x L(-1) at atmospheric pressure and temperature of 20 degrees C, which lays a foundation for fault diagnose from dissolved gas analysis. PMID:26904820

  20. Cavity-Enhanced Ultrafast Transient Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Yuning; Reber, Melanie Roberts; Keleher, Kevin; Allison, Thomas K.

    2014-06-01

    We introduce cavity enhanced ultrafast transient absorption spectroscopy, which employs frequency combs and high-finesse optical cavities. % The schematic of apparatus is shown in Figure 1. Sub-100 fs pulses with a repetition rate of 90 MHz are generated by a home-built Ytterbium fiber laser. The amplified light has a power up to 10 W, which is used to pump an optical parametric oscillator, followed by second-harmonic generation(SHG) that converts the wavelength from near-IR to visible. A pump comb at 530 nm is separately generated by SHG. Both pump and probe combs are coupled into high-finesse cavities. Compared to the conventional transient absorption spectroscopy method, the detection sensitivity can be improved by a factor of (F/π)^2 ˜ 10^5, where F is the finesse of cavity. This ultrasensitive technology enables the direct all-optical dynamics study in molecular beams. We will apply the cavity enhanced ultrafast transient absorption spectroscopy to investigate the dynamics of visible chromophores and then extend the wavelength to mid-IR to study vibrational dynamics of small hydrogen-bonded clusters.

  1. Temporal laser pulse manipulation using multiple optical ring-cavities

    NASA Technical Reports Server (NTRS)

    Nguyen, Quang-Viet (Inventor); Kojima, Jun (Inventor)

    2010-01-01

    An optical pulse stretcher and a mathematical algorithm for the detailed calculation of its design and performance is disclosed. The optical pulse stretcher has a plurality of optical cavities, having multiple optical reflectors such that an optical path length in each of the optical cavities is different. The optical pulse stretcher also has a plurality of beam splitters, each of which intercepts a portion of an input optical beam and diverts the portion into one of the plurality of optical cavities. The input optical beam is stretched and a power of an output beam is reduced after passing through the optical pulse stretcher and the placement of the plurality of optical cavities and beam splitters is optimized through a model that takes into account optical beam divergence and alignment in the pluralities of the optical cavities. The optical pulse stretcher system can also function as a high-repetition-rate (MHz) laser pulse generator, making it suitable for use as a stroboscopic light source for high speed ballistic projectile imaging studies, or it can be used for high speed flow diagnostics using a laser light sheet with digital particle imaging velocimetry. The optical pulse stretcher system can also be implemented using fiber optic components to realize a rugged and compact optical system that is alignment free and easy to use.

  2. Cavity solitons and localized patterns in a finite-size optical cavity

    SciTech Connect

    Kozyreff, G.; Gelens, L.

    2011-08-15

    In appropriate ranges of parameters, laser-driven nonlinear optical cavities can support a wide variety of optical patterns, which could be used to carry information. The intensity peaks appearing in these patterns are called cavity solitons and are individually addressable. Using the Lugiato-Lefever equation to model a perfectly homogeneous cavity, we show that cavity solitons can only be located at discrete points and at a minimal distance from the edges. Other localized states which are attached to the edges are identified. By interpreting these patterns in an information coding frame, the information capacity of this dynamical system is evaluated. The results are explained analytically in terms of the the tail characteristics of the cavity solitons. Finally, the influence of boundaries and of cavity imperfections on cavity solitons are compared.

  3. Stable fiber-based Fabry-Perot cavity

    SciTech Connect

    Steinmetz, T.; Colombe, Y.; Hunger, D.; Haensch, T. W.; Balocchi, A.; Warburton, R. J.; Reichel, J.

    2006-09-11

    The development of a fiber-based, tunable optical cavity with open access is reported. The cavity is of the Fabry-Perot type and is formed with miniature spherical mirrors positioned on the end of single- or multimode optical fibers by a transfer technique, which involves lifting a high-quality mirror from a smooth convex substrate, either a ball lens or microlens. The cavities typically have a finesse of {approx}1000 and a mode volume of 600 {mu}m{sup 3}. The detection of small ensembles of cold Rb atoms guided through such a cavity on an atom chip is demonstrated.

  4. 17 THz continuous-wave optical modulator

    NASA Astrophysics Data System (ADS)

    Weber, J. J.; Green, J. T.; Yavuz, D. D.

    2012-01-01

    We use coherently rotating hydrogen molecules and demonstrate a continuous-wave optical modulator at a frequency of 17.6 THz that can modulate any laser within the optical region of the spectrum. The molecules are coherently excited using two intense laser beams spaced by the Raman transition frequency inside a high-finesse cavity.

  5. A master equation for a two-sided optical cavity

    PubMed Central

    Barlow, Thomas M.; Bennett, Robert; Beige, Almut

    2015-01-01

    Quantum optical systems, like trapped ions, are routinely described by master equations. The purpose of this paper is to introduce a master equation for two-sided optical cavities with spontaneous photon emission. To do so, we use the same notion of photons as in linear optics scattering theory and consider a continuum of travelling-wave cavity photon modes. Our model predicts the same stationary state photon emission rates for the different sides of a laser-driven optical cavity as classical theories. Moreover, it predicts the same time evolution of the total cavity photon number as the standard standing-wave description in experiments with resonant and near-resonant laser driving. The proposed resonator Hamiltonian can be used, for example, to analyse coherent cavity-fiber networks [E. Kyoseva et al., New J. Phys. 14, 023023 (2012)].

  6. NO_2 Trace Measurements by Optical-Feedback Cavity-Enhanced Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ventrillard-Courtillot, I.; Desbois, Th.; Foldes, T.; Romanini, D.

    2009-06-01

    In order to reach the sub-ppb NO_2 detection level required for environmental applications in remote areas, we develop a spectrometer based on a technique introduced a few years ago, named Optical-Feedback Cavity-Enhanced Absorption Spectroscopy (OF-CEAS) [1]. It allows very sensitive and selective measurements, together with the realization of compact and robust set-ups as was subsequently demonstrated during measurements campaigns in harsh environments [2]. OF-CEAS benefits from the optical feedback to efficiently inject a cw-laser in a V-shaped high finesse cavity (typically 10 000). Cavity-enhanced absorption spectra are acquired on a small spectral region (˜1 cm^{-1}) that enables selective and quantitative measurements at a fast acquisition rate with a detection limit of several 10^{-10} cm^{-1} as reported in this work. Spectra are obtained with high spectral definition (150 MHz highly precisely spaced data points) and are self calibrated by cavity rind-down measurements regularly performed (typically every second). NO_2 measurements are performed with a commercial extended cavity diode laser around 411 nm, spectral region where intense electronic transitions occur. We will describe the set-up developed for in-situ measurements allowing real time concentration measurements at typically 5 Hz; and then report on the measurements performed with calibrated NO_2 reference samples to evaluate the linearity of the apparatus. The minimum detectable absorption loss is estimated by considering the standard deviation of the residual of one spectrum. We achieved 2x10^{-10} cm^{-1} for a single spectrum recorded in less than 100 ms at 100 mbar. It leads to a potential detection limit of 3x10^8 molecules/cm^3, corresponding to about 150 pptv at this pressure. [1] J. Morville, S. Kassi, M. Chenevier, and D. Romanini, Appl. Phys. B, 80, 1027 (2005). [2] D. Romanini, M. Chenevrier, S. Kassi, M. Schmidt, C. Valant, M. Ramonet, J. Lopez, and H.-J. Jost, Appl. Phys. B, 83, 659

  7. Quantum optics, cavity QED, and quantum optomechanics

    NASA Astrophysics Data System (ADS)

    Meystre, Pierre

    2013-05-01

    Quantum optomechanics provides a universal tool to achieve the quantum control of mechanical motion. It does that in devices spanning a vast range of parameters, with mechanical frequencies from a few Hertz to GHz, and with masses from 10-20 g to several kilos. Its underlying ideas can be traced back to the study of gravitational wave antennas, quantum optics, cavity QED and laser cooling which, when combined with the recent availability of advanced micromechanical and nanomechanical devices, opens a path to the realization of macroscopic mechanical systems that operate deep in the quantum regime. At the fundamental level this development paves the way to experiments that will lead to a more profound understanding of quantum mechanics; and from the point of view of applications, quantum optomechanical techniques will provide motion and force sensing near the fundamental limit imposed by quantum mechanics (quantum metrology) and significantly expand the toolbox of quantum information science. After a brief summary of key historical developments, the talk will give a broad overview of the current state of the art of quantum optomechanics, and comment on future prospects both in applied and in fundamental science. Work supported by NSF, ARO and the DARPA QuASAR and ORCHID programs.

  8. Stability properties of a rotating astigmatic optical cavity

    NASA Astrophysics Data System (ADS)

    Habraken, Steven J. M.; Nienhuis, Gerard

    2009-02-01

    We study the effects of rotation on the stability properties of an astigmatic two-mirror cavity. We show that rotation can both stabilize and destabilize a cavity and investigate the effects of such a rotationally-induced transition on the spatial structure and the orbital angular momentum of the cavity modes. Our method relies on the connection between ray and wave optics and is exact within the time-dependent paraxial approximation.

  9. Electromagnetic vacuum confinement effects in the optical microscopic cavity

    NASA Astrophysics Data System (ADS)

    De Martini, Francesco; Marrocco, Michele; Mataloni, Paolo; Murra, Daniele

    1992-10-01

    The process of the spontaneous emission (SpE) from an active microscopic cavity (microcavity) is shown with emphasis on mirror separation of the order of the optical wavelength. The relevant effects of SpE enhancement and inhibition, non-exponential decay, and emission anisotropy are outlined for a cavity terminated by mirrors bearing either metal -- or semiconductor -- multilayered coatings. Finally, an experiment regarding the possibility of detecting the field distribution within the cavity of the emission wavelength is shown.

  10. Fiber-coupled, Littrow-grating cavity displacement sensor.

    PubMed

    Allen, Graham; Sun, Ke-Xun; Byer, Robert

    2010-04-15

    We have demonstrated a compact, optical-fiber-fed, optical displacement sensor utilizing a Littrow-mounted diffraction grating to form a low-finesse Fabry-Perot cavity. Length changes of the cavity are read out via the Pound-Drever-Hall rf modulation technique at 925 MHz. The sensor has a nominal working distance of 2 cm and a total dynamic range of 160 nm. The displacement noise floor was less than 3x10(-10) m/sqrt[Hz] above 10(-2) Hz, limited by the frequency drift of the reference laser. A frequency-stabilized laser would reduce the noise floor to below 10(-12) m/sqrt[Hz]. The use of a 925 MHz modulation frequency demonstrates high-precision readout of a low-finesse compact resonant cavity. PMID:20410986

  11. Molecular frequency reference at 1.56  μm using a 12C16O overtone transition with the noise-immune cavity-enhanced optical heterodyne molecular spectroscopy method.

    PubMed

    Saraf, Shailendhar; Berceau, Paul; Stochino, Alberto; Byer, Robert; Lipa, John

    2016-05-15

    We report on a molecular clock based on the interrogation of the 3ν rotational-vibrational combination band at 1563 nm of carbon monoxide C1612O. The laser stabilization scheme is based on the noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) technique in frequency modulation (FM) saturation spectroscopy. We use a high-finesse ultra-low expansion (ULE) glass optical cavity with CO as the molecular reference for long-term stabilization of the cavity resonance. We report an Allan deviation of 1.8×10-12 at 1 s that improves to ∼3.5×10-14 with 1000 s of averaging. PMID:27176959

  12. Cavity cooling of an optically levitated submicron particle

    PubMed Central

    Kiesel, Nikolai; Blaser, Florian; Delić, Uroš; Grass, David; Kaltenbaek, Rainer; Aspelmeyer, Markus

    2013-01-01

    The coupling of a levitated submicron particle and an optical cavity field promises access to a unique parameter regime both for macroscopic quantum experiments and for high-precision force sensing. We report a demonstration of such controlled interactions by cavity cooling the center-of-mass motion of an optically trapped submicron particle. This paves the way for a light–matter interface that can enable room-temperature quantum experiments with mesoscopic mechanical systems. PMID:23940352

  13. Calculations of laser cavity dumping for optical communications

    NASA Technical Reports Server (NTRS)

    Robinson, D. L.; Rayman, M. D.

    1988-01-01

    For deep-space pulse-position modulation (PPM) optical communication links using Nd:YAG lasers, two types of laser transmitter modulation techniques are available for efficiently producing laser pulses over a broad range of repetition rates: Q-switching and cavity dumping. The desired modulation scheme is dependent on the required pulse repetition frequency and link parameters. These two techniques are discussed, theoretical and numerical calculations of the internal energy of the laser cavity in cavity dumping are described, and an example of cavity dumping is applied to a link for a proposed experiment package on Cassini.

  14. Cavity enhanced atomic magnetometry

    PubMed Central

    Crepaz, Herbert; Ley, Li Yuan; Dumke, Rainer

    2015-01-01

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations. PMID:26481853

  15. Cavity enhanced atomic magnetometry.

    PubMed

    Crepaz, Herbert; Ley, Li Yuan; Dumke, Rainer

    2015-01-01

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations. PMID:26481853

  16. Cavity enhanced atomic magnetometry

    NASA Astrophysics Data System (ADS)

    Crepaz, Herbert; Ley, Li Yuan; Dumke, Rainer

    2015-10-01

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations.

  17. Non-linear optics of ultrastrongly coupled cavity polaritons

    NASA Astrophysics Data System (ADS)

    Crescimanno, Michael; Liu, Bin; McMaster, Michael; Singer, Kenneth

    2016-05-01

    Experiments at CWRU have developed organic cavity polaritons that display world-record vacuum Rabi splittings of more than an eV. This ultrastrongly coupled polaritonic matter is a new regime for exploring non-linear optical effects. We apply quantum optics theory to quantitatively determine various non-linear optical effects including types of low harmonic generation (SHG and THG) in single and double cavity polariton systems. Ultrastrongly coupled photon-matter systems such as these may be the foundation for technologies including low-power optical switching and computing.

  18. Polarization-controlled optical ring cavity (PORC) tunable pulse stretcher

    NASA Astrophysics Data System (ADS)

    Williamson, Andrew P.; Kiefer, Johannes

    2016-08-01

    A new concept and a theoretical approach for modeling a tunable polarization-controlled optical ring cavity pulse stretcher is demonstrated. The technique discussed herein permits highly simplified and flexible tuning of the temporal shape of nanosecond duration pulses. Using half-wave plates positioned extra- and intracavity, transmission to reflection ratios across both input faces of a polarization beam splitter can easily be controlled. The resulting models indicate a further reduction in peak intensity of 30%, with respect to conventional dielectric beam splitting optical ring cavities, when configured under equivalent and optimized cavity settings.

  19. Optical-feedback cavity-enhanced absorption spectroscopy in a linear cavity: model and experiments

    NASA Astrophysics Data System (ADS)

    Manfred, Katherine M.; Ciaffoni, Luca; Ritchie, Grant A. D.

    2015-08-01

    Optical-feedback cavity-enhanced absorption spectroscopy is a highly sensitive trace gas sensing technique that relies on feedback from a resonant intracavity field to successively lock the laser to the cavity as the wavelength is scanned across a molecular absorption with a comb of resonant frequencies. V-shaped optical cavities have been favoured in the past in order to avoid additional feedback fields from non-resonant reflections that potentially suppress the locking to the resonant cavity frequency. A model of the laser-cavity coupling demonstrates, however, that the laser can stably lock to a resonant linear cavity, within certain constraints on the relative intensity of the two feedback sources. By mode mismatching the field into the linear cavity, we have shown that it is theoretically and practically possible to spatially filter out the unwanted non-resonant component in order for the resonant field to dominate the feedback competition at the laser. A 5.3 cw quantum cascade laser scanning across a absorption feature demonstrated stable locking to achieve a minimum detectable absorption coefficient of for 1-s averaging. Detailed investigations of feedback effects on the laser output verified the validity of our theoretical models.

  20. Design and optimization of microbolometer multilayer optical cavity

    SciTech Connect

    Awad, E.; Al-Khalli, N.; Debbar, N.; Abdel-Rahman, M.; Alduraibi, M.

    2015-03-30

    Microbolometers are the most widely used detectors in long-wave infrared uncooled thermal imagers. An optical cavity is required within a microbolometer structure to increase its optical absorption. In this work we present a detailed study on the design and optimization of a microbolometer optical cavity using Essential-Macleod package. In the simulations, the cavity is considered as thin film multi-layers that form cascaded Fabry-Perot optical cavities. In the design phase, the layers structures are selected including materials and initial thickness. The absorbing layers are chosen to be vanadium-pentoxide (V{sub 2}O{sub 5}) and titanium (Ti). In the optimization phase, the designed layer thicknesses are varied to maximize optical absorption within the absorbing layers. The simulations show that Ti layer absorption dominates over V{sub 2}O{sub 5} layer. Also, the optimization proves that the air-gap cavity thickness is not simply quarter-wavelength because of the complex cascaded Fabry-Perot structure. The optimized air-gap thickness here is ≈3.5 µm at 10.6µm wavelength.

  1. Design and optimization of microbolometer multilayer optical cavity

    NASA Astrophysics Data System (ADS)

    Awad, E.; Al-Khalli, N.; Abdel-Rahman, M.; Debbar, N.; Alduraibi, M.

    2015-03-01

    Microbolometers are the most widely used detectors in long-wave infrared uncooled thermal imagers. An optical cavity is required within a microbolometer structure to increase its optical absorption. In this work we present a detailed study on the design and optimization of a microbolometer optical cavity using Essential-Macleod package. In the simulations, the cavity is considered as thin film multi-layers that form cascaded Fabry-Perot optical cavities. In the design phase, the layers structures are selected including materials and initial thickness. The absorbing layers are chosen to be vanadium-pentoxide (V2O5) and titanium (Ti). In the optimization phase, the designed layer thicknesses are varied to maximize optical absorption within the absorbing layers. The simulations show that Ti layer absorption dominates over V2O5 layer. Also, the optimization proves that the air-gap cavity thickness is not simply quarter-wavelength because of the complex cascaded Fabry-Perot structure. The optimized air-gap thickness here is ≈3.5 µm at 10.6µm wavelength.

  2. Non-adiabatic Dynamics of Molecules in Optical Cavities

    NASA Astrophysics Data System (ADS)

    Kowalewski, Markus; Bennett, Kochise; Mukamel, Shaul

    Molecular systems coupled to optical cavities are promising candidates for a novel kind of photo chemistry. Strong coupling to the vacuum field of the cavity can modify the potential energy surfaces opening up new reaction pathways. We present a derivation of the non-adiabatic couplings for single molecules in the strong coupling regime. The possibilities for photo chemistry are demonstrated for a set of model systems representing typical situations found in molecules. Supported by the Alexander von Humboldt Foundation.

  3. Electromagnetic Wave Chaos in Gradient Refractive Index Optical Cavities

    SciTech Connect

    Wilkinson, P. B.; Fromhold, T. M.; Taylor, R. P.; Micolich, A. P.

    2001-06-11

    Electromagnetic wave chaos is investigated using two-dimensional optical cavities formed in a cylindrical gradient refractive index lens with reflective surfaces. When the planar ends of the lens are cut at an angle to its axis, the geometrical ray paths are chaotic. In this regime, the electromagnetic mode spectrum of the cavity is modulated by both real and ghost periodic ray paths, which also {open_quotes}scar{close_quotes} the electric field intensity distributions of many modes. When the cavity is coupled to waveguides, the eigenmodes generate complex series of resonant peaks in the electromagnetic transmission spectrum.

  4. Cavity cooling a single charged levitated nanosphere.

    PubMed

    Millen, J; Fonseca, P Z G; Mavrogordatos, T; Monteiro, T S; Barker, P F

    2015-03-27

    Optomechanical cavity cooling of levitated objects offers the possibility for laboratory investigation of the macroscopic quantum behavior of systems that are largely decoupled from their environment. However, experimental progress has been hindered by particle loss mechanisms, which have prevented levitation and cavity cooling in a vacuum. We overcome this problem with a new type of hybrid electro-optical trap formed from a Paul trap within a single-mode optical cavity. We demonstrate a factor of 100 cavity cooling of 400 nm diameter silica spheres trapped in vacuum. This paves the way for ground-state cooling in a smaller, higher finesse cavity, as we show that a novel feature of the hybrid trap is that the optomechanical cooling becomes actively driven by the Paul trap, even for singly charged nanospheres. PMID:25860743

  5. Optical trapping of dielectric nanoparticles in resonant cavities

    SciTech Connect

    Hu Juejun; Lin Shiyun; Crozier, Kenneth; Kimerling, Lionel C.

    2010-11-15

    We theoretically investigate the opto-mechanical interactions between a dielectric nanoparticle and the resonantly enhanced optical field inside a high Q, small-mode-volume optical cavity. We develop an analytical method based on open system analysis to account for the resonant perturbation due to particle introduction and predict trapping potential in good agreement with three-dimensional (3D) finite-difference time-domain (FDTD) numerical simulations. Strong size-dependent trapping dynamics distinctly different from free-space optical tweezers arise as a consequence of the finite cavity perturbation. We illustrate single nanoparticle trapping from an ensemble of monodispersed particles based on size-dependent trapping dynamics. We further discover that the failure of the conventional dipole approximation in the case of resonant cavity trapping originates from a new perturbation interaction mechanism between trapped particles and spatially localized photons.

  6. Optical re-injection in cavity-enhanced absorption spectroscopy

    PubMed Central

    Leen, J. Brian; O’Keefe, Anthony

    2014-01-01

    Non-mode-matched cavity-enhanced absorption spectrometry (e.g., cavity ringdown spectroscopy and integrated cavity output spectroscopy) is commonly used for the ultrasensitive detection of trace gases. These techniques are attractive for their simplicity and robustness, but their performance may be limited by the reflection of light from the front mirror and the resulting low optical transmission. Although this low transmitted power can sometimes be overcome with higher power lasers and lower noise detectors (e.g., in the near-infrared), many regimes exist where the available light intensity or photodetector sensitivity limits instrument performance (e.g., in the mid-infrared). In this article, we describe a method of repeatedly re-injecting light reflected off the front mirror of the optical cavity to boost the cavity's circulating power and deliver more light to the photodetector and thus increase the signal-to-noise ratio of the absorption measurement. We model and experimentally demonstrate the method's performance using off-axis cavity ringdown spectroscopy (OA-CRDS) with a broadly tunable external cavity quantum cascade laser. The power coupled through the cavity to the detector is increased by a factor of 22.5. The cavity loss is measured with a precision of 2 × 10−10 cm−1/\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\sqrt {{\\rm Hz;}}$\\end{document} Hz ; an increase of 12 times over the standard off-axis configuration without reinjection and comparable to the best reported sensitivities in the mid-infrared. Finally, the re-injected CRDS system is used to measure the spectrum of several volatile organic compounds, demonstrating the improved ability to resolve weakly absorbing spectroscopic features. PMID:25273701

  7. Optical re-injection in cavity-enhanced absorption spectroscopy.

    PubMed

    Leen, J Brian; O'Keefe, Anthony

    2014-09-01

    Non-mode-matched cavity-enhanced absorption spectrometry (e.g., cavity ringdown spectroscopy and integrated cavity output spectroscopy) is commonly used for the ultrasensitive detection of trace gases. These techniques are attractive for their simplicity and robustness, but their performance may be limited by the reflection of light from the front mirror and the resulting low optical transmission. Although this low transmitted power can sometimes be overcome with higher power lasers and lower noise detectors (e.g., in the near-infrared), many regimes exist where the available light intensity or photodetector sensitivity limits instrument performance (e.g., in the mid-infrared). In this article, we describe a method of repeatedly re-injecting light reflected off the front mirror of the optical cavity to boost the cavity's circulating power and deliver more light to the photodetector and thus increase the signal-to-noise ratio of the absorption measurement. We model and experimentally demonstrate the method's performance using off-axis cavity ringdown spectroscopy (OA-CRDS) with a broadly tunable external cavity quantum cascade laser. The power coupled through the cavity to the detector is increased by a factor of 22.5. The cavity loss is measured with a precision of 2 × 10(-10) cm(-1)/√Hz; an increase of 12 times over the standard off-axis configuration without reinjection and comparable to the best reported sensitivities in the mid-infrared. Finally, the re-injected CRDS system is used to measure the spectrum of several volatile organic compounds, demonstrating the improved ability to resolve weakly absorbing spectroscopic features. PMID:25273701

  8. Optical re-injection in cavity-enhanced absorption spectroscopy

    SciTech Connect

    Leen, J. Brian O’Keefe, Anthony

    2014-09-15

    Non-mode-matched cavity-enhanced absorption spectrometry (e.g., cavity ringdown spectroscopy and integrated cavity output spectroscopy) is commonly used for the ultrasensitive detection of trace gases. These techniques are attractive for their simplicity and robustness, but their performance may be limited by the reflection of light from the front mirror and the resulting low optical transmission. Although this low transmitted power can sometimes be overcome with higher power lasers and lower noise detectors (e.g., in the near-infrared), many regimes exist where the available light intensity or photodetector sensitivity limits instrument performance (e.g., in the mid-infrared). In this article, we describe a method of repeatedly re-injecting light reflected off the front mirror of the optical cavity to boost the cavity's circulating power and deliver more light to the photodetector and thus increase the signal-to-noise ratio of the absorption measurement. We model and experimentally demonstrate the method's performance using off-axis cavity ringdown spectroscopy (OA-CRDS) with a broadly tunable external cavity quantum cascade laser. The power coupled through the cavity to the detector is increased by a factor of 22.5. The cavity loss is measured with a precision of 2 × 10{sup −10} cm{sup −1}/√(Hz;) an increase of 12 times over the standard off-axis configuration without reinjection and comparable to the best reported sensitivities in the mid-infrared. Finally, the re-injected CRDS system is used to measure the spectrum of several volatile organic compounds, demonstrating the improved ability to resolve weakly absorbing spectroscopic features.

  9. A scanning cavity microscope.

    PubMed

    Mader, Matthias; Reichel, Jakob; Hänsch, Theodor W; Hunger, David

    2015-01-01

    Imaging the optical properties of individual nanosystems beyond fluorescence can provide a wealth of information. However, the minute signals for absorption and dispersion are challenging to observe, and only specialized techniques requiring sophisticated noise rejection are available. Here we use signal enhancement in a high-finesse scanning optical microcavity to demonstrate ultra-sensitive imaging. Harnessing multiple interactions of probe light with a sample within an optical resonator, we achieve a 1,700-fold signal enhancement compared with diffraction-limited microscopy. We demonstrate quantitative imaging of the extinction cross-section of gold nanoparticles with a sensitivity less than 1 nm(2); we show a method to improve the spatial resolution potentially below the diffraction limit by using higher order cavity modes, and we present measurements of the birefringence and extinction contrast of gold nanorods. The demonstrated simultaneous enhancement of absorptive and dispersive signals promises intriguing potential for optical studies of nanomaterials, molecules and biological nanosystems. PMID:26105690

  10. A scanning cavity microscope

    PubMed Central

    Mader, Matthias; Reichel, Jakob; Hänsch, Theodor W.; Hunger, David

    2015-01-01

    Imaging the optical properties of individual nanosystems beyond fluorescence can provide a wealth of information. However, the minute signals for absorption and dispersion are challenging to observe, and only specialized techniques requiring sophisticated noise rejection are available. Here we use signal enhancement in a high-finesse scanning optical microcavity to demonstrate ultra-sensitive imaging. Harnessing multiple interactions of probe light with a sample within an optical resonator, we achieve a 1,700-fold signal enhancement compared with diffraction-limited microscopy. We demonstrate quantitative imaging of the extinction cross-section of gold nanoparticles with a sensitivity less than 1 nm2; we show a method to improve the spatial resolution potentially below the diffraction limit by using higher order cavity modes, and we present measurements of the birefringence and extinction contrast of gold nanorods. The demonstrated simultaneous enhancement of absorptive and dispersive signals promises intriguing potential for optical studies of nanomaterials, molecules and biological nanosystems. PMID:26105690

  11. Microgel photonics: a breathing cavity onto optical fiber tip

    NASA Astrophysics Data System (ADS)

    Ricciardi, A.; Aliberti, A.; Giaquinto, M.; Micco, A.; Cusano, A.

    2015-09-01

    We experimentally demonstrate a novel multifunctional optical fiber probe resulting from the integration between two rapidly emerging technologies such as Lab-on-Fiber and Microgel Photonics. The device consists of a microgel based cavity formed by metallic slabs supporting plasmonic resonances, directly integrated on the optical fiber tip. By exploiting the multiresponsivity of microgel systems, variations of temperature, PH, ionic strength, as well as molecular binding events, make the cavity to `breath', thus modulating the interference pattern in the reflection spectrum. The microgel layer can be synthetized in such a way to obtain different thicknesses, corresponding to different operating regimes, opening new avenues for the realization of advanced multifunctional nanoprobes.

  12. An optical storage cavity-based, Compton-backscatter x-ray source using the MKV free electron laser

    NASA Astrophysics Data System (ADS)

    Hadmack, Michael R.

    A compact, high-brightness x-ray source is presently under development at the University of Hawai`i Free Electron Laser Laboratory. This source utilizes Compton backscattering of an infrared laser from a relativistic electron beam to produce a narrow beam of monochromatic x-rays. The scattering efficiency is greatly increased by tightly focusing the two beams at an interaction point within a near-concentric optical storage cavity, designed with high finesse to coherently stack the incident laser pulses and greatly enhance the number of photons available for scattering with the electron beam. This dissertation describes the effort and progress to integrate and characterize the most important and challenging aspects of the design of this system. A low-power, near-concentric, visible-light storage cavity has been constructed as a tool for the exploration of the performance, alignment procedures, and diagnostics required for the operation of a high power infrared storage cavity. The use of off-axis reflective focussing elements is essential to the design of the optical storage cavity, but requires exquisite alignment to minimize astigmatism and other optical aberrations. Experiments using a stabilized HeNe laser have revealed important performance characteristics, and allowed the development of critical alignment and calibration procedures, which can be directly applied to the high power infrared storage cavity. Integration of the optical and electron beams is similarly challenging. A scanning-wire beam profiler has been constructed and tested, which allows for high resolution measurement of the size and position of the laser and electron beams at the interaction point. This apparatus has demonstrated that the electron and laser beams can be co-aligned with a precision of less than 10 microm, as required to maximize the x-ray production rate. Equally important is the stabilization of the phase of the GHz repetition rate electron pulses arriving at the interaction point

  13. Cavity QED detection of interfering matter waves

    SciTech Connect

    Bourdel, T.; Donner, T.; Ritter, S.; Oettl, A.; Koehl, M.; Esslinger, T.

    2006-04-15

    We observe the build-up of a matter wave interference pattern from single atom detection events in a double-slit experiment. The interference arises from two overlapping atom laser beams extracted from a rubidium Bose-Einstein condensate. Our detector is a high-finesse optical cavity which realizes a quantum measurement of the presence of an atom and thereby projects delocalized atoms into a state with zero or one atom in the resonator. The experiment reveals simultaneously the granular and the wave nature of matter. We present a setup which is suited for applications in atom interferometry and cavity QED.

  14. Optical cavity integrated surface ion trap for enhanced light collection

    NASA Astrophysics Data System (ADS)

    Benito, Francisco M.

    Ion trap systems allow the faithful storage and manipulation of qubits encoded in the energy levels of the ions, and can be interfaced with photonic qubits that can be transmitted to connect remote quantum systems. Single photons transmitted from two remote sites, each entangled with one quantum memory, can be used to entangle distant quantum memories by interfering on a beam splitter. Efficient remote entanglement generation relies upon efficient light collection from single ions into a single mode fiber. This can be realized by integrating an ion trap with an optical cavity and employing the Purcell effect for enhancing the light collection. Remote entanglement can be used as a resource for a quantum repeater for provably secure long-distance communication or as a method for communicating within a distributed quantum information processor. We present the integration of a 1 mm optical cavity with a micro-fabricated surface ion trap. The plano-concave cavity is oriented normal to the chip surface where the planar mirror is attached underneath the trap chip. The cavity is locked using a 780 nm laser which is stabilized to Rubidium and shifted to match the 369 nm Doppler transition in Ytterbium. The linear ion trap allows ions to be shuttled in and out of the cavity mode. The Purcell enhancement of spontaneous emission into the cavity mode would then allow efficient collection of the emitted photons, enabling faster remote entanglement generation.

  15. Optothermal transport behavior in whispering gallery mode optical cavities

    NASA Astrophysics Data System (ADS)

    Soltani, Soheil; M. Armani, Andrea

    2014-08-01

    Over the past century, whispering gallery mode optical cavities have enabled numerous advances in science and engineering, such as discoveries in quantum mechanics and non-linear optics, as well as the development of optical gyroscopes and add drop filters. One reason for their widespread appeal is their ability to confine light for long periods of time, resulting in high circulating intensities. However, when sufficiently large amounts of optical power are coupled into these cavities, they begin to experience optothermal or photothermal behavior, in which the optical energy is converted into heat. Above the optothermal threshold, the resonance behavior is no longer solely defined by electromagnetics. Previous work has primarily focused on the role of the optothermal coefficient of the material in this instability. However, the physics of this optothermal behavior is significantly more complex. In the present work, we develop a predictive theory based on a generalizable analytical expression in combination with a geometry-specific COMSOL Multiphysics finite element method model. The simulation couples the optical and thermal physics components, accounting for geometry variations as well as the temporal and spatial profile of the optical field. To experimentally verify our theoretical model, the optothermal thresholds of a series of silica toroidal resonant cavities are characterized at different wavelengths (visible through near-infrared) and using different device geometries. The silica toroid offers a particularly rigorous case study for the developed optothermal model because of its complex geometrical structure which provides multiple thermal transport paths.

  16. Optothermal transport behavior in whispering gallery mode optical cavities

    SciTech Connect

    Soltani, Soheil; Armani, Andrea M.

    2014-08-04

    Over the past century, whispering gallery mode optical cavities have enabled numerous advances in science and engineering, such as discoveries in quantum mechanics and non-linear optics, as well as the development of optical gyroscopes and add drop filters. One reason for their widespread appeal is their ability to confine light for long periods of time, resulting in high circulating intensities. However, when sufficiently large amounts of optical power are coupled into these cavities, they begin to experience optothermal or photothermal behavior, in which the optical energy is converted into heat. Above the optothermal threshold, the resonance behavior is no longer solely defined by electromagnetics. Previous work has primarily focused on the role of the optothermal coefficient of the material in this instability. However, the physics of this optothermal behavior is significantly more complex. In the present work, we develop a predictive theory based on a generalizable analytical expression in combination with a geometry-specific COMSOL Multiphysics finite element method model. The simulation couples the optical and thermal physics components, accounting for geometry variations as well as the temporal and spatial profile of the optical field. To experimentally verify our theoretical model, the optothermal thresholds of a series of silica toroidal resonant cavities are characterized at different wavelengths (visible through near-infrared) and using different device geometries. The silica toroid offers a particularly rigorous case study for the developed optothermal model because of its complex geometrical structure which provides multiple thermal transport paths.

  17. Coupled mode theory in non-Hermitian optical cavities.

    PubMed

    Wu, Bingbing; Wu, Bei; Xu, Jing; Xiao, Junjun; Chen, Yuntian

    2016-07-25

    We study the coupling of mode in time for non-Hermitian cavities. Using variational principle, we provide a self-consistent approach to study the mode hybridization in non-Hermitian cavities from the first-principle of Maxwell's equations. We first extend the reaction concept for time reversal adjoint system using the scalar inner product. We apply our theory to the non-Hermitian parity-time symmetric cavities, and obtain excellent agreement with results obtained by finite element fullwave simulations. In contrast, the conventional coupled mode theory using complex inner product fails to capture the bifurcation of the dispersion of parity-time symmetric cavities, as non-Hermicity increases. Our theory may have potential applications in non-Hermitian optical systems. PMID:27464111

  18. Gain-enhanced optical cooling in cavity optomechanics

    NASA Astrophysics Data System (ADS)

    Ge, Li; Faez, Sanli; Marquardt, Florian; Tureci, Hakan

    2013-03-01

    We study the optical cooling of the mechanical motion of the resonator mirror in a cavity-optomechanical system that contains an optical gain medium. We find that the optical damping caused by radiation pressure force is vanishingly small if the active medium is pumped incoherently above its lasing threshold. In addition, we find that the spontaneous emission of the active medium always tends to increase the final effective temperature of the mechanical motion. In the presence of an additional seeding signal, i.e. a coherent drive of fixed frequency within the width of the gain curve however, we find that the cooling rate can be enhanced significantly with respect to that of a passive cavity. We attribute this effect to a reduced effective optical damping in the presence of incoherent pumping.

  19. Optical diagnostics in the oral cavity: an overview

    PubMed Central

    Wilder-Smith, P; Holtzman, J; Epstein, J; Le, A

    2014-01-01

    As the emphasis shifts from damage mitigation to disease prevention or reversal of early disease in the oral cavity, the need for sensitive and accurate detection and diagnostic tools become more important. Many novel and emergent optical diagnostic modalities for the oral cavity are becoming available to clinicians with a variety of desirable attributes including: (i) non-invasiveness, (ii) absence of ionizing radiation, (iii) patient-friendliness, (iv) real-time information (v) repeatability, and (vi) high-resolution surface and subsurface images. In this article, the principles behind optical diagnostic approaches, their feasibility and applicability for imaging soft and hard tissues, and their potential usefulness as a tool in the diagnosis of oral mucosal lesions, dental pathologies, and other dental applications will be reviewed. The clinical applications of light-based imaging technologies in the oral cavity and of their derivative devices will be discussed to provide the reader with a comprehensive understanding of emergent diagnostic modalities. PMID:20561224

  20. Laser Pulse-Stretching Using Multiple Optical Ring-Cavities

    NASA Technical Reports Server (NTRS)

    Kojima, Jun; Nguyen, Quang-Viet; Lee, Chi-Ming (Technical Monitor)

    2002-01-01

    We describe a simple and passive nanosecond-long (ns-long) laser 'pulse-stretcher' using multiple optical ring-cavities. We present a model of the pulse-stretching process for an arbitrary number of optical ring-cavities. Using the model, we optimize the design of a pulse-stretcher for use in a spontaneous Raman scattering excitation system that avoids laser-induced plasma spark problems. From the optimized design, we then experimentally demonstrate and verify the model with a 3-cavity pulse-stretcher system that converts a 1000 mJ, 8.4 ns-long input laser pulse into an approximately 75 ns-long (FWHM) output laser pulse with a peak power reduction of 0.10X, and an 83% efficiency.

  1. Augmentation of Cavity Optical Inspection by Replicas Without Performance Degradation

    SciTech Connect

    Ge, M.; Burk, D.; Hicks, D.; Wu, G.; Thompson, C.; Cooley, L.D.; /Fermilab

    2009-01-01

    Although cavity optical inspection systems provide a huge amount of qualitative information about surface features, the amount of quantitative topographic informa-tion is limited. Here, we report the use of silicone-based RTV for replicas and moldings that provide increased details of topographic data associated with the optical cavity images. Profilometry scans of the molds yield mi-crometer-scale details associated with equator weld struc-tures and weld pits. This confirms at least two different types of pits, one which is bowl-shaped, and one which has a small peak at the bottom. The contour information extracted from profilometry can be used to evaluate mechanisms by which pits and other features limit RF performance. We present calculations based on a con-formal transformation of the profiles above. We also show that application of the replica followed by rinsing does not adversely affect the cavity performance.

  2. Optical modeling of certical-cavity surface-emitting lasers

    SciTech Connect

    Hadley, G.R.

    1996-12-31

    Vertical-cavity surface-emitting lasers (VCSELs) are presently the subject of intense research due to their potential as compact, efficient, astigmatic laser sources for a number of important applications. Of special interest are the selectively-oxidized VCSELs that have recently set records for threshold current and wall-plug efficiency. The onset of higher-order modes at powers of a few milliWatts, however, presently limits the wide utilization of these devices and indicates the need for improvements in design. Unfortunately, their complexity precludes optimization based solely upon empirical methods, and points instead to the need for better numerical models. Modeling the optical field in a vertical-cavity laser, however, is especially difficult due to both the high Q of the optical cavity and the distributed reflectivity of the mirrors. Our approach to this dilemma has been the development of modeling techniques on two complexity scales. We first derived an effective- index model that is numerically efficient and thus can be included together with carrier transport and thermal models to make up a self-consistent modeling package. In addition to its use in the overall VCSEL model, this simplified optical model has been extremely valuable in elucidating the basic principles of waveguiding in VCSELs that in turn have led to new ideas in device design. More specifically, the derived expression for the effective index shows clearly that index guiding in a VCSEL depends only on variations in optical cavity length, and thus can be engineered without the need to alter the material index of refraction. Also, we have designed index- guided and antiguided devices whose cavity lengths are modified in certain regions by etching of the cavity material prior to growth of the second mirror. Fabrication of these new device designs is presently in progress.

  3. Narrow linewidth laser system realized by linewidth transfer using a fiber-based frequency comb for the magneto-optical trapping of strontium.

    PubMed

    Akamatsu, Daisuke; Nakajima, Yoshiaki; Inaba, Hajime; Hosaka, Kazumoto; Yasuda, Masami; Onae, Atsushi; Hong, Feng-Lei

    2012-07-01

    A narrow linewidth diode laser system at 689 nm is realized by phase-locking an extended cavity diode laser to one tooth of a narrow linewidth optical frequency comb. The optical frequency comb is phase-locked to a narrow linewidth laser at 1064 nm, which is frequency stabilized to a high-finesse optical cavity. We demonstrate the magneto-optical trapping of Sr using an intercombination transition with the developed laser system. PMID:22772290

  4. Weak Langmuir optical turbulence in a fiber cavity

    NASA Astrophysics Data System (ADS)

    Xu, G.; Garnier, J.; Mussot, A.; Trillo, S.; Churkin, D.; Tarasov, N.; Turitsyn, S.; Picozzi, A.

    2016-07-01

    We study theoretically and numerically the dynamics of a passive optical fiber ring cavity pumped by a highly incoherent wave: an incoherently injected fiber laser. The theoretical analysis reveals that the turbulent dynamics of the cavity is dominated by the Raman effect. The forced-dissipative nature of the fiber cavity is responsible for a large diversity of turbulent behaviors: Aside from nonequilibrium statistical stationary states, we report the formation of a periodic pattern of spectral incoherent solitons, or the formation of different types of spectral singularities, e.g., dispersive shock waves and incoherent spectral collapse behaviors. We derive a mean-field kinetic equation that describes in detail the different turbulent regimes of the cavity and whose structure is formally analogous to the weak Langmuir turbulence kinetic equation in the presence of forcing and damping. A quantitative agreement is obtained between the simulations of the nonlinear Schrödinger equation with cavity boundary conditions and those of the mean-field kinetic equation and the corresponding singular integrodifferential reduction, without using adjustable parameters. We discuss the possible realization of a fiber cavity experimental setup in which the theoretical predictions can be observed and studied.

  5. Optical modulator based on coupled photonic crystal cavities

    NASA Astrophysics Data System (ADS)

    Serafimovich, Pavel G.; Kazanskiy, Nikolay L.

    2016-07-01

    We propose and numerically investigate an optical signal modulator based on two-photonic crystal nanobeam cavities coupled through a waveguide. The suggested modulator shifts the resonant frequency over a scalable range. We design a compact optical modulator based on photonic crystal nanobeams cavities that exhibits high stability to manufacturing. Photonic crystal waveguide tuning in the low-intensity region of the resonant mode is demonstrated. The advantages of the suggested approach over the single-resonator optical modulator approaches include the possibilities to shift the modulator frequency over a scalable range that depends on switching energy level and to effectively electrically tune the device in the low-intensity region of the resonant mode.

  6. Resonant modes of optical cavities with phase-conjugate mirrors.

    PubMed

    Bélanger, P A; Hardy, A; Siegman, A E

    1980-02-15

    The lowest-order self-consistent Gaussian transverse modes are derived, also the resonant frequencies of an optical resonator formed by conventional paraxial optical components plus a phase-conjugate mirror (PCM) on one end. The conventional optical elements are described by an over-all ABCD matrix. Cavities with purely real elements (no aperturing) have a continuous set of self-reproducing Gaussian modes described by a semicircular locus in the 1/q plane for one round trip; all Gaussian beams are self-reproducing after two round trips. Complex ABCD matrices, such as are produced by Gaussian aperturing in the cavity, lead to unique self-consistent perturbation-stable Gaussian modes. The resonant frequency spectrum of a PCM cavity consists of a central resonance at the driving frequency omega(0) of the PCM element, independent of the cavity length L, plus half-axial sidebands spaced by Deltaomega(ax) = 2pi(c/4L), with phase and amplitude constraints on each pair of upper and lower sidebands. PMID:20216900

  7. Nanoplasmonics: New Design Concepts For Nanoscale Optical Cavities

    SciTech Connect

    Maier, Stefan A.

    2010-10-07

    The design of nanoplasmonic cavities exploiting coherent processes such as sub- and superradiance as well as Fano-type interactions will be discussed, under the framework of plasmon hybridization theory. In such cavities, interactions between bright and dark localized plasmon modes lead to a complex mode spectrum, which can be visualized using electron energy loss spectroscopy. First implementations fabricated using electron beam lithography will be presented. Furthermore, it will be shown how the concept of transformation optics can be utilized for the design of nanoresonators with a broadband absorption spectrum, showing high promise for light harvesting over the whole visible and infrared range of the spectrum.

  8. Modes of a twisted optical cavity

    SciTech Connect

    Habraken, Steven J. M.; Nienhuis, Gerard

    2007-03-15

    An astigmatic optical resonator consists of two astigmatic mirrors facing each other. The resonator is twisted when the symmetry axes of the mirrors are nonparallel. We present an algebraic method to obtain the complete set of the paraxial eigenmodes of such a resonator. Basic ingredients are the complex eigenvectors of the four-dimensional transfer matrix that describes the transformation of a ray of light over a roundtrip of the resonator. The relation between the fundamental mode and the higher-order modes is expressed in terms of raising operators in the spirit of the ladder operators of the quantum harmonic oscillator.

  9. Fiber Optic Based Thermometry System for Superconducting RF Cavities

    SciTech Connect

    Kochergin, Vladimir

    2013-05-06

    Thermometry is recognized as the best technique to identify and characterize losses in SRF cavities. The most widely used and reliable apparatus for temperature mapping at cryogenic temperatures is based on carbon resistors (RTDs). The use of this technology on multi-cell cavities is inconvenient due to the very large number of sensors required to obtain sufficient spatial resolution. Recent developments make feasible the use of multiplexible fiber optic sensors for highly distributed temperature measurements. However, sensitivity of multiplexible cryogenic temperature sensors was found extending only to 12K at best and thus was not sufficient for SRF cavity thermometry. During the course of the project the team of MicroXact, JLab and Virginia Tech developed and demonstrated the multiplexible fiber optic sensor with adequate response below 20K. The demonstrated temperature resolution is by at least a factor of 60 better than that of the best multiplexible fiber optic temperature sensors reported to date. The clear path toward at least 10times better temperature resolution is shown. The first to date temperature distribution measurements with ~2.5mm spatial resolution was done with fiber optic sensors at 2K to4K temperatures. The repeatability and accuracy of the sensors were verified only at 183K, but at this temperature both parameters significantly exceeded the state of the art. The results of this work are expected to find a wide range of applications, since the results are enabling the whole new testing capabilities, not accessible before.

  10. Biosensors based on GaN nanoring optical cavities

    NASA Astrophysics Data System (ADS)

    Kouno, Tetsuya; Takeshima, Hoshi; Kishino, Katsumi; Sakai, Masaru; Hara, Kazuhiko

    2016-05-01

    Biosensors based on GaN nanoring optical cavities were demonstrated using room-temperature photoluminescence measurements. The outer diameter, height, and thickness of the GaN nanorings were approximately 750–800, 900, and 130–180 nm, respectively. The nanorings functioned as whispering-gallery-mode (WGM)-type optical cavities and exhibited sharp resonant peaks like lasing actions. The evanescent component of the WGM was strongly affected by the refractive index of the ambient environment, the type of liquid, and the sucrose concentration of the analyzed solution, resulting in shifts of the resonant wavelengths. The results indicate that the GaN nanorings can potentially be used in sugar sensors of the biosensors.

  11. Single cavity filters on end-faces of optical fibers

    NASA Astrophysics Data System (ADS)

    Meister, Stefan; Schweda, Dawid; Dziedzina, Marcus; Al-Saadi, Aws; Franke, Bülent A.; Scharfenorth, Chris; Grimm, Bernd; Dufft, Daniela; Schrader, Sigurd K.; Eichler, Hans J.

    2010-02-01

    We have developed thin film Fabry-Perot filters directly coated on optical fibers to archive a high level of integration with a reduction of optical elements. Such band-pass filters can be used in fiber optical sensor systems, and for fiber communication, e.g. CWDM applications. The filters cavities consist of a single spacer and two dielectric mirrors. The dielectric mirrors are deposited by PVD directly on end-faces of single-mode optical fibers. Dielectric as well as polymeric materials were applied as the spacer layer. Polymeric spacer layers were deposited by dip coating. The influence of the mirror reflectivity on the transmission band of the Fabry-Perot filters was investigated. Furthermore, the optical performance of filters with first order (λ/2) as well as higher order spacers was analyzed. The experimental results are compared with numerical analysis of Fabry-Perot cavities on the end-face of cylindrical waveguides. The spectral characteristic of the filters are calculated using a software solving Maxwelĺs equations by a FDTD method. The layer design of the filters and the deposition process were optimized for maximum transmission and narrow bandwidth of the transmission peak. Passive band-pass filters on fiber end-faces were designed, fabricated and characterized for transmission wavelengths of 945 nm, 1300 nm, as well as 1550 nm. Bandwidths as narrow as 1 nm could be achieved for 945 nm.

  12. High finesse microfiber knot resonators made from double-ended tapered fibers.

    PubMed

    Xiao, Limin; Birks, T A

    2011-04-01

    We fabricated optical microfiber knot resonators from thin tapered fibers (diameter down to 1 μm) linked to untapered fiber at both ends. We demonstrated a finesse of about 100, over twice as high as previously reported for microfiber resonators. Low-loss encapsulation of microfiber knot resonators in hydrophobic silica aerogel was also investigated. PMID:21478995

  13. Exact analysis of low-finesse multimode fiber extrinsic Fabry-Perot interferometers.

    PubMed

    Han, Ming; Wang, Anbo

    2004-08-20

    A straightforward theory is presented to accurately model the light inferences in a low-finesse multimode fiber extrinsic Fabry-Perot (FP) interferometer. The effect on the fringe visibility of the gap length, sensor structure imperfections, and modal power distributions is explored. The analysis is particularly useful in the design and optimization of sensors that use an extrinsic FP cavity as the sensing element. PMID:15352389

  14. Cooling enhancement in optical refrigeration by non-resonant optical cavities

    NASA Astrophysics Data System (ADS)

    Farfan, B. G.; Gragossian, A.; Symonds, G.; Ghasemkhani, M. R.; Albrecht, A. R.; Sheik-Bahae, M.; Epstein, R. I.

    2016-05-01

    We present a study of cooling enhancement in optical refrigerators by the implementation of advanced non-resonant optical cavities. Cavity designs have been studied to maximize pump light-trapping to improve absorption and thereby increase the efficiency of optical refrigeration. The approaches of non-resonant optical cavities by Herriott-cell and totalinternal- reflection were studied. Ray-tracing simulations and experiments were performed to analyze and optimize the different light-trapping configurations. Light trapping was studied for laser sources with high quality beams and for beams with large divergences, roughly corresponding to the output from fiber lasers and from diode lasers, respectively. We present a trade-off analysis between performance, reliability, and manufacturability.

  15. Nonperturbative atom-photon interactions in an optical cavity

    SciTech Connect

    Carmichael, H.J.; Tian, L.; Ren, W.

    1994-12-31

    One of the principal developments in cavity quantum electrodynamics in the last few years has been the extension of the ideas originally applied to systems of Rydberg atoms in microwave cavities to optical frequencies. As a corollary of this, more attention is being paid to quantum fluctuations and photon statistics. Another development, still in its infancy, is a move toward experiments using slowed or trapped atoms, or velocity selected beams; these methods are needed to enter the nonperturbative (strong dipole coupling) regime for one atom where there are experiments on subtle quantum-statistical effects go carry out. In this chapter we solve a number of theoretical problems related to these themes. Although the focus of the work is on optical systems, most of what we do is also relevant at microwave frequencies. We emphasize quantum fluctuations and photon statistics, and we try always to separate the quantum physics from those aspects of the physics that are understandable in classical terms. On the whole we only pay attention to the nonperturbative regime of cavity quantum electrodynamics where the dipole coupling strength is larger than the dissipation rates. 59 refs., 14 figs.

  16. Broadband cavity ringdown spectroscopy for sensitive and rapid molecular detection.

    PubMed

    Thorpe, Michael J; Moll, Kevin D; Jones, R Jason; Safdi, Benjamin; Ye, Jun

    2006-03-17

    We demonstrate highly efficient cavity ringdown spectroscopy in which a broad-bandwidth optical frequency comb is coherently coupled to a high-finesse optical cavity that acts as the sample chamber. 125,000 optical comb components, each coupled into a specific longitudinal cavity mode, undergo ringdown decays when the cavity input is shut off. Sensitive intracavity absorption information is simultaneously available across 100 nanometers in the visible and near-infrared spectral regions. Real-time, quantitative measurements were made of the trace presence, the transition strengths and linewidths, and the population redistributions due to collisions and the temperature changes for molecules such as C2H2, O2, H2O, and NH3. PMID:16543457

  17. Collective cavity quantum electrodynamics with multiple atomic levels

    SciTech Connect

    Arnold, Kyle J.; Baden, Markus P.; Barrett, Murray D.

    2011-09-15

    We study the transmission spectra of ultracold rubidium atoms coupled to a high-finesse optical cavity. Under weak probing with {pi}-polarized light, the linear response of the system is that of a collective spin with multiple levels coupled to a single mode of the cavity. By varying the atom number, we change the collective coupling of the system. We observe the change in transmission spectra when going from a regime where the collective coupling is much smaller than the separation of the atomic levels to a regime where both are of comparable size. The observations are in good agreement with a reduced model we developed for our system.

  18. Four-wave mixing in a ring cavity

    NASA Astrophysics Data System (ADS)

    Mikhailov, Eugeniy E.; Evans, Jesse; Budker, Dmitry; Rochester, Simon M.; Novikova, Irina

    2014-10-01

    We investigate a four-wave-mixing process in an N interaction scheme in Rb vapor placed inside a low-finesse ring cavity. We observe strong amplification and generation of a probe signal, circulating in the cavity, in the presence of two strong optical pump fields. We study the variations in probe field gain and dispersion as functions of experimental parameters with an eye on the potential application of such a system for enhanced rotation measurements. Density-matrix calculations are performed to model the system and are shown to provide good qualitative agreement with the experiment.

  19. Compact carbon monoxide sensor utilizing a confocal optical cavity.

    NASA Technical Reports Server (NTRS)

    Scott, B.; Magyar, J.; Weyant, R.; Hall, J.

    1973-01-01

    The carbon monoxide sensor discussed in this paper utilizes a unique confocal cavity which allows the complete system to be packaged in a small volume suitable for hand-held use. The optical system is the heart of the instrument with equal emphasis placed on the electronics support circuitry, consisting essentially of a thermal infrared pyroelectric detector and lock-in amplifier. The pyroelectric detector offers a major advantage over other thermal detectors, providing a signal-to-noise ratio and detectivity that remain nearly constant over the frequency range from dc to 2000 Hz. Since bias voltage is not required, low frequency noise is not generated in the detector.

  20. Single atom as a mirror of an optical cavity.

    PubMed

    Hétet, G; Slodička, L; Hennrich, M; Blatt, R

    2011-09-23

    By tightly focusing a laser field onto a single cold ion trapped in front of a far-distant dielectric mirror, we could observe a quantum electrodynamic effect whereby the ion behaves as the optical mirror of a Fabry-Pérot cavity. We show that the amplitude of the laser field is significantly altered due to a modification of the electromagnetic mode structure around the atom in a novel regime in which the laser intensity is already changed by the atom alone. We propose a direct application of this system as a quantum memory for single photons. PMID:22026849

  1. Optical heterodyne detection for cavity ring-down spectroscopy

    DOEpatents

    Levenson, Marc D.; Paldus, Barbara A.; Zare, Richard N.

    2000-07-25

    A cavity ring-down system for performing cavity ring-down spectroscopy (CRDS) using optical heterodyne detection of a ring-down wave E.sub.RD during a ring-down phase or a ring-up wave E.sub.RU during a ring up phase. The system sends a local oscillator wave E.sub.LO and a signal wave E.sub.SIGNAL to the cavity, preferably a ring resonator, and derives an interference signal from the combined local oscillator wave E.sub.LO and the ring-down wave E.sub.RD (or ring-up wave E.sub.RU). The local oscillator wave E.sub.LO has a first polarization and the ring-down wave E.sub.RD has a second polarization different from the first polarization. The system has a combining arrangement for combining or overlapping local oscillator wave E.sub.LO and the ring-down wave E.sub.RD at a photodetector, which receives the interference signal and generates a heterodyne current I.sub.H therefrom. Frequency and phase differences between the waves are adjustable.

  2. Dye laser studies using zig-zag optical cavity

    SciTech Connect

    Klimek, D.E.; Mandl, A.E.; Willman, B. )

    1994-06-01

    The authors report a substantial advance in dye laser performance using a zig-zag optical cavity. This configuration drastically reduces the effects of intrapulse medium disturbances due to acoustics and thermal lensing on pulse duration, beam quality, and extraction efficiency. Laser outputs of up to 2 J were observed from Coumarin-498 dye pumped by a KrF excimer laser. The dye laser output faithfully replicates the flat-top KrF laser pump pulse over the entire 1.7-[mu]s pulse duration. An intrinsic laser photon conversion efficiency (Photons[sub in]/Photons[sub absorbed]) of 44% was measured. When unstable resonator optics were used, beam qualities of about 2 XDL were measured.

  3. A micropillar for cavity optomechanics

    NASA Astrophysics Data System (ADS)

    Kuhn, Aurélien; Neuhaus, Leonhard; Van Brackel, Emmanuel; Chartier, Claude; Ducloux, Olivier; Le Traon, Olivier; Michel, Christophe; Pinard, Laurent; Flaminio, Raffaele; Deléglise, Samuel; Briant, Tristan; Cohadon, Pierre-François; Heidmann, Antoine

    2014-12-01

    Demonstrating the quantum ground state of a macroscopic mechanical object is a major experimental challenge in physics, at the origin of the rapid emergence of cavity optomechanics. We have developed a new generation of optomechanical devices, based on a microgram quartz micropillar with a very high mechanical quality factor. The structure is used as end mirror in a Fabry-Perot cavity with a high optical finesse, leading to ultra-sensitive interferometric measurement of the resonator displacement. We expect to reach the ground state of this optomechanical resonator by combining cryogenic cooling in a dilution fridge at 30 mK and radiation-pressure cooling. We have already carried out a quantum-limited measurement of the micropillar thermal noise at low temperature.

  4. A micropillar for cavity optomechanics

    SciTech Connect

    Kuhn, Aurélien; Neuhaus, Leonhard; Deléglise, Samuel; Briant, Tristan; Cohadon, Pierre-François; Heidmann, Antoine; Van Brackel, Emmanuel; Chartier, Claude; Ducloux, Olivier; Le Traon, Olivier; Michel, Christophe; Pinard, Laurent; Flaminio, Raffaele

    2014-12-04

    Demonstrating the quantum ground state of a macroscopic mechanical object is a major experimental challenge in physics, at the origin of the rapid emergence of cavity optomechanics. We have developed a new generation of optomechanical devices, based on a microgram quartz micropillar with a very high mechanical quality factor. The structure is used as end mirror in a Fabry-Perot cavity with a high optical finesse, leading to ultra-sensitive interferometric measurement of the resonator displacement. We expect to reach the ground state of this optomechanical resonator by combining cryogenic cooling in a dilution fridge at 30 mK and radiation-pressure cooling. We have already carried out a quantum-limited measurement of the micropillar thermal noise at low temperature.

  5. A closed-cycle dilution refrigerator with free-space and fiber optical access for quantum optomechanics experiments at 25mK

    NASA Astrophysics Data System (ADS)

    Groeblacher, Simon; Wieczorek, Witlef; Christ, Peter; Buehler, Matthias; Wernicke, Doreen; Hoehne, Jens; Aspelmeyer, Markus

    2011-03-01

    We report on the operation of a closed-cycle dilution refrigerator for quantum optomechanics experiments at 25mK. The dilution fridge is accessible both via free-space as well as fiber coupling, allowing us to perform a variety of optical experiments at low temperatures. It is designed to vibrationally isolate the experiment allowing for stable operation of a high-finesse optical cavity. This enables us to perform cavity-optomechanics experiments at ultra-low temperatures.

  6. Disorder-induced transparency in a one-dimensional waveguide side coupled with optical cavities

    SciTech Connect

    Zhang, Yongyou Dong, Guangda; Zou, Bingsuo

    2014-05-07

    Disorder influence on photon transmission behavior is theoretically studied in a one-dimensional waveguide side coupled with a series of optical cavities. For this sake, we propose a concept of disorder-induced transparency appearing on the low-transmission spectral background. Two kinds of disorders, namely, disorders of optical cavity eigenfrequencies and relative phases in the waveguide side coupled with optical cavities are considered to show the disorder-induced transparency. They both can induce the optical transmission peaks on the low-transmission backgrounds. The statistical mean value of the transmission also increases with increasing the disorders of the cavity eigenfrequencies and relative phases.

  7. Coupling of Solute Vibrational Modes with a Fabry-Perot Optical Cavity Mode

    NASA Astrophysics Data System (ADS)

    Dunkelberger, Adam; Compton, Ryan; Fears, Kenan; Spann, Bryan; Long, James; Simpkins, Blake; Owrutsky, Jeffrey

    2015-03-01

    Electronic transitions of systems confined in optical microcavities can strongly couple to cavity modes, giving rise to new, mixed-character modes. Recent studies have demonstrated similar coherent coupling between the vibrational modes of a thin polymer film and a Fabry-Perot optical cavity mode. This coupling manifests experimentally as a splitting of the transmissive cavity mode into two dispersive branches separated by the vacuum Rabi splitting. Here we present recent experimental results for the coupling of solution-phase compounds with an optical cavity. Solutions of W(CO)6, Mo(CO)6, and NCS- contained in cavities show strong coupling between the solute chromophores in the mid-infrared and cavity modes. We show that the methodology established with polymer-filled cavities is generally applicable to liquids but that the fluidity of the sample complicates the cavity construction. Varied cavity thicknesses can give rise to spatial gradients in coupling strength and difficulty in targeting a specific cavity-mode order. We also compare the transmission of the mixed vibrational-cavity modes in cavities constructed from either metallic or dielectric reflectors which impacts the cavity resonance line width. NRC Postdoctoral Fellow.

  8. Microcontroller-based locking in optics experiments.

    PubMed

    Huang, K; Le Jeannic, H; Ruaudel, J; Morin, O; Laurat, J

    2014-12-01

    Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments. PMID:25554277

  9. Microcontroller-based locking in optics experiments

    SciTech Connect

    Huang, K.; Le Jeannic, H.; Ruaudel, J.; Morin, O.; Laurat, J.

    2014-12-15

    Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments.

  10. Cavity optomechanics and its applications

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Mishkatul

    2009-05-01

    Cavity optomechanics is an emerging field at the intersection of quantum optics, atomic physics, nanoscience and gravitational wave interferometry. It involves cavities (with one or more mechanical degrees of freedom) driven by laser radiation. The ensuing optical control of macroscopic mechanical motion may have implications for precision sensing, coherent control of atoms and molecules, and quantum information processing. Due to recent innovations optomechanical physics has been realized in a variety of experimental systems spanning many orders of magnitude in mass and time-scales. In this talk, I will first introduce the basic paradigm of a laser-driven two mirror cavity used for cooling a vibrational mode. A three-mirror configuration recently implemented using a partially transmissive dielectric membrane in a high finesse cavity will then be discussed, and shown to be superior to the two-mirror design in a number of ways. One implication of the three-mirror configuration is the possibility of scaling optomechanical techniques to multiple oscillators. This topic will be explored by analysing the case of two membranes in a cavity where it will be shown that the collective(center-of-mass and breathing) modes of vibration can be cooled independently, analogous to a chain of trapped ions. Finally, future directions for possible applications to the control of atoms and molecules will be indicated briefly.

  11. Long distance measurement using optical sampling by cavity tuning.

    PubMed

    Wu, Hanzhong; Zhang, Fumin; Liu, Tingyang; Balling, Petr; Li, Jianshuang; Qu, Xinghua

    2016-05-15

    We experimentally demonstrate a method enabling absolute distance measurement based on optical sampling by cavity tuning. The cross-correlation patterns can be obtained by sweeping the repetition frequency of the frequency comb. The 114 m long fiber delay line, working as the reference arm, is actively stabilized by using a feedback servo loop with 10-10 level stability. The unknown distance can be measured via the instantaneous repetition frequency corresponding to the peak of the fringe packet. We compare the present technique with the reference incremental interferometer, and the experimental results show an agreement within 3 μm over 60 m distance, corresponding to 10-8 level in relative. PMID:27177004

  12. Few-Cycle and Cavity-Enhanced Optical Parametric Amplification

    NASA Astrophysics Data System (ADS)

    Siddiqui, Aleem Mohammad

    Optical parametric amplifiers have emerged as important optical sources by extending the properties of few-cycle laser sources, which exist only in materials with sufficiently large gain bandwidths, to wide array of spectral ranges. The work reported in this thesis relates to two areas for the continued development of optical parametric amplification based sources. First, we present a white light seeded, carrier-envelope stable, degenerately pumped OPA producing near tranform-limited sub 7 fs, 3 microJ pulses at the driver wavelength from a long pulse, non-CEP stable Ti:sapphire regenerative amplifier. Problems to the spectral phase jump at the driver wavelength, 800 nm, were avoided by using a near infrared OPA to produce white light continuum down to 800 nm where the spectral phase is smooth. Secondly, enhancement cavities are used in conjunction with parametric amplifiers resulting in a new technique entitled, cavity-enhanced optical parametric chirped-pulse amplification (C-OPCPA). C-OPCPA increases the capabilities of nonlinear crystals and can allow continued scaling of parametric amplifier systems to high repetition rate. This work contains the first theoretical and experimental investigation of C-OPCPA. Numerically, passive pump pulse shaping of the intracavity pump power is shown to enable octave spanning gain. Experimentally, a first proof-of-principle experiment demonstrates a 78 MHz C-OPCPA with more than 50% conversion with under 1 W of incident pump power. A comparison to a single pass system shows improvements in the C-OPCPA of orders of magnitude in conversion efficiency and 3 fold increase in phase matching bandwidth in 10 and 20 mm periodically poled lithium niobate phase matched for parametric amplification with 1030 nm pump wavelength and a 1550 nm signal wavelength. A Yb-fiber laser based CPA system producing up to 5 W of 500 fs pulses comprises the pump source, and a Er-fiber laser the signal. (Copies available exclusively from MIT Libraries

  13. QCL - Optical-Feedback Cavity Enhanced Absorption Spectroscopy For The Analysis Of Atmospheric 13CO2/12CO2 In Ice-Core Gas Bubbles

    NASA Astrophysics Data System (ADS)

    Gorrotxategi Carbajo, Paula; Romanini, Daniele; Maisons, Gregory; Carras, Mathieu; Chappellaz, Jerome; Kerstel, Erik

    2013-04-01

    In the context of a globally warming climate it is crucial to study the climate variability in the past and to understand the underlying mechanisms. The composition of gas stored in bubbles in polar ice presents a paleo-climate archive that provides a powerful means to study the exact mechanisms involved in the ~40% increase in the atmospheric CO2 concentration between glacial and interglacial climates. It is particularly important to understand such natural coupling between climate and the carbon cycle, as it will partly determine what natural feedback can be expected on the atmospheric CO2 concentration in a future warmer world. The source of the CO2 released into the atmosphere during previous deglaciations can be constrained from isotopic measurements by the fact that the different CO2 reservoirs (terrestrial biosphere, oceans) and associated mechanisms (biological or physical) have different isotopic signatures. Unfortunately, such isotope studies have been seriously hampered by the experimental difficulty of extracting the CO2 without contamination or fractionation, and measuring the isotope signal off-line on an isotope ratio mass spectrometer (IRMS). Here we present an alternative method that leverages the extreme sensitivity afforded by Optical Feedback Cavity Enhanced Absorption Spectroscopy (OF-CEAS) in the Mid-Infrared [1]. This region of the spectrum is accessed by a custom-developed Quantum Cascade Laser operating near 4.35 µm. The feedback to the laser of light that has been spectrally filtered by a high-finesse, V-shaped enhancement cavity has the effect of spectrally narrowing the laser emission and to auto-lock the laser frequency to one of the cavity's longitudinal modes, with clear advantages in terms of acquisition time and signal-to-noise ratio of the measurement. The line strengths in this region are about 5 orders of magnitude higher than in the more easily accessible NIR region near 1.6 µm and about 1000 times higher than at 2 µm. The

  14. Cavity Enhanced Thomson Scattering for Low Temperature Plasmas

    NASA Astrophysics Data System (ADS)

    Yalin, Azer; Friss, Adam; Lee, Brian; Franka, Isaiah

    2013-09-01

    This contribution describes the design, simulation, and initial experimental development of a novel laser Thomson scattering (LTS) system for measurement of weakly-ionized low temperature plasmas. The LTS approach uses a high power intra-cavity beam of power ~10-100 kW to provide increased scattered photon counts and sensitivity as compared to conventional LTS experiments that use light sources with orders of magnitude lower average power. The high power intra-cavity beam is generated by locking a narrow linewidth source laser to a high-finesse optical cavity via Pound-Drever-Hall locking. The plasma (to be studied) is housed with the high-finesse optical cavity. The high-power source is combined with a detection system comprised of a high-suppression triple monochromator and a low-noise photomultiplier tube used in photon counting mode. We present simulations of signal strengths and scattering spectra including elastic scatter background, detector dark counts, and random (counting) noise contributions. Expected experimental performance is assessed from fits to the simulated data. The number density and electron temperature of a 1010 cm-3 plasma should be accurately measurable with standard deviation of <5% in a measurement time of 5 minutes per wavelength channel. We also present experimental development including characterization of laser locking, and initial Rayleigh and Raman signals which will be used to calibrate the Thomson system.

  15. Mean-field theory of atomic self-organization in optical cavities

    NASA Astrophysics Data System (ADS)

    Jäger, Simon B.; Schütz, Stefan; Morigi, Giovanna

    2016-08-01

    Photons mediate long-range optomechanical forces between atoms in high-finesse resonators, which can induce the formation of ordered spatial patterns. When a transverse laser drives the atoms, the system undergoes a second-order phase transition that separates a uniform spatial density from a Bragg grating maximizing scattering into the cavity and is controlled by the laser intensity. Starting from a Fokker-Planck equation describing the semiclassical dynamics of the N -atom distribution function, we systematically develop a mean-field model and analyze its predictions for the equilibrium and out-of-equilibrium dynamics. The validity of the mean-field model is tested by comparison with the numerical simulations of the N -body Fokker-Planck equation and by means of a Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy. The mean-field theory predictions well reproduce several results of the N -body Fokker-Planck equation for sufficiently short times and are in good agreement with existing theoretical approaches based on field-theoretical models. The mean field, on the other hand, predicts thermalization time scales which are at least one order of magnitude shorter than the ones predicted by the N -body dynamics. We attribute this discrepancy to the fact that the mean-field ansatz discards the effects of the long-range incoherent forces due to cavity losses.

  16. Applications of cavity optomechanics

    SciTech Connect

    Metcalfe, Michael

    2014-09-15

    Cavity-optomechanics” aims to study the quantum properties of mechanical systems. A common strategy implemented in order to achieve this goal couples a high finesse photonic cavity to a high quality factor mechanical resonator. Then, using feedback forces such as radiation pressure, one can cool the mechanical mode of interest into the quantum ground state and create non-classical states of mechanical motion. On the path towards achieving these goals, many near-term applications of this field have emerged. After briefly introducing optomechanical systems and describing the current state-of-the-art experimental results, this article summarizes some of the more exciting practical applications such as ultra-sensitive, high bandwidth accelerometers and force sensors, low phase noise x-band integrated microwave oscillators and optical signal processing such as optical delay-lines, wavelength converters, and tunable optical filters. In this rapidly evolving field, new applications are emerging at a fast pace, but this article concentrates on the aforementioned lab-based applications as these are the most promising avenues for near-term real-world applications. New basic science applications are also becoming apparent such as the generation of squeezed light, testing gravitational theories and for providing a link between disparate quantum systems.

  17. Optimized Multi-Ion Cavity Coupling

    NASA Astrophysics Data System (ADS)

    Begley, Stephen; Vogt, Markus; Gulati, Gurpreet Kaur; Takahashi, Hiroki; Keller, Matthias

    2016-06-01

    Recent technological advances in cavity quantum electrodynamics (CQED) are paving the way to utilize multiple quantum emitters confined in a single optical cavity. In such systems, it is crucially important to control the quantum mechanical coupling of individual emitters to the cavity mode. In this regard, combining ion trap technologies with CQED provides a particularly promising approach due to the well-established motional control over trapped ions. Here, we experimentally demonstrate coupling of up to five trapped ions in a string to a high-finesse optical cavity. By changing the axial position and spacing of the ions in a fully deterministic manner, we systematically characterize their coupling to the cavity mode through visibility measurements of the cavity emission. In good agreement with the theoretical model, the results demonstrate that the geometrical configuration of multiple trapped ions can be manipulated to obtain optimal cavity coupling. Our system presents a new ground for exploring CQED with multiple quantum emitters, enabled by the highly controllable collective light-matter interaction.

  18. Optimized Multi-Ion Cavity Coupling.

    PubMed

    Begley, Stephen; Vogt, Markus; Gulati, Gurpreet Kaur; Takahashi, Hiroki; Keller, Matthias

    2016-06-01

    Recent technological advances in cavity quantum electrodynamics (CQED) are paving the way to utilize multiple quantum emitters confined in a single optical cavity. In such systems, it is crucially important to control the quantum mechanical coupling of individual emitters to the cavity mode. In this regard, combining ion trap technologies with CQED provides a particularly promising approach due to the well-established motional control over trapped ions. Here, we experimentally demonstrate coupling of up to five trapped ions in a string to a high-finesse optical cavity. By changing the axial position and spacing of the ions in a fully deterministic manner, we systematically characterize their coupling to the cavity mode through visibility measurements of the cavity emission. In good agreement with the theoretical model, the results demonstrate that the geometrical configuration of multiple trapped ions can be manipulated to obtain optimal cavity coupling. Our system presents a new ground for exploring CQED with multiple quantum emitters, enabled by the highly controllable collective light-matter interaction. PMID:27314716

  19. Controlled optical high-order sidebands via bichromatic driving of a cavity mode detected by an undriven second cavity mode

    NASA Astrophysics Data System (ADS)

    Li, Jiahua; Li, Jiahui; Yu, Rong; Wu, Ying

    2015-08-01

    We propose a scheme for optical high-order sideband generation and efficient sideband information transfer from one optical mode to the other in a hybrid system consisting of a quantum dot coupled to both modes of a lossy bimodal photonic crystal cavity. Here one mode of the cavity is coherently driven by a two-tone continuous-wave laser field and the two cavity modes are not coupled to each other due to their orthogonal polarizations. The influences of the system parameters including the cavity-waveguide coupling rate and all kinds of relative detunings on optical high-order sideband generation and transfer efficiency are discussed. In addition to numerical simulations demonstrating this effect, a physical explanation of the underlying mechanism and an experimental feasibility of the proposed bimodal cavity scheme are also presented. Due to an intrinsic highly multimode sideband structure in the proposed scheme, the ability to engineer and convert photons between different frequencies in a solid-state approach has extensive technological implications not only for classical communication systems, but also future integrated quantum networks.

  20. One-dimensional array of ion chains coupled to an optical cavity

    NASA Astrophysics Data System (ADS)

    Cetina, Marko; Bylinskii, Alexei; Karpa, Leon; Gangloff, Dorian; Beck, Kristin M.; Ge, Yufei; Scholz, Matthias; Grier, Andrew T.; Chuang, Isaac; Vuletić, Vladan

    2013-05-01

    We present a novel system where an optical cavity is integrated with a microfabricated planar-electrode ion trap. The trap electrodes produce a tunable periodic potential allowing the trapping of up to 50 separate ion chains aligned with the cavity and spaced by 160 μm in a one-dimensional array along the cavity axis. Each chain can contain up to 20 individually addressable Yb+ ions coupled to the cavity mode. We demonstrate deterministic distribution of ions between the sites of the electrostatic periodic potential and control of the ion-cavity coupling. The measured strength of this coupling should allow access to the strong collective coupling regime with ≲10 ions. The optical cavity could serve as a quantum information bus between ions or be used to generate a strong wavelength-scale periodic optical potential.

  1. Intra-Cavity Total Reflection For High Sensitivity Measurement Of Optical Properties

    DOEpatents

    Pipino, Andrew Charles Rule

    1999-11-16

    An optical cavity resonator device is provided for conducting sensitive murement of optical absorption by matter in any state with diffraction-limited spatial resolution through utilization of total internal reflection within a high-Q (high quality, low loss) optical cavity. Intracavity total reflection generates an evanescent wave that decays exponentially in space at a point external to the cavity, thereby providing a localized region where absorbing materials can be sensitively probed through alteration of the Q-factor of the otherwise isolated cavity. When a laser pulse is injected into the cavity and passes through the evanescent state, an amplitude loss resulting from absorption is incurred that reduces the lifetime of the pulse in the cavity. By monitoring the decay of the injected pulse, the absorption coefficient of manner within the evanescent wave region is accurately obtained from the decay time measurement.

  2. Intra-Cavity Total Reflection For High Sensitivity Measurement Of Optical Properties

    DOEpatents

    Pipino, Andrew C. R.; Hudgens, Jeffrey W.

    1999-08-24

    An optical cavity resonator device is provided for conducting sensitive murement of optical absorption by matter in any state with diffraction-limited spatial resolution through utilization of total internal reflection within a high-Q (high quality, low loss) optical cavity. Intracavity total reflection generates an evanescent wave that decays exponentially in space at a point external to the cavity, thereby providing a localized region where absorbing materials can be sensitively probed through alteration of the Q-factor of the otherwise isolated cavity. When a laser pulse is injected into the cavity and passes through the evanescent state, an amplitude loss resulting from absorption is incurred that reduces the lifetime of the pulse in the cavity. By monitoring the decay of the injected pulse, the absorption coefficient of manner within the evanescent wave region is accurately obtained from the decay time measurement.

  3. Duality relation between nonspherical mirror optical cavities and its application to gravitational-wave detectors.

    PubMed

    Agresti, Juri; Chen, Yanbei; D'Ambrosio, Erika; Savov, Pavlin

    2012-09-01

    In this paper, we analytically prove a unique duality relation between the eigenspectra of paraxial optical cavities with nonspherical mirrors: a one-to-one mapping between eigenmodes and eigenvalues of cavities deviating from flat mirrors by h(r) and cavities deviating from concentric mirrors by -h(r), where h need not be a small perturbation. We then illustrate its application to optical cavities, proposed for advanced interferometric gravitational-wave detectors, where the mirrors are designed to support beams with rather flat intensity profiles over the mirror surfaces. This unique mapping might be very useful in future studies of alternative optical designs for advanced gravitational wave interferometers or experiments employing optical cavities with nonstandard mirrors. PMID:23201935

  4. Atom-mediated effective interactions between modes of a bimodal cavity

    SciTech Connect

    Prado, F. O.; Luiz, F. S.; Villas-Boas, J. M.; Alcalde, A. M.; Duzzioni, E. I.; Sanz, L.

    2011-11-15

    We show a procedure for engineering effective interactions between two modes in a bimodal cavity. Our system consists of one or more two-level atoms, excited by a classical field, interacting with both modes. The two effective Hamiltonians have forms similar to beam-splitter and quadratic beam-splitter interactions. We also demonstrate that the nonlinear Hamiltonian can be used to prepare an entangled coherent state, also known as a multidimensional entangled coherent state, which has been pointed out as an important entanglement resource. We show that the nonlinear interaction parameter can be enhanced considering N independent atoms trapped inside a high-finesse optical cavity.

  5. Properties of linear entropy of the atom in a tripartite cavity-optomechanical system

    NASA Astrophysics Data System (ADS)

    Liao, Q. H.; Nie, W. J.; Xu, J.; Liu, Y.; Zhou, N. R.; Yan, Q. R.; Chen, A.; Liu, N. H.; Ahmad, M. A.

    2016-05-01

    We investigate the dynamics of linear entropy of an atom in a tripartite cavity-optomechanical system consisting of a two-level atom in a high-finesse optical cavity with a vibrating mirror at one end. The influence of atomic coherence on the time evolution of linear entropy is examined. It is shown that a Greenberger–Horne–Zeilinger like state can be generated. Moreover, it is found that the entanglement between the atom and the subsystem of field and mirror can be controlled by atomic coherence and the parameters of optomechanical coupling coefficient and atom-field coupling strength.

  6. Musical instrument recordings made with a fiber Fabry-Perot cavity: photonic guitar pickup.

    PubMed

    Ballard, Nicholas; Paz-Soldan, Daniel; Kung, Peter; Loock, Hans-Peter

    2010-04-10

    A 1 cm long, low-finesse fiber-optic cavity was used as a transducer for the vibrations of the soundboard of an acoustic guitar and of a violin. The reflected light is detected and then amplified and recorded using conventional audio instrumentation. The fiber-optic pickup is found to have a high response range in both amplitude (up to 100 microm displacement) and audio frequency (DC to 20 kHz) and good linearity up to a displacement of 225 microm. The audio noise is found to arise from the fiber-optic cables and, to a lesser extent, from the laser and laser driver. PMID:20390023

  7. Generation of atom-light entanglement in an optical cavity for quantum enhanced atom interferometry

    NASA Astrophysics Data System (ADS)

    Haine, Simon A.; Lau, Wing Yung Sarah

    2016-02-01

    We theoretically investigate the generation of atom-light entanglement via Raman superradiance in an optical cavity, and show how this can be used to enhance the sensitivity of atom interferometry. We model a realistic optical cavity, and show that by careful temporal shaping of the optical local oscillator used to measure the light emitted from the cavity, information in the optical mode can be combined with the signal from the atom interferometer to reduce the quantum noise, and thus increase the sensitivity. It was found in Phys. Rev. Lett. 110, 053002 (2013), 10.1103/PhysRevLett.110.053002 that an atomic "seed" was required in order to reduce spontaneous emission and allow for single mode behavior of the device. In this paper we find that the optical cavity reduces the need for an atomic seed, which allows for stronger atom-light correlations and a greater level of quantum enhancement.

  8. A photonic crystal cavity-optical fiber tip nanoparticle sensor for biomedical applications

    NASA Astrophysics Data System (ADS)

    Shambat, Gary; Rajasekhar Kothapalli, Sri; Khurana, Aman; Provine, J.; Sarmiento, Tomas; Cheng, Kai; Cheng, Zhen; Harris, James; Daldrup-Link, Heike; Sam Gambhir, Sanjiv; Vučković, Jelena

    2012-05-01

    We present a sensor capable of detecting solution-based nanoparticles using an optical fiber tip functionalized with a photonic crystal cavity. When sensor tips are retracted from a nanoparticle solution after being submerged, we find that a combination of convective fluid forces and optically induced trapping cause an aggregation of nanoparticles to form directly on cavity surfaces. A simple readout of quantum dot photoluminescence coupled to the optical fiber shows that nanoparticle presence and concentration can be detected through modified cavity properties. Our sensor can detect both gold and iron oxide nanoparticles and can be utilized for molecular sensing applications in biomedicine.

  9. Cavity Optical Pulse Extraction: ultra-short pulse generation as seeded Hawking radiation

    PubMed Central

    Eilenberger, Falk; Kabakova, Irina V.; de Sterke, C. Martijn; Eggleton, Benjamin J.; Pertsch, Thomas

    2013-01-01

    We show that light trapped in an optical cavity can be extracted from that cavity in an ultrashort burst by means of a trigger pulse. We find a simple analytic description of this process and show that while the extracted pulse inherits its pulse length from that of the trigger pulse, its wavelength can be completely different. Cavity Optical Pulse Extraction is thus well suited for the development of ultrashort laser sources in new wavelength ranges. We discuss similarities between this process and the generation of Hawking radiation at the optical analogue of an event horizon with extremely high Hawking temperature. Our analytic predictions are confirmed by thorough numerical simulations. PMID:24060831

  10. Selective engineering of cavity resonance for frequency matching in optical parametric processes

    SciTech Connect

    Lu, Xiyuan; Rogers, Steven; Jiang, Wei C.; Lin, Qiang

    2014-10-13

    We propose to selectively engineer a single cavity resonance to achieve frequency matching for optical parametric processes in high-Q microresonators. For this purpose, we demonstrate an approach, selective mode splitting (SMS), to precisely shift a targeted cavity resonance, while leaving other cavity modes intact. We apply SMS to achieve efficient parametric generation via four-wave mixing in high-Q silicon microresonators. The proposed approach is of great potential for broad applications in integrated nonlinear photonics.

  11. Selective engineering of cavity resonance for frequency matching in optical parametric processes

    NASA Astrophysics Data System (ADS)

    Lu, Xiyuan; Rogers, Steven; Jiang, Wei C.; Lin, Qiang

    2014-10-01

    We propose to selectively engineer a single cavity resonance to achieve frequency matching for optical parametric processes in high-Q microresonators. For this purpose, we demonstrate an approach, selective mode splitting (SMS), to precisely shift a targeted cavity resonance, while leaving other cavity modes intact. We apply SMS to achieve efficient parametric generation via four-wave mixing in high-Q silicon microresonators. The proposed approach is of great potential for broad applications in integrated nonlinear photonics.

  12. Performance of resonator fiber optic gyroscope using external-cavity laser stabilization and optical filtering

    NASA Astrophysics Data System (ADS)

    Qiu, Tiequn; Wu, Jianfeng; Strandjord, Lee K.; Sanders, Glen A.

    2014-05-01

    A bench-top resonator fiber optic gyroscope (RFOG) was assembled and tested, showing encouraging progress toward navigation grade performance. The gyro employed a fiber length of 19 meters of polarizing fiber for the sensing coil which was wound on an 11.5 cm diameter PZT cylinder. A bias stability of approximately 0.1 deg/hr was observed over a 2 hour timeframe, which is the best bias stability reported to date in an RFOG to our knowledge. Special care was taken to minimize laser phase noise, including stabilization to an optical cavity which was also used for optical filtering, giving angle random walk (ARW) values in the range of 0.008 deg/rt-hr. The ARW performance and bias stability are within 2x and 10x, respectively, of many civil inertial navigation grade requirements.

  13. All-optical signal amplifier and distributor using cavity-atom coupling systems

    NASA Astrophysics Data System (ADS)

    Duan, Yafan; Lin, Gongwei; Niu, Yueping; Gong, Shangqing

    2016-05-01

    We report an all-optical signal amplifier and a signal distributor using cavity-atom coupling systems. In this system we couple atoms with an optical cavity and realize the great enhancement of a control laser by the cavity with the help of two high coupling lasers. By this effect, we can use one weak control field to control another strong target field and the intensity changes are linear with our experimental conditions. This can be used as an all-optical signal amplifier, also known as a ‘transphasor’. In our experiment, the gain of the weak field to strong field can be as high as 60. Furthermore, we can realize the distribution of optical signals, if we coordinate multiple cavity-atom coupling systems.

  14. Cancellation of lateral displacement noise of three-port gratings for coupling light to cavities.

    PubMed

    Meinders, Melanie; Kroker, Stefanie; Singh, Amrit Pal; Kley, E-Bernhard; Tünnermann, Andreas; Danzmann, Karsten; Schnabel, Roman

    2015-05-01

    Reflection gratings enable light coupling to optical cavities without transmission through substrates. Gratings that have three ports and are mounted in a second-order Littrow configuration even allow the coupling to high-finesse cavities using low diffraction efficiencies. In contrast to conventional transmissive cavity couplers, however, the phase of the diffracted light depends on the lateral position of the grating, which introduces an additional noise coupling. Here, we experimentally demonstrate that this kind of noise cancels out once both diffracted output ports of the grating are combined. We achieve the same signal-to-shot-noise ratio as for a conventional coupler. From this perspective, three-port grating couplers in a second-order Littrow configuration remain a valuable approach to reducing optical absorption of cavity coupler substrates in future gravitational-wave detectors. PMID:25927782

  15. Cavities

    MedlinePlus

    ... The tooth may hurt even without stimulation (spontaneous toothache). If irreversible damage to the pulp occurs and ... To detect cavities early, a dentist inquires about pain, examines the teeth, probes the teeth with dental instruments, and may take x-rays. People should ...

  16. External cavity diode laser based upon an FBG in an integrated optical fiber platform.

    PubMed

    Lynch, Stephen G; Holmes, Christopher; Berry, Sam A; Gates, James C; Jantzen, Alexander; Ferreiro, Teresa I; Smith, Peter G R

    2016-04-18

    An external cavity diode laser is demonstrated using a Bragg grating written into a novel integrated optical fiber platform as the external cavity. The cavity is fabricated using flame-hydrolysis deposition to bond a photosensitive fiber to a silica-on-silicon wafer, and a grating written using direct UV-writing. The laser operates on a single mode at the acetylene P13 line (1532.83 nm) with 9 mW output power. The noise properties of the laser are characterized demonstrating low linewidth operation (< 14 kHz) and superior relative intensity noise characteristics when compared to a commercial tunable external cavity diode laser. PMID:27137276

  17. Low light level all-optical switching in a four-level atom-cavity system

    NASA Astrophysics Data System (ADS)

    Duan, Yafan; Lin, Gongwei; Zhang, Shicheng; Niu, Yueping; Gong, Shangqing

    2016-01-01

    We report on an all-optical switching in a double ∧ four-level atom-cavity system both theoretically and experimentally. In this system, an extra coherence between two ground states is induced by two coupling lasers, thus the loss of the cavity field decreases. Then, we can use one weak field to control another weak field at low light levels. Compared to the three-level atom-cavity system, the power of the switching laser can be much weaker in the four-level atom-cavity system.

  18. Tuning the Sensitivity of an Optical Cavity with Slow and Fast Light

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Myneni, Krishna; Chang, H.; Toftul, A.; Schambeau, C.; Odutola, J. A.; Diels, J. C.

    2012-01-01

    We have measured mode pushing by the dispersion of a rubidium vapor in a Fabry-Perot cavity and have shown that the scale factor and sensitivity of a passive cavity can be strongly enhanced by the presence of such an anomalous dispersion medium. The enhancement is the result of the atom-cavity coupling, which provides a positive feedback to the cavity response. The cavity sensitivity can also be controlled and tuned through a pole by a second, optical pumping, beam applied transverse to the cavity. Alternatively, the sensitivity can be controlled by the introduction of a second counter-propagating input beam that interferes with the first beam, coherently increasing the cavity absorptance. We show that the pole in the sensitivity occurs when the sum of the effective group index and an additional cavity delay factor that accounts for mode reshaping goes to zero, and is an example of an exceptional point, commonly associated with coupled non-Hermitian Hamiltonian systems. Additionally we show that a normal dispersion feature can decrease the cavity scale factor and can be generated through velocity selective optical pumping

  19. Power enhancement of burst-mode UV pulses using a doubly-resonant optical cavity

    SciTech Connect

    Rahkman, Abdurahim; Notcutt, Mark; Liu, Yun

    2015-11-24

    We report a doubly-resonant enhancement cavity (DREC) that can realize a simultaneous enhancement of two incoming laser beams at different wavelengths and different temporal structures. The double-resonance condition is theoretically analyzed and different DREC locking methods are experimentally investigated. Simultaneous locking of a Fabry-Perot cavity to both an infrared (IR, 1064 nm) and its frequency tripled ultraviolet (UV, 355 nm) pulses has been demonstrated by controlling the frequency difference between the two beams with a fiber optic frequency shifter. The DREC technique opens a new paradigm in the applications of optical cavities to power enhancement of burst-mode lasers with arbitrary macropulse width and repetition rate.

  20. Coupled-Cavity Interferometer for the Optics Laboratory

    ERIC Educational Resources Information Center

    Peterson, R. W.

    1975-01-01

    Describes the construction of a flexible coupled-cavity interferometer for student use. A helium-neon laser and phonograph turntable are the main components. Lists activities which may be performed with the apparatus. (Author/CP)

  1. Nonorthogonal pairs of copropagating optical modes in deformed microdisk cavities

    SciTech Connect

    Wiersig, Jan; Eberspaecher, Alexander; Shim, Jeong-Bo; Ryu, Jung-Wan; Shinohara, Susumu; Hentschel, Martina; Schomerus, Henning

    2011-08-15

    Recently, it has been shown that spiral-shaped microdisk cavities support highly nonorthogonal pairs of copropagating modes with a preferred sense of rotation (spatial chirality) [J. Wiersig et al., Phys. Rev. A 78, 053809 (2008)]. Here, we provide numerical evidence which indicates that such pairs are a common feature of deformed microdisk cavities which lack mirror symmetries. In particular, we demonstrate that discontinuities of the cavity boundary such as the notch in the spiral cavity are not needed. We find a quantitative relation between the nonorthogonality and the chirality of the modes which agrees well with the predictions from an effective non-Hermitian Hamiltonian. A comparison to ray-tracing simulations is given.

  2. Vacuum-induced suppression and enhancement of four-wave mixing in an optical cavity

    NASA Astrophysics Data System (ADS)

    Chen, Haixia; Wang, Xiuxiu; Ahmed, Irfan; Yao, Xin; Wu, Zhenkun; Zhu, Dayu; Zhang, Yanpeng

    2015-09-01

    We report on an experimental study of vacuum-induced suppression and enhancement of four-wave mixing (FWM) signal in a composite atom-cavity system. By scanning the additional dressing field, the suppression ratio of the FWM signal can reach 90 % compared with 40 % without cavity. We attribute the enhanced suppression and enhancement to the atom-cavity coupling arising from a vacuum-induced Raman process, which amplifies the dressing effect from the additional field. Also, the dressing asymmetry of the atom-cavity coupling is discussed and used to estimate the nonlinearity of atomic medium in the cavity. The suppression and enhancement can be interpreted by a dressed-state picture and agree with theoretical calculations. The investigation may find applications in optical switch and quantum memory controlled by cavity.

  3. Feasibility of a feedback control of atomic self-organization in an optical cavity

    SciTech Connect

    Ivanov, D. A. Ivanova, T. Yu.

    2015-08-15

    Many interesting nonlinear effects are based on the strong interaction of motional degrees of freedom of atoms with an optical cavity field. Among them is the spatial self-organization of atoms in a pattern where the atoms group in either odd or even sites of the cavity-induced optical potential. An experimental observation of this effect can be simplified by using, along with the original cavity-induced feedback, an additional electronic feedback based on the detection of light leaking the cavity and the control of the optical potential for the atoms. Following our previous study, we show that this approach is more efficient from the laser power perspective than the original scheme without the electronic feedback.

  4. Nano-scale optical actuation based on two-dimensional heterostructure photonic crystal cavities

    NASA Astrophysics Data System (ADS)

    Lin, Tong; Zhou, Guangya; Chau, Fook Siong; Tian, Feng; Deng, Jie

    2015-03-01

    Nowadays, nano-electro-mechanical systems (NEMS) actuators using electrostatic forces are facing the bottleneck of the electromagnetic interference which greatly degrades their performances. On the contrary, the hybrid circuits driven by optical gradient forces which are immune to the electromagnetic interference show prominent advantages in communication, quantum computation, and other application systems. In this paper we propose an optical actuator utilizing the optical gradient force generated by a hetero-structure photonic crystal cavity. This type of cavity has a longitudinal air-slot and characteristics of ultrahigh quality factor (Q) and ultra-small mode volume (V) which is capable of producing a much larger force compared with the waveguide-based structures. Due to the symmetry property, attractive optical gradient force is generated. Additionally, the optomechanical coefficient (gom) of this cavity is two orders of magnitude larger than that of the coupled nanobeam photonic crystal cavities. The 2D hetero-structure cavity, comb drives, folded beam suspensions and the displacement sensor compose the whole device. The cavity serves as the optical actuator whilst the butt-coupled waveguide acts as the displacement sensor which is theoretically proved to be insensitive to the temperature variations. As known, the thermo-optic effect prevails especially in the cavity-based structures. The butt-coupled waveguide can be used to decouple the thermal effect and the optoemchanical effect (OM) with the aid of comb drives. The results demonstrate that the proposed optical gradient force actuator show great potential in the future of all-optical reconfigurable circuits.

  5. Optical quantum computation with cavities in the intermediate coupling region

    NASA Astrophysics Data System (ADS)

    Mei, F.; Yu, Y. F.; Feng, X. L.; Zhu, S. L.; Zhang, Z. M.

    2010-07-01

    Large-scale quantum computation is currently a hot area of research. The scalable quantum computation scheme with cavities originally proposed by Duan and Kimble (Phys. Rev. Lett., 92 (2004) 127902) is further developed here to operate in the intermediate coupling region, which not only greatly relaxes experimental demands on the Purcell factor, but also eliminates the need to consider internal trade-off between cavity quality and efficiency. In our scheme, by controlling the reflectivity of the input single-photon pulse in the cavity, we can realize local atom-photon and nonlocal atom-atom controlled phase-flip (CPF) gates. We also introduce a theoretical model to analyze the performance of our scheme under practical noise. Furthermore, we show that the nonlocal CPF gate can be used to realize a quantum repeater.

  6. Flight-Like Optical Reference Cavity for GRACE Follow-On Laser Frequency Stabilization

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; deVine, G.; Klipstein, W. M.; McKenzie, K.; Spero, R.; Thompson, R.; Yu, N.; Stephens, M.; Leitch, J.; Pierce, R.; Shaddock, D.; Lam, T.

    2011-01-01

    We describe a prototype optical cavity and associated optics that has been developed to provide a stable frequency reference for a future space-based laser ranging system. This instrument is being considered for inclusion as a technology demonstration on the recently announced GRACE follow-on mission, which will monitor variations in the Earth's gravity field.

  7. Optical bistability and second-harmonic generation in thin film coupled cavity photonic crystal structures

    NASA Astrophysics Data System (ADS)

    Diao, Liyong

    This thesis deals with design, fabrication and modeling of bistable and multi-stable switching dynamics and second-harmonic generation in two groups of thin film coupled cavity photonic crystal structures. The first component studies optical bistability and multistability in such structures. Optical bistability and multistability are modelled by a nonlinear transfer matrix method. The second component is focused on the modelling and experimental measurement of second-harmonic generation in such structures. It is found that coupled cavity structures can reduce the threshold and index change for bistable operation, but single cavity structures can do the same. However, there is a clear advantage in using coupled cavity structures for multistability in that the threshold for multistability can be reduced. Second-harmonic generation is enhanced by field localization due to the resonant effect at the fundamental wavelength in single and coupled cavity structures by simulated and measured results. The work in this thesis makes three significant contributions. First, in the successful fabrication of thin film coupled cavity structures, the simulated linear transmissions of such structures match those of the fabricated structures almost exactly. Second, the newly defined figure of merit at the maximum transmission point on the bistable curve can be used to compare the material damage tolerance to any other Kerr effect nonlinear gate. Third, the simulated second-harmonic generation agrees excellently with experimental results. More generally optical thin film fabrication has commercial applications in many industry sections, such as electronics, opto-electronics, optical coating, solar cell and MEMS.

  8. Lateral shearing optical gradient force in coupled nanobeam photonic crystal cavities

    NASA Astrophysics Data System (ADS)

    Du, Han; Zhang, Xingwang; Deng, Jie; Zhao, Yunshan; Chau, Fook Siong; Zhou, Guangya

    2016-04-01

    We report the experimental observation of lateral shearing optical gradient forces in nanoelectromechanical systems (NEMS) controlled dual-coupled photonic crystal (PhC) nanobeam cavities. With an on-chip integrated NEMS actuator, the coupled cavities can be mechanically reconfigured in the lateral direction while maintaining a constant coupling gap. Shearing optical gradient forces are generated when the two cavity centers are laterally displaced. In our experiments, positive and negative lateral shearing optical forces of 0.42 nN and 0.29 nN are observed with different pumping modes. This study may broaden the potential applications of the optical gradient force in nanophotonic devices and benefit the future nanooptoelectromechanical systems.

  9. Cavity Nonlinear Optics at Low Photon Numbers from Collective Atomic Motion

    SciTech Connect

    Gupta, Subhadeep; Moore, Kevin L.; Murch, Kater W.; Stamper-Kurn, Dan M.

    2007-11-23

    We report on Kerr nonlinearity and dispersive optical bistability of a Fabry-Perot optical resonator due to the displacement of ultracold atoms trapped within. In the driven resonator, such collective motion is induced by optical forces acting upon up to 10{sup 5} {sup 87}Rb atoms prepared in the lowest band of a one-dimensional intracavity optical lattice. The longevity of atomic motional coherence allows for strongly nonlinear optics at extremely low cavity photon numbers, as demonstrated by the observation of both branches of optical bistability at photon numbers below unity.

  10. New limit on Lorentz violation using a double-pass optical ring cavity.

    PubMed

    Michimura, Yuta; Matsumoto, Nobuyuki; Ohmae, Noriaki; Kokuyama, Wataru; Aso, Yoichi; Ando, Masaki; Tsubono, Kimio

    2013-05-17

    A search for Lorentz violation in electrodynamics was performed by measuring the resonant frequency difference between two counterpropagating directions of an optical ring cavity. Our cavity contains a dielectric element, which makes our cavity sensitive to the violation. The laser frequency is stabilized to the counterclockwise resonance of the cavity, and the transmitted light is reflected back into the cavity for resonant frequency comparison with the clockwise resonance. This double-pass configuration enables a null experiment and gives high common mode rejection of environmental disturbances. We found no evidence for odd-parity anisotropy at the level of δc/c ≲ 10(-14). Within the framework of the standard model extension, our result put more than 5 times better limits on three odd-parity parameters κ(o+)(JK) and a 12 times better limit on the scalar parameter κ(tr) compared with the previous best limits. PMID:25167384

  11. In situ characterization of an optically thick atom-filled cavity

    NASA Astrophysics Data System (ADS)

    Munns, J. H. D.; Qiu, C.; Ledingham, P. M.; Walmsley, I. A.; Nunn, J.; Saunders, D. J.

    2016-01-01

    A means for precise experimental characterization of the dielectric susceptibility of an atomic gas inside an optical cavity is important for the design and operation of quantum light-matter interfaces, particularly in the context of quantum information processing. Here we present a numerically optimized theoretical model to predict the spectral response of an atom-filled cavity, accounting for both homogeneous and inhomogeneous broadening at high optical densities. We investigate the regime where the two broadening mechanisms are of similar magnitude, which makes the use of common approximations invalid. Our model agrees with an experimental implementation with warm caesium vapor in a ring cavity. From the cavity response, we are able to extract important experimental parameters, for instance the ground-state populations, total number density, and the magnitudes of both homogeneous and inhomogeneous broadening.

  12. High-Q silica zipper cavity for optical radiation pressure driven MOMS switch

    SciTech Connect

    Tetsumoto, Tomohiro; Tanabe, Takasumi

    2014-07-15

    We design a silica zipper cavity that has high optical and mechanical Q (quality factor) values and demonstrate numerically the feasibility of a radiation pressure driven micro opto-mechanical system (MOMS) directional switch. The silica zipper cavity has an optical Q of 4.0 × 10{sup 4} and an effective mode volume V{sub mode} of 0.67λ{sup 3} when the gap between two cavities is 34 nm. The mechanical Q (Q{sub m}) is determined by thermo-elastic damping and is 2.0 × 10{sup 6} in a vacuum at room temperature. The opto-mechanical coupling rate g{sub OM} is as high as 100 GHz/nm, which allows us to move the directional cavity-waveguide system and switch 1550-nm light with 770-nm light by controlling the radiation pressure.

  13. Demonstration of the stabilization technique for nonplanar optical resonant cavities utilizing polarization

    SciTech Connect

    Akagi, T.; Araki, S.; Funahashi, Y.; Honda, Y.; Okugi, T.; Omori, T.; Shimizu, H.; Terunuma, N.; Urakawa, J.; Miyoshi, S.; Takahashi, T. Tanaka, R.; Uesugi, Y.; Yoshitama, H.; Sakaue, K.; Washio, M.

    2015-04-15

    Based on our previously developed scheme to stabilize nonplanar optical resonant cavities utilizing polarization caused by a geometric phase in electromagnetic waves traveling along a twisted path, we report an application of the technique for a cavity installed in the Accelerator Test Facility, a 1.3-GeV electron beam accelerator at KEK, in which photons are generated by laser-Compton scattering. We successfully achieved a power enhancement of 1200 with 1.4% fluctuation, which means that the optical path length of the cavity has been controlled with a precision of 14 pm under an accelerator environment. In addition, polarization switching utilizing a geometric phase of the nonplanar cavity was demonstrated.

  14. Self-organisation and cooling of a large ensemble of particles in optical cavities.

    PubMed

    Zhao, Yongkai; Lu, Weiping; Barker, P F; Dong, Guangjiong

    2009-01-01

    We present an investigation of the dynamics of centre-of-mass of a neutral particle cloud in a cavity pumped by an optical field. We derive an expression for the pump threshold for spatial self-organization of the particles and analyze its scaling laws in terms of the system parameters. Using a newly developed statistical model, we simulate the dynamics of the particles and numerically obtain the scaling laws. We show good agreement between the analytic formulae and simulations. We further use the scaling relation to discuss the operating conditions for cavity cooling a large ensemble of particles. Finally, we study cavity cooling of an ensemble of molecules with an initial temperature of around 10 mK. We show that 35% of the molecules are trapped by the optical field intensity in the cavity and a final temperature below 1 mK is reached. PMID:20151551

  15. XTREME OPTICS: the behavior of cavity optics for the Jefferson Lab free-electron laser

    SciTech Connect

    Michelle D. Shinn; Christopher Behre; Stephen Benson; David Douglas; Fred Dylla; Christopher Gould; Joseph Gubeli; David Hardy; Kevin Jordan; George Neil; and Shukui Zhanga

    2006-09-25

    The cavity optics within high power free-electron lasers based on energy-recovering accelerators are subjected to extreme conditions associated with illumination from a broad spectrum of radiation, often at high irradiances. This is especially true for the output coupler, where absorption of radiation by both the mirror substrate and coating places significant design restrictions to properly manage heat load and prevent mirror distortion. Besides the fundamental lasing wavelength, the mirrors are irradiated with light at harmonics of the fundamental, THz radiation generated by the bending magnets downstream of the wiggler, and x-rays produced when the electron beam strikes accelerator diagnostic components (e.g., wire scanners and view screens) or from inadvertent beam loss. The optics must reside within high vacuum at ~ 10-8 Torr and this requirement introduces its own set of complications. This talk discusses the performance of numerous high reflector and output coupler optics assemblies and provides a detailed list of lessons learned gleaned from years of experience operating the Upgrade IR FEL, a 10 kW-class, sub-ps laser with output wavelength from 1 to 6 microns.

  16. Generation and purification of maximally entangled atomic states in optical cavities

    SciTech Connect

    Lougovski, P.; Walther, H.; Solano, E.

    2005-01-01

    We present a probabilistic scheme for generating and purifying maximally entangled states of two atoms inside an optical cavity via no-photon detection at the cavity output, where ideal detectors are not required. The intermediate mixed states can be continuously purified so as to violate Bell inequalities in a parametrized manner. The scheme relies on an additional strong-driving field that realizes, atypically, simultaneous Jaynes-Cummings and anti-Jaynes-Cummings interactions.

  17. Cavity Optomechanics with High-Stress Silicon Nitride Films

    NASA Astrophysics Data System (ADS)

    Wilson, Dalziel Joseph

    There has been a barrage of interest in recent years to marry the fields of nanomechanics and quantum optics. Mechanical systems provide sensitive and scalable architectures for sensing applications ranging from atomic force microscopy to gravity wave interferometry. Optical resonators driven by low noise lasers provide a quiet and well-understood means to read-out and manipulate mechanical motion, by way of the radiation pressure force. Taken to an extreme, a device consisting of a high-Q nanomechanical oscillator coupled to a high-finesse optical cavity may enable ground-state preparation of the mechanical element, thus paving the way for a new class of quantum technology based on chip-scale phononic devices coupled to optical photons. By way of mutual coupling to the optical field, this architecture may enable coupling of single phonons to real or artificial atoms, an enticing prospect because of the vast "quantum optics toolbox" already developed for cavity quantum electrodynamics. The first step towards these goals --- ground-state cooling of the mechanical element in a "cavity optomechanical" system --- has very recently been realized in a cryogenic setup. The work presented in this thesis describes an effort to extend this capability to a room temperature apparatus, so that the usual panoply of table-top optical/atomic physics tools can be brought to bear. This requires a mechanical oscillator with exceptionally low dissipation, as well as careful attention to extraneous sources of noise in both the optical and mechanical componentry. Our particular system is based on a high- Q, high-stress silicon nitride membrane coupled to a high-finesse Fabry-Perot cavity. The purpose of this thesis is to record in detail the procedure for characterizing/modeling the physical properties of the membrane resonator, the optical cavity, and their mutual interaction, as well as extraneous sources of noise related to multimode thermal motion of the oscillator, thermal motion

  18. Complex ABCD transformations for optical ring cavities with losses and gain

    SciTech Connect

    Kudashov, V N; Radin, A M; Plachenov, A B

    1999-04-30

    Complex ABCD field transformations are investigated for inhomogeneous optical ring cavities with losses and gain. It is shown that the sets of eigenfunctions, corresponding to counterpropagating waves, are really biorthogonal: the functions in each of these sets are really orthogonal relative to one another, and have a complex weighting factor independent of the mode number. Bidirectional and unidirectional stability conditions are formulated for such cavities. These conditions are qualitatively different from those for loss-free cavities. A simple algorithm is proposed for the evaluation of the ABCD matrix for a medium with an arbitrary longitudinal inhomogeneity along the beam. (laser applications and other topics in quantum electronics)

  19. Modeling of optically controlled reflective bistability in a vertical cavity semiconductor saturable absorber

    NASA Astrophysics Data System (ADS)

    Mishra, L.

    2015-05-01

    Bistability switching between two optical signals has been studied theoretically utilizing the concept of cross absorption modulation in a vertical cavity semiconductor saturable absorber (VCSSA). The probe beam is fixed at a wavelength other than the low power cavity resonance wavelength, which exhibits bistable characteristic by controlling the power of a pump beam (λpump≠λprobe). The cavity nonlinear effects that arises simultaneously from the excitonic absorption bleaching, and the carrier induced nonlinear index change has been considered in the model. The high power absorption in the active region introduces thermal effects within the nonlinear cavity due to which the effective cavity length changes. This leads to a red-shift of the cavity resonance wavelength, which results a change in phase of the optical fields within the cavity. In the simulation, the phase-change due to this resonance shifting is considered to be constant over time, and it assumes the value corresponding to the maximum input power. Further, an initial phase detuning of the probe beam has been considered to investigate its effect on switching. It is observed from the simulated results that, the output of the probe beam exhibits either clockwise or counter-clockwise bistability, depending on its initial phase detuning.

  20. Non-adiabatic dynamics of molecules in optical cavities

    NASA Astrophysics Data System (ADS)

    Kowalewski, Markus; Bennett, Kochise; Mukamel, Shaul

    2016-02-01

    Strong coupling of molecules to the vacuum field of micro cavities can modify the potential energy surfaces thereby opening new photophysical and photochemical reaction pathways. While the influence of laser fields is usually described in terms of classical field, coupling to the vacuum state of a cavity has to be described in terms of dressed photon-matter states (polaritons) which require quantized fields. We present a derivation of the non-adiabatic couplings for single molecules in the strong coupling regime suitable for the calculation of the dressed state dynamics. The formalism allows to use quantities readily accessible from quantum chemistry codes like the adiabatic potential energy surfaces and dipole moments to carry out wave packet simulations in the dressed basis. The implications for photochemistry are demonstrated for a set of model systems representing typical situations found in molecules.

  1. Optomechanical Entanglement Between an Ion and an Optical Cavity Field

    NASA Astrophysics Data System (ADS)

    Bhattacherjee, Aranya B.

    2016-04-01

    I study an optomechanical system in which the mechanical motion of a single trapped ion is coupled to a cavity field for the realization of a strongly quantum correlated two-mode system. I show that for large pump intensities the steady state photon number exhibits bistable behaviour. I further analyze the occurrence of normal mode splitting (NMS) due to mixing of the fluctuations of the cavity field and the fluctuations of the ion motion which indicates a coherent energy exchange. I also find that in the parameter regime where NMS exists, the steady state of the system shows continuous variable entanglement. Such a two-mode optomechanical system can be used for the realization of continuous variable quantum information interfaces and networks.

  2. Effect of irradiation on nonlinear optical recirculation cavity performance

    NASA Astrophysics Data System (ADS)

    Saitta, M.; Tikhoplav, R.; Jovanovic, I.

    2012-02-01

    In applications such as the production of hydrogen ions for accelerators in spallation neutron sources, charge stripping of hydrogen ions using high-power lasers represents an attractive technical approach. The use of laser-ion interaction in conjunction with a laser recirculation cavity holds promise for improved efficiency, but the high-radiation environment raises concerns about the longevity of the key components of such a system, especially the nonlinear crystal used for frequency conversion. We present the results of an in-reactor irradiation experiment in which a sample beta-barium borate crystal has been irradiated with fast neutrons and gamma-rays, accompanied with the Monte Carlo analysis of the irradiation dose and its comparison with typical conditions at the Spallation Neutron Source at Oak Ridge National Laboratory. The results suggest that our design of the laser recirculation cavity exhibits a radiation hardness consistent with maintaining enhancement factors of the order of 10 over >10 years, but a more detailed experimental study is needed to investigate the radiation hardness of cavity designs exhibiting greater enhancement factors.

  3. Thermal analysis of optical reference cavities for low sensitivity to environmental temperature fluctuations.

    PubMed

    Dai, Xiaojiao; Jiang, Yanyi; Hang, Chao; Bi, Zhiyi; Ma, Longsheng

    2015-02-23

    The temperature stability of optical reference cavities is significant in state-of-the-art ultra-stable narrow-linewidth laser systems. In this paper, the thermal time constant and thermal sensitivity of reference cavities are analyzed when reference cavities respond to environmental perturbations via heat transfer of thermal conduction and thermal radiation separately. The analysis as well as simulation results indicate that a reference cavity enclosed in multiple layers of thermal shields with larger mass, higher thermal capacity and lower emissivity is found to have a larger thermal time constant and thus a smaller sensitivity to environmental temperature perturbations. The design of thermal shields for reference cavities may vary according to experimentally achievable temperature stability and the coefficient of thermal expansion of reference cavities. A temperature fluctuation-induced length instability of reference cavities as low as 6 × 10(-16) on a day timescale can be achieved if a two-layer thermal shield is inserted between a cavity with the coefficient of thermal expansion of 1 × 10(-10) /K and an outer vacuum chamber with temperature fluctuation amplitude of 1 mK and period of 24 hours. PMID:25836547

  4. Optical-bistability-enabled control of resonant light transmission for an atom-cavity system

    NASA Astrophysics Data System (ADS)

    Sawant, Rahul; Rangwala, S. A.

    2016-02-01

    The control of light transmission through a standing-wave Fabry-Pérot cavity containing atoms is theoretically and numerically investigated, when the cavity mode beam and an intersecting control beam are both close to specific atomic resonances. A four-level atomic system is considered and its interaction with the cavity mode is studied by solving for the cavity field and atomic state populations. The conditions for optical bistability of the atom-cavity system are obtained. The response of the intracavity intensity to an intersecting beam on atomic resonance is understood in the presence of stationary atoms (closed system) and nonstatic atoms (open system) in the cavity. The nonstatic system of atoms is modelled by adjusting the atomic state populations to represent the exchange of atoms in the cavity mode, which corresponds to a thermal environment where atoms are moving in and out of the cavity mode volume. The control behavior with three- and two-level atomic systems is also studied, and the rich physics arising out of these systems for closed and open atomic systems is discussed. The solutions to the models are used to interpret the steady-state and transient behavior observed by Sharma et al. [Phys. Rev. A 91, 043824 (2015)], 10.1103/PhysRevA.91.043824.

  5. High contrast all-optical diode based on direction-dependent optical bistability within asymmetric ring cavity

    NASA Astrophysics Data System (ADS)

    Xia, Xiu-Wen; Zhang, Xin-Qin; Xu, Jing-Ping; Yang, Ya-Ping

    2016-08-01

    We propose a simple all-optical diode which is comprised of an asymmetric ring cavity containing a two-level atomic ensemble. Attributed to spatial symmetry breaking of the ring cavity, direction-dependent optical bistability is obtained in a classical bistable system. Therefore, a giant optical non-reciprocity is generated, which guarantees an all-optical diode with a high contrast up to 22 dB. Furthermore, its application as an all-optical logic AND gate is also discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11274242, 11474221, and 11574229), the Joint Fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics (Grant No. U1330203), and the National Key Basic Research Special Foundation of China (Grant Nos. 2011CB922203 and 2013CB632701).

  6. Extreme nonlinear response of ultranarrow optical transitions in cavity QED for laser stabilization

    SciTech Connect

    Martin, M. J.; Meiser, D.; Ye Jun; Holland, M. J.; Thomsen, J. W.

    2011-12-15

    We explore the potential of direct spectroscopy of ultranarrow optical transitions of atoms localized in an optical cavity. In contrast to stabilization against a reference cavity, which is the approach currently used for the most highly stabilized lasers, stabilization against an atomic transition does not suffer from Brownian thermal noise. Spectroscopy of ultranarrow optical transitions in a cavity operates in a very highly saturated regime in which nonlinear effects such as bistability play an important role. From the universal behavior of the Jaynes-Cummings model with dissipation, we derive the fundamental limits for laser stabilization using direct spectroscopy of ultranarrow atomic lines. We find that, with current lattice clock experiments, laser linewidths of about 1 mHz can be achieved in principle, and the ultimate limitations of this technique are at the 1 {mu}Hz level.

  7. Acid-etched Fabry-Perot micro-cavities in optical fibres

    NASA Astrophysics Data System (ADS)

    Machavaram, V. R.; Badcock, R. A.; Fernando, G. F.

    2007-07-01

    Significant progress has been made in recent years on the design and fabrication of optical fibre-based sensor systems for applications in structural health monitoring. Two sensor designs have tended to dominate namely, fibre Bragg gratings and extrinsic fibre Fabry-Perot sensors. However, the cost and time associated with these sensors is relatively high and as a consequence, the current paper describes a simple procedure to fabricate intrinsic fibre Fabry-Perot interferometric strain sensors. The technique involves the use of hydrofluoric acid to etch a cavity in a cleaved optical fibre. Two such etched cavities were fusion spliced to create an intrinsic fibre Fabry-Perot cavity. The feasibility of using this device for strain monitoring was demonstrated. Excellent correlation was obtained between the optical and surface-mounted electrical resistance strain gauge.

  8. Single-shot optical readout of a quantum bit using cavity quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Sun, Shuo; Waks, Edo

    2016-07-01

    We propose a method to perform single-shot optical readout of a quantum bit (qubit) using cavity quantum electrodynamics. We selectively couple the optical transitions associated with different qubit basis states to the cavity and utilize the change in cavity transmissivity to generate a qubit readout signal composed of many photons. We show that this approach enables single-shot optical readout even when the qubit does not have a good cycling transition, which is required for standard resonance fluorescence measurements. We calculate the probability that the measurement detects the correct qubit state using the example of a quantum-dot spin under various experimental conditions and demonstrate that it can exceed 0.99.

  9. Very high repetition-rate electro-optical cavity-dumped Nd: YVO4 laser with optics and dynamics stabilities

    NASA Astrophysics Data System (ADS)

    Liu, Xuesong; Shi, Zhaohui; Huang, Yutao; Fan, Zhongwei; Yu, Jin; Zhang, Jing; Hou, Liqun

    2015-02-01

    In this paper, a very high repetition-rate, short-pulse, electro-optical cavity-dumped Nd: YVO4 laser is experimentally and theoretically investigated. The laser performance is optimized from two aspects. Firstly, the laser resonator is designed for a good thermal stability under large pump power fluctuation through optics methods. Secondly, dynamics simulation as well as experiments verifies that cavity dumping at very high repetition rate has better stability than medium/high repetition rate. At 30 W, 880 nm pump power, up to 500 kHz, constant 5 ns, stable 1064 nm fundamental-mode laser pulses can be obtained with 10 W average output power.

  10. Stability improvements for the NIST Yb optical lattice clock

    NASA Astrophysics Data System (ADS)

    Fasano, R. J.; Schioppo, M.; McGrew, W. F.; Brown, R. C.; Hinkley, N.; Yoon, T. H.; Beloy, K.; Oates, C. W.; Ludlow, A. D.

    2016-05-01

    To reach the fundamental limit given by quantum projection noise, optical lattice clocks require advanced laser stabilization techniques. The NIST ytterbium clock has benefited from several generations of extremely high finesse optical cavities, with cavity linewidths below 1 kHz. Characterization of the cavity drift rate has allowed compensation to the mHz/s level, improving the medium-term stability of the cavity. Based on recent measurements using Ramsey spectroscopy with synchronous interrogation, we report a fractional instability σy(1s) <=10-16 , dominated by atom number fluctuation noise. We also provide updates on our cryogenic sapphire cavity with a reduced thermal noise floor, which will improve our Dick-limited fractional instability at 1 s to below 10-16. Also at University of Colorado.

  11. Passive intrinsic-linewidth narrowing of ultraviolet extended-cavity diode laser by weak optical feedback

    NASA Astrophysics Data System (ADS)

    Samutpraphoot, Polnop; Weber, Sophie; Lin, Qian; Gangloff, Dorian; Bylinskii, Alexei; Braverman, Boris; Kawasaki, Akio; Raab, Christoph; Kaenders, Wilhelm; Vuletić, Vladan

    2014-05-01

    We present a simple method for narrowing the intrinsic Lorentzian linewidth of a commercial ultraviolet grating extended-cavity diode laser (TOPTICA DL Pro) using weak optical feedback from a long external cavity. We achieve a suppression in frequency noise spectral density of 20 dB measured at frequencies around 1 MHz, corresponding to the narrowing of the intrinsic Lorentzian linewidth from 200 kHz to 2 kHz. The system is suitable for experiments requiring a tunable ultraviolet laser with narrow linewidth and low high-frequency noise, such as precision spectroscopy, optical clocks, and quantum information science experiments.

  12. Control of light polarization using optically spin-injected vertical external cavity surface emitting lasers

    SciTech Connect

    Frougier, J. Jaffrès, H.; Deranlot, C.; George, J.-M.; Baili, G.; Dolfi, D.; Alouini, M.; Sagnes, I.; Garnache, A.

    2013-12-16

    We fabricated and characterized an optically pumped (100)-oriented InGaAs/GaAsP multiple quantum well Vertical External Cavity Surface Emitting Laser (VECSEL). The structure is designed to allow the integration of a Metal-Tunnel-Junction ferromagnetic spin-injector for future electrical injection. We report here the control at room temperature of the electromagnetic field polarization using optical spin injection in the active medium of the VECSEL. The switching between two highly circular polarization states had been demonstrated using an M-shaped extended cavity in multi-modes lasing. This result witnesses an efficient spin-injection in the active medium of the LASER.

  13. Transportable cavity-stabilized laser system for optical carrier frequency transmission experiments.

    PubMed

    Parker, B; Marra, G; Johnson, L A M; Margolis, H S; Webster, S A; Wright, L; Lea, S N; Gill, P; Bayvel, P

    2014-12-10

    We report the design and performance of a transportable laser system at 1543 nm, together with its application as the source for a demonstration of optical carrier frequency transmission over 118 km of an installed dark fiber network. The laser system is based around an optical reference cavity featuring an elastic mounting that bonds the cavity to its support, enabling the cavity to be transported without additional clamping. The cavity exhibits passive fractional frequency insensitivity to vibration along the optical axis of 2.0×10(-11)  m(-1) s(2). With active fiber noise cancellation, the optical carrier frequency transmission achieves a fractional frequency instability, measured at the user end, of 2.6×10(-16) at 1 s, averaging down to below 3×10(-18) after 20,000 s. The fractional frequency accuracy of the transfer is better than 3×10(-18). This level of performance is sufficient for comparison of state-of-the-art optical frequency standards and is achieved in an urban fiber environment. PMID:25608055

  14. Fiber optical accelerometer based on 45 degrees Fabry-Perot cavity

    NASA Astrophysics Data System (ADS)

    Han, Jing; Zhang, Wentao; Wang, Zhaogang; Sun, Baochen; Xu, Binhong; Li, Fang

    2014-11-01

    The paper proposes an accelerometer construction based on 45-degrees Fabry-Perot (F-P) interferometer cavity. The uniform intensity cantilever consists of a mass block in the middle and a 45-degrees F-P cavity fixed inside the mass. The mass block can oscillate freely when the vibrating sensor is subject to the vibration and the F-P cavity length is changing. The G-lens end face and total reflective film make up the two reflective films of the F-P cavity, and the reflectivity are 4% and 90% respectively. In the F-P cavity, a 45-degrees mirror fixed in the middle of the G-lens and total reflective film. The mirror can change the transmission of the light and increase the optical path difference. The total reflective film fixed in the steel tube and the G-lens fixed in the fine tuning bolt. The bolt can fine adjust the F-P cavity in sensor encapsulating. The sensor structure lead to the optical loss in the airborne and tilted mirror, besides the distance of F-P gap in steel tube and the optical coupling efficiency can't work out accurately, so we did a series deterministic test before encapsulating, for example the selection of the structures, the diameter of the optical fibers and the diameter of the reflective films. At last, 9/125 μm optical fiber, 1.4 mm total reflective film and the structure of total reflective film out of steel tube were used for the accelerometer. The sensitivity can reach 0.042 rad/g and the resonant frequency of the accelerometer is 400 Hz.

  15. Evanescent wave cavity ring-down spectroscopy for ultrasensitive chemical detection

    NASA Astrophysics Data System (ADS)

    Pipino, Andrew C. R.

    1999-01-01

    A new technology will be described which extends the cavity ring-down optical absorption technique to condensed matter by using a miniature, high-finesse, monolithic, total- internal-reflection-ring resonator. Evanescent waves that are generated by total-internal reflection permit input and output coupling by photon tunneling and probe the presence of absorbing species at a cavity facet. The TIR-ring design permits broadband cavity ring-down measurements of adsorbates, thin films, and liquids by eliminating the use of multilayer coatings. The basic sensing concept will first be reviewed by describing recent experiments employing a non-ring prototype in which a totally reflecting element was incorporated in a conventional ring-down cavity. The basic design issues for miniature TIR-ring cavities will then be briefly reviewed along with some numerical result obtained using a wave optics model that show the magnitude of different optical losses as a function of cavity size. A competition between losses results in an optimum size for chemical detection which occurs when the round-trip loss of the 'empty' cavity is minimized. The first experimental results will be presented for a square, fused-silica TIR- ring cavity for which the theoretically predicted photon decay time has been achieved.

  16. External electro-optic sampling utilizing a poled polymer asymmetric Fabry Perot cavity as an electro-optical probe tip

    NASA Astrophysics Data System (ADS)

    Chen, Kaixin; Zhang, Hongbo; Zhang, Daming; Yang, Han; Yi, Maobin

    2002-09-01

    External electro-optic sampling utilizing a poled polymer asymmetry Fabry-Perot cavity as electro-optic probe tip has been demonstrated. Electro-optical polymer spin coated on the high-reflectivity mirror (HRM) was corona poled. Thus, an asymmetric F-P cavity was formed based on the different reflectivity of the polymer and HRM and it converted the phase modulation that originates from electro-optic effect of the poled polymer to amplitude modulation, so only one laser beam is needed in this system. The principle of the sampling was analyzed by multiple reflection and index ellipsoid methods. A 1.2 GHz microwave signal propagating on coplanar waveguide transmission line was sampled, and the voltage sensitivity about 0.5 mV/ Hz was obtained.

  17. Design a high-q optical cavity for the project of laser notching h- beam at 38.5 mhz

    SciTech Connect

    Yang, Xi; Ankenbrandt, Charles M.; /Fermilab

    2005-04-01

    Ray matrix formalism is used to represent a two-mirror resonator with a thermal lens in the middle. By tracking a ray vector, which starts from the place where the laser and H{sup -} beams intercept, through the optical cavity, the cavity property can be analyzed. The cavity design can be optimized in such a way that at the interception, the spacious jitter of the laser beam caused by the cavity misalignment is the minimum.

  18. An integrated quantum repeater at telecom wavelength with single atoms in optical fiber cavities

    NASA Astrophysics Data System (ADS)

    Uphoff, Manuel; Brekenfeld, Manuel; Rempe, Gerhard; Ritter, Stephan

    2016-03-01

    Quantum repeaters promise to enable quantum networks over global distances by circumventing the exponential decrease in success probability inherent in direct photon transmission. We propose a realistic, functionally integrated quantum-repeater implementation based on single atoms in optical cavities. Entanglement is directly generated between the single-atom quantum memory and a photon at telecom wavelength. The latter is collected with high efficiency and adjustable temporal and spectral properties into a spatially well-defined cavity mode. It is heralded by a near-infrared photon emitted from a second, orthogonal cavity. Entanglement between two remote quantum memories can be generated via an optical Bell-state measurement, while we propose entanglement swapping based on a highly efficient, cavity-assisted atom-atom gate. Our quantum-repeater scheme eliminates any requirement for wavelength conversion such that only a single system is needed at each node. We investigate a particular implementation with rubidium and realistic parameters for Fabry-Perot cavities based on hbox {CO}_2 laser-machined optical fibers. We show that the scheme enables the implementation of a rather simple quantum repeater that outperforms direct entanglement generation over large distances and does not require any improvements in technology beyond the state of the art.

  19. Cavity-Free Scheme for Nondestructive Detection of a Single Optical Photon.

    PubMed

    Xia, Keyu; Johnsson, Mattias; Knight, Peter L; Twamley, Jason

    2016-01-15

    Detecting a single photon without absorbing it is a long-standing challenge in quantum optics. All experiments demonstrating the nondestructive detection of a photon make use of a high quality cavity. We present a cavity-free scheme for nondestructive single-photon detection. By pumping a nonlinear medium we implement an interfield Rabi oscillation which leads to a ∼π phase shift on a weak probe coherent laser field in the presence of a single signal photon without destroying the signal photon. Our cavity-free scheme operates with a fast intrinsic time scale in comparison with similar cavity-based schemes. We implement a full real-space multimode numerical analysis of the interacting photonic modes and confirm the validity of our nondestructive scheme in the multimode case. PMID:26824538

  20. Proposal for a telecom quantum repeater with single atoms in optical cavities

    NASA Astrophysics Data System (ADS)

    Uphoff, Manuel; Brekenfeld, Manuel; Niemietz, Dominik; Ritter, Stephan; Rempe, Gerhard

    2016-05-01

    Quantum repeaters hold the promise to enable long-distance quantum communication via entanglement generation over arbitrary distances. Single atoms in optical cavities have been shown to be ideally suited for the experimental realization of many tasks in quantum communication. To utilize these systems for a quantum repeater, it would be desirable to operate them at telecom wavelengths. We propose to use a cascaded scheme employing transitions at telecom wavelengths between excited states of alkali atoms for entanglement generation between a single photon at telecom wavelength and a single atom at the crossing point of two cavity modes. A cavity-assisted quantum gate can be used for entanglement swapping. We estimate the performance of these systems using numerical simulations based on experimental parameters obtained for CO2 laser-machined fiber cavities in our laboratory. Finally, we show that a quantum repeater employing the aforementioned scheme and current technology could outperform corresponding schemes based on direct transmission.

  1. All-optical transistor based on a cavity optomechanical system with a Bose-Einstein condensate

    SciTech Connect

    Chen, Bin; Jiang, Cheng; Li, Jin-Jin; Zhu, Ka-Di

    2011-11-15

    We propose a scheme of an all-optical transistor based on a coupled Bose-Einstein condensate cavity system. The calculated results show that, in such an optomechanical system, the transmission of the probe beam is strongly dependent on the optical pump power. Therefore, the optical pump field can serve as a ''gate'' field of the transistor, effectively controlling the propagation of the probe field (the ''signal'' field). The scheme proposed here may have potential applications in optical communication and quantum information processing.

  2. Time-delay concealment and complexity enhancement of an external-cavity laser through optical injection.

    PubMed

    Li, Nianqiang; Pan, Wei; Locquet, A; Citrin, D S

    2015-10-01

    The concealment of the time-delay signature (TDS) of chaotic external-cavity lasers is necessary to ensure the security of optical chaos-based cryptosystems. We show that this signature can be removed simply by optically injecting an external-cavity laser with a large linewidth-enhancement factor into a second, noninjection-locked, semiconductor laser. Concealment is ensured both in the amplitude and in the phase of the optical field, satisfying a sought-after property of optical chaos-based communications. Meanwhile, enhancement of the dynamical complexity, characterized by permutation entropy, coincides with strong TDS suppression over a wide range of parameters, the area for which depends sensitively on the linewidth-enhancement factor. PMID:26421545

  3. Nonlinear dynamics of a cigar-shaped Bose-Einstein condensate in an optical cavity

    NASA Astrophysics Data System (ADS)

    Zhang, J. M.; Cui, F. C.; Zhou, D. L.; Liu, W. M.

    2009-03-01

    We investigate the nonlinear dynamics of a combined system which is composed of a cigar-shaped Bose-Einstein condensate and an optical cavity with the two sides coupled dispersively. This system is characterized by the cavity-induced nonlinearity; after integrating out the fast degree of freedom of the cavity mode, the potential felt by the condensate depends on the condensate itself. Adopting a discrete-mode approximation for the condensate, we map out the steady configurations of the system. It is found that due to the nonlinearity of the system, the nonlinear levels of the system may fold up in some parameter regimes. That will lead to the breakdown of adiabatic evolution of the system. Analysis of the dynamical stability of the steady states indicates that the same level structure also results in optical bistability.

  4. All-optical light confinement in dynamic cavities in cold atoms.

    PubMed

    Wu, Jin-Hui; Artoni, M; La Rocca, G C

    2009-09-25

    We show how to realize in a cold atomic sample a dynamic magneto-optically controlled cavity in which a slow-light pulse can be confined and released on demand. The probe optical pulse is retrieved from the atomic spin coherence initially stored within the cavity and is subsequently confined there subject to a slow-light regime with little loss and diffusion for time intervals as long as a few hundred microseconds before being extracted from either side of the cavity. Our proof-of-principle scheme illustrates the underlying physics of this new mechanism for coherent light confinement and manipulation in cold atoms. This may ease the realization of nonlinear interactions between weak light pulses where strong atom-photon interactions are required for quantum information processing. PMID:19905513

  5. Power enhancement of burst-mode UV pulses using a doubly-resonant optical cavity

    DOE PAGESBeta

    Rahkman, Abdurahim; Notcutt, Mark; Liu, Yun

    2015-11-24

    We report a doubly-resonant enhancement cavity (DREC) that can realize a simultaneous enhancement of two incoming laser beams at different wavelengths and different temporal structures. The double-resonance condition is theoretically analyzed and different DREC locking methods are experimentally investigated. Simultaneous locking of a Fabry-Perot cavity to both an infrared (IR, 1064 nm) and its frequency tripled ultraviolet (UV, 355 nm) pulses has been demonstrated by controlling the frequency difference between the two beams with a fiber optic frequency shifter. The DREC technique opens a new paradigm in the applications of optical cavities to power enhancement of burst-mode lasers with arbitrarymore » macropulse width and repetition rate.« less

  6. Entanglement of movable mirror and cavity field enhanced by an optical parametric amplifier

    NASA Astrophysics Data System (ADS)

    Cai-yun, Zhang; Hu, Li; Gui-xia, Pan; Zong-qiang, Sheng

    2016-07-01

    A scheme to generate entanglement in a cavity optomechanical system filled with an optical parametric amplifier is proposed. With the help of the optical parametric amplifier, the stationary macroscopic entanglement between the movable mirror and the cavity field can be notably enhanced, and the entanglement increases when the parametric gain increases. Moreover, for a given parametric gain, the degree of entanglement of the cavity optomechanical system increases with increasing input laser power. Project supported by the National Natural Science Foundation of China (Grant No. 11247001), the Scientific Research Foundation of the Higher Education Institutions of Anhui Province, China (Grant No. KJ2012A083), and the Doctor (Master) Fund of Anhui University of Science and Technology, China.

  7. Controllable optical bistability in a cavity optomechanical system with a Bose–Einstein condensate

    NASA Astrophysics Data System (ADS)

    Hamideh Kazemi, Seyedeh; Ghanbari, Saeed; Mahmoudi, Mohammad

    2016-05-01

    The optical bistability (OB) in a two-mode optomechanical system with a Bose–Einstein condensate (BEC) is studied. By investigating the behavior of steady state solutions, we show that how OB develops in the system for a certain range of cavity-pump detunings and pump amplitudes. We then investigate the effects of the decay rate of the cavity photons and coupling strength between the cavity and the BEC as well as the pump-atom detuning on the optical behaviour of the system. We find that one can control the OB threshold and width of the bistability curve via adjusting properly the coupling strength and the detuning. By applying Routh–Hurwitz criterion, we then derive stability conditions for different branches of the OB curve. Moreover, by introducing an effective potential for the system, a simple physical interpretation is obtained.

  8. Observation of motion-dependent nonlinear dispersion with narrow-linewidth atoms in an optical cavity.

    PubMed

    Westergaard, Philip G; Christensen, Bjarke T R; Tieri, David; Matin, Rastin; Cooper, John; Holland, Murray; Ye, Jun; Thomsen, Jan W

    2015-03-01

    As an alternative to state-of-the-art laser frequency stabilization using ultrastable cavities, it has been proposed to exploit the nonlinear effects from coupling of atoms with a narrow transition to an optical cavity. Here, we have constructed such a system and observed nonlinear phase shifts of a narrow optical line by a strong coupling of a sample of strontium-88 atoms to an optical cavity. The sample temperature of a few mK provides a domain where the Doppler energy scale is several orders of magnitude larger than the narrow linewidth of the optical transition. This makes the system sensitive to velocity dependent multiphoton scattering events (Dopplerons) that affect the cavity field transmission and phase. By varying the number of atoms and the intracavity power, we systematically study this nonlinear phase signature which displays roughly the same features as for much lower temperature samples. This demonstration in a relatively simple system opens new possibilities for alternative routes to laser stabilization at the sub-100 mHz level and superradiant laser sources involving narrow-line atoms. The understanding of relevant motional effects obtained here has direct implications for other atomic clocks when used in relation to ultranarrow clock transitions. PMID:25793810

  9. The measurement of the optical cavity length for the Infrared Free-Electron Laser

    SciTech Connect

    C.J. Curtis; J.C. Dahlberg; W.A. Oren; K.J. Tremblay

    1999-10-01

    One of the final tasks involved in the alignment of the newly constructed Free Electron Laser at the Thomas Jefferson National Accelerator Facility was to accurately measure the length between two mirrors which make up the optical cavity. This presentation examines the survey techniques and equipment assembled in order to complete these measurements, together with the possible sources of error, and the accuracy achieved.

  10. Geometric phase in cavity QED containing a nonlinear optical medium and a quantum well

    NASA Astrophysics Data System (ADS)

    Mohamed, A.-B. A.; Eleuch, H.

    2015-11-01

    The geometric phase (GP) in cavity QED filled with a nonlinear medium and containing a quantum well is analyzed. We observe collapses and revivals. The optical nonlinearity leads to high frequency oscillations of the GP. The GP is very sensitive not only to the dissipation rates but also to the amplitude of the laser pump.

  11. Observation of Motion-Dependent Nonlinear Dispersion with Narrow-Linewidth Atoms in an Optical Cavity

    NASA Astrophysics Data System (ADS)

    Westergaard, Philip G.; Christensen, Bjarke T. R.; Tieri, David; Matin, Rastin; Cooper, John; Holland, Murray; Ye, Jun; Thomsen, Jan W.

    2015-03-01

    As an alternative to state-of-the-art laser frequency stabilization using ultrastable cavities, it has been proposed to exploit the nonlinear effects from coupling of atoms with a narrow transition to an optical cavity. Here, we have constructed such a system and observed nonlinear phase shifts of a narrow optical line by a strong coupling of a sample of strontium-88 atoms to an optical cavity. The sample temperature of a few mK provides a domain where the Doppler energy scale is several orders of magnitude larger than the narrow linewidth of the optical transition. This makes the system sensitive to velocity dependent multiphoton scattering events (Dopplerons) that affect the cavity field transmission and phase. By varying the number of atoms and the intracavity power, we systematically study this nonlinear phase signature which displays roughly the same features as for much lower temperature samples. This demonstration in a relatively simple system opens new possibilities for alternative routes to laser stabilization at the sub-100 mHz level and superradiant laser sources involving narrow-line atoms. The understanding of relevant motional effects obtained here has direct implications for other atomic clocks when used in relation to ultranarrow clock transitions.

  12. Application of principles of nonimaging optics to the construction of solid state laser pump cavities

    NASA Astrophysics Data System (ADS)

    Janevski, Zoran; Pantelic, Dejan V.

    1990-07-01

    In laser systems where it is impossible or impractical to use lamps and rod whose effective perimeters are matched, some elements of construction of cavities using nonimaging optical concentrators can be used to achieve improved designs in regard to efficiency and pumping uniformity.

  13. Multiconical emission of a monolithic mini-cavity optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Peckus, Martynas; Staliunas, Kestutis; Saffman, Mark; Slekys, Gintas; Sirutkaitis, Valdas; Smilgevicius, Valerijus; Grigonis, Rimantas

    2005-07-01

    We show experimentally, and interpret theoretically the conical and multiconical emission of degenerate optical parametric oscillators in monolithic mini-cavities. We show the tunability of the conical emission angle, the switching between different resonant cones, and simultaneous emission on different cones, depending on the pump angle as well as on the length of the resonator.

  14. Transverse patterns of mini-cavity optical parametric oscillator with seed injection

    NASA Astrophysics Data System (ADS)

    Peckus, Martynas; Staliunas, Kestutis; Smilgevicius, Valerijus; Slekys, Gintas; Rukavicius, Valdemaras; Sirutkaitis, Valdas

    2007-02-01

    We show experimentally, and interpret theoretically the conical and multiconical emission of optical parametric oscillators with seed injection in monolithic mini-cavities. We show the tunability of the conical emission angle, the switching between different resonant cones, and simultaneous emission on different cones, depending on the pump angle as well as on the length of the resonator.

  15. Proton irradiation robustness of dielectric mirrors for high-finesse Fabry-Pérot resonators in the near-infrared spectral range

    NASA Astrophysics Data System (ADS)

    Chen, Qun-Feng; Nevsky, Alexander; Schiller, Stephan; Campa, Erwin Portuondo; Lecomte, Steve; Parker, David

    2014-08-01

    We demonstrate that a proton irradiation with fluences of 3.6 × 1010/cm2 at low energy (<36 MeV) and 1.46 × 1010/cm2 at high energy (40 and 90 MeV combined) on the dielectric mirrors of Fabry-Pérot cavities with a finesse of about 700,000 causes less than 5 % change in the finesse. Furthermore, no influence on the coupling efficiency to the cavities was observed, the efficiency being approximately 70 %. The irradiation was carried out with a spectrum approximating the proton energy spectrum of a highly elliptic Earth orbit with duration of 5 years, proposed for the Space-Time Explorer and Quantum Equivalence Space Test (STE-QUEST) mission [http://sci.esa.int/ste-quest/].

  16. Response of a Fabry Perot optical cavity to phase modulation sidebands for use in electro-optic control systems

    NASA Astrophysics Data System (ADS)

    Skeldon, Kenneth D.; Strain, Kenneth A.

    1997-09-01

    The worldwide endeavor to build long baseline laser interferometers to detect and study gravitational radiation is well under way. In the German British GEO600 project, it is proposed to pass the sidebands induced on the light by an electro-optic phase modulator through a Fabry Perot optical cavity used in transmission, called a mode cleaner. This can be achieved when the phase modulation frequency is matched to the first longitudinal-mode frequency of the mode cleaner cavity so that both carrier and sidebands are transmitted. The primary function of the mode cleaner is to reduce the geometry fluctuations associated with the light, and thus any such noise induced by the modulation process is also suppressed. We present the results of an experiment that investigates the feasibility of passing modulation sidebands through an optical cavity and the factors limiting its success. In particular, we show that it is possible to avoid introducing excess noise associated with the transmitted sidebands, provided that certain experimental criteria are satisfied. The research was carried out on a prototype mode cleaner cavity built and tested at Glasgow University but which is similar to the equivalent apparatus planned for GEO600.

  17. Response of a Fabry-Perot optical cavity to phase modulation sidebands for use in electro-optic control systems.

    PubMed

    Skeldon, K D; Strain, K A

    1997-09-20

    The worldwide endeavor to build long baseline laser interferometers to detect and study gravitational radiation is well under way. In the German-British GEO600 project, it is proposed to pass the sidebands induced on the light by an electro-optic phase modulator through a Fabry-Perot optical cavity used in transmission, called a mode cleaner. This can be achieved when the phase modulation frequency is matched to the first longitudinal-mode frequency of the mode cleaner cavity so that both carrier and sidebands are transmitted. The primary function of the mode cleaner is to reduce the geometry fluctuations associated with the light, and thus any such noise induced by the modulation process is also suppressed. We present the results of an experiment that investigates the feasibility of passing modulation sidebands through an optical cavity and the factors limiting its success. In particular, we show that it is possible to avoid introducing excess noise associated with the transmitted sidebands, provided that certain experimental criteria are satisfied. The research was carried out on a prototype mode cleaner cavity built and tested at Glasgow University but which is similar to the equivalent apparatus planned for GEO600. PMID:18259548

  18. Resonant microwave cavity for 8.5-12 GHz optically detected electron spin resonance with simultaneous nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Colton, J. S.; Wienkes, L. R.

    2009-03-01

    We present a newly developed microwave resonant cavity for use in optically detected magnetic resonance (ODMR) experiments. The cylindrical quasi-TE011 mode cavity is designed to fit in a 1 in. magnet bore to allow the sample to be optically accessed and to have an adjustable resonant frequency between 8.5 and 12 GHz. The cavity uses cylinders of high dielectric material, so-called "dielectric resonators," in a double-stacked configuration to determine the resonant frequency. Wires in a pseudo-Helmholtz configuration are incorporated into the cavity to provide frequencies for simultaneous nuclear magnetic resonance (NMR). The system was tested by measuring cavity absorption as microwave frequencies were swept, by performing ODMR on a zinc-doped InP sample, and by performing optically detected NMR on a GaAs sample. The results confirm the suitability of the cavity for ODMR with simultaneous NMR.

  19. Fabrication of optical cavities with femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Lin, Jintian; Song, Jiangxin; Tang, Jialei; Fang, Wei; Sugioka, Koji; Cheng, Ya

    2014-03-01

    We report on fabrication of three-dimensional (3D) high-quality (Q) whispering-gallery-mode microcavities by femtosecond laser micromachining. The main fabrication procedures include the formation of on-chip freestanding microdisk through selective material removal by femtosecond laser pulses, followed by surface smoothing processes (CO2 laser reflow for amorphous glass and focused ion beam (FIB) sidewall milling for crystalline materials) to improve the Q factors. Fused silica microcavities with 3D geometries are demonstrated with Q factors exceeding 106. A microcavity laser based on Nd:glass has been fabricated, showing a threshold as low as 69μW via free space continuous-wave optical excitation at the room temperature. CaF2 crystalline microcavities with Q factor of ~4.2×104 have also been demonstrated. This technique allows us to fabricate 3D high-Q microcavities in various transparent materials such as glass and crystals, which will benefit a broad spectrum of applications such as nonlinear optics, quantum optics, and bio-sensing.

  20. All-optical transistor using a photonic-crystal cavity with an active Raman gain medium

    NASA Astrophysics Data System (ADS)

    Arkhipkin, V. G.; Myslivets, S. A.

    2013-09-01

    We propose a design of an all-optical transistor based on a one-dimensional photonic-crystal cavity doped with a four-level N-type active Raman gain medium. The calculated results show that in a photonic-crystal cavity of this kind transmission and reflection of the probe (Raman) beam are strongly dependent on the optical switching power. Transmission and reflection of the probe beam can be greatly amplified or attenuated. Therefore the optical switching field can serve as a gate field of the transistor to effectively control propagation of the weak probe field. It is shown that the group velocity of the probe pulse can be controlled in the range from subluminal (slow light) to superluminal (fast light).

  1. Tunable all-optical plasmonic diode based on Fano resonance in nonlinear waveguide coupled with cavities.

    PubMed

    Fan, Cairong; Shi, Fenghua; Wu, Hongxing; Chen, Yihang

    2015-06-01

    Tunable all-optical plasmonic diode is proposed based on the Fano resonance in an asymmetric and nonlinear system, comprising metal-insulator-metal waveguides coupled with nanocavities. The spatial asymmetry of the system gives rise to the nonreciprocity of the field localizations at the nonlinear gap between the coupled cavities and to the nonreciprocal nonlinear response. Nonlinear Fano resonance, originating from the interference between the discrete cavity mode and the continuum traveling mode, is observed and effectively tuned by changing the input power. By combining the unidirectional nonlinear response with the steep dispersion of the Fano asymmetric line shape, a transmission contrast ratio up to 41.46 dB can be achieved between forward and backward transmission. Our all-optical plasmonic diode with compact structure can find important applications in integrated optical nanocircuits. PMID:26030529

  2. Thermal lens microscope sensitivity enhancement using a passive Fabry–Perot-type optical cavity

    NASA Astrophysics Data System (ADS)

    Cabrera, H.; Cedeño, E.; Grima, P.; Marín, E.; Calderón, A.; Delgado, O.

    2016-05-01

    We developed a thermal lens microscope equipped with a passive optical cavity, which provides an optical feedback for the multiple pass of the probe laser beam to enhance sensitivity. Considering the maximum absorption peak for Fe(II) at 532 nm wavelength, we have achieved a 6.6-fold decrease in the limit of detection (LOD) to a level of 0.077 μg · l‑1 without a cavity. The possibilities to use thermal lens detection combined with an optical resonator was proposed and a drastic thermal lens signal enhancement was achieved using very low excitation power. The corresponding LOD for Fe(II) was further decreased to the level of 0.006 μg · l‑1 which represents an 85-fold decrease of the LOD value. This setup is a promising device, which can be applied as a sensitive tool for detecting chemical traces in small volumes of solutions.

  3. Dual-pump Kerr Micro-cavity Optical Frequency Comb with varying FSR spacing.

    PubMed

    Wang, Weiqiang; Chu, Sai T; Little, Brent E; Pasquazi, Alessia; Wang, Yishan; Wang, Leiran; Zhang, Wenfu; Wang, Lei; Hu, Xiaohong; Wang, Guoxi; Hu, Hui; Su, Yulong; Li, Feitao; Liu, Yuanshan; Zhao, Wei

    2016-01-01

    In this paper, we demonstrate a novel dual-pump approach to generate robust optical frequency comb with varying free spectral range (FSR) spacing in a CMOS-compatible high-Q micro-ring resonator (MRR). The frequency spacing of the comb can be tuned by an integer number FSR of the MRR freely in our dual-pump scheme. The dual pumps are self-oscillated in the laser cavity loop and their wavelengths can be tuned flexibly by programming the tunable filter embedded in the cavity. By tuning the pump wavelength, broadband OFC with the bandwidth of >180 nm and the frequency-spacing varying from 6 to 46-fold FSRs is realized at a low pump power. This approach could find potential and practical applications in many areas, such as optical metrology, optical communication, and signal processing systems, for its excellent flexibility and robustness. PMID:27338250

  4. Dual-pump Kerr Micro-cavity Optical Frequency Comb with varying FSR spacing

    PubMed Central

    Wang, Weiqiang; Chu, Sai T.; Little, Brent E.; Pasquazi, Alessia; Wang, Yishan; Wang, Leiran; Zhang, Wenfu; Wang, Lei; Hu, Xiaohong; Wang, Guoxi; Hu, Hui; Su, Yulong; Li, Feitao; Liu, Yuanshan; Zhao, Wei

    2016-01-01

    In this paper, we demonstrate a novel dual-pump approach to generate robust optical frequency comb with varying free spectral range (FSR) spacing in a CMOS-compatible high-Q micro-ring resonator (MRR). The frequency spacing of the comb can be tuned by an integer number FSR of the MRR freely in our dual-pump scheme. The dual pumps are self-oscillated in the laser cavity loop and their wavelengths can be tuned flexibly by programming the tunable filter embedded in the cavity. By tuning the pump wavelength, broadband OFC with the bandwidth of >180 nm and the frequency-spacing varying from 6 to 46-fold FSRs is realized at a low pump power. This approach could find potential and practical applications in many areas, such as optical metrology, optical communication, and signal processing systems, for its excellent flexibility and robustness. PMID:27338250

  5. High precision optical cavity length and width measurements using double modulation.

    PubMed

    Staley, A; Hoak, D; Effler, A; Izumi, K; Dwyer, S; Kawabe, K; King, E J; Rakhmanov, M; Savage, R L; Sigg, D

    2015-07-27

    We use doubly phase modulated light to measure both the length and the linewidth of an optical resonator with high precision. The first modulation is at RF frequencies and is set near a multiple of the free spectral range, whereas the second modulation is at audio frequencies to eliminate offset errors at DC. The light in transmission or in reflection of the optical resonator is demodulated while sweeping the RF frequency over the optical resonance. We derive expressions for the demodulated power in transmission, and show that the zero crossings of the demodulated signal in transmission serve as a precise measure of the cavity linewidth at half maximum intensity. We demonstrate the technique on two resonant cavities, with lengths 16 m and a 4 km, and achieve an absolute length accuracy as low as 70 ppb. The cavity width for the 16 m cavity was determined with an accuracy of approximately 6000 ppm. Through an analysis of the systematic errors we show that this result could be substantially improved with the reduction of technical sources of uncertainty. PMID:26367601

  6. Time- and space-modulated Raman signals in graphene-based optical cavities

    NASA Astrophysics Data System (ADS)

    Reserbat-Plantey, Antoine; Klyatskaya, Svetlana; Reita, Valérie; Marty, Laëtitia; Arcizet, Olivier; Ruben, Mario; Bendiab, Nedjma; Bouchiat, Vincent

    2013-11-01

    We present fabrication and optical characterization of micro-cavities made of multilayer graphene (MLG) cantilevers clamped by metallic electrodes and suspended over Si/SiO2 substrates. Graphene cantilevers act as semi-transparent mirrors closing air wedge optical cavities. This simple geometry implements a standing-wave optical resonator along with a mechanical one. Equal thickness interference fringes are observed in both Raman and Rayleigh backscattered signals, with interfringe given by their specific wavelength. Chromatic dispersion within the cavity makes possible the spatial modulation of graphene Raman lines and selective rejection of the silicon background signal. Electrostatic actuation of the multilayer graphene cantilever by a gate voltage tunes the cavity length and induces space and time modulation of the backscattered light, including the Raman lines. We demonstrate the potential of these systems for high-sensitivity Raman measurements of generic molecular species grafted on a multilayer graphene surface. The Raman signal of the molecular layer can be modulated both in time and space in a similar fashion and shows enhancement with respect to a collapsed membrane.

  7. Realizing mode conversion and optical diode effect by coupling photonic crystal waveguides with cavity

    NASA Astrophysics Data System (ADS)

    Ye, Han; Zhang, Jin-Qian-Nan; Yu, Zhong-Yuan; Wang, Dong-Lin; Chen, Zhi-Hui

    2015-09-01

    We propose a novel two-dimensional photonic crystal structure consisting of two line defect waveguides and a cavity to realize mode conversion based on the coupling effect. The W1/cavity/W2 structure breaks the spatial symmetry and successfully converts the even (odd) mode to the odd (even) mode in the W2 waveguide during the forward (backward) transmission. When considering the incidence of only the even mode, the optical diode effect emerges and achieves approximate 35 dB unidirectionality at the resonant frequency. Moreover, owing to the narrow bandpass feature and the flexibility of the tuning cavity, utilization of the proposed structure as a wavelength filter is demonstrated in a device with a Y-branch splitter. Here, we provide a heuristic design for a mode converter, optical diode, and wavelength filter derived from the coupling effect between a cavity and adjacent waveguides, and expect that the proposed structure can be applied as a building block in future all-optical integrated circuits. Project supported by the National Natural Science Foundation of China (Grant Nos. 61372037 and 61307069), Beijing Excellent Ph. D. Thesis Guidance Foundation, China (Grant No. 20131001301), and the Natural Science Foundation of Shanxi Province, China (Grant No. 2013021017-3).

  8. High-quality-factor planar optical cavities with laterally stopped, slowed, or reversed light.

    PubMed

    Byrnes, Steven J; Khorasaninejad, Mohammadreza; Capasso, Federico

    2016-08-01

    In a planar optical cavity, the resonance frequencies increase as a function of in-plane wavevector according to a standard textbook formula. This has well-known consequences in many different areas of optics, from the shifts of etalon peaks at non-normal angles, to the properties of transverse modes in laser diodes, to the effective mass of microcavity photons, and so on. However, this standard formula is valid only when the reflection phase of each cavity mirror is approximately independent of angle. There is a certain type of mirror-a subwavelength dielectric grating near a guided mode resonance-with not only a strongly angle-dependent reflection phase, but also very high reflectance and low losses. Simulations show that by using such mirrors, high-quality-factor planar cavities can be designed that break all these textbook rules, leading to resonant modes that are slow, stopped or even backward-propagating in the in-plane direction. In particular, we demonstrate experimentally high-Q planar cavities whose resonance frequency is independent of in-plane wavevector-i.e., the resonant modes have zero in-plane group velocity, for one polarization but both in-plane directions. We discuss potential applications in various fields including lasers, quantum optics, and exciton-polariton condensation. PMID:27505803

  9. Hybrid apparatus for Bose-Einstein condensation and cavity quantum electrodynamics: Single atom detection in quantum degenerate gases

    SciTech Connect

    Oettl, Anton; Ritter, Stephan; Koehl, Michael; Esslinger, Tilman

    2006-06-15

    We present and characterize an experimental system in which we achieve the integration of an ultrahigh finesse optical cavity with a Bose-Einstein condensate (BEC). The conceptually novel design of the apparatus for the production of BECs features nested vacuum chambers and an in vacuo magnetic transport configuration. It grants large scale spatial access to the BEC for samples and probes via a modular and exchangeable ''science platform.'' We are able to produce {sup 87}Rb condensates of 5x10{sup 6} atoms and to output couple continuous atom lasers. The cavity is mounted on the science platform on top of a vibration isolation system. The optical cavity works in the strong coupling regime of cavity quantum electrodynamics and serves as a quantum optical detector for single atoms. This system enables us to study atom optics on a single particle level and to further develop the field of quantum atom optics. We describe the technological modules and the operation of the combined BEC cavity apparatus. Its performance is characterized by single atom detection measurements for thermal and quantum degenerate atomic beams. The atom laser provides a fast and controllable supply of atoms coupling with the cavity mode and allows for an efficient study of atom field interactions in the strong coupling regime. Moreover, the high detection efficiency for quantum degenerate atoms distinguishes the cavity as a sensitive and weakly invasive probe for cold atomic clouds.

  10. Cavity-Enhanced Light Scattering in Optical Lattices to Probe Atomic Quantum Statistics

    SciTech Connect

    Mekhov, Igor B.; Maschler, Christoph; Ritsch, Helmut

    2007-03-09

    Different quantum states of atoms in optical lattices can be nondestructively monitored by off-resonant collective light scattering into a cavity. Angle resolved measurements of photon number and variance give information about atom-number fluctuations and pair correlations without single-site access. Observation at angles of diffraction minima provides information on quantum fluctuations insensitive to classical noise. For transverse probing, no photon is scattered into a cavity from a Mott insulator phase, while the photon number is proportional to the atom number for a superfluid.

  11. Negative and positive hysteresis in double-cavity optical bistability in a three-level atom

    SciTech Connect

    Babu, H. Aswath; Wanare, Harshawardhan

    2011-03-15

    We present dual hysteretic behavior of a three-level ladder system exhibiting optical bistability in a double-cavity configuration in the mean-field limit. The two fields coupling the atomic system experience competing cooperative effects along the two transitions. We observe a hump-like feature in the bistable curve arising due to cavity-induced inversion, which transforms into a negative-hysteresis loop. Apart from negative- and positive-hysteresis regions, the system offers a variety of controllable nonlinear dynamical features, ranging from switching, periodic self-pulsing to chaos.

  12. Electro-optic harmonic conversion to switch a laser beam out of a cavity

    DOEpatents

    Haas, Roger A.; Henesian, Mark A.

    1987-01-01

    The invention is a switch to permit a laser beam to escape a laser cavity through the use of an externally applied electric field across a harmonic conversion crystal. Amplification takes place in the laser cavity, and then the laser beam is switched out by the laser light being harmonically converted with dichroic or polarization sensitive elements present to alter the optical path of the harmonically converted laser light. Modulation of the laser beam can also be accomplished by varying the external electric field.

  13. 1300 nm optically pumped quantum dot spin vertical external-cavity surface-emitting laser

    NASA Astrophysics Data System (ADS)

    Alharthi, S. S.; Orchard, J.; Clarke, E.; Henning, I. D.; Adams, M. J.

    2015-10-01

    We report a room temperature optically pumped Quantum Dot-based Spin-Vertical-External-Cavity Surface-Emitting laser (QD Spin-VECSEL) operating at the telecom wavelength of 1.3 μm. The active medium was composed of 5 × 3 QD layers; each threefold group was positioned at an antinode of the standing wave of the optical field. Circularly polarized lasing in the QD-VECSEL under Continuous-Wave optical pumping has been realized with a threshold pump power of 11 mW. We further demonstrate at room temperature control of the QD-VECSEL output polarization ellipticity via the pump polarization.

  14. Enhanced gain and narrow linewidth of an optical cavity by the Doppler effect in a four-level atomic system

    NASA Astrophysics Data System (ADS)

    Peng, Yandong; Yang, Aihong; Zhang, Huiyun; Li, Peng; Jiang, Lin; Zhang, Luyin

    2013-07-01

    A scheme for high gain and narrow linewidth of an optical cavity with a four-level atomic system is proposed by the Doppler effect via active Raman gain (ARG) process. Atomic motion leads to Doppler frequency shift which induces constructive interference for the linear susceptibility. The enhanced normal dispersion greatly narrows the cavity linewidth, and the amplified gain gives rise to a high cavity transmission. Simulation results show that the cavity linewidth based on ARG is about one order of magnitude narrower than that based on electromagnetically-induced transparency under the same conditions, and the cavity transmission intensity could be enhanced by nearly 30 times.

  15. Electro-optic resonant phase modulator

    NASA Technical Reports Server (NTRS)

    Chen, Chien-Chung (Inventor); Hemmati, Hamid (Inventor); Robinson, Deborah L. (Inventor)

    1992-01-01

    An electro-optic resonant cavity is used to achieve phase modulation with lower driving voltages. Laser damage thresholds are inherently higher than with previously used integrated optics due to the utilization of bulk optics. Phase modulation is achieved at higher speeds with lower driving voltages than previously obtained with non-resonant electro-optic phase modulators. The instant scheme uses a data locking dither approach as opposed to the conventional sinusoidal locking schemes. In accordance with a disclosed embodiment, a resonant cavity modulator has been designed to operate at a data rate in excess of 100 megabits per sec. By carefully choosing the cavity finesse and its dimension, it is possible to control the pulse switching time to within 4 nano-sec. and to limit the required switching voltage to within 10 V. This cavity locking scheme can be applied by using only the random data sequence, and without the need of dithering of the cavity. Compared to waveguide modulators, the resonant cavity has a comparable modulating voltage requirement. Because of its bulk geometry, the resonant cavity modulator has the potential of accommodating higher throughput power. Mode matching into the bulk device is easier and typically can be achieved with higher efficiency. An additional control loop is incorporated into the modulator to maintain the cavity on resonance.

  16. Fabry-Pérot filter cavities for wide-spaced frequency combs with large spectral bandwidth

    NASA Astrophysics Data System (ADS)

    Steinmetz, T.; Wilken, T.; Araujo-Hauck, C.; Holzwarth, R.; Hänsch, T. W.; Udem, T.

    2009-08-01

    We use low-finesse Fabry-Pérot cavities in series to generate frequency combs with a large mode spacing in a way that allows its application to a large optical bandwidth. The attenuation of laser modes closest to the pass bands of the cavity exceeds 70 dB for a filter ratio of m=20 relative to the resonant modes centered within the pass bands. We also identify the best cavity geometry to suppress spurious transmission of higher order transversal modes. Such a thinned out frequency comb can be used to calibrate traditional spectrographs for precision astronomy. In the time domain mode filtering generates a pulse train with a multiplied repetition rate. High-fidelity filtering, as described here, implies small variations of the pulse energies.

  17. Demonstration of a cavity coupler based on a resonant waveguide grating.

    PubMed

    Brückner, Frank; Friedrich, Daniel; Clausnitzer, Tina; Burmeister, Oliver; Britzger, Michael; Kley, Ernst-Bernhard; Danzmann, Karsten; Tünnermann, Andreas; Schnabel, Roman

    2009-01-01

    Thermal noise in multilayer optical coatings may not only limit the sensitivity of future gravitational wave detectors in their most sensitive frequency band but is also a major impediment for experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. Here, we present the experimental realization and characterization of a cavity coupler, which is based on a surface relief guided ode resonant grating. Since the required thickness of the dielectric coating is dramatically decreased compared to conventional mirrors, it is expected to provide low mechanical loss and, thus, low thermal noise. The cavity coupler was incorporated into a Fabry-Perot resonator together with a conventional high quality mirror. The finesse of this cavity was measured to be F = 657, which corresponds to a coupler reflectivity of R = 99.08 %. PMID:19129884

  18. Temporal characterization of FEL micropulses as function of cavity length detuning using frequency-resolved optical gating

    SciTech Connect

    Richman, B.A.; DeLong, K.W.; Trebino, R.

    1995-12-31

    Results of frequency resolved optical gating (FROG) measurements on the Stanford mid-IR FEL system show the effect of FEL cavity length detuning on the micropulse temporal structure. The FROG technique enables the acquisition of complete and uniquely invertible amplitude and phase temporal dependence of optical pulses. Unambiguous phase and amplitude profiles are recovered from the data. The optical pulses are nearly transform limited, and the pulse length increases with cavity length detuning.

  19. Electro-optical transduction via a mechanical membrane

    NASA Astrophysics Data System (ADS)

    Stambaugh, Corey; Lawall, John

    2013-03-01

    Both cavity opto-mechanics and cavity electro-mechanics have been studied as means to achieve ground state cooling of mechanical systems. Recent focus has turned to hybrid systems that attempt to convert photons between microwave and optical frequencies through mechanical transduction. This should allow quantum information stored in an electrical cavity to be transferred optically over longer distances. In this talk we describe our hybrid system, a silicon nitride membrane that is coupled to a piezoelectric element and placed within a high finesse Fabry-Perot cavity. This setup allows us to both sense and perturb the mechanical motion of the membrane. Results regarding the coupling between the different domains and the design strategies to optimize these couplings will be discussed.

  20. Localization transition in the presence of cavity backaction

    NASA Astrophysics Data System (ADS)

    Rojan, Katharina; Kraus, Rebecca; Fogarty, Thomás; Habibian, Hessam; Minguzzi, Anna; Morigi, Giovanna

    2016-07-01

    We study the localization transition of an atom confined by an external optical lattice in a high-finesse cavity. The atom-cavity coupling yields an effective secondary lattice potential, whose wavelength is incommensurate with the periodicity of the optical lattice. The cavity lattice can induce localization of the atomic wave function analogously to the Aubry-André localization transition. Starting from the master equation for the cavity and the atom we perform a mapping of the system dynamics to a Hubbard Hamiltonian, which can be reduced to the Harper's Hamiltonian in appropriate limits. We evaluate the phase diagram for the atom's ground state and show that the transition between extended and localized wave function is controlled by the strength of the cavity nonlinearity, which determines the size of the localized region and the behavior of the Lyapunov exponent. The Lyapunov exponent, in particular, exhibits resonancelike behavior in correspondence with the optomechanical resonances. Finally we discuss the experimental feasibility of these predictions.

  1. Cavity Quantum Electrodynamics: A Universal Quantum Optics Toolbox

    NASA Astrophysics Data System (ADS)

    Rempe, Gerhard

    2016-05-01

    Electromagnetic resonators provide unparalleled capabilities in controlling the interaction between light and matter. The recently developed techniques for trapping and cooling atoms between closely spaced mirrors now open up new experimental avenues for genuine quantum-mechanical experiments. Particularly exciting possibilities concern long-distance quantum networking and scalable quantum computation. Recent achievements like the nondestructive detection of an optical photon, the realization of a quantum gate between a single atom and a single photon, and the heralded and efficient conversion of a flying qubit into a stationary qubit are past highlights. The longstanding dream of a quantum gate between individually addressable photonic qubits might become reality in the future. The talk will summarize recent experiments and give an outlook onto future directions.

  2. Quantum phases and dynamics of bosonic atoms trapped in a single-mode optical cavity

    NASA Astrophysics Data System (ADS)

    Sundar, Bhuvanesh; Mueller, Erich

    2016-05-01

    Motivated by experiments performed by R. Landig et al. (arXiv:1511.00007), we theoretically explore the behavior of bosonic atoms trapped in a single-mode cavity in the presence of a two-dimensional optical lattice. As explained by arXiv:1511.00007, Rayleigh scattering of light from the lattice-inducing beams into the cavity produces infinite-range cavity-mediated interactions between the atoms, leading to competition between superfluid, supersolid, Mott insulating and charge density wave phases. We calculate the phase diagram for a uniform trap using a variation of the Gutzwiller Ansatz. We also calculate the spatial distribution of the different phases in the gas in the presence of a harmonic trap. We explore hysteretic behavior when parameters of the system are changed.

  3. Nonequilibrium phase transition of interacting bosons in an intra-cavity optical lattice.

    PubMed

    Bakhtiari, M Reza; Hemmerich, A; Ritsch, H; Thorwart, M

    2015-03-27

    We investigate the nonlinear light-matter interaction of a Bose-Einstein condensate trapped in an external periodic potential inside an optical cavity which is weakly coupled to vacuum radiation modes and driven by a transverse pump field. Based on a generalized Bose-Hubbard model which incorporates a single cavity mode, we include the collective backaction of the atoms on the cavity light field and determine the nonequilibrium quantum phases within the nonperturbative bosonic dynamical mean-field theory. With the system parameters adapted to recent experiments, we find a quantum phase transition from a normal phase to a self-organized superfluid phase, which is related to the Hepp-Lieb-Dicke superradiance phase transition. For even stronger pumping, a self-organized Mott insulator phase arises. PMID:25860742

  4. Impurity-free quantum well intermixing for large optical cavity high-power laser diode structures

    NASA Astrophysics Data System (ADS)

    Kahraman, Abdullah; Gür, Emre; Aydınlı, Atilla

    2016-08-01

    We report on the correlation of atomic concentration profiles of diffusing species with the blueshift of the quantum well luminescence from both as-grown and impurity free quantum wells intermixed on actual large optical cavity high power laser diode structures. Because it is critical to suppress catastrophic optical mirror damage, sputtered SiO2 and thermally evaporated SrF2 were used both to enhance and suppress quantum well intermixing, respectively, in these (Al)GaAs large optical cavity structures. A luminescence blueshift of 55 nm (130 meV) was obtained for samples with 400 nm thick sputtered SiO2. These layers were used to generate point defects by annealing the samples at 950 °C for 3 min. The ensuing Ga diffusion observed as a shifting front towards the surface at the interface of the GaAs cap and AlGaAs cladding, as well as Al diffusion into the GaAs cap layer, correlates well with the observed luminescence blue shift, as determined by x-ray photoelectron spectroscopy. Although this technique is well-known, the correlation between the photoluminescence peak blue shift and diffusion of Ga and Al during impurity free quantum well intermixing on actual large optical cavity laser diode structures was demonstrated with both x ray photoelectron and photoluminescence spectroscopy, for the first time.

  5. Monitoring the Evaporation of Fluids from Fiber-Optic Micro-Cell Cavities

    PubMed Central

    Preter, Eyal; Preloznik, Borut; Artel, Vlada; Sukenik, Chaim N.; Donlagic, Denis; Zadok, Avi

    2013-01-01

    Fiber-optic sensors provide remote access, are readily embedded within structures, and can operate in harsh environments. Nevertheless, fiber-optic sensing of liquids has been largely restricted to measurements of refractive index and absorption spectroscopy. The temporal dynamics of fluid evaporation have potential applications in monitoring the quality of water, identification of fuel dilutions, mobile point-of-care diagnostics, climatography and more. In this work, the fiber-optic monitoring of fluids evaporation is proposed and demonstrated. Sub-nano-liter volumes of a liquid are applied to inline fiber-optic micro-cavities. As the liquid evaporates, light is refracted out of the cavity at the receding index boundary between the fluid and the ambient surroundings. A sharp transient attenuation in the transmission of light through the cavity, by as much as 50 dB and on a sub-second time scale, is observed. Numerical models for the transmission dynamics in terms of ray-tracing and wavefront propagation are provided. Experiments show that the temporal transmission profile can distinguish between different liquids. PMID:24212122

  6. Cavity Self-Stabilization and Enhancement of Laser Gyroscopes by (Coupled) Optical Resonators

    NASA Technical Reports Server (NTRS)

    Smith, David D.

    2006-01-01

    We analyze the effect of a highly dispersive element placed inside a modulated optical cavity on the frequency and amplitude of the modulation to determine the conditions for cavity self-stabilization and enhanced gyroscopic sensitivity. Hence, we model cavity rotation or instability by an arbitrary AM/FM modulation, and the dispersive element as a phase and amplitude filter. We find that anomalous dispersion may be used to self-stabilize a laser cavity, provided the magnitude of the group index of refraction is smaller than the phase index of refraction in the cavity. The optimal stabilization is found to occur when the group index is zero. Group indices with magnitudes larger than the phase index (both normal and anomalous dispersion) are found to enhance the sensitivity of a laser gyroscope to rotation. Furthermore, our results indicate that atomic media, even coherent superpositions in multilevel atoms, are not useful for these applications, because the amplitude and phase filters work against one another, i.e., decreasing the modulation frequency increases its amplitude and vice versa, with one exception: negative group indices whose magnitudes are larger than the phase index result in negative, but enhanced, beat frequencies. On the other hand, for optical resonators the dispersion reversal associated with critical coupling enables the amplitude and phase filters to work together under a greater variety of circumstances than for atomic media. We find that for single over-coupled resonators, or in the case of under-coupled coupled-resonator-induced absorption, the absorption and normal dispersion on-resonance increase the contrast and frequency of the beat-note, respectively, resulting in a substantial enhancement of the gyroscopic response. Moreover, for cavity self-stabilization, we propose the use of a variety of coupled-resonator induced transparency that is accompanied by anomalous dispersion.

  7. Optical quantum simulation of Abelian gauge field using cold atomic ensembles coupled with arrays of optical cavities

    NASA Astrophysics Data System (ADS)

    Liu, YiMin; Liu, RongWan

    2014-12-01

    A potentially practical scheme is proposed to realize optical quantum simulation of artificial Abelian gauge field in a scalable architecture consisting of cold atomic ensembles with optical cavities. In the present model, the collective excitations of cold atomic ensembles can be converted to the bosonic modes within the low-excitation limit, where the structure of two-dimension (2D) square plaquette enables the polaritons to move like a charged particle subjected to an external magnetic field. We find that the energy spectrum of this hybrid system exhibits a shape of Hofstadter buttery. Our work provides a different perspective to the quantum simulation of condensed matter and many-body physics in the context of cavity quantum electrodynamics. The experimental feasibility are justified using the existing techniques.

  8. Study of Optimal Cavity Parameter in Optically Pumped D2O Gas Terahertz Laser

    NASA Astrophysics Data System (ADS)

    He, Zhihong; Zhang, Yuping; Zhang, Huiyun; Zhang, Qingmao; Liao, Jianhong; Zhou, Yongheng; Liu, Songhao; Luo, Xizhang

    2010-05-01

    Heavy water gas (D2O gas) which owns special structure property, can generate terahertz radiation by optically pumping technology, and its 385 μm wavelength radiation can be widely used. In this research, on the base of semi-classical density matrix theory, we set up a three-level energy system as its theoretical model, a TEA-CO2 laser 9R (22) output line (λ = 9.26 μm) acted as pumping source, D2O gas molecules were operating medium, the expressions of pumping absorption coefficient G p and Terahertz signal gain coefficient G s were deduced. It was shown that the gain of Terahertz signal was related with the energy-level parameters of operating molecules and some operating parameters of the Terahertz laser cavity, mainly including cavity length. By means of iteration method, the output power density of Terahertz pulse signal was calculated numerically. Changing the parameter of cavity length and keeping others steady, the relationship curve between the output power intensity (Is) of Terahertz pulse laser and the operating cavity length (L) was obtained. The curve showed that the power intensity (Is) increased with cavity length (L) in a certain range, but decreased when the length (L) exceeded some value because of the absorption effect, and there was an optimal cavity length for the highest output power. We used a grating tuned TEA-CO2 laser as pumping power and a sample tube of variable length in 70-160 cm as terahertz laser operating cavity to experiment. The results of theoretical calculation and experiment matched with each other, and it is helpful for miniaturizing terahertz laser volume to make it practical.

  9. Mechanical oscillator with optical cavity read-out for high sensitivity force detection

    NASA Astrophysics Data System (ADS)

    Michels, Thomas; Miao, Houxun; Srinivasan, Kartik; Zou, Jie; Rangelow, Ivo W.; Aksyuk, Vladimir

    2013-03-01

    Incorporating cavity optomechanics into micro and nano-scale electro mechanical systems (MEMS, NEMS) is a topic of high interest since it enables measurement of mechanical motion near the fundamental limits of precision imposed by quantum mechanics. We have developed an on-chip cavity optomechanical transducer platform that combines high bandwidth and sensitivity near the standard quantum limit with compactness, robustness, small size, and potential for low cost batch fabrication inherent in MEMS. We present a novel MEMS transducer with a fiber pigtailed on-chip Si microdisk optical cavity used to readout the motion of a mechanical oscillator probe. The SiN torsional oscillator can be excited by an electrical signal supplied to an integrated thermal actuator. The oscillator is evanescently coupled to a high-Q whispering gallery mode of the optical cavity and the motion is detected by measuring the resonance frequency shift of the mode. One side of the oscillator probe overhangs the edge of the chip, where it can be easily coupled to a variety of off-chip samples and physical systems of interest. A 10 um long probe is currently designed to have a stiffness of 1 N/m to 3 N/m and a resonance frequency of 100 kHz to 500 kHz, while the design can be easily and broadly tailored for specific sensing applications.

  10. Nonlinear all-optical switch based on a white-light cavity

    NASA Astrophysics Data System (ADS)

    Li, Na; Xu, Jingping; Song, Ge; Zhu, Chengjie; Xie, Shuangyuan; Yang, Yaping; Zubairy, M. Suhail; Zhu, Shi-Yao

    2016-04-01

    It is well known that there is a bottleneck for nonlinear all-optical switching, namely, the switching power and the switching time cannot be lowered simultaneously. A lower switching power requires a resonator with a high quality (Q ) factor, but leads to a longer switching time. We propose to overcome this bottleneck by replacing the nonlinear cavity in such an all-optical switch by a white-light cavity. This can be done by doping three-level atoms in the ring resonator and applying incoherent pump and coherent driving fields on it. The white-light cavity possesses broadband resonance in a linear region. Therefore, for the incident pulse, a broad range of frequency components can take part in the nonlinear process, and so it requires lower power to achieve switching compared to the conventional ring resonator. On the other hand, the refractive index of a white-light cavity has negative dispersion, leading to a fast group velocity. This results in a shorter time to build up the resonant response, yielding a short switching time.

  11. Scheme for generating the singlet state of three atoms trapped in distant cavities coupled by optical fibers

    SciTech Connect

    Wang, Dong-Yang; Wen, Jing-Ji; Bai, Cheng-Hua; Hu, Shi; Cui, Wen-Xue; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

    2015-09-15

    An effective scheme is proposed to generate the singlet state with three four-level atoms trapped in three distant cavities connected with each other by three optical fibers, respectively. After a series of appropriate atom–cavity interactions, which can be arbitrarily controlled via the selective pairing of Raman transitions and corresponding optical switches, a three-atom singlet state can be successfully generated. The influence of atomic spontaneous decay, photon leakage of cavities and optical fibers on the fidelity of the state is numerically simulated showing that the three-atom singlet state can be generated with high fidelity by choosing the experimental parameters appropriately.

  12. Generating and probing entangled states for optical atomic clocks

    NASA Astrophysics Data System (ADS)

    Braverman, Boris; Kawasaki, Akio; Vuletic, Vladan

    2016-05-01

    The precision of quantum measurements is inherently limited by projection noise caused by the measurement process itself. Spin squeezing and more complex forms of entanglement have been proposed as ways of surpassing this limitation. In our system, a high-finesse asymmetric micromirror-based optical cavity can mediate the atom-atom interaction necessary for generating entanglement in an 171 Yb optical lattice clock. I will discuss approaches for creating, characterizing, and optimally utilizing these nonclassical states for precision measurement, as well as recent progress toward their realization. This research is supported by DARPA QuASAR, NSF, and NSERC.

  13. Surface plasmon polaritons in a topological insulator embedded in an optical cavity

    NASA Astrophysics Data System (ADS)

    Li, L. L.; Xu, W.

    2014-03-01

    Very recently, the surface plasmons in a topological insulator (TI) have been experimentally observed by exciting these collective modes with polarized light [P. Di Pietro, M. Ortolani, O. Limaj, A. Di Gaspare, V. Giliberti, F. Giorgianni, M. Brahlek, N. Bansal, N. Koirala, S. Oh, P. Calvani, and S. Lupi, Nat. Nanotechnol. 8, 556 (2013)]. Motivated by this experimental work, here we present a theoretical study on the surface plasmon polaritons (SPPs) induced by plasmon-photon interactions in a TI thin film embedded in an optical cavity. It is found that the frequencies of SPP modes are within the terahertz (THz) bandwidth and can be tuned effectively by adjusting the surface electron density and/or the optical cavity length. Since the surface electron density can be well controlled by the gate-voltage applied perpendicular to the TI surface, our theoretical results indicate that gated TI thin films may have potential applications in the electrically tunable THz plasmonic devices.

  14. Passive intrinsic-linewidth narrowing of ultraviolet extended-cavity diode laser by weak optical feedback.

    PubMed

    Samutpraphoot, Polnop; Weber, Sophie; Lin, Qian; Gangloff, Dorian; Bylinskii, Alexei; Braverman, Boris; Kawasaki, Akio; Raab, Christoph; Kaenders, Wilhelm; Vuletić, Vladan

    2014-05-19

    We present a simple method for narrowing the intrinsic Lorentzian linewidth of a commercial ultraviolet grating extended-cavity diode laser (TOPTICA DL Pro) using weak optical feedback from a long external cavity. We achieve a suppression in frequency noise spectral density of 20 dB measured at frequencies around 1 MHz, corresponding to the narrowing of the intrinsic Lorentzian linewidth from 200 kHz to 2 kHz. Provided additional active low-frequency noise suppression and long-term drift compensation, the system is suitable for experiments requiring a tunable ultraviolet laser with narrow linewidth and low high-frequency noise, such as precision spectroscopy, optical clocks, and quantum information science experiments. PMID:24921280

  15. Curvature sensing using an added-signal in a fiber optic cavity ring-down system

    NASA Astrophysics Data System (ADS)

    Silva, Susana O.; Biswas, P.; Bandyopadhyay, S.; Jorge, P. A.; Marques, M. B.; Frazão, O.

    2015-09-01

    This work presents a fiber-optic Cavity Ring-Down (CRD) configuration using an added-signal for curvature sensing. An Optical Time-Domain Reflectometer (OTDR) was used to send impulses down into the fiber loop cavity, inside of which a long period grating (LPG) was placed to act as sensing device. The added-signal was obtained by the sum of several conventional CRD impulses, thus providing an improvement on the curvature sensitivity when compared to the conventional CRD signal processing. Sensitivity to applied curvature of 15.3 μs/m-1 was obtained. This result was found to be 20-fold the one obtained for the conventional CRD signal processing.

  16. Optical cavity characterization of the Tor Vergata Fabry-Pérot interferometer

    NASA Astrophysics Data System (ADS)

    Giovannelli, Luca; Berrilli, Francesco; Del Moro, Dario; Greco, Vincenzo; Piazzesi, Roberto; Sordini, Andrea; Stangalini, Marco

    2014-08-01

    We report the first optical and control performances of the Tor Vergata Fabry-Ṕerot interferometer prototype designed and realized in the framework of the ADvanced Astronomy for HELIophysics (ADAHELI) solar mission project. The characterization of the the coated surfaces of the two plates defining the optical cavity has been carried out with a Zygo interferometer able to measure the microroughness and global curvature of the cavity. The peak-to-valley errors are compliant with the manufacturer specifications and correspond to λ/70 and λ/80 @632.8 nm respectively. In addition, we present a first estimate of the interferometer spectral stability in stable open-air condition. A spectral uncertainty equal to 0.95 pm is found as the typical RMS over one hour of the passband central wavelength position.

  17. All-optical switching in silicon-on-insulator photonic wire nano-cavities.

    PubMed

    Belotti, Michele; Galli, Matteo; Gerace, Dario; Andreani, Lucio Claudio; Guizzetti, Giorgio; Md Zain, Ahmad R; Johnson, Nigel P; Sorel, Marc; De La Rue, Richard M

    2010-01-18

    We report on experimental demonstration of all-optical switching in a silicon-on-insulator photonic wire nanocavity operating at telecom wavelengths. The switching is performed with a control pulse energy as low as approximately 0.1 pJ on a cavity device that presents very high signal transmission, an ultra-high quality-factor, almost diffraction-limited modal volume and a footprint of only 5 microm(2). High-speed modulation of the cavity mode is achieved by means of optical injection of free carriers using a nanosecond pulsed laser. Experimental results are interpreted by means of finite-difference time-domain simulations. The possibility of using this device as a logic gate is also demonstrated. PMID:20173973

  18. Multiqubit controlled unitary gate by adiabatic passage with an optical cavity

    SciTech Connect

    Goto, Hayato; Ichimura, Kouichi

    2004-07-01

    A new implementation of quantum gates by adiabatic passage with an optical cavity is proposed. This implementation allows one to perform not only elementary gates, such as one-qubit gates and a controlled-NOT gate, but also multiqubit controlled unitary gates. Some quantum gates are numerically simulated. From the simulation results, it is concluded that this implementation of the three-qubit controlled gates is more efficient than decomposing into the elementary gates.

  19. Compact efficient eye-safe intracavity optical parametric oscillator with a shared cavity configuration

    SciTech Connect

    Chen, Y. F.; Su, K. W.; Chang, Y. T.; Yen, W. C

    2007-06-10

    We present a compact efficient eye-safe intracavity optical parametric oscillator pumpedby a passively Q-switched Nd:YAG laser in a shared cavity configuration. A signal pulse of 3.3 mJ energy at a 1573 nm wavelength with a peak power of150 kW was achieved. The effective conversion efficiency with respective to the optimized 1064 nm Q-switched pulse energy was as high as 51%.

  20. Design of high-Q polystyrene nonlinear cavity for ultrafast all-optical switching in mid-infrared photonic crystal slabs with cavity-waveguide structure

    NASA Astrophysics Data System (ADS)

    Fathollahi Khalkhali, T.; Rezaei, B.; Soltani Vala, A.; Kalafi, M.

    2014-09-01

    In this study, we design a nonlinear cavity with ultrafast response speed material in photonic crystal slabs for all-optical switching. We consider triangular lattice photonic crystal slab made from air holes in anisotropic Tellurium background which is on top of Teflon substrate. The cavity itself is then created by enlarging one of the air holes and infiltrating it with polystyrene. Optimization of structural parameters yields a single mode cavity with quality factor of Q=2.5×10, by using the three-dimensional finite-difference time-domain (FDTD) simulation and filter diagonalization approach. This shows great enhancement compared with previous studies in which organic polymer materials have been used. In order to study the coupling characteristic of cavity mode and waveguides, the nonlinear cavity is placed between two waveguides, symmetrically. At the end, we used the FDTD method to investigate shift magnitude of cavity mode resonance frequency under pump light. The designed structure can be helpful to achieve extremely fast response speed in all-optical switching devices with high efficiency in the mid-infrared wavelength range.

  1. Direct measurement of optical force induced by near-field plasmonic cavity using dynamic mode AFM

    SciTech Connect

    Guan, Dongshi; Hang, Zhi Hong; Marset, Zsolt; Liu, Hui; Kravchenko, Ivan I.; Chan, Ho Bun; Chan, C. T.; Tong, Penger

    2015-11-20

    Plasmonic nanostructures have attracted much attention in recent years because of their potential applications in optical manipulation through near-field enhancement. Continuing experimental efforts have been made to develop accurate techniques to directly measure the near-field optical force induced by the plasmonic nanostructures in the visible frequency range. In this work, we report a new application of dynamic mode atomic force microscopy (DM-AFM) in the measurement of the enhanced optical force acting on a nano-structured plasmonic resonant cavity. The plasmonic cavity is made of an upper gold-coated glass sphere and a lower quartz substrate patterned with an array of subwavelength gold disks. In the near-field when the sphere is positioned close to the disk array, plasmonic resonance is excited in the cavity and the induced force by a 1550 nm infrared laser is found to be increased by an order of magnitude compared with the photon pressure generated by the same laser light. Lastly, the experiment demonstrates that DM-AFM is a powerful tool for the study of light induced forces and their enhancement in plasmonic nanostructures.

  2. Direct measurement of optical force induced by near-field plasmonic cavity using dynamic mode AFM

    DOE PAGESBeta

    Guan, Dongshi; Hang, Zhi Hong; Marset, Zsolt; Liu, Hui; Kravchenko, Ivan I.; Chan, Ho Bun; Chan, C. T.; Tong, Penger

    2015-11-20

    Plasmonic nanostructures have attracted much attention in recent years because of their potential applications in optical manipulation through near-field enhancement. Continuing experimental efforts have been made to develop accurate techniques to directly measure the near-field optical force induced by the plasmonic nanostructures in the visible frequency range. In this work, we report a new application of dynamic mode atomic force microscopy (DM-AFM) in the measurement of the enhanced optical force acting on a nano-structured plasmonic resonant cavity. The plasmonic cavity is made of an upper gold-coated glass sphere and a lower quartz substrate patterned with an array of subwavelength goldmore » disks. In the near-field when the sphere is positioned close to the disk array, plasmonic resonance is excited in the cavity and the induced force by a 1550 nm infrared laser is found to be increased by an order of magnitude compared with the photon pressure generated by the same laser light. Lastly, the experiment demonstrates that DM-AFM is a powerful tool for the study of light induced forces and their enhancement in plasmonic nanostructures.« less

  3. Direct Measurement of Optical Force Induced by Near-Field Plasmonic Cavity Using Dynamic Mode AFM.

    PubMed

    Guan, Dongshi; Hang, Zhi Hong; Marcet, Zsolt; Liu, Hui; Kravchenko, I I; Chan, C T; Chan, H B; Tong, Penger

    2015-01-01

    Plasmonic nanostructures have attracted much attention in recent years because of their potential applications in optical manipulation through near-field enhancement. Continuing experimental efforts have been made to develop accurate techniques to directly measure the near-field optical force induced by the plasmonic nanostructures in the visible frequency range. In this work, we report a new application of dynamic mode atomic force microscopy (DM-AFM) in the measurement of the enhanced optical force acting on a nano-structured plasmonic resonant cavity. The plasmonic cavity is made of an upper gold-coated glass sphere and a lower quartz substrate patterned with an array of subwavelength gold disks. In the near-field when the sphere is positioned close to the disk array, plasmonic resonance is excited in the cavity and the induced force by a 1550 nm infrared laser is found to be increased by an order of magnitude compared with the photon pressure generated by the same laser light. The experiment demonstrates that DM-AFM is a powerful tool for the study of light induced forces and their enhancement in plasmonic nanostructures. PMID:26586455

  4. Direct Measurement of Optical Force Induced by Near-Field Plasmonic Cavity Using Dynamic Mode AFM

    PubMed Central

    Guan, Dongshi; Hang, Zhi Hong; Marcet, Zsolt; Liu, Hui; Kravchenko, I. I.; Chan, C. T.; Chan, H. B.; Tong, Penger

    2015-01-01

    Plasmonic nanostructures have attracted much attention in recent years because of their potential applications in optical manipulation through near-field enhancement. Continuing experimental efforts have been made to develop accurate techniques to directly measure the near-field optical force induced by the plasmonic nanostructures in the visible frequency range. In this work, we report a new application of dynamic mode atomic force microscopy (DM-AFM) in the measurement of the enhanced optical force acting on a nano-structured plasmonic resonant cavity. The plasmonic cavity is made of an upper gold-coated glass sphere and a lower quartz substrate patterned with an array of subwavelength gold disks. In the near-field when the sphere is positioned close to the disk array, plasmonic resonance is excited in the cavity and the induced force by a 1550 nm infrared laser is found to be increased by an order of magnitude compared with the photon pressure generated by the same laser light. The experiment demonstrates that DM-AFM is a powerful tool for the study of light induced forces and their enhancement in plasmonic nanostructures. PMID:26586455

  5. Temperature Sensitivity of an Atomic Vapor Cell-Based Dispersion-Enhanced Optical Cavity

    NASA Technical Reports Server (NTRS)

    Myneni, K.; Smith, D. D.; Chang, H.; Luckay, H. A.

    2015-01-01

    Enhancement of the response of an optical cavity to a change in optical path length, through the use of an intracavity fast-light medium, has previously been demonstrated experimentally and described theoretically for an atomic vapor cell as the intracavity resonant absorber. This phenomenon may be used to enhance both the scale factor and sensitivity of an optical cavity mode to the change in path length, e.g. in gyroscopic applications. We study the temperature sensitivity of the on-resonant scale factor enhancement, S(sub o), due to the thermal sensitivity of the lower-level atom density in an atomic vapor cell, specifically for the case of the Rb-87 D(sub 2) transition. A semi-empirical model of the temperature-dependence of the absorption profile, characterized by two parameters, a(sub o)(T) and gamma(sub a)(T) allows the temperature-dependence of the cavity response, S(sub o)(T) and dS(sub o)/dT to be predicted over a range of temperature. We compare the predictions to experiment. Our model will be useful in determining the useful range for S(sub o), given the practical constraints on temperature stability for an atomic vapor cell.

  6. Direct Measurement of Optical Force Induced by Near-Field Plasmonic Cavity Using Dynamic Mode AFM

    NASA Astrophysics Data System (ADS)

    Guan, Dongshi; Hang, Zhi Hong; Marcet, Zsolt; Liu, Hui; Kravchenko, I. I.; Chan, C. T.; Chan, H. B.; Tong, Penger

    2015-11-01

    Plasmonic nanostructures have attracted much attention in recent years because of their potential applications in optical manipulation through near-field enhancement. Continuing experimental efforts have been made to develop accurate techniques to directly measure the near-field optical force induced by the plasmonic nanostructures in the visible frequency range. In this work, we report a new application of dynamic mode atomic force microscopy (DM-AFM) in the measurement of the enhanced optical force acting on a nano-structured plasmonic resonant cavity. The plasmonic cavity is made of an upper gold-coated glass sphere and a lower quartz substrate patterned with an array of subwavelength gold disks. In the near-field when the sphere is positioned close to the disk array, plasmonic resonance is excited in the cavity and the induced force by a 1550 nm infrared laser is found to be increased by an order of magnitude compared with the photon pressure generated by the same laser light. The experiment demonstrates that DM-AFM is a powerful tool for the study of light induced forces and their enhancement in plasmonic nanostructures.

  7. Cold atoms in cavity QED for quantum information processing

    NASA Astrophysics Data System (ADS)

    Vernooy, David William

    2000-11-01

    The new field of quantum information science has exploded into virtually every area of modern physics because of the promise it holds for understanding physical limits to communication, computation and more generally the processing of information. Remarkably, this has come concomitantly with stunning successes at integrating laser cooling and trapping techniques with high finesse microresonators. A regime where some of the new theoretical ideas may be experimentally tested in the particular setting of cavity quantum electrodynamics (QED) has now been reached. This thesis contains three inter-related parts. First, work with microspheres as a possible next generation microcavity is presented, including both successful attempts to push the limits of their quality factors in the near infrared and first experimental results at atomic interaction with the mode of the sphere at the one-photon level. The unique properties of these resonators led to some theoretical investigations of the atom-field interaction emphasizing the quantization of the atomic center of mass degrees of freedom. This has been largely unexplored both theoretically and experimentally to this point, yet remains an extremely important aspect of most serious implementations of quantum information processing in the setting of optical cavity QED. Finally, the emphasis of the last part of this thesis is on an attempt at intracavity atomic localization in the laboratory. Results to date include the first ever trapping of single atoms inside a high finesse microresonator. The techniques and capabilities developed en route to this achievement should form the experimental backbone for future work in optical cavity QED.

  8. FINESSE: Field Investigations to Enable Solar System Science and Exploration

    NASA Technical Reports Server (NTRS)

    Heldmann, Jennifer; Lim, Darlene; Colaprete, Anthony

    2015-01-01

    The FINESSE (Field Investigations to Enable Solar System Science and Exploration) team is focused on a science and exploration field-based research program aimed at generating strategic knowledge in preparation for the human and robotic exploration of the Moon, near-Earth asteroids (NEAs) and Phobos and Deimos. We follow the philosophy that "science enables exploration and exploration enables science." 1) FINESSE Science: Understand the effects of volcanism and impacts as dominant planetary processes on the Moon, NEAs, and Phobos & Deimos. 2) FINESSE Exploration: Understand which exploration concepts of operations (ConOps) and capabilities enable and enhance scientific return. To accomplish these objectives, we are conducting an integrated research program focused on scientifically-driven field exploration at Craters of the Moon National Monument and Preserve in Idaho and at the West Clearwater Lake Impact Structure in northern Canada. Field deployments aimed at reconnaissance geology and data acquisition were conducted in 2014 at Craters of the Moon National Monument and Preserve. Targets for data acquisition included selected sites at Kings Bowl eruptive fissure, lava field and blowout crater, Inferno Chasm vent and outflow channel, North Crater lava flow and Highway lava flow. Field investigation included (1) differential GPS (dGPS) measurements of lava flows, channels (and ejecta block at Kings Bowl); (2) LiDAR imaging of lava flow margins, surfaces and other selected features; (3) digital photographic documentation; (4) sampling for geochemical and petrographic analysis; (5) UAV aerial imagery of Kings Bowl and Inferno Chasm features; and (6) geologic assessment of targets and potential new targets. Over the course of the 5-week field FINESSE campaign to the West Clearwater Impact Structure (WCIS) in 2014, the team focused on several WCIS research topics, including impactites, central uplift formation, the impact-generated hydrothermal system, multichronometer

  9. Stacked optical antennas for plasmon propagation in a 5 nm-confined cavity

    PubMed Central

    Saeed, A.; Panaro, S.; Zaccaria, R. Proietti; Raja, W.; Liberale, C.; Dipalo, M.; Messina, G. C.; Wang, H.; De Angelis, F.; Toma, A.

    2015-01-01

    The sub-wavelength concentration and propagation of electromagnetic energy are two complementary aspects of plasmonics that are not necessarily co-present in a single nanosystem. Here we exploit the strong nanofocusing properties of stacked optical antennas in order to highly concentrate the electromagnetic energy into a 5 nm metal-insulator-metal (MIM) cavity and convert free radiation into guided modes. The proposed nano-architecture combines the concentration properties of optical nanoantennas with the propagation capability of MIM systems, paving the way to highly miniaturized on-chip plasmonic waveguiding. PMID:26057661

  10. Imaging of hard- and soft-tissue structure in the oral cavity by optical coherence tomography

    SciTech Connect

    Colston, Bill W.; Everett, Mathew J.; Da Silva, Luiz B. Otis, Linda L. Stroeve, Pieter Nathel, Howard

    1998-06-01

    We have developed a prototype optical coherent tomography (OCT) system for the imaging of hard and soft tissue in the oral cavity. High-resolution images of {ital in vitro} porcine periodontal tissues have been obtained with this system. The images clearly show the enamel{endash}cementum and the gingiva{endash}tooth interfaces, indicating OCT is a potentially useful technique for diagnosis of periodontal diseases. To our knowledge, this is the first application of OCT for imaging biologic hard tissue. {copyright} 1998 Optical Society of America

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

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Liu, Yun-Feng; Jia, Chen; He, Xing-Dao

    2016-06-01

    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 red 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.

  12. Bridging the Gap between RF and Optical Patch Antenna Analysis via the Cavity Model.

    PubMed

    Unal, G S; Aksun, M I

    2015-01-01

    Although optical antennas with a variety of shapes and for a variety of applications have been proposed and studied, they are still in their infancy compared to their radio frequency (rf) counterparts. Optical antennas have mainly utilized the geometrical attributes of rf antennas rather than the analysis tools that have been the source of intuition for antenna engineers in rf. This study intends to narrow the gap of experience and intuition in the design of optical patch antennas by introducing an easy-to-understand and easy-to-implement analysis tool in rf, namely, the cavity model, into the optical regime. The importance of this approach is not only its simplicity in understanding and implementation but also its applicability to a broad class of patch antennas and, more importantly, its ability to provide the intuition needed to predict the outcome without going through the trial-and-error simulations with no or little intuitive guidance by the user. PMID:26522889

  13. Bridging the Gap between RF and Optical Patch Antenna Analysis via the Cavity Model

    PubMed Central

    Unal, G. S.; Aksun, M. I.

    2015-01-01

    Although optical antennas with a variety of shapes and for a variety of applications have been proposed and studied, they are still in their infancy compared to their radio frequency (rf) counterparts. Optical antennas have mainly utilized the geometrical attributes of rf antennas rather than the analysis tools that have been the source of intuition for antenna engineers in rf. This study intends to narrow the gap of experience and intuition in the design of optical patch antennas by introducing an easy-to-understand and easy-to-implement analysis tool in rf, namely, the cavity model, into the optical regime. The importance of this approach is not only its simplicity in understanding and implementation but also its applicability to a broad class of patch antennas and, more importantly, its ability to provide the intuition needed to predict the outcome without going through the trial-and-error simulations with no or little intuitive guidance by the user. PMID:26522889

  14. Bridging the Gap between RF and Optical Patch Antenna Analysis via the Cavity Model

    NASA Astrophysics Data System (ADS)

    Unal, G. S.; Aksun, M. I.

    2015-11-01

    Although optical antennas with a variety of shapes and for a variety of applications have been proposed and studied, they are still in their infancy compared to their radio frequency (rf) counterparts. Optical antennas have mainly utilized the geometrical attributes of rf antennas rather than the analysis tools that have been the source of intuition for antenna engineers in rf. This study intends to narrow the gap of experience and intuition in the design of optical patch antennas by introducing an easy-to-understand and easy-to-implement analysis tool in rf, namely, the cavity model, into the optical regime. The importance of this approach is not only its simplicity in understanding and implementation but also its applicability to a broad class of patch antennas and, more importantly, its ability to provide the intuition needed to predict the outcome without going through the trial-and-error simulations with no or little intuitive guidance by the user.

  15. Optically pumped GaN vertical cavity surface emitting laser with high index-contrast nanoporous distributed Bragg reflector.

    PubMed

    Lee, Seung-Min; Gong, Su-Hyun; Kang, Jin-Ho; Ebaid, Mohamed; Ryu, Sang-Wan; Cho, Yong-Hoon

    2015-05-01

    Laser operation of a GaN vertical cavity surface emitting laser (VCSEL) is demonstrated under optical pumping with a nanoporous distributed Bragg reflector (DBR). High reflectivity, approaching 100%, is obtained due to the high index-contrast of the nanoporous DBR. The VCSEL system exhibits low threshold power density due to the formation of high Q-factor cavity, which shows the potential of nanoporous medium for optical devices. PMID:25969197

  16. Bose–Einstein condensation versus Dicke–Hepp–Lieb transition in an optical cavity

    SciTech Connect

    Piazza, Francesco; Strack, Philipp; Zwerger, Wilhelm

    2013-12-15

    We provide an exact solution for the interplay between Bose–Einstein condensation and the Dicke–Hepp–Lieb self-organization transition of an ideal Bose gas trapped inside a single-mode optical cavity and subject to a transverse laser drive. Based on an effective action approach, we determine the full phase diagram at arbitrary temperature, which features a bi-critical point where the transitions cross. We calculate the dynamically generated band structure of the atoms and the associated suppression of the critical temperature for Bose–Einstein condensation in the phase with a spontaneous periodic density modulation. Moreover, we determine the evolution of the polariton spectrum due to the coupling of the cavity photons and the atomic field near the self-organization transition, which is quite different above or below the Bose–Einstein condensation temperature. At low temperatures, the critical value of the Dicke–Hepp–Lieb transition decreases with temperature and thus thermal fluctuations can enhance the tendency to a periodic arrangement of the atoms. -- Highlights: •Atoms inside a driven cavity can undergo two transitions: self-organization and BEC. •The phase diagram has four phases which coexist at a bi-critical point. •Atom–cavity coupling creates a dynamical lattice for the atoms. •Finite temperature can enhance the tendency towards self-organization. •We calculate the detailed spectrum of the polaritonic excitations.

  17. Feasibility of fiber optic displacement sensor scanning system for imaging of dental cavity

    NASA Astrophysics Data System (ADS)

    Rahman, Husna Abdul; Che Ani, Adi Izhar; Harun, Sulaiman Wadi; Yasin, Moh.; Apsari, Retna; Ahmad, Harith

    2012-07-01

    The purpose of this study is to investigate the potential of intensity modulated fiber optic displacement sensor scanning system for the imaging of dental cavity. Here, we discuss our preliminary results in the imaging of cavities on various teeth surfaces, as well as measurement of the diameter of the cavities which are represented by drilled holes on the teeth surfaces. Based on the analysis of displacement measurement, the sensitivities and linear range for the molar, canine, hybrid composite resin, and acrylic surfaces are obtained at 0.09667 mV/mm and 0.45 mm 0.775 mV/mm and 0.4 mm 0.5109 mV/mm and 0.5 mm and 0.25 mV/mm and 0.5 mm, respectively, with a good linearity of more than 99%. The results also show a clear distinction between the cavity and surrounding tooth region. The stability, simplicity of design, and low cost of fabrication make it suitable for restorative dentistry.

  18. Asymmetric tunable Fabry-Perot cavity using switchable polymer stabilized cholesteric liquid crystal optical Bragg mirror

    NASA Astrophysics Data System (ADS)

    Sathaye, Kedar S.; Dupont, Laurent; de Bougrenet de la Tocnaye, Jean-Louis

    2012-03-01

    Optical properties of an asymmetric Fabry-Perot (FP) cavity interferometer made up of a conventional metallic mirror and a polymer stabilized cholesteric liquid crystal (PSCLC) Bragg mirror have been investigated. The first FP cavity design comprises a gold mirror, an isotropic layer made up of the polymer glue, a quarter wave plate to convert the input linearly polarized modes into the circularly polarized modes inside the cavity, and the PSCLC Bragg mirror, all sandwiched between two indium tin oxide glass plates. The second FP cavity has a layer of conducting polymer deposited on the quarter-wave plate to apply the electric field only to the cholesteric stack. To have reflectivity above 95% in visible range we implement 30 layers of cholesteric liquid crystal in a planar Grandjean texture. The device compactness and the mirror parallelism due to the monolithic fabrication of FP are advantageous from the technical point of view. We test the FP tunability by shifting the resonance wavelength through an entire period; by applying electric field and/or by varying the temperature.

  19. Thermal radiation from optically driven Kerr (χ{sup (3)}) photonic cavities

    SciTech Connect

    Khandekar, Chinmay; Rodriguez, Alejandro W.; Lin, Zin

    2015-04-13

    We describe thermal radiation from nonlinear (χ{sup (3)}) photonic cavities coupled to external channels and subject to incident monochromatic light. Our work extends related work on nonlinear mechanical oscillators to the problem of thermal radiation, demonstrating that bistability can enhance thermal radiation by orders of magnitude and result in strong lineshape alternations, including “super-narrow spectral peaks” occurring at the onset of kinetic phase transitions. We show that when the cavities are designed to exhibit perfect linear emissivity (rate matching), such thermally activated transitions can be exploited to dramatically tune the output power and radiative properties of the cavity, leading to a kind of Kerr-mediated thermo-optic effect. Finally, we demonstrate that in certain parameter regimes, the output radiation exhibits Stokes and anti-Stokes side peaks whose relative magnitudes can be altered by tuning the internal temperature of the cavity relative to its surroundings, a consequence of strong correlations and interference between the emitted and reflected radiation.

  20. T-shaped cavity dual-frequency Nd:YAG laser with electro-optical modulation

    NASA Astrophysics Data System (ADS)

    Xing, Junhong; Jiao, Mingxing; Liu, Yun

    2016-05-01

    A T-shaped cavity dual-frequency Nd:YAG laser with electro-optical modulation is proposed, which consists of both p- and s-cavities sharing the same gain medium of Nd:YAG. Each cavity was not only able to select longitudinal mode but also tune frequency using an electro-optic birefringent filter polarization beam splitter + lithium niobate. The frequency difference of dual frequency was tuned through the whole gain bandwidth of Nd:YAG, which is far above the usually accepted free spectral range value in the case of a single-axis laser. As a result, the simultaneous operation of orthogonally and linearly polarized dual-frequency laser was obtained, which coincides with the theoretical analysis based on Jones matrices. The obtained frequency difference ranges from 0 to 132 GHz. This offers a simple and widely tunable source with potential for portable frequency reference applications in terahertz-wave generation and absolute-distance interferometry measurement areas.

  1. Hybridization of plasmonic antenna and cavity modes: Extreme optics of nanoparticle-on-mirror nanogaps

    NASA Astrophysics Data System (ADS)

    Tserkezis, C.; Esteban, R.; Sigle, D. O.; Mertens, J.; Herrmann, L. O.; Baumberg, J. J.; Aizpurua, J.

    2015-11-01

    The precise structural details of metallic nanogaps within optical antennae are found to dramatically modify the plasmonic response, producing a complex pattern of electromagnetic modes that can be directly observed in scattering experiments. We analyze this situation theoretically in the nanoparticle-on-mirror construct, which forms a plasmonic nanogap sensitive to even atomic-scale restructuring of nanoparticle morphology. We focus on the effect of nanoparticle faceting, which allows the formation of ultrathin cavities between the particle and the underlying metallic film in the nanoparticle-on-mirror geometry. Two different sets of modes are identified: longitudinal antenna modes, which are strongly radiative and excited for all facet width ranges, and transverse cavity modes produced at large facets and exhibiting extreme confinement. The interaction and hybridization of antenna and cavity modes is determined by their symmetry and the precise morphology of the nanogap edges. Understanding such complex optics from nanoparticle-on-mirror structures is important to elucidate a wide variety of emerging photochemical and optoelectronic processes.

  2. Nonlinear optical effects and Hong-Ou-Mandel interference in cavity quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Mirza, Imran M.; van Enk, Steven J.

    Pure quantum interference among single photons is one of the key ingredients to perform linear optics quantum computation (LOQC). The Hong-Ou-Mandel interference (HOMI) [C. K. Hong, Z. Y. Ou and L. Mandel, Phys. Rev. Lett. 59, (18), 2044-2046 (1987)] i.e. complete destructive interference between two identical and indistinguishable photons simultaneously entering input ports of a 50/50 beam splitter, is a well-known example in this context. In this talk, I'll present our theoretical study of HOMI in a coupled Jaynes-Cummings array. In particular and by applying quantum jump/trajectory formalism, I'll focus on how partial quantum interference between two photons survive both non-linearities produced by two-level emitter and spectral filtering due to optical cavities in our coupled cavity array setup [Imran M. Mirza and Steven J. van Enk, Opt. Comm. 343, 172-177 (2015)]. Along with LOQC, this work is crucial from the perspective of exploiting coupled cavity arrays to store single photons reliably (without altering their temporal and spectral traits) [Imran M. Mirza, Steven J. van Enk and Jeff Kimble, JOSA B, 10, 2640-2649, (2013)].

  3. Mirror Birefringence in a Fabry-Perot Cavity and the Detection of Vacuum Birefringence in a Magnetic Field

    NASA Technical Reports Server (NTRS)

    Chui, T. C. P.; Shao, M.; Redding, D.; Gursel, Y.; Boden, A.

    1995-01-01

    We discuss the effect of mirror birefringence in two optical schemes designed to detect the quantum-electrodynamics (QED) predictions of vacuum birefringence under the influence of a strong magnetic field, B. Both schemes make use of a high finesse Fabry-Perot cavity (F-P) to increase the average path length of the light in the magnetic field. The first scheme, which we called the frequency scheme, is based on measurement of the beat frequency of two orthogonal polarized laser beams in the cavity. We show that mirror birefringence contributes to the detection uncertainties in first order, resulting in a high susceptibility to small thermal disturbances. We estimate that an unreasonably high thermal stability of 10-9 K is required to resolve the effect to 0.1%. In the second scheme, which we called the polarization rotation scheme, laser polarized at 45 relative to the B field is injected into the cavity.

  4. Nanofiber-based all-optical switches

    NASA Astrophysics Data System (ADS)

    Le Kien, Fam; Rauschenbeutel, A.

    2016-01-01

    We study all-optical switches operating on a single four-level atom with the N -type transition configuration in a two-mode nanofiber cavity with a significant length (on the order of 20 mm) and a moderate finesse (on the order of 300) under the electromagnetically induced transparency (EIT) conditions. In our model, the gate and probe fields are the quantum nanofiber-cavity fields excited by weak classical light pulses, and the parameters of the D2 line of atomic cesium are used. We examine two different switching schemes. The first scheme is based on the effect of the presence of a photon in the gate mode on the EIT of the probe mode. The second scheme is based on the use of EIT to store a photon of the gate mode in the population of an appropriate atomic level, which leads to the reduction of the transmission of the field in the probe mode. We investigate the dependencies of the switching contrast on various parameters, such as the cavity length, the mirror reflectivity, and the detunings and powers of the cavity driving field pulses. For a nanofiber cavity with fiber radius of 250 nm, cavity length of 20 mm, and cavity finesse of 313 and a cesium atom at a distance of 200 nm from the fiber surface, we numerically obtain a switching contrast on the order of about 67% for the first scheme and of about 95% for the second scheme. These switching operations require small mean numbers of photons in the nanofiber cavity gate and probe modes.

  5. Polarized optical injection in long-wavelength vertical-cavity surface emitting lasers

    NASA Astrophysics Data System (ADS)

    Hurtado, A.; Schires, K.; Khan, N.; Al-Seyab, R.; Henning, I. D.; Adams, M. J.

    2011-05-01

    We report a comprehensive study of the effects of polarized optical injection in long-wavelength Vertical-Cavity Surface Emitting Lasers (LW-VCSELs) emitting at the telecom wavelength of 1550nm. We analyze the properties of the polarization switching and bistability that can be induced in a 1550nm-VCSEL under orthogonal and arbitrary polarized optical injection. Additionally, we study the injection locking bandwidth of these devices when subject to different polarized optical injection. Furthermore, we also analyze the relationship existing between the injection locking bandwidth and the polarization switching range when the device is subject to orthogonally-polarized optical injection. Finally, we have identified regions of different nonlinear dynamics outside the injection locking bandwidth, including regions of periodic dynamics (such as limit cycle and period doubling) and chaos when these devices are subject to parallel and to orthogonal optical injection. This rich variety of nonlinear effects observed at 1550nm offers exciting prospects for novel practical uses of VCSELs in optical switching/routing applications in optical networks.

  6. Electric-optic resonant phase modulator

    NASA Technical Reports Server (NTRS)

    Chen, Chien-Chung (Inventor); Robinson, Deborah L. (Inventor); Hemmati, Hamid (Inventor)

    1994-01-01

    An electro-optic resonant cavity is used to achieve phase modulation with lower driving voltages. Laser damage thresholds are inherently higher than with previously used integrated optics due to the utilization of bulk optics. Phase modulation is achieved at higher speeds with lower driving voltages than previously obtained with non-resonant electro-optic phase modulators. The instant scheme uses a data locking dither approach as opposed to the conventional sinusoidal locking schemes. In accordance with a disclosed embodiment, a resonant cavity modulator has been designed to operate at a data rate in excess of 100 Mbps. By carefully choosing the cavity finesse and its dimension, it is possible to control the pulse switching time to within 4 ns and to limit the required switching voltage to within 10 V. Experimentally, the resonant cavity can be maintained on resonance with respect to the input laser signal by monitoring the fluctuation of output intensity as the cavity is switched. This cavity locking scheme can be applied by using only the random data sequence, and without the need of additional dithering of the cavity. Compared to waveguide modulators, the resonant cavity has a comparable modulating voltage requirement. Because of its bulk geometry, resonant cavity modulator has the potential of accommodating higher throughput power. Furthermore, mode matching into a bulk device is easier and typically can be achieved with higher efficiency. On the other hand, unlike waveguide modulators which are essentially traveling wave devices, the resonant cavity modulator requires that the cavity be maintained in resonance with respect to the incoming laser signal. An additional control loop is incorporated into the modulator to maintain the cavity on resonance.

  7. High-Q silicon photonic crystal cavity for enhanced optical nonlinearities

    SciTech Connect

    Dharanipathy, Ulagalandha Perumal; Tonin, Mario; Houdré, Romuald; Minkov, Momchil Savona, Vincenzo

    2014-09-08

    We fabricate and experimentally characterize an H0 photonic crystal slab nanocavity with a design optimized for maximal quality factor, Q = 1.7 × 10{sup 6}. The cavity, fabricated from a silicon slab, has a resonant mode at λ = 1.59 μm and a measured Q-factor of 400 000. It displays nonlinear effects, including high-contrast optical bistability, at a threshold power among the lowest ever reported for a silicon device. With a theoretical modal volume as small as V = 0.34(λ/n){sup 3}, this cavity ranks among those with the highest Q/V ratios ever demonstrated, while having a small footprint suited for integration in photonic circuits.

  8. Tuning all-Optical Analog to Electromagnetically Induced Transparency in nanobeam cavities using nanoelectromechanical system

    PubMed Central

    Shi, Peng; Zhou, Guangya; deng, Jie; Tian, Feng; Chau, Fook Siong

    2015-01-01

    We report the observations of all-optical electromagnetically induced transparency in nanostructures using waveguide side-coupled with photonic crystal nanobeam cavities, which has measured linewidths much narrower than individual resonances. The quality factor of transparency resonance can be 30 times larger than those of measured individual resonances. When the gap between cavity and waveguide is reduced to 10 nm, the bandwidth of destructive interference region can reach 10 nm while the width of transparency resonance is 0.3 nm. Subsequently, a comb-drive actuator is introduced to tune the line shape of the transparency resonance. The width of the peak is reduced to 15 pm and the resulting quality factor exceeds 105. PMID:26415907

  9. Fully referenced single-comb interferometry using optical sampling by laser-cavity tuning.

    PubMed

    Potvin, Simon; Boudreau, Sylvain; Deschênes, Jean-Daniel; Genest, Jérôme

    2013-01-10

    The correction of setup and laser instabilities in a single-comb interferometric measurement using optical sampling by laser-cavity tuning is investigated. A two-reference solution that allows full correction of the interferogram is presented. The technique is compared to a slightly simpler one-reference correction. For the one-reference case, all the subtleties involved in this partial correction and the dependence between the achievable measurement accuracy and the setup parameters are highlighted. The parameters considered are the comb bandwidth, the laser-frequency noise, the required spectral resolution, the cavity scan speed, and the length of the delay line. For both referencing approaches, experimental results using a fiber delay line of 10 km and a 100 MHz mode-locked laser with its repetition rate swept at 500 Hz are shown. PMID:23314642

  10. Cavity quantum optomechanics of ultracold atoms in an optical lattice: Normal-mode splitting

    SciTech Connect

    Bhattacherjee, Aranya B.

    2009-10-15

    We consider the dynamics of a movable mirror (cantilever) of a cavity coupled through radiation pressure to the light scattered from ultracold atoms in an optical lattice. Scattering from different atomic quantum states creates different quantum states of the scattered light, which can be distinguished by measurements of the displacement spectrum of the cantilever. We show that for large pump intensities the steady-state displacement of the cantilever shows bistable behavior. Due to atomic back action, the displacement spectrum of the cantilever is modified and depends on the position of the condensate in the Brillouin zone. We further analyze the occurrence of splitting of the normal mode into three modes due to mixing of the mechanical motion with the fluctuations of the cavity field and the fluctuations of the condensate with finite atomic two-body interaction.

  11. Design and analysis of photonic crystal micro-cavity based optical sensor platform

    NASA Astrophysics Data System (ADS)

    Goyal, Amit Kumar; Dutta, Hemant Sankar; Pal, Suchandan

    2016-04-01

    In this paper, the design of a two-dimensional photonic crystal micro-cavity based integrated-optic sensor platform is proposed. The behaviour of designed cavity is analyzed using two-dimensional Finite Difference Time Domain (FDTD) method. The structure is designed by deliberately inserting some defects in a photonic crystal waveguide structure. Proposed structure shows a quality factor (Q) of about 1e5 and the average sensitivity of 500nm/RIU in the wavelength range of 1450 - 1580 nm. Sensing technique is based on the detection of shift in upper-edge cut-off wavelength for a reference signal strength of -10 dB in accordance with the change in refractive index of analyte.

  12. Cavity-dumped femtosecond optical parametric oscillator based on periodically poled stoichiometric lithium tantalate

    NASA Astrophysics Data System (ADS)

    Yoon, E.; Joo, T.

    2016-03-01

    A synchronously pumped cavity-dumped femtosecond optical parametric oscillator (OPO) based on a periodically poled stoichiometric lithium tantalate (PPSLT) crystal is reported. The OPO runs in positive group velocity dispersion (GVD) mode to deliver high pulse energy at high repetition rate. It delivers pulse energy over 130 nJ up to 500 kHz and 70 nJ at 1 MHz of repetition rate at 1100 nm. Pulse duration is as short as 42 fs, and the OPO is tunable in the near infrared region from 1050 to 1200 nm. Dispersion property of the OPO was also explored. The cavity-dumped output carries a positive GVD, which can be compensated easily by an external prism pair, and large negative third order dispersion (TOD), which results in a pedestal in the pulse shape. Approaches to obtain clean pulse shape by reducing the large TOD are proposed.

  13. Direct generation of optical frequency combs in χ(2) nonlinear cavities

    NASA Astrophysics Data System (ADS)

    Mosca, Simona; Ricciardi, Iolanda; Parisi, Maria; Maddaloni, Pasquale; Santamaria, Luigi; De Natale, Paolo; De Rosa, Maurizio

    2016-06-01

    Quadratic nonlinear processes are currently exploited for frequency comb transfer and extension from the visible and near infrared regions to other spectral ranges where direct comb generation cannot be accomplished. However, frequency comb generation has been directly observed in continuously pumped quadratic nonlinear crystals placed inside an optical cavity. At the same time, an introductory theoretical description of the phenomenon has been provided, showing a remarkable analogy with the dynamics of third-order Kerr microresonators. Here, we give an overview of our recent work on χ(2) frequency comb generation. Furthermore, we generalize the preliminary three-wave spectral model to a many-mode comb and present a stability analysis of different cavity field regimes. Although our work is a very early stage, it lays the groundwork for a novel class of highly efficient and versatile frequency comb synthesizers based on second-order nonlinear materials.

  14. Quantum simulation of 2D topological physics in a 1D array of optical cavities

    PubMed Central

    Luo, Xi-Wang; Zhou, Xingxiang; Li, Chuan-Feng; Xu, Jin-Shi; Guo, Guang-Can; Zhou, Zheng-Wei

    2015-01-01

    Orbital angular momentum of light is a fundamental optical degree of freedom characterized by unlimited number of available angular momentum states. Although this unique property has proved invaluable in diverse recent studies ranging from optical communication to quantum information, it has not been considered useful or even relevant for simulating nontrivial physics problems such as topological phenomena. Contrary to this misconception, we demonstrate the incredible value of orbital angular momentum of light for quantum simulation by showing theoretically how it allows to study a variety of important 2D topological physics in a 1D array of optical cavities. This application for orbital angular momentum of light not only reduces required physical resources but also increases feasible scale of simulation, and thus makes it possible to investigate important topics such as edge-state transport and topological phase transition in a small simulator ready for immediate experimental exploration. PMID:26145177

  15. Dynamics of a low-threshold optically pumped organic vertical-cavity surface-emitting laser

    NASA Astrophysics Data System (ADS)

    Shayesteh, Mohammad Reza; Darvish, Ghafar

    2016-06-01

    We propose a low-threshold optically pumped organic vertical-cavity surface-emitting laser (OVCSEL). This device has the capability to apply both electrical and optical excitation. The microcavity structure consists of an organic light emitting diode with field-effect electron transport inserted in a high-quality factor double distributed Bragg reflector. The simulated quality factor of the microcavity is shown to be as high as 16,000. Also, we investigate threshold behaviour and the dynamics of the optically pumped OVCSEL with sub-picosecond pulses. Results from numerical simulation show that lasing threshold is 12.8 pJ/0.64 µJ cm-2 when pumped by sub-picosecond pulses of λ = 400 nm wavelength light.

  16. Coherent Optical Frequency Domain Reflectometry (OFDR) using a fiber grating external cavity laser

    NASA Astrophysics Data System (ADS)

    Huang, Kao-Yang; Carter, Gary M.

    1994-12-01

    An optical frequency domain reflectometry (OFDR) system containing a narrow linewidth fiber grating external cavity laser is demonstrated to have 62-dB of sensitivity when detecting Fresnel backreflection and 2 m of resolution at a 115 m range in optical fiber. With this system we were able to detect Rayleigh backscattering in optical fiber with 20-dB signal-to-noise ratio. The phase noise limitation on the distance range for the OFDR was investigated, and the measured signal-to-noise ratio (SNR) data followed the theoretical simulation over the ranges measured. This technique has potential to be applied to the OFDR at 1550 nm with very high dynamic range by using an erbium doped fiber laser.

  17. Rydberg-induced optical nonlinearities from a cold atomic ensemble trapped inside a cavity

    NASA Astrophysics Data System (ADS)

    Boddeda, R.; Usmani, I.; Bimbard, E.; Grankin, A.; Ourjoumtsev, A.; Brion, E.; Grangier, P.

    2016-04-01

    We experimentally characterize the optical nonlinear response of a cold atomic medium placed inside an optical cavity, and excited to Rydberg states. The excitation to S and D Rydberg levels is carried out via a two-photon transition in an electromagnetically induced transparency configuration, with a weak (red) probe beam on the lower transition, and a strong (blue) coupling beam on the upper transition. The observed optical nonlinearities induced by S states for the probe beam can be explained using a semi-classical model with van der Waals’ interactions. For the D states, it appears necessary to take into account a dynamical decay of Rydberg excitations into a long-lived dark state. We show that the measured nonlinearities can be explained by using a Rydberg bubble model with a dynamical decay.

  18. Optical Phased Array Antennas using Coupled Vertical Cavity Surface Emitting Lasers

    NASA Technical Reports Server (NTRS)

    Mueller, Carl H.; Rojas, Roberto A.; Nessel, James A.; Miranda, Felix A.

    2007-01-01

    High data rate communication links are needed to meet the needs of NASA as well as other organizations to develop space-based optical communication systems. These systems must be robust to high radiation environments, reliable, and operate over a wide temperature range. Highly desirable features include beam steering capability, reconfigurability, low power consumption, and small aperture size. Optical communication links, using coupled vertical cavity surface emitting laser radiating elements are promising candidates for the transmit portion of these communication links. In this talk we describe a mission scenario, and how the antenna requirements are derived from the mission needs. We describe a potential architecture for this type of antenna, and outline the advantages and drawbacks of this approach relative to competing technologies. The technology we are proposing used coupled arrays of 1550 nm vertical cavity surface emitting lasers for transmission. The feasibility of coupling these arrays together, to form coherent high-power beams that can be modulated at data rates exceeding 1 Gbps, will be explored. We will propose an architecture that enables electronic beam steering, thus mitigating the need for ancillary acquisition, tracking and beam pointing equipment such as needed for current optical communicatin systems. The beam-steering capability we are proposing also opens the possibility of using this technology for inter-satellite communicatin links, and satellite-to-surface links.

  19. Short cavity active mode locking fiber laser for optical sensing and imaging

    NASA Astrophysics Data System (ADS)

    Lee, Hwi Don; Han, Ga Hee; Jeong, Syung Won; Jeong, Myung Yung; Kim, Chang-Seok; Shin, Jun Geun; Lee, Byeong Ha; Eom, Tae Joong

    2014-05-01

    We demonstrate a highly linear wavenumber- swept active mode locking (AML) fiber laser for optical sensing and imaging without any wavenumber-space resampling process. In this all-electric AML wavenumber-swept mechanism, a conventional wavelength selection filter is eliminated and, instead, the suitable programmed electric modulation signal is directly applied to the gain medium. Various types of wavenumber (or wavelength) tunings can be implemented because of the filter-less cavity configuration. Therefore, we successfully demonstrate a linearly wavenumber-swept AML fiber laser with 26.5 mW of output power to obtain an in-vivo OCT image at the 100 kHz swept rate.

  20. Chiral symmetry breaking in a microring optical cavity by engineered dissipation

    NASA Astrophysics Data System (ADS)

    Shu, Fang-Jie; Zou, Chang-Ling; Zou, Xu-Bo; Yang, Lan

    2016-07-01

    We propose a method to break the chiral symmetry of light in traveling wave resonators by coupling the optical modes to a lossy channel. Through the engineered dissipation, an indirect dissipative coupling between two oppositely propagating modes can be realized. Combined with reactive coupling, it can break the chiral symmetry of the resonator, allowing light propagating only in one direction. The chiral symmetry breaking is numerically verified by the simulation of an electromagnetic field in a microring cavity, with proper refractive index distributions. This work provokes us to emphasize the dissipation engineering in photonics, and that the generalized idea can also be applied to other systems.

  1. All-optical flip-flop operation based on bistability in V-cavity laser.

    PubMed

    Wu, Yingchen; Zhu, Yu; Liao, Xiaolu; Meng, Jianjun; He, Jian-Jun

    2016-06-13

    We theoretically analyzed and experimentally demonstrated an injection-locking based all-optical flip-flop memory using a simple and compact tunable V-cavity laser (VCL). A bistable region in the tuning characteristics of the VCL is employed for the flip-flop operation. The state of the VCL can be set and reset by injecting signal pulses at two different wavelengths. The pulse power for both set and reset signal is only about 1 pJ. Short response times of about 150 ps are measured for storing and erasing. PMID:27410271

  2. Spectral engineering by flexible tunings of optical Tamm states and Fabry-Perot cavity resonance.

    PubMed

    Zhang, Xu-Lin; Song, Jun-Feng; Feng, Jing; Sun, Hong-Bo

    2013-11-01

    We present a design for spectral engineering in a metal dual distributed Bragg reflector (DBR)-based structure. Optical Tamm states and Fabry-Perot cavity mode, dual windows for light-matter interaction enhancement, can be excited simultaneously and tuned flexibly, including their respective bandwidth and resonant wavelength, due to the variable reflection phase from the outer DBR's internal surface. The design can find applications in solar cells for light trappings. Via calculations of overall absorptivity, the proposed simpler dual-states-based scheme is demonstrated to be almost as effective as the coherent-light-trapping scheme, owing to the dual-states-induced broader-band absorption enhancement. PMID:24177099

  3. Evanescent-wave and ambient chiral sensing by signal-reversing cavity ringdown polarimetry

    NASA Astrophysics Data System (ADS)

    Sofikitis, Dimitris; Bougas, Lykourgos; Katsoprinakis, Georgios E.; Spiliotis, Alexandros K.; Loppinet, Benoit; Rakitzis, T. Peter

    2014-10-01

    Detecting and quantifying chirality is important in fields ranging from analytical and biological chemistry to pharmacology and fundamental physics: it can aid drug design and synthesis, contribute to protein structure determination, and help detect parity violation of the weak force. Recent developments employ microwaves, femtosecond pulses, superchiral light or photoionization to determine chirality, yet the most widely used methods remain the traditional methods of measuring circular dichroism and optical rotation. However, these signals are typically very weak against larger time-dependent backgrounds. Cavity-enhanced optical methods can be used to amplify weak signals by passing them repeatedly through an optical cavity, and two-mirror cavities achieving up to 105 cavity passes have enabled absorption and birefringence measurements with record sensitivities. But chiral signals cancel when passing back and forth through a cavity, while the ubiquitous spurious linear birefringence background is enhanced. Even when intracavity optics overcome these problems, absolute chirality measurements remain difficult and sometimes impossible. Here we use a pulsed-laser bowtie cavity ringdown polarimeter with counter-propagating beams to enhance chiral signals by a factor equal to the number of cavity passes (typically >103) to suppress the effects of linear birefringence by means of a large induced intracavity Faraday rotation; and to effect rapid signal reversals by reversing the Faraday rotation and subtracting signals from the counter-propagating beams. These features allow absolute chiral signal measurements in environments where background subtraction is not feasible: we determine optical rotation from α-pinene vapour in open air, and from maltodextrin and fructose solutions in the evanescent wave produced by total internal reflection at a prism surface. The limits of the present polarimeter, when using a continuous-wave laser locked to a stable, high-finesse cavity

  4. High-sensitivity optical monitoring of a micromechanical resonator with a quantum-limited optomechanical sensor.

    PubMed

    Arcizet, O; Cohadon, P-F; Briant, T; Pinard, M; Heidmann, A; Mackowski, J-M; Michel, C; Pinard, L; Français, O; Rousseau, L

    2006-09-29

    We experimentally demonstrate the high-sensitivity optical monitoring of a micromechanical resonator and its cooling by active control. Coating a low-loss mirror upon the resonator, we have built an optomechanical sensor based on a very high-finesse cavity (30 000). We have measured the thermal noise of the resonator with a quantum-limited sensitivity at the 10(-19) m/sqrt[Hz] level, and cooled the resonator down to 5 K by a cold-damping technique. Applications of our setup range from quantum optics experiments to the experimental demonstration of the quantum ground state of a macroscopic mechanical resonator. PMID:17026032

  5. Quantitative determination of the O({sup 3}P) density via visible cavity-enhanced spectroscopy

    SciTech Connect

    Gupta, Manish; Owano, Thomas; Baer, Douglas; O'Keefe, Anthony

    2006-12-11

    A simple method has been developed to quantitatively measure the ground state oxygen atom, O({sup 3}P), density. The technique exploits cavity-enhanced spectroscopy to probe the relatively weak O({sup 1}D)(leftarrow)O({sup 3}P{sub 1}) transition near 636 nm. O({sup 3}P{sub 1}) densities of approximately 3.4x10{sup 14} at./cm{sup 3} were measured in an inductively coupled plasma produced within a high-finesse optical cavity, and a minimum detectable atom state density of 1.3x10{sup 12} at./cm{sup 3} was determined. The absorption profile yielded a translational temperature of 453 K. The technique can be readily extended to other atomic species.

  6. Numerical studies of the fluid and optical fields associated with complex cavity flows

    NASA Technical Reports Server (NTRS)

    Atwood, Christopher A.

    1992-01-01

    Numerical solutions for the flowfield about several cavity configurations have been computed using the Reynolds averaged Navier-Stokes equations. Comparisons between numerical and experimental results are made in two dimensions for free shear layers and a rectangular cavity, and in three dimensions for the transonic aero-window problem of the Stratospheric Observatory for Infrared Astronomy (SOFIA). Results show that dominant acoustic frequencies and magnitudes of the self excited resonant cavity flows compare well with the experiment. In addition, solution sensitivity to artificial dissipation and grid resolution levels are determined. Optical path distortion due to the flow field is modelled geometrically and is found to match the experiment. The fluid field was computed using a diagonalized scheme within an overset mesh framework. An existing code, OVERFLOW, was utilized with the additions of characteristic boundary condition and output routines required for reduction of the unsteady data. The newly developed code is directly applicable to a generalized three dimensional structured grid zone. Details are provided in a paper included in Appendix A.

  7. Ionizing Radiation Detectors Based on Ge-Doped Optical Fibers Inserted in Resonant Cavities

    PubMed Central

    Avino, Saverio; D’Avino, Vittoria; Giorgini, Antonio; Pacelli, Roberto; Liuzzi, Raffaele; Cella, Laura; De Natale, Paolo; Gagliardi, Gianluca

    2015-01-01

    The measurement of ionizing radiation (IR) is a crucial issue in different areas of interest, from environmental safety and industrial monitoring to aerospace and medicine. Optical fiber sensors have recently proven good candidates as radiation dosimeters. Here we investigate the effect of IR on germanosilicate optical fibers. A piece of Ge-doped fiber enclosed between two fiber Bragg gratings (FBGs) is irradiated with gamma radiation generated by a 6 MV medical linear accelerator. With respect to other FBG-based IR dosimeters, here the sensor is only the bare fiber without any special internal structure. A near infrared laser is frequency locked to the cavity modes for high resolution measurement of radiation induced effects on the fiber optical parameters. In particular, we observe a variation of the fiber thermo-optic response with the radiation dose delivered, as expected from the interaction with Ge defect centers, and demonstrate a detection limit of 360 mGy. This method can have an impact in those contexts where low radiation doses have to be measured both in small volumes or over large areas, such as radiation therapy and radiation protection, while bare optical fibers are cheap and disposable. PMID:25686311

  8. Ionizing radiation detectors based on Ge-doped optical fibers inserted in resonant cavities.

    PubMed

    Avino, Saverio; D'Avino, Vittoria; Giorgini, Antonio; Pacelli, Roberto; Liuzzi, Raffaele; Cella, Laura; De Natale, Paolo; Gagliardi, Gianluca

    2015-01-01

    The measurement of ionizing radiation (IR) is a crucial issue in different areas of interest, from environmental safety and industrial monitoring to aerospace and medicine. Optical fiber sensors have recently proven good candidates as radiation dosimeters. Here we investigate the effect of IR on germanosilicate optical fibers. A piece of Ge-doped fiber enclosed between two fiber Bragg gratings (FBGs) is irradiated with gamma radiation generated by a 6 MV medical linear accelerator. With respect to other FBG-based IR dosimeters, here the sensor is only the bare fiber without any special internal structure. A near infrared laser is frequency locked to the cavity modes for high resolution measurement of radiation induced effects on the fiber optical parameters. In particular, we observe a variation of the fiber thermo-optic response with the radiation dose delivered, as expected from the interaction with Ge defect centers, and demonstrate a detection limit of 360 mGy. This method can have an impact in those contexts where low radiation doses have to be measured both in small volumes or over large areas, such as radiation therapy and radiation protection, while bare optical fibers are cheap and disposable. PMID:25686311

  9. Plasmonic crystal cavity on single-mode optical fiber end facet for label-free biosensing

    NASA Astrophysics Data System (ADS)

    He, Xiaolong; Yi, Hui; Long, Jing; Zhou, Xin; Yang, Jie; Yang, Tian

    2016-06-01

    Surface plasmon resonance (SPR) devices on single-mode optical fiber (SMF) end facets are desired for label-free biosensing, due to flexible light delivery, in vivo inspection capability, and seamless integration with fiber-optic communication techniques. We report a plasmonic crystal cavity structure that has a steep resonance near the plasmonic bandedge, a fabrication process to efficiently transfer and align the structure onto a bare SMF end facet, and characterization of its sensing performance. With a sensitivity of 571 nm RIU-1, a figure of merit of 68 RIU-1 and a real-time refractive index detection limit of 3.5 × 10-6 RIU, our sensors can be readily applied in common SPR biosensing experiments. They are over an order of magnitude more sensitive than reported modified-end multimode fiber SPR devices, while there are no reports on previous SMF end facet devices' detection limits which have very low figures of merit.

  10. Observation of Noise-Assisted Transport in an All-Optical Cavity-Based Network

    NASA Astrophysics Data System (ADS)

    Viciani, Silvia; Lima, Manuela; Bellini, Marco; Caruso, Filippo

    2015-08-01

    Recent theoretical and experimental efforts have shown the remarkable and counterintuitive role of noise in enhancing the transport efficiency of complex systems. Here, we realize simple, scalable, and controllable optical fiber cavity networks that allow us to analyze the performance of transport networks for different conditions of interference, dephasing, and disorder. In particular, we experimentally demonstrate that the transport efficiency reaches a maximum when varying the external dephasing noise, i.e., a bell-like shape behavior that had been predicted only theoretically. These optical platforms are very promising simulators of quantum transport phenomena and could be used, in particular, to design and test optimal topologies of artificial light-harvesting structures for future solar energy technologies.

  11. Cavity enhancement of the magneto-optical Kerr effect of a magnetic cobalt nanowires array

    NASA Astrophysics Data System (ADS)

    Moradi, Mehrdad; Ghanaatshoar, Majid

    2016-01-01

    In this paper, the optimization and amplification of magneto-optical (MO) response of Silicon (Si)/Cobalt (Co)-nanowires (NWs) in the presence of zinc sulphide (ZnS) and SiO2 thin layers were investigated. The existence of ZnS layer with ideal thickness on the Si/Co structure, leads to an appropriate optical cavity which amplifies the MO Kerr signal (KS). In addition, the capping layer, SiO2, which is useful in manufacturing process, acts as a complementary layer for ZnS layer. The proposed structure Si/Co/ZnS/SiO2 with appropriate thicknesses enhances the KS of Si/Co-nanowire up to 20 times relative to same structure without covering layers.

  12. Transient optical parametric oscillations in resonantly pumped multistable cavity polariton condensates

    NASA Astrophysics Data System (ADS)

    Brichkin, A. S.; Tikhodeev, S. G.; Gavrilov, S. S.; Gippius, N. A.; Novikov, S. I.; Larionov, A. V.; Schneider, C.; Kamp, M.; Höfling, S.; Kulakovskii, V. D.

    2015-09-01

    Transitional processes accompanying switches between steady states in multistable cavity polariton systems are studied experimentally in a low-symmetry high-Q microcavity under resonant optical excitation at normal incidence. We show that the establishment of a high-energy polariton state is influenced by an optical parametric oscillation. Therefore, the emission spectrum reveals the energy-separated signal-idler pairs in both spin components. Accordingly, the time dependencies of the polariton emission exhibit oscillations whose periods correspond to the spectral positions of the scattered states. Thus, the sharp transitions between the steady states of a no-equilibrium polariton condensate enable one to visualize the near-condensate eigenmodes and explore their spectral and spin properties depending on the condensate amplitude and average spin.

  13. [Research on trace gas spectral measurement on intra-cavity fiber optic laser].

    PubMed

    Zhang, Hong-Xia; Liu, Kun; Jia, Da-Gong; Liu, Tie-Gen; Peng, Gang-Ding; Wang, Yan; Zhang, Yi-Mo

    2011-08-01

    Due to the advantages of immunity of electrical/electronic, high performance cost ratio, remote detection and multiplexing capability, intra-cavity fiber optic gas measurement has aroused wide concern. The trace gas measurement system has been developed based on the elaborated gas cell and reflector. The wavelength sweeping technique (WST) is realized when the Fabry-Perot type tunable optical filter is applied by the sawtooth driver voltage. Multi absorption lines can be obtained and one scanning measurement with WST is equal to multiple independent detections, so the gas measurement sensitivity is improved remarkably. The experimental results show that the acetylene detection sensitivity is reduced to less than 100 ppm and the relative measurement error is less than 3% of practical gas concentration. PMID:22007380

  14. Dynamics of a degenerate Fermi gas in a one-dimensional optical lattice coupled to a cavity

    SciTech Connect

    Sun Qing; Hu Xinghua; Liu, W. M.; Ji Anchun

    2011-04-15

    We systematically study the dynamics of a one-dimensional degenerate Fermi gas in an optical-lattice potential coupled to a single-mode cavity field. We derive an effective model to study the nonperturbative effect caused by the cavity field. Our numerical results show that due to the addition of the optical-lattice potential, the system undergoes second-order transition to a bistable density-wave steady state, where the atoms form a density wave and the cavity field is bistable. In addition, the coherent oscillating behavior of the cavity photon number can be observed. We also present a feasible experimental protocol to realize these phenomena, which may be beneficial for future quantum-information applications.

  15. Probing quantum phases of ultracold atoms in optical lattices by transmission spectra in cavity quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Mekhov, Igor B.; Maschler, Christoph; Ritsch, Helmut

    2007-05-01

    Studies of ultracold gases in optical lattices provide a means for testing fundamental and application-oriented quantum many-body concepts of condensed-matter physics in well controllable atomic systems; examples include strongly correlated phases and quantum-information processing. Standard methods to observe quantum properties of Bose-Einstein condensates are based on matter-wave interference between atoms released from traps, a method that ultimately destroys the system. Here, we propose a new approach on the basis of optical measurements that conserves the number of atoms. We prove that atomic quantum statistics can be mapped on transmission spectra of high-Q cavities, where atoms create a quantum refractive index. This can be useful for studying phase transitions-for example, between Mott insulator and superfluid states-as various phases show qualitatively distinct light scattering. Joining the paradigms of cavity quantum electrodynamics and ultracold gases could enable conceptually new investigations of both light and matter at ultimate quantum levels. We predict effects accessible in experiments that recently became possible.

  16. Annular Bragg resonators (ABR): the ideal tool for biochemical sensing, nonlinear optics, and cavity QED

    NASA Astrophysics Data System (ADS)

    Scheuer, Jacob; Green, William M. J.; Yariv, Amnon

    2006-02-01

    Circular resonators are fundamentally interesting elements that are essential for research involving highly confined fields and strong photon-atom interactions such as cavity QED, as well as for practical applications in optical communication systems as and biochemical sensing. The important characteristics of a ring resonator are the Q-factor, the free spectral range (FSR) and the modal volume, where the last two are primarily determined by the resonator dimensions. The Total-Internal-Reflection (TIR) mechanism employed in "conventional" resonators couples between these characteristics and limits the ability to realize compact devices with large FSR, small modal volume and high Q. Recently, we proposed and analyzed a new class of a resonator in an annular geometry that is based on a single defect surrounded by radial Bragg reflectors on both sides. The radial Bragg confinement breaks the link between the characteristics of the mode and paves a new way for the realization of compact and low loss resonators. Such properties as well as the unique mode profile of the ABRs make this class of devices an excellent tool for ultra-sensitive biochemical detection as well as for studies in nonlinear optics and cavity QED.

  17. Coupling of erbium dopants to yttrium orthosilicate photonic crystal cavities for on-chip optical quantum memories

    NASA Astrophysics Data System (ADS)

    Miyazono, Evan; Zhong, Tian; Craiciu, Ioana; Kindem, Jonathan M.; Faraon, Andrei

    2016-01-01

    Erbium dopants in crystals exhibit highly coherent optical transitions well suited for solid-state optical quantum memories operating in the telecom band. Here, we demonstrate coupling of erbium dopant ions in yttrium orthosilicate to a photonic crystal cavity fabricated directly in the host crystal using focused ion beam milling. The coupling leads to reduction of the photoluminescence lifetime and enhancement of the optical depth in microns-long devices, which will enable on-chip quantum memories.

  18. Parametrically Amplified Bright-state Polariton of Four- and Six-wave Mixing in an Optical Ring Cavity

    PubMed Central

    Chen, Haixia; Zhang, Yiqi; Yao, Xin; Wu, Zhenkun; Zhang, Xun; Zhang, Yanpeng; Xiao, Min

    2014-01-01

    We report experimental studies of bright-state polaritons of four-wave mixing (FWM) and six-wave mixing (SWM) signals through cascade nonlinear optical parametric amplification processes in an atom-cavity composite system for the first time. Also, the coexisting cavity transmission modes of parametrically amplified FWM and SWM signals are observed. Finally, electromagnetically induced absorption by the FWM cavity modes in the probe beam is investigated. The investigations can find potential applications in multi-channel narrow-band long-distance quantum communication. PMID:24401795

  19. Parametrically Amplified Bright-state Polariton of Four- and Six-wave Mixing in an Optical Ring Cavity

    NASA Astrophysics Data System (ADS)

    Chen, Haixia; Zhang, Yiqi; Yao, Xin; Wu, Zhenkun; Zhang, Xun; Zhang, Yanpeng; Xiao, Min

    2014-01-01

    We report experimental studies of bright-state polaritons of four-wave mixing (FWM) and six-wave mixing (SWM) signals through cascade nonlinear optical parametric amplification processes in an atom-cavity composite system for the first time. Also, the coexisting cavity transmission modes of parametrically amplified FWM and SWM signals are observed. Finally, electromagnetically induced absorption by the FWM cavity modes in the probe beam is investigated. The investigations can find potential applications in multi-channel narrow-band long-distance quantum communication.

  20. Bistability characteristics of different types of optical modes amplified by quantum dot vertical cavity semiconductor optical amplifiers

    NASA Astrophysics Data System (ADS)

    Qasaimeh, Omar

    2016-04-01

    We have studied the characteristics of optical bistability of different types of optical modes amplified by small-size quantum dot vertical cavity semiconductor optical amplifiers operated in reflection. Our analysis reveals that TE01 mode exhibits stronger intensity-dependent non-linearity in small radius devices, which results in stronger optical phase modulation and therefore larger hysteresis width compared with the other modes. The effect of the wavelength detuning of the input signal on the shape of the hysteresis loop is studied. We find that butterfly hysteresis loop exhibits the largest hysteresis width compared with clockwise and counterclockwise loops. Our analysis reveals that doping the quantum dots with p-type doping slightly reduces the hysteresis width while doping the dots with n-type doping clearly increases the hysteresis width for any wavelength detuning. We estimate that the hysteresis width of quantum dot active layer will exhibit higher hysteresis width compared with quantum well active layer having the same threshold gain.

  1. CFD-based aero-optical analysis of flow fields over two-dimensional cavities with active flow control

    NASA Astrophysics Data System (ADS)

    Tan, Yan

    Prediction and control of optical wave front distortions and aberrations in a high energy laser beam due to interaction with an unsteady highly non-uniform flow field is of great importance in the development of directed energy weapon systems for Unmanned Air Vehicles (UAV). The unsteady shear layer over the weapons bay cavity is the primary cause of this distortion of the optical wave front. The large scale vortical structure of the shear layer over the cavity can be significantly reduced by employing an active flow control technique combined with passive flow control. This dissertation explores various active and passive control methods to suppress the cavity oscillations and thereby improve the aero-optics of cavity flow. In active flow control technique, a steady or a pulsed jet is applied at the sharp leading edge of cavities of different aspect ratios L/D (=2, 4, 15), where L and D are the width and the depth of a cavity respectively. In the passive flow control approach, the sharp leading or trailing edge of the cavity is modified into a round edge of different radii. Both of these active and passive flow control approaches are studied independently and in combination. Numerical simulations are performed, with and without active flow control for subsonic free stream flow past two-dimensional sharp and round leading or trailing edge cavities using Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations with a two-equation Shear Stress Transport (SST) turbulence model or a hybrid SST/Large Eddy Simulation (LES) model. Aero-optical analysis is developed and applied to all the simulation cases. Index of refraction and Optical Path Difference (OPD) are compared for flow fields without and with active flow control. Root-Mean-Square (RMS) value of OPD is calculated and compared with the experimental data, where available. The effect of steady and pulsed blowing on buffet loading on the downstream face of the cavity is also computed. Using the numerical

  2. Engineering Strong Interactions Between mm-wave and Optical Photons

    NASA Astrophysics Data System (ADS)

    Stone, Mark; Suleymanzade, Aziza; Estes, Jeremy; Eustice, Scott; Schuster, David; Simon, Jonathan

    2016-05-01

    We propose an atomic interface of Rydberg atoms as a means of engineering effective strong interactions between single mm-wave and optical photons. The atomic sample resides at the intersection of a high-finesse optical cavity and a superconducting mm-wave cavity, where it can coherently interact with photons of both regimes. The use of mm-wave (100 GHz) frequencies allows strong coupling at higher temperatures and with less sensitivity to stray electric fields. A hybrid cryogenic vacuum chamber at 4 Kelvin enables access to superconductivity as well as a UHV environment with optical access necessary for cold atom experiments. Strong interactions between these separate quantum degrees of freedom has important applications in quantum computing as well as simulation of many-body interacting systems.

  3. Variable temperature spectroscopy of as-grown and passivated CdS nanowire optical waveguide cavities.

    PubMed

    van Vugt, Lambert K; Piccione, Brian; Cho, Chang-Hee; Aspetti, Carlos; Wirshba, Aaron D; Agarwal, Ritesh

    2011-04-28

    Semiconductor nanowire waveguide cavities hold promise for nanophotonic applications such as lasers, waveguides, switches, and sensors due to the tight optical confinement in these structures. However, to realize their full potential, high quality nanowires, whose emission at low temperatures is dominated by free exciton emission, need to be synthesized. In addition, a proper understanding of their complex optical properties, including light-matter coupling in these subwavelength structures, is required. We have synthesized very high-quality wurztite CdS nanowires capped with a 5 nm SiO(2) conformal coating with diameters spanning 100-300 nm using physical vapor and atomic layer deposition techniques and characterized their spatially resolved photoluminescence over the 77-298 K temperature range. In addition to the Fabry-Pérot resonator modulated emission from the ends of the wires, the low temperature emission from the center of the wire shows clear free excitonic peaks and LO phonon replicas, persisting up to room-temperature in the passivated wires. From laser scanning measurements we determined the absorption in the vicinity of the excitonic resonances. In addition to demonstrating the high optical quality of the nanowire crystals, these results provide the fundamental parameters for strong light-matter coupling studies, potentially leading to low threshold polariton lasers, sensitive sensors and optical switches at the nanoscale. PMID:21214218

  4. Optical Injection Locking of Vertical Cavity Surface-Emitting Lasers: Digital and Analog Applications

    NASA Astrophysics Data System (ADS)

    Parekh, Devang

    With the rise of mobile (cellphones, tablets, notebooks, etc.) and broadband wireline communications (Fiber to the Home), there are increasing demands being placed on transmitters for moving data from device to device and around the world. Digital and analog fiber-optic communications have been the key technology to meet this challenge, ushering in ubiquitous Internet and cable TV over the past 20 years. At the physical layer, high-volume low-cost manufacturing of semiconductor optoelectronic devices has played an integral role in allowing for deployment of high-speed communication links. In particular, vertical cavity surface emitting lasers (VCSEL) have revolutionized short reach communications and are poised to enter more markets due to their low cost, small size, and performance. However, VCSELs have disadvantages such as limited modulation performance and large frequency chirp which limits fiber transmission speed and distance, key parameters for many fiber-optic communication systems. Optical injection locking is one method to overcome these limitations without re-engineering the VCSEL at the device level. By locking the frequency and phase of the VCSEL by the direct injection of light from another laser oscillator, improved device performance is achieved in a post-fabrication method. In this dissertation, optical injection locking of VCSELs is investigated from an applications perspective. Optical injection locking of VCSELs can be used as a pathway to reduce complexity, cost, and size of both digital and analog fiber-optic communications. On the digital front, reduction of frequency chirp via bit pattern inversion for large-signal modulation is experimentally demonstrated showing up to 10 times reduction in frequency chirp and over 90 times increase in fiber transmission distance. Based on these results, a new reflection-based interferometric model for optical injection locking was established to explain this phenomenon. On the analog side, the resonance

  5. Cavity Optomechanics at Millikelvin Temperatures

    NASA Astrophysics Data System (ADS)

    Meenehan, Sean Michael

    The field of cavity optomechanics, which concerns the coupling of a mechanical object's motion to the electromagnetic field of a high finesse cavity, allows for exquisitely sensitive measurements of mechanical motion, from large-scale gravitational wave detection to microscale accelerometers. Moreover, it provides a potential means to control and engineer the state of a macroscopic mechanical object at the quantum level, provided one can realize sufficiently strong interaction strengths relative to the ambient thermal noise. Recent experiments utilizing the optomechanical interaction to cool mechanical resonators to their motional quantum ground state allow for a variety of quantum engineering applications, including preparation of non-classical mechanical states and coherent optical to microwave conversion. Optomechanical crystals (OMCs), in which bandgaps for both optical and mechanical waves can be introduced through patterning of a material, provide one particularly attractive means for realizing strong interactions between high-frequency mechanical resonators and near-infrared light. Beyond the usual paradigm of cavity optomechanics involving isolated single mechanical elements, OMCs can also be fashioned into planar circuits for photons and phonons, and arrays of optomechanical elements can be interconnected via optical and acoustic waveguides. Such coupled OMC arrays have been proposed as a way to realize quantum optomechanical memories, nanomechanical circuits for continuous variable quantum information processing and phononic quantum networks, and as a platform for engineering and studying quantum many-body physics of optomechanical meta-materials. However, while ground state occupancies (that is, average phonon occupancies less than one) have been achieved in OMC cavities utilizing laser cooling techniques, parasitic absorption and the concomitant degradation of the mechanical quality factor fundamentally limit this approach. On the other hand, the high

  6. Low loss optomechanical cavities based on silicon oscillator

    NASA Astrophysics Data System (ADS)

    Borrielli, A.; Pontin, A.; Cataliotti, F. S.; Marconi, L.; Marin, F.; Marino, F.; Pandraud, G.; Prodi, G. A.; Serra, E.; Bonaldi, M.

    2015-05-01

    In an optomechanical cavity the optical and mechanical degree of freedom are strongly coupled by the radiation pressure of the light. This field of research has been gathering a lot of momentum during the last couple of years, driven by the technological advances in microfabrication and the first observation of quantum phenomena. These results open new perspectives in a wide range of applications, including high sensitivity measurements of position, acceleration, force, mass, and for fundamental research. We are working on low frequency pondero-motive light squeezing as a tool for improving the sensitivity of audio frequency measuring devices such as magnetic resonance force microscopes and gravitational-wave detectors. It is well known that experiments aiming to produce and manipulate non-classical (squeezed) light by effect of optomechanical interaction need a mechanical oscillator with low optical and mechanical losses. These technological requirements permit to maximize the force per incoming photon exerted by the cavity field on the mechanical element and to improve the element's response to the radiation pressure force and, at the same time, to decrease the influence of the thermal bath. In this contribution we describe a class of mechanical devices for which we measured a mechanical quality factor up to 1.2 × 106 and with which it was possible to build a Fabry-Perot cavity with optical finesse up to 9 × 104. From our estimations, these characteristics meet the requirements for the generation of radiation squeezing and quantum correlations in the ˜ 100kHz region. Moreover our devices are characterized by high reproducibility to allow inclusion in integrated systems. We show the results of the characterization realized with a Michelson interferometer down to 4.2K and measurements in optical cavities performed at cryogenic temperature with input optical powers up to a few mW. We also report on the dynamical stability and the thermal response of the system.

  7. Overlapping double potential wells in a single optical microtube cavity with vernier-scale-like tuning effect

    NASA Astrophysics Data System (ADS)

    Madani, A.; Bolaños Quiñones, V. A.; Ma, L. B.; Miao, S. D.; Jorgensen, M. R.; Schmidt, O. G.

    2016-04-01

    Spatially and temporally overlapping double potential wells are realized in a hybrid optical microtube cavity due to the coexistence of an aggregate of luminescent quantum dots embedded in the tube wall and the cone-shaped tube's geometry. The double potential wells produce two independent sets of optical modes with different sets of mode numbers, indicating phase velocity separation for the modes overlapping at the same frequency. The overlapping mode position can be tuned by modifying the tube cavity, where these mode sets shift with different magnitudes, allowing for a vernier-scale-like tuning effect.

  8. Design verification of large time constant thermal shields for optical reference cavities.

    PubMed

    Zhang, J; Wu, W; Shi, X H; Zeng, X Y; Deng, K; Lu, Z H

    2016-02-01

    In order to achieve high frequency stability in ultra-stable lasers, the Fabry-Pérot reference cavities shall be put inside vacuum chambers with large thermal time constants to reduce the sensitivity to external temperature fluctuations. Currently, the determination of thermal time constants of vacuum chambers is based either on theoretical calculation or time-consuming experiments. The first method can only apply to simple system, while the second method will take a lot of time to try out different designs. To overcome these limitations, we present thermal time constant simulation using finite element analysis (FEA) based on complete vacuum chamber models and verify the results with measured time constants. We measure the thermal time constants using ultrastable laser systems and a frequency comb. The thermal expansion coefficients of optical reference cavities are precisely measured to reduce the measurement error of time constants. The simulation results and the experimental results agree very well. With this knowledge, we simulate several simplified design models using FEA to obtain larger vacuum thermal time constants at room temperature, taking into account vacuum pressure, shielding layers, and support structure. We adopt the Taguchi method for shielding layer optimization and demonstrate that layer material and layer number dominate the contributions to the thermal time constant, compared with layer thickness and layer spacing. PMID:26931831

  9. Broadband optical ultrasound sensor with a unique open-cavity structure

    PubMed Central

    Chow, Colin M.; Zhou, Yun; Guo, Yunbo; Norris, Theodore B.; Wang, Xueding; Deng, Cheri X.; Ye, Jing Yong

    2011-01-01

    High-resolution ultrasound imaging requires quality sensors with wide bandwidth and high sensitivity, as shown in a wide range of applications, including intravascular imaging of cardiovascular diseases. However, piezoelectric technology, the current dominant approach for hydrophone fabrication, has encountered many technical limitations in the high-frequency range. Using optical techniques for the detection of high-frequency ultrasound signals has attracted much recent attention. One of the most studied approaches is based on a Fabry–Pérot interferometer, consisting of an optical cavity sandwiched between two mirrors. This technique offers promising sensitivity and bandwidth, and a potential alternative to piezoelectric polyvinylidene fluoride (PVDF) hydrophones. We propose an innovative optical ultrasound sensor using only a single mirror in a total-internal-reflection configuration. Besides retaining the advantages of Fabry–Pérot interferometer-based ultrasound sensors, this unique design provides a bandwidth of at least 160 MHz, a potential decrease in fabrication cost, and an increase in signal fidelity. PMID:21280922

  10. External cavity quantum cascade lasers with ultra rapid acousto-optic tuning

    SciTech Connect

    Lyakh, A. Barron-Jimenez, R.; Dunayevskiy, I.; Go, R.; Patel, C. Kumar N.

    2015-04-06

    We report operation of tunable external cavity quantum cascade lasers with emission wavelength controlled by an acousto-optic modulator (AOM). A long-wave infrared quantum cascade laser wavelength tuned from ∼8.5 μm to ∼9.8 μm when the AOM frequency was changed from ∼41MHz to ∼49 MHz. The laser delivered over 350 mW of average power at the center of the tuning curve in a linewidth of ∼4.7 cm{sup −1}. Measured wavelength switching time between any two wavelengths within the tuning range of the QCL was less than 1 μs. Spectral measurements of infrared absorption features of Freon demonstrated a capability of obtaining complete spectral data in less than 20 μs.

  11. External cavity quantum cascade lasers with ultra rapid acousto-optic tuning

    NASA Astrophysics Data System (ADS)

    Lyakh, A.; Barron-Jimenez, R.; Dunayevskiy, I.; Go, R.; Patel, C. Kumar N.

    2015-04-01

    We report operation of tunable external cavity quantum cascade lasers with emission wavelength controlled by an acousto-optic modulator (AOM). A long-wave infrared quantum cascade laser wavelength tuned from ˜8.5 μm to ˜9.8 μm when the AOM frequency was changed from ˜41MHz to ˜49 MHz. The laser delivered over 350 mW of average power at the center of the tuning curve in a linewidth of ˜4.7 cm-1. Measured wavelength switching time between any two wavelengths within the tuning range of the QCL was less than 1 μs. Spectral measurements of infrared absorption features of Freon demonstrated a capability of obtaining complete spectral data in less than 20 μs.

  12. Simultaneous strain and temperature sensing using a slightly tapered optical fiber with an inner cavity.

    PubMed

    Chen, H F; Wang, D N; Wang, Y

    2015-03-21

    An ultracompact optical fiber mode interferometer capable of performing simultaneous strain and temperature sensing is demonstrated. The device is fabricated by using femtosecond laser micromachining together with fusion splicing techniques and followed by a tapering process. The transmission spectrum of the device exhibits a number of resonance wavelength dips, corresponding to different orders of cladding mode, which allow simultaneous strain and temperature sensing by monitoring the variation of selected two wavelength dips. The sensitivity achieved is -16.12 pm με(-1) and 85.95 pm °C(-1) for strain and temperature, respectively. The device has a spatially precise sensing capability owing to the small size of the inner air-cavity. PMID:25631366

  13. Measurement of angular antispring effect in optical cavity by radiation pressure

    SciTech Connect

    Sakata, Shihori; Nishizawa, Atsushi; Ishizaki, Hideharu; Kawamura, Seiji; Miyakawa, Osamu

    2010-03-15

    We present a measurement of an angular antispring effect caused by radiation pressure in an optical cavity with a mirror of 20 mg suspended by a silica fiber of 10 {mu}m in diameter. The antispring effect occurred since the torque on the suspended mirror is increased with the higher radiation pressure force, pushing the system towards instability. We measured shifts of the rotational resonant frequencies of the suspended mirror from 2.0 Hz to 1.0 Hz with the increased circulating power. It is verified that the result agrees with the theoretical curve to show the antispring effect. The result proves that it will be possible to make a reliable control system model of the radiation pressure effect for the second generation of the gravitational wave detectors.

  14. Frequency locking of an optical cavity using linear-quadratic Gaussian integral control

    NASA Astrophysics Data System (ADS)

    Sayed Hassen, S. Z.; Heurs, M.; Huntington, E. H.; Petersen, I. R.; James, M. R.

    2009-09-01

    We show that a systematic modern control technique such as linear-quadratic Gaussian (LQG) control can be applied to a problem in experimental quantum optics which has previously been addressed using traditional approaches to controller design. An LQG controller which includes integral action is synthesized to stabilize the frequency of the cavity to the laser frequency and to reject low frequency noise. The controller is successfully implemented in the laboratory using a dSpace digital signal processing board. One important advantage of the LQG technique is that it can be extended in a straightforward way to control systems with multiple measurements and multiple feedback loops. This work is expected to pave the way for extremely stable lasers with fluctuations approaching the quantum noise limit and which could be potentially used in a wide range of applications.

  15. Probing dark energy with an atom interferometer in an optical cavity

    NASA Astrophysics Data System (ADS)

    Jaffe, Matthew; Haslinger, Philipp; Hamilton, Paul; Mueller, Holger; Khoury, Justin; Elder, Benjamin

    2016-05-01

    If dark energy -- which drives the accelerated expansion of the universe -- consists of a light scalar field, it might be detectable as a ``fifth force'' between normal-matter objects, in potential conflict with precision tests of gravity. Chameleon fields and other theories with screening mechanisms can evade such tests by suppressing this force in regions of high density, such as the laboratory. Our experiments constrain these dark energy models using atoms in an ultrahigh-vacuum chamber as probes to expose the screened fields. Using a cesium matter wave interferometer in an optical cavity, we set stringent bounds on coupling screened theories to matter. A further 4 to 5 orders of magnitude would completely rule out chameleon and f(R) theories. I will describe this first tabletop dark energy search, and present the hundredfold boost in sensitivity we have since achieved.

  16. A transportable optical lattice clock

    NASA Astrophysics Data System (ADS)

    Vogt, Stefan; Häfner, Sebastian; Grotti, Jacopo; Koller, Silvio; Al-Masoudi, Ali; Sterr, Uwe; Lisdat, Christian

    2016-06-01

    We present the experimental setup and first results of PTB's transportable 87Sr clock. It consists of a physics package, several compact laser breadboards, and a transportable high finesse cavity for the clock laser. A comparison of the transportable system with our stationary optical lattice clock yields an instability of 2.2 x 10-15 √s/τ for the transportable clock. The current fractional uncertainty of 1 × 10-15 is still limited by the not yet fully evaluated light shift from the free running optical lattice laser operated near the magic wavelength. We are currently improving our transportable system to reach an uncertainty at or below the 10-17 level, which will finaly be limited by the uncertainty in blackbody radiation shift correction.

  17. Millimeter-long fiber Fabry-Perot cavities.

    PubMed

    Ott, Konstantin; Garcia, Sebastien; Kohlhaas, Ralf; Schüppert, Klemens; Rosenbusch, Peter; Long, Romain; Reichel, Jakob

    2016-05-01

    We demonstrate fiber Fabry-Perot (FFP) cavities with concave mirrors that can be operated at cavity lengths as large as 1.5 mm without significant deterioration of the finesse. This is achieved by using a laser dot machining technique to shape spherical mirrors with ultralow roughness and employing single-mode fibers with large mode area for good mode matching to the cavity. Additionally, in contrast to previous FFPs, these cavities can be used over an octave-spanning frequency range with adequate coatings. We also show directly that shape deviations caused by the fiber's index profile lead to a finesse decrease as observed in earlier attempts to build long FFP cavities, and show a way to overcome this problem. PMID:27137597

  18. FINESSE Spaceward Bound - Teacher Engagement in NASA Science and Exploration Field Research

    NASA Technical Reports Server (NTRS)

    Jones, A. J. P.; Heldmann, J. L.; Sheely, T.; Karlin, J.; Johnson, S.; Rosemore, A.; Hughes, S.; Nawotniak, S. Kobs; Lim, D. S. S.; Garry, W. B.

    2016-01-01

    The FINESSE (Field Investigations to Enable Solar System Science and Exploration) team of NASA's Solar System Exploration Research Virtual Institute (SSERVI) is focused on a science and exploration field-based research program aimed at generating strategic knowledge in preparation for the human and robotic exploration of the Moon, Near Earth Asteroids, and the moons of Mars. The FINESSE science program is infused with leading edge exploration concepts since "science enables exploration and exploration enables science." The FINESSE education and public outreach program leverages the team's field investigations and educational partnerships to share the excitement of lunar, Near Earth Asteroid, and martian moon science and exploration locally, nationally, and internationally. The FINESSE education plan is in line with all of NASA's Science Mission Directorate science education objectives, particularly to enable STEM (science, technology, engineering, and mathematics) education and leverage efforts through partnerships.

  19. Optical motion sensor for resonant-bar gravitational wave antennas.

    PubMed

    Richard, J P; Pang, Y; Hamilton, J J

    1992-04-01

    An experiment is described in which an optical method was used to measure fluctuations in the separation between two mirrors of a Fabry-Perot sensor cavity. Noise measurements were made to determine the sensitivity of this device to vibration amplitudes in the frequency range 1.1-2.1 kHz, which is of interestfor resonant-bar gravitational wave antennas. The rms spectral noise density for length fluctuations inthis range was 3.7 x 10(15-) m/Hz((1/2)) and can be related to electronic noise of the circuitry plus vibrationalnoise from the environment. The cavity finesse was relatively low at 117, and the power dissipated in the mirrors was estimated to be 1.9 muW. On a multimode gravitational wave detector, the sensor cavity would be formed by one reference mirror and by one mirror mounted on the last resonator. For a 1200-kg bar, 1.2-g last resonator system operating at 1600 Hz, the sensor described here would exhibit a noise temperature of 18 muK; the resolution in h in the case of negligible thermal noise from the mechanical system would be 3.7 x 10(-18)/Hz((1/2)). Improvements in the sensitivity in a quiet antenna-like environment should be possible with higher finesse mirrors. PMID:20720800

  20. Kilohertz-Resolution Spectroscopy of Cold Atoms with an Optical Frequency Comb

    SciTech Connect

    Fortier, T. M.; Le Coq, Y.; Stalnaker, J. E.; Diddams, S. A.; Oates, C. W.; Hollberg, L.; Ortega, D.

    2006-10-20

    We have performed sub-Doppler spectroscopy on the narrow intercombination line of cold calcium atoms using the amplified output of a femtosecond laser frequency comb. Injection locking of a 657-nm diode laser with a femtosecond comb allows for two regimes of amplification, one in which many lines of the comb are amplified, and one where a single line is predominantly amplified. The output of the laser in both regimes was used to perform kilohertz-level spectroscopy. This experiment demonstrates the potential for high-resolution absolute-frequency spectroscopy over the entire spectrum of the frequency comb output using a single high-finesse optical reference cavity.

  1. Kilohertz-resolution spectroscopy of cold atoms with an optical frequency comb.

    PubMed

    Fortier, T M; Coq, Y Le; Stalnaker, J E; Ortega, D; Diddams, S A; Oates, C W; Hollberg, L

    2006-10-20

    We have performed sub-Doppler spectroscopy on the narrow intercombination line of cold calcium atoms using the amplified output of a femtosecond laser frequency comb. Injection locking of a 657-nm diode laser with a femtosecond comb allows for two regimes of amplification, one in which many lines of the comb are amplified, and one where a single line is predominantly amplified. The output of the laser in both regimes was used to perform kilohertz-level spectroscopy. This experiment demonstrates the potential for high-resolution absolute-frequency spectroscopy over the entire spectrum of the frequency comb output using a single high-finesse optical reference cavity. PMID:17155398

  2. Cavity-based quantum networks with single atoms and optical photons

    NASA Astrophysics Data System (ADS)

    Reiserer, Andreas; Rempe, Gerhard

    2015-10-01

    Distributed quantum networks will allow users to perform tasks and to interact in ways which are not possible with present-day technology. Their implementation is a key challenge for quantum science and requires the development of stationary quantum nodes that can send and receive as well as store and process quantum information locally. The nodes are connected by quantum channels for flying information carriers, i.e., photons. These channels serve both to directly exchange quantum information between nodes and to distribute entanglement over the whole network. In order to scale such networks to many particles and long distances, an efficient interface between the nodes and the channels is required. This article describes the cavity-based approach to this goal, with an emphasis on experimental systems in which single atoms are trapped in and coupled to optical resonators. Besides being conceptually appealing, this approach is promising for quantum networks on larger scales, as it gives access to long qubit coherence times and high light-matter coupling efficiencies. Thus, it allows one to generate entangled photons on the push of a button, to reversibly map the quantum state of a photon onto an atom, to transfer and teleport quantum states between remote atoms, to entangle distant atoms, to detect optical photons nondestructively, to perform entangling quantum gates between an atom and one or several photons, and even provides a route toward efficient heralded quantum memories for future repeaters. The presented general protocols and the identification of key parameters are applicable to other experimental systems.

  3. Selection of Optical Cavity Surface Coatings for 1micron Laser Based Missions

    NASA Technical Reports Server (NTRS)

    Hedgeland, Randy J.; Straka, Sharon; Matsumura, Mark; Hammerbacher, Joseph

    2004-01-01

    The particulate surface cleanliness level on several coatings for aluminum and beryllium substrates were examined for use in the optical cavities of high pulse energy Nd:YAG Q-switched, diode-pumped lasers for space flight applications. Because of the high intensity of the lasers, any contaminants in the laser beam path could damage optical coatings and limit the instrument mission objectives at the operating wavelength of 1 micron (micrometer). Our goal was to achieve an EST-STD-CC1246D Level 100 particulate distribution or better to ensure particulate redistribution during launch would not adversely affect the performance objectives. Tapelifts were performed to quantify the amount of particles using in-house developed procedures. The primary candidate coatings included chromate conversion coating aluminum (Al), uncoated Al electroless Nickel (Ni) on Al, Ni-gold (Au) on Al, anodized Al, and gold (Au)/Ni on Beryllium (Be). The results indicate that there were advantages in Ni and Au coating applications for the two major substrates, Al and Be, when considering applications that need to meet launch environments.

  4. Ultrasensitive and compact tunable electro-optic filter in a 2D silicon photonic-crystal cavity

    NASA Astrophysics Data System (ADS)

    Ebrahimy, Mehdi N.; Naziri, Mohammad; Andalib, Alireza; Daie Kuzekanani, Ziaddin

    2016-06-01

    In this work, we designed and simulated a high Q-factor photonic crystal cavity with a PN junction to demonstrate a high-sensitivity and high tunable electro-optic filter (EOF). For this purpose, we used a cavity based on 2D photonic crystal structures and created a PN junction with 1 μm width in the center of the cavity to change the refractive index of it. The electro-optic sensitivity of the cavity was improved by reducing modal volume and scattering power. Reverse bias in the range of (‑3.88 V–0.288 V) is applied to the PN junction and the output spectrum is investigated for various bias voltages. The output wavelengths of designed EOF can be tuned by manipulating cavity cells. In final response of EOF the maximum transmission efficiency is more than 93%, the overall Q-factor is more than 14 500. The whole device fits in a compact 102.6 μm2 (17.4 μm  ×  5.9 μm) footprint.

  5. Real-time detection of lipid bilayer assembly and detergent-initiated solubilization using optical cavities

    NASA Astrophysics Data System (ADS)

    Sun, V.; Armani, A. M.

    2015-02-01

    The cellular membrane governs numerous fundamental biological processes. Therefore, developing a comprehensive understanding of its structure and function is critical. However, its inherent biological complexity gives rise to numerous inter-dependent physical phenomena. In an attempt to develop a model, two different experimental approaches are being pursued in parallel: performing single cell experiments (top down) and using biomimetic structures (bottom up), such as lipid bilayers. One challenge in many of these experiments is the reliance on fluorescent probes for detection which can create confounds in this already complex system. In the present work, a label-free detection method based on an optical resonant cavity is used to detect one of the fundamental physical phenomena in the system: assembly and solubilization of the lipid bilayer. The evanescent field of the cavity strongly interacts with the lipid bilayer, enabling the detection of the bilayer behavior in real-time. Two independent detection mechanisms confirm the formation and detergent-assisted solubilization of the lipid bilayers: (1) a refractive index change and (2) a material loss change. Both mechanisms can be monitored in parallel, on the same device, thus allowing for cross-confirmation of the results. To verify the proposed method, we have detected the formation of self-assembled phosphatidylcholine lipid bilayers from small unilamellar vesicles on the device surface in real-time. Subsequently, we exposed the bilayers to two different detergents (non-ionic Triton X-100 and anionic sodium dodecyl sulfate) to initiate solubilization, and this process was also detected in real-time. After the bilayer solubilization, the device returned to its initial state, exhibiting minimal hysteresis. The experimental wash-off was also collected and analyzed using dynamic light scattering.

  6. Phase dynamics in vertical-cavity surface-emitting lasers with delayed optical feedback and cross-polarized reinjection

    NASA Astrophysics Data System (ADS)

    Javaloyes, J.; Marconi, M.; Giudici, M.

    2014-08-01

    We study theoretically the nonlinear polarization dynamics of vertical-cavity surface-emitting lasers in the presence of an external cavity providing delayed optical feedback and cross-polarized reinjection. We show that, far from the laser threshold, the dynamics remains confined close to the equatorial plane of a Poincaré sphere with a fixed radius. It entails that the evolution of the system is described by two phase variables: the orientation phase of the quasilinear polarization and the optical phase of the field. We explore the complex modal structure given by the double reinjection configuration and how it evolves between the cases of single cross-polarized reinjection and single optical feedback, hence disclosing the relationship with the Lang-Kobayashi model. We also reinterpret the square-wave switching observed by J. Mulet et al. [Phys. Rev. A 76, 043801 (2007), 10.1103/PhysRevA.76.043801] in terms of phase kinks.

  7. Simultaneous measurement of temperature and refractive index using focused ion beam milled Fabry-Perot cavities in optical fiber micro-tips.

    PubMed

    André, Ricardo M; Warren-Smith, Stephen C; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Zibaii, M I; Latifi, H; Marques, Manuel B; Bartelt, Hartmut; Frazão, Orlando

    2016-06-27

    Optical fiber micro-tips are promising devices for sensing applications in small volume and difficult to access locations, such as biological and biomedical settings. The tapered fiber tips are prepared by dynamic chemical etching, reducing the size from 125 μm to just a few μm. Focused ion beam milling is then used to create cavity structures on the tapered fiber tips. Two different Fabry-Perot micro-cavities have been prepared and characterized: a solid silica cavity created by milling two thin slots and a gap cavity. A third multi-cavity structure is fabricated by combining the concepts of solid silica cavity and gap cavity. This micro-tip structure is analyzed using a fast Fourier transform method to demultiplex the signals of each cavity. Simultaneous measurement of temperature and external refractive index is then demonstrated, presenting sensitivities of - 15.8 pm/K and -1316 nm/RIU, respectively. PMID:27410566

  8. Preparation and properties of magneto-optical micro-cavities composed of Co thin film and dielectric multilayers

    NASA Astrophysics Data System (ADS)

    Inoue, M.; Matsumoto, K.; Arai, K. I.; Fujii, T.; Abe, M.

    1999-05-01

    Magneto-optical (MO) Kerr effect of micro-cavities composed of a Co thin film and SiO 2/SiN multilayer films was investigated theoretically and experimentally. The micro-cavity structure was found to be very effective for enhancing the MO Kerr effect: the MO Kerr rotation angle exceeding 10° at a designated wavelength of light was obtained, the value of which is more than 100 times larger than that of a Co single-layer film. The large MO Kerr effect is caused by the localization of light originating from the multilayer structure.

  9. Compact electro-optic modulator on silicon-on-insulator substrates using cavities with ultra-small modal volumes

    NASA Astrophysics Data System (ADS)

    Schmidt, Bradley; Xu, Qianfan; Shakya, Jagat; Manipatruni, Sasikanth; Lipson, Michal

    2007-03-01

    We experimentally demonstrate a micron-size electro-optic modulator using a high-index-contrast silicon Fabry-Pérot resonator cavity. This compact device consists of a 1-D cavity formed within a single mode silicon channel waveguide and an embedded p-i-n junction on a silicon-oninsulator platform. The entire device is 6.0 microns in length. We demonstrate modulation depths as large as 5.87 dB at speeds of 250 Mbps limited only by fabrication imperfections, with optimized theoretical speeds of several Gbps.

  10. 1300 nm optically pumped quantum dot spin vertical external-cavity surface-emitting laser

    SciTech Connect

    Alharthi, S. S. Henning, I. D.; Adams, M. J.; Orchard, J.; Clarke, E.

    2015-10-12

    We report a room temperature optically pumped Quantum Dot-based Spin-Vertical-External-Cavity Surface-Emitting laser (QD Spin-VECSEL) operating at the telecom wavelength of 1.3 μm. The active medium was composed of 5 × 3 QD layers; each threefold group was positioned at an antinode of the standing wave of the optical field. Circularly polarized lasing in the QD-VECSEL under Continuous-Wave optical pumping has been realized with a threshold pump power of 11 mW. We further demonstrate at room temperature control of the QD-VECSEL output polarization ellipticity via the pump polarization.

  11. Electro-optical channel drop switching in a photonic crystal waveguide-cavity side-coupling system

    NASA Astrophysics Data System (ADS)

    Chang, Kao-Der; Liu, Cheng-Yang

    2014-04-01

    The electro-optical channel drop switching in a photonic crystal waveguide-cavity side-coupling system is reported. The line waveguide is formed by removing a single row of dielectric cylinders. The twin optical microcavities side coupled between linear waveguides is studied by solving Maxwell's equations. We determine the general characteristics of the coupling element required to achieve channel drop tunneling. By modulating the conductance of the twin microcavities, the electrical tunability of the resonant modes is observed in the transmission spectrum. The spectral characteristics suggest a potential application for this switching device as an efficient multichannel optical switch in the photonic integrated circuits.

  12. Phase noise and squeezing spectra of the output field of an optical cavity containing an interacting Bose–Einstein condensate

    NASA Astrophysics Data System (ADS)

    Dalafi, A.; Naderi, M. H.

    2016-07-01

    We present a theoretical study of the phase noise, intensity and quadrature squeezing power spectra of the transmitted field of a driven optical cavity containing an interacting one-dimensional Bose–Einstein condensate. We show how the pattern of the output power spectrum of the cavity changes due to the nonlinear effect of atomic collisions. Furthermore, it is shown that due to a one-to-one correspondence between the splitting of the peaks in the phase noise power spectrum of the cavity output field and the s-wave scattering frequency of the atom–atom interaction, one can measure the strength of interatomic interaction. In addition, we show how the atomic collisions affect the squeezing behavior of the output field.

  13. Optical pressure/acoustic sensor with precise Fabry-Perot cavity length control using angle polished fiber.

    PubMed

    Wang, Wenhui; Wu, Nan; Tian, Ye; Wang, Xingwei; Niezrecki, Christopher; Chen, Julie

    2009-09-14

    This paper presents a novel Fabry-Perot (FP) optical fiber pressure/acoustic sensor. It consists of two V-shaped grooves having different sized widths, a diaphragm on the surface of the larger V-groove, and a 45 degrees angle-polished fiber. The precision of FP cavity length is determined by the fabrication process of photolithography and anisotropic etching of a silicon crystal. Therefore, the cavity length can be controlled on the order of ten nm. Sensors were fabricated and tested. Test results indicate that the sensors' cavity lengths have been controlled precisely. The packaged sensor has demonstrated very good static and dynamic responses compared to a commercially available pressure sensor and a microphone. PMID:19770876

  14. Coaxial multishell nanowires with high-quality electronic interfaces and tunable optical cavities for ultrathin photovoltaics.

    PubMed

    Kempa, Thomas J; Cahoon, James F; Kim, Sun-Kyung; Day, Robert W; Bell, David C; Park, Hong-Gyu; Lieber, Charles M

    2012-01-31

    Silicon nanowires (NWs) could enable low-cost and efficient photovoltaics, though their performance has been limited by nonideal electrical characteristics and an inability to tune absorption properties. We overcome these limitations through controlled synthesis of a series of polymorphic core/multishell NWs with highly crystalline, hexagonally-faceted shells, and well-defined coaxial (p/n) and p/intrinsic/n (p/i/n) diode junctions. Designed 200-300 nm diameter p/i/n NW diodes exhibit ultralow leakage currents of approximately 1 fA, and open-circuit voltages and fill-factors up to 0.5 V and 73%, respectively, under one-sun illumination. Single-NW wavelength-dependent photocurrent measurements reveal size-tunable optical resonances, external quantum efficiencies greater than unity, and current densities double those for silicon films of comparable thickness. In addition, finite-difference-time-domain simulations for the measured NW structures agree quantitatively with the photocurrent measurements, and demonstrate that the optical resonances are due to Fabry-Perot and whispering-gallery cavity modes supported in the high-quality faceted nanostructures. Synthetically optimized NW devices achieve current densities of 17 mA/cm(2) and power-conversion efficiencies of 6%. Horizontal integration of multiple NWs demonstrates linear scaling of the absolute photocurrent with number of NWs, as well as retention of the high open-circuit voltages and short-circuit current densities measured for single NW devices. Notably, assembly of 2 NW elements into vertical stacks yields short-circuit current densities of 25 mA/cm(2) with a backside reflector, and simulations further show that such stacking represents an attractive approach for further enhancing performance with projected efficiencies of > 15% for 1.2 μm thick 5 NW stacks. PMID:22307592

  15. Coaxial multishell nanowires with high-quality electronic interfaces and tunable optical cavities for ultrathin photovoltaics

    PubMed Central

    Kempa, Thomas J.; Cahoon, James F.; Kim, Sun-Kyung; Day, Robert W.; Bell, David C.; Park, Hong-Gyu; Lieber, Charles M.

    2012-01-01

    Silicon nanowires (NWs) could enable low-cost and efficient photovoltaics, though their performance has been limited by nonideal electrical characteristics and an inability to tune absorption properties. We overcome these limitations through controlled synthesis of a series of polymorphic core/multishell NWs with highly crystalline, hexagonally-faceted shells, and well-defined coaxial (p/n) and p/intrinsic/n (p/i/n) diode junctions. Designed 200–300 nm diameter p/i/n NW diodes exhibit ultralow leakage currents of approximately 1 fA, and open-circuit voltages and fill-factors up to 0.5 V and 73%, respectively, under one-sun illumination. Single-NW wavelength-dependent photocurrent measurements reveal size-tunable optical resonances, external quantum efficiencies greater than unity, and current densities double those for silicon films of comparable thickness. In addition, finite-difference-time-domain simulations for the measured NW structures agree quantitatively with the photocurrent measurements, and demonstrate that the optical resonances are due to Fabry-Perot and whispering-gallery cavity modes supported in the high-quality faceted nanostructures. Synthetically optimized NW devices achieve current densities of 17 mA/cm2 and power-conversion efficiencies of 6%. Horizontal integration of multiple NWs demonstrates linear scaling of the absolute photocurrent with number of NWs, as well as retention of the high open-circuit voltages and short-circuit current densities measured for single NW devices. Notably, assembly of 2 NW elements into vertical stacks yields short-circuit current densities of 25 mA/cm2 with a backside reflector, and simulations further show that such stacking represents an attractive approach for further enhancing performance with projected efficiencies of > 15% for 1.2 μm thick 5 NW stacks. PMID:22307592

  16. Route to polarization switching induced by optical injection in vertical-cavity surface-emitting lasers

    NASA Astrophysics Data System (ADS)

    Sciamanna, M.; Panajotov, K.

    2006-02-01

    We perform a theoretical investigation of the polarization dynamics in a vertical-cavity surface-emitting laser (VCSEL) subject to orthogonal optical injection, i.e., the injected field has a linear polarization (LP) orthogonal to that of the free-running VCSEL. In agreement with previous experiments [Z. G. Pan , Appl. Phys. Lett. 63, 2999 (1993)], an increase of the injection strength may lead to a polarization switching accompanied by an injection locking. We find that this route to polarization switching is typically accompanied by a cascade of bifurcations to wave-mixing dynamics and time-periodic and possibly chaotic regimes. A detailed mapping of the polarization dynamics in the plane of the injection parameters (detuning, injection strength) unveils a large richness of dynamical scenarios. Of particular interest is the existence of another injection-locked solution for which the two LP modes both lock to the master laser frequency, i.e., an elliptically polarized injection-locked (EPIL) steady state. Modern continuation techniques allow us to unveil an unfolding mechanism of the EPIL solution as the detuning varies and also to link the existence of the EPIL solution to a resonance condition between the master laser frequency and the free-running frequency of the normally depressed LP mode in the slave laser. We furthermore report an additional case of bistability, in which the EPIL solution may coexist with the second injection-locked solution (the one being locked to the master polarization). This case of bistability is a result of the interaction between optical injection and the two-polarization-mode characteristics of VCSEL devices.

  17. Damping of quasiparticles in a Bose-Einstein condensate coupled to an optical cavity

    NASA Astrophysics Data System (ADS)

    Kónya, G.; Szirmai, G.; Domokos, P.

    2014-07-01

    We present a general theory for calculating the damping rate of elementary density-wave excitations in a Bose-Einstein condensate strongly coupled to a single radiation field mode of an optical cavity. Thereby we give a detailed derivation of the huge resonant enhancement in the Beliaev damping of a density-wave mode, predicted recently by Kónya et al. [Phys. Rev. A 89, 051601(R) (2014), 10.1103/PhysRevA.89.051601]. The given density-wave mode constitutes the polaritonlike soft mode of the self-organization phase transition. The resonant enhancement takes place, in both the normal and the ordered phases, outside the critical region. We show that the large damping rate is accompanied by a significant frequency shift of this polariton mode. Going beyond the Born-Markov approximation and determining the poles of the retarded Green's function of the polariton, we reveal a strong coupling between the polariton and a collective mode in the phonon bath formed by the other density-wave modes.

  18. Energy-efficiency of optical network units with vertical-cavity surface-emitting lasers.

    PubMed

    Wong, Elaine; Mueller, Michael; Dias, Maluge P I; Chan, Chien Aun; Amann, Markus C

    2012-07-01

    The energy savings of 10 Gbps vertical-cavity surface-emitting lasers (VCSELs) for use in energy-efficient optical network units (ONUs) is critically examined in this work. We experimentally characterize and analytically show that the fast settling time and low power consumption during active and power-saving modes allow the VCSEL-ONU to achieve significant energy savings over the distributed feedback laser (DFB) based ONU. The power consumption per customer using VCSEL-ONUs and DFB-ONUs, is compared through an illustrative example of 10G-EPON for Video-on-Demand delivery. Using energy consumption models and numerical analyses in sleep and doze mode operations, we present an impact study of network and protocol parameters, e.g. polling cycle time, network load, and upstream access scheme used, on the achievable energy savings of VCSEL-ONUs over DFB-ONUs. Guidance on the specific power-saving mode to maximum energy savings throughout the day, is also presented. PMID:22772191

  19. Calibration of a Cavity Ring Down Spectrometry and Nephelometry Setup for Measuring Aerosol Optical Properties

    NASA Astrophysics Data System (ADS)

    Colon-Bernal, I. D.

    2014-12-01

    Aerosols have a great impact on climate and global warming which is not yet fully understood. We want to have a better understanding how of how the optical properties of biomass burning aerosols, coming from cooking and forest wildfires, interact with light and affect the Earths radiation budget and its impact on climate. Cavity Ring-Down Spectrometry and integrating Nephelometry was used to determine the extinction of scattering and absorbing polystyrene latex (PSL) spheres of 390 nm and 404nm respectfully and a soot sample of 400 nm. The extinction coefficients obtained for the scattering 404 nm PSL spheres, 390 nm absorbing PSL spheres and the soot sample were: 1.337E-05 m-1, 9.569E-05 m-1, and 2.200E-05 m-1 respectively. The Single Scattering Albedo was also obtained for the lab standards, which were 0.7077 for the scattering PSL spheres and 0.0643 for the absorbing PSL spheres. Samples for the flaming stage and smoldering stage were observed under a Scanning Electron Microscope (SEM) to study how their morphology varies from one stage to the other. We determined the soot sample can attenuate light but less than what our PSL spheres are capable of after comparing extinction cross-sections. Error correlations need to be determined for the 400 nm soot particles and be applied to our data. Lastly, different morphologies were observed for the two burning stages analyzed under the SEM.

  20. A selective optical sensor based on [9]mercuracarborand-3, a new type of ionophore with a chloride complexing cavity

    NASA Technical Reports Server (NTRS)

    Badr, I. H.; Johnson, R. D.; Diaz, M.; Hawthorne, M. F.; Bachas, L. G.; Daunert, S. (Principal Investigator)

    2000-01-01

    A highly selective optical sensor for chloride, based on the multidentate Lewis acid ionophore [9]mercuracarborand-3, is described herein. This sensor is constructed by embedding the mercuracarborand ionophore, a suitable pH-sensitive lipophilic dye, and lipophilic cationic sites in a plasticized polymeric membrane. The multiple complementary interactions offered by the preorganized complexing cavity of [9]mercuracarborand-3 is shown to control the anion selectivity pattern of the optical film. The film exhibits a significantly enhanced selectivity for chloride over a variety of lipophilic anions such as perchlorate, nitrate, salicylate, and thiocyanate. Furthermore, the optical selectivity coefficients obtained for chloride over other biologically relevant anions are shown to meet the selectivity requirements for the determination of chloride in physiological fluids, unlike previously reported chloride optical sensors. In addition, the optical film responds to chloride reversibly over a wide dynamic range (16 microM-136 mM) with fast response and recovery times.

  1. Electric dipole coupling in optical cavities and its implications for energy transfer, up-conversion, and pooling

    NASA Astrophysics Data System (ADS)

    LaCount, Michael D.; Lusk, Mark T.

    2016-06-01

    Resonant energy transfer, energy transfer up-conversion, and energy pooling are considered within optical cavities to elucidate the relationship between exciton dynamics and donor-acceptor separation distance. This is accomplished by using perturbation theory to derive analytic expressions for the electric dipole coupling tensors of perfect planar and rectangular channel reflectors—directly related to a number of important energy-transfer processes. In the near field, the separation dependence along the cavity axis is not influenced by the cavity and is essentially the same as for three-dimensional free space. This is in sharp contrast with the reduced sensitivity to separation found in idealized low-dimensional settings. The cavity dynamics only correspond to their reduced-dimensional counterparts in the far field where such excitonic processes are not typically of interest. There is an intermediate regime, though, where sufficiently small cavities cause a substantial decrease in separation sensitivity that results in one component of the dipole-dipole coupling tensor being much larger than those of free space.

  2. Multiphoton resonances for all-optical quantum logic with multiple cavities

    NASA Astrophysics Data System (ADS)

    Everitt, Mark S.; Garraway, Barry M.

    2014-07-01

    We develop a theory for the interaction of multilevel atoms with multimode cavities yielding cavity-enhanced multiphoton resonances. The locations of the resonances are predicted from the use of effective two- and three-level Hamiltonians. As an application we show that quantum gates can be realized when photonic qubits are encoded on the cavity modes in arrangements where ancilla atoms transit the cavity. The fidelity of operations is increased by conditional measurements on the atom and by the use of a selected, dual-rail, Hilbert space. A universal set of gates is proposed, including the Fredkin gate and iswap operation; the system seems promising for scalability.

  3. Simultaneous measurement of refractive index and temperature with micro silica sphere cavity hybrid Fabry Perot optical fiber sensor

    NASA Astrophysics Data System (ADS)

    Ranjbar Naeini, O. R.; Latifi, H.; Zibaii, M. I.

    2015-09-01

    In this article, a novel Micro Silica Sphere Cavity Hybrid Fabry Perot optical fiber sensor is reported where refractive index (RI) and temperature can be simultaneously measured. The sensor is based on Micro Silica Sphere that was fabricated using a capillary tube. The micro silica sphere and optical fiber form a Hybrid Fabry Perot cavity. The temperature cross sensitivity of this sensor is small enough to be used for accurate RI measurement. The temperature sensitivity and RI sensitivity are -0.0028 dBm/ºC, -0.0044 dBm/ºC , -24.09 dBm/RIU and -20.6 dBm/RIU respectively, using two selected resonances.

  4. Sub-kilohertz linewidth narrowing of a mid-infrared optical parametric oscillator idler frequency by direct cavity stabilization.

    PubMed

    Ricciardi, I; Mosca, S; Parisi, M; Maddaloni, P; Santamaria, L; De Natale, P; De Rosa, M

    2015-10-15

    We stabilize the idler frequency of a singly resonant optical parametric oscillator directly to the resonance of a mid-infrared Fabry-Perot reference cavity. This is accomplished by the Pound-Drever-Hall locking scheme, controlling either the pump laser or the resonant signal frequency. A residual relative frequency noise power spectral density below 10(3)  Hz(2)/Hz is reached on average, with a Gaussian linewidth of 920 Hz over 100 ms, which reveals the potential for reaching spectral purity down to the hertz level by locking the optical parametric oscillator against a mid-infrared cavity with state-of-the-art superior performance. PMID:26469609

  5. Nanofriction in Cavity Quantum Electrodynamics.

    PubMed

    Fogarty, T; Cormick, C; Landa, H; Stojanović, Vladimir M; Demler, E; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics. PMID:26684118

  6. Nanofriction in Cavity Quantum Electrodynamics

    NASA Astrophysics Data System (ADS)

    Fogarty, T.; Cormick, C.; Landa, H.; Stojanović, Vladimir M.; Demler, E.; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics.

  7. A novel approach to a PPM-modulated frequency-doubled electro-optic cavity-dumped Nd:YAG laser

    NASA Technical Reports Server (NTRS)

    Robinson, D. L.

    1989-01-01

    A technique which can provide frequency doubling, with high efficiency, while cavity dumping a laser for pulse position M-ary modulation while being used for an optical communication link is discussed. This approach uses a secondary cavity that provides feedback of the undoubled fundamental light, which is normally lost, into the primary cavity to be recirculated and frequency doubled. Specific operations of the electrooptic modulator and frequency-doubling crystal are described along with the overall modulation scheme and experimental setup.

  8. Cavity Enhanced Absorption Spectroscopy using a Prism Cavity and Supercontinuum Source

    NASA Astrophysics Data System (ADS)

    Lehmann, Kevin K.; Johnston, Paul S.

    2010-03-01

    The multiplex advantage of current cavity enhanced spectrometers is limited by the limited high reflectivity bandwidth of the dielectric mirrors used to construct the high finesse cavity. We report on our development of a spectrometer that uses Brewster's angle retroreflectors that is excited with supercontinuum radiation generated by a 1.06 μm pumped photonic crystal fiber, which covers the 500-1800 nm spectral range. Recent progress will be discussed including modeling of the prism cavity losses, alternative prism materials for use in the UV and mid-IR, and a new higher power source pumped by a mode-locked laser.

  9. Optical feedback cavity-enhanced absorption spectroscopy with a 3.24 μm interband cascade laser

    SciTech Connect

    Manfred, K. M.; Ritchie, G. A. D.; Lang, N.; Röpcke, J.; Helden, J. H. van

    2015-06-01

    The development of interband cascade lasers (ICLs) has made the strong C-H transitions in the 3 μm spectral region increasingly accessible. We present the demonstration of a single mode distributed feedback ICL coupled to a V-shaped optical cavity in an optical feedback cavity-enhanced absorption spectroscopy (OF-CEAS) experiment. We achieved a minimum detectable absorption coefficient, α{sub min}, of (7.1±0.2)×10{sup −8} cm{sup −1} for a spectrum of CH{sub 4} at 3.24 μm with a two second acquisition time (100 scans averaged). This corresponds to a detection limit of 3 ppb CH{sub 4} at atmospheric pressure, which is comparable to previously reported OF-CEAS instruments with diode lasers or quantum cascade lasers. The ability to frequency lock an ICL source in the important 3 μm region to an optical cavity holds great promise for future spectroscopic applications.

  10. Optimizing the external optical cavity parameters for performance improvement of a fiber grating Fabry-Perot laser

    NASA Astrophysics Data System (ADS)

    Hisham, Hisham Kadhum; Abas, Ahmad Fauzi; Amouzad Mahdiraji, Ghafour; Mahdi, Mohd Adzir; Mahamd Adikan, Faisal Rafiq

    2015-04-01

    The effects of the external optical cavity parameters (external optical cavity length ( L ext), amplitude coupling ( C o) and anti-reflection coating (ARC) reflectivity coefficients) on the noise and modulation spectra of a fiber grating Fabry-Perot laser are numerically analyzed for designing a laser that operates in strong feedback regime (Regime V). Fiber Bragg grating (FBG) is used as a wavelength selective element to control the properties of the laser output by controlling the external optical feedback (OFB) level. The study is performed by modifying a set of rate equations that are solved by considering the effects of external OFB and ambient temperature ( T) variations. We proposed a model to calculate the temperature dependence (TD) of laser characteristics according to the TD of laser parameters. An accurate analytical expression for the TD of threshold carrier density ( N th,fe) has been derived. The TD of N th,fe was calculated according to the TD of laser cavity parameters instead of using well-known empirical Pankove relationship via the use of characteristics temperature ( T o) and current ( I o). Results show that the optimum external fiber length ( L ext) is 3.1 cm. Also, it is shown that ARC with reflectivity value of 1 × 10-2 is sufficient for the laser to operate at low noise, good modulation response, and low fabrication complexity.

  11. Optically driven quantum dots as source of coherent cavity phonons: a proposal for a phonon laser scheme.

    PubMed

    Kabuss, Julia; Carmele, Alexander; Brandes, Tobias; Knorr, Andreas

    2012-08-01

    We present a microscopically based scheme for the generation of coherent cavity phonons (phonon laser) by an optically driven semiconductor quantum dot coupled to a THz acoustic nanocavity. External laser pump light on an anti-Stokes resonance creates an effective Lambda system within a two-level dot that leads to coherent phonon statistics. We use an inductive equation of motion method to estimate a realistic parameter range for an experimental realization of such phonon lasers. This scheme for the creation of nonequilibrium phonons is robust with respect to radiative and phononic damping and only requires optical Rabi frequencies of the order of the electron-phonon coupling strength. PMID:23006175

  12. Optical reflectance of pyrheliometer absorption cavities: progress toward SI-traceable measurements of solar irradiance.

    PubMed

    Patrick, Heather J; Germer, Thomas A; Zarobila, Clarence J; Cooksey, Catherine C; Yoon, Howard W

    2016-08-10

    We have accurately determined the absorptance of three pyrheliometer cavities at 532 nm by measuring the residual reflectance using an angle-resolved bidirectional reflectometer. Measurements were performed at a normal incidence as a function of the viewing angle and position on the cavity cone. By numerically integrating the measured angle-resolved scatter over both the direction and position and accounting for an obstructed view of the cavity, we determined that the effective cavity reflectance was between 8×10-4 and 9×10-4. Thus, the absorptance of the three cavities ranged from 0.99909±0.00014 to 0.99922±0.00012 (k=2 combined expanded uncertainties). These measurements, when extended over the spectral range of operation of the pyrheliometer, are required to establish SI traceability for absolute solar irradiance measurements. PMID:27534478

  13. Adiabatic transfer of light in a double cavity and the optical Landau-Zener problem

    SciTech Connect

    Miladinovic, N.; Hasan, F.; Linnington, I. E.; O'Dell, D. H. J.; Chisholm, N.; Hinds, E. A.

    2011-10-15

    We analyze the evolution of an electromagnetic field inside a double cavity when the difference in length between the two cavities is changed, e.g., by translating the common mirror. We find that this allows photons to be moved deterministically from one cavity to the other. We are able to obtain the conditions for adiabatic transfer by first mapping the Maxwell wave equation for the electric field onto a Schroedinger-like wave equation and then using the Landau-Zener result for the transition probability at an avoided crossing. Our analysis reveals that this mapping only rigorously holds when the two cavities are weakly coupled (i.e., in the regime of a highly reflective common mirror) and that, generally speaking, care is required when attempting a Hamiltonian description of cavity electrodynamics with time-dependent boundary conditions.

  14. The Measurement of Aerosol Optical Properties using Continuous Wave Cavity Ring-Down Techniques

    NASA Technical Reports Server (NTRS)

    Strawa, Anthony W.; Castaneda, Rene; Owano, Thomas; Baer, Douglas S.; Paldus, Barbara A.; Gore, Warren J. (Technical Monitor)

    2002-01-01

    Large uncertainties in the effects that aerosols have on climate require improved in situ measurements of extinction coefficient and single-scattering albedo. This paper describes the use of continuous wave cavity ring-down (CW-CRD) technology to address this problem. The innovations in this instrument are the use of CW-CRD to measure aerosol extinction coefficient, the simultaneous measurement of scattering coefficient, and small size suitable for a wide range of aircraft applications. Our prototype instrument measures extinction and scattering coefficient at 690 nm and extinction coefficient at 1550 nm. The instrument itself is small (60 x 48 x 15 cm) and relatively insensitive to vibrations. The prototype instrument has been tested in our lab and used in the field. While improvements in performance are needed, the prototype has been shown to make accurate and sensitive measurements of extinction and scattering coefficients. Combining these two parameters, one can obtain the single-scattering albedo and absorption coefficient, both important aerosol properties. The use of two wavelengths also allows us to obtain a quantitative idea of the size of the aerosol through the Angstrom exponent. Minimum sensitivity of the prototype instrument is 1.5 x 10(exp -6)/m (1.5 M/m). Validation of the measurement of extinction coefficient has been accomplished by comparing the measurement of calibration spheres with Mie calculations. This instrument and its successors have potential to help reduce uncertainty currently associated with aerosol optical properties and their spatial and temporal variation. Possible applications include studies of visibility, climate forcing by aerosol, and the validation of aerosol retrieval schemes from satellite data.

  15. The Measurement of Aerosol Optical Properties Using Continuous Wave Cavity Ring-Down Techniques

    NASA Technical Reports Server (NTRS)

    Strawa, A. W.; Owano, T.; Castaneda, R.; Baer, D. S.; Paldus, B. A.; Gore, Warren J. (Technical Monitor)

    2002-01-01

    Large uncertainties in the effects that aerosols have on climate require improved in-situ measurements of extinction coefficient and single-scattering albedo. This abstract describes the use of continuous wave cavity ring-down (CW-CRD) technology to address this problem. The innovations in this instrument are the use of CW-CRD to measure aerosol extinction coefficient, the simultaneous measurement of scattering coefficient, and small size suitable for a wide range of aircraft applications. Our prototype instrument measures extinction and scattering coefficient at 690 nm and extinction coefficient at 1550 nm. The instrument itself is small (60 x 48 x 15 cm) and relatively insensitive to vibrations. The prototype instrument has been tested in our lab and used in the field. While improvements in performance are needed, the prototype has been shown to make accurate and sensitive measurements of extinction and scattering coefficients. Combining these two parameters, one can obtain the single-scattering albedo and absorption coefficient, both important aerosol properties. The use of two wavelengths also allows us to obtain a quantitative idea of the size of the aerosol through the Angstrom exponent. Minimum sensitivity of the prototype instrument is 1.5 x 10(exp -6)/m (1.5/Mm). Validation of the measurement of extinction coefficient has been accomplished by comparing the measurement of calibration spheres with Mie calculations. This instrument and its successors have potential to help reduce uncertainty currently associated with aerosol optical properties and their spatial and temporal variation. Possible applications include studies of visibility, climate forcing by aerosol, and the validation of aerosol retrieval schemes from satellite data.

  16. Laser frequency stabilisation by the Pound - Drever - Hall method using an acousto-optic phase modulator operating in the pure Raman - Nath diffraction regime

    SciTech Connect

    Baryshev, Vyacheslav N

    2012-04-30

    Frequency stabilisation of diode laser radiation has been implemented by the Pound - Drever - Hall method using a new acousto-optic phase modulator, operating in the pure Raman - Nath diffraction regime. It is experimentally shown that, as in the case of saturated-absorption spectroscopy in atomic vapour, the spatial divergence of the frequency-modulated output spectrum of this modulator does not interfere with obtaining error signals by means of heterodyne frequency-modulation spectroscopy with a frequency discriminator based on a high-Q Fabry - Perot cavity with finesse of several tens of thousands.

  17. Conditional Spin Squeezing via Quantum Non-demolition Measurements with an Optical Cycling Transition

    NASA Astrophysics Data System (ADS)

    Weiner, Joshua; Cox, Kevin; Norcia, Matthew; Bohnet, Justin; Chen, Zilong; Thompson, James

    2013-04-01

    We present experimental progress towards quantum non-demolition (QND) measurements of the collective pseudo-spin Jz composed of the maximal mF hyperfine ground states of an ensemble of ˜10^5 ^87Rb atoms confined in a low finesse F = 710 optical cavity. Measuring the phase shift imposed by the atoms on a cavity probe field constitutes a QND measurement that can be used to prepare a conditionally spin squeezed state. By probing on a closed optical transition, we highly suppress both fundamental and technical noise due to Raman scattering compared to probing on an open transition. It may be possible to generate spin squeezed states with >10 dB enhancement in quantum phase estimation relative to the standard quantum limit. The resulting spin squeezed states may specifically enable magnetic field sensing beyond the standard quantum limit as well as broadly impact atomic sensors and tests of fundamental physics.

  18. Efficient optical coupling into a single plasmonic nanostructure using a fiber-coupled microspherical cavity

    NASA Astrophysics Data System (ADS)

    Takashima, Hideaki; Kitajima, Kazutaka; Tanaka, Yoshito; Fujiwara, Hideki; Sasaki, Keiji

    2014-02-01

    Toward complete coupling between propagating light (PL) and a single localized-surface-plasmon (LSP) nanostructure, we propose a tapered-fiber-coupled microspherical cavity system combining an Au-coated probe tip. This system possesses the unique characteristic of precise adjustability for the fiber-cavity coupling rate and the cavity-plasmon coupling rate, which is indispensable for achieving the critical coupling conditions. We successfully demonstrate the 93% PL coupling into the LSP antenna with an effective area of a 58 nm circle, exceeding the diffraction limit.

  19. Non-destructive assessment of cavity wall adaptation of class V composite restoration using swept-source optical coherence tomography.

    PubMed

    Senawongse, Pisol; Pongprueksa, Pong; Harnirattisai, Choltacha; Sumi, Yasunori; Otsuki, Masayuki; Shimada, Yasushi; Tagami, Junji

    2011-01-01

    The purpose of this study was to evaluate gap formations under class V restoration using swept-source optical coherence tomography (SS-OCT). Wedge-shaped cavities were prepared on the buccal surface of 40 extracted premolar teeth at 2 locations; 1) cemento-enamel junction (CEJ) with enamel and cementum margin and 2) root surfaces with cementum margin. The cavity was treated with Clearfil S(3) Bond, restored with Clearfil Majesty and polished with abrasive disks. The specimens were kept in water at 37°C for 24 hours and subjected to a thermocycling procedure. Gap formations at the tooth-restoration interface were measured with SS-OCT image and conventional dye leakage under a microscope. There was no effect of the locations of the cavity and the margins of the cavity on the gap formation. Therefore, a significant effect of the observational methods was observed. The gap formation was 0.89±0.48 mm with the SS-OCT, and the gap formation was 0.34±0.41 mm with the dye leakage. The observation with SS-OCT demonstrated a greater degree of gap formation than the observation with dye leakage. PMID:21778598

  20. High-peak-power optically-pumped AlGaInAs eye-safe laser with a silicon wafer as an output coupler: comparison between the stack cavity and the separate cavity.

    PubMed

    Wen, C P; Tuan, P H; Liang, H C; Tsou, C H; Su, K W; Huang, K F; Chen, Y F

    2015-11-30

    An intrinsic silicon wafer is exploited as an output coupler to develop a high-peak-power optically-pumped AlGaInAs laser at 1.52 μm. The gain chip is sandwiched with the diamond heat spreader and the silicon wafer to a stack cavity. It is experimentally confirmed that not only the output stability but also the conversion efficiency are considerably enhanced in comparison with the separate cavity in which the silicon wafer is separated from other components. The average output power obtained with the stack cavity was 2.02 W under 11.5 W average pump power, corresponding to an overall optical-to-optical efficiency of 17.5%; the slope efficiency was 18.6%. The laser operated at 100 kHz repetition rate and the pulse peak power was 0.4 kW. PMID:26698707

  1. GaInNAs-based Hellish-vertical cavity semiconductor optical amplifier for 1.3 μm operation.

    PubMed

    Chaqmaqchee, Faten Adel Ismail; Mazzucato, Simone; Oduncuoglu, Murat; Balkan, Naci; Sun, Yun; Gunes, Mustafa; Hugues, Maxime; Hopkinson, Mark

    2011-01-01

    Hot electron light emission and lasing in semiconductor heterostructure (Hellish) devices are surface emitters the operation of which is based on the longitudinal injection of electrons and holes in the active region. These devices can be designed to be used as vertical cavity surface emitting laser or, as in this study, as a vertical cavity semiconductor optical amplifier (VCSOA). This study investigates the prospects for a Hellish VCSOA based on GaInNAs/GaAs material for operation in the 1.3-μm wavelength range. Hellish VCSOAs have increased functionality, and use undoped distributed Bragg reflectors; and this coupled with direct injection into the active region is expected to yield improvements in the gain and bandwidth. The design of the Hellish VCSOA is based on the transfer matrix method and the optical field distribution within the structure, where the determination of the position of quantum wells is crucial. A full assessment of Hellish VCSOAs has been performed in a device with eleven layers of Ga0.35In0.65N0.02As0.08/GaAs quantum wells (QWs) in the active region. It was characterised through I-V, L-V and by spectral photoluminescence, electroluminescence and electro-photoluminescence as a function of temperature and applied bias. Cavity resonance and gain peak curves have been calculated at different temperatures. Good agreement between experimental and theoretical results has been obtained. PMID:21711630

  2. GaInNAs-based Hellish-vertical cavity semiconductor optical amplifier for 1.3 μm operation

    PubMed Central

    2011-01-01

    Hot electron light emission and lasing in semiconductor heterostructure (Hellish) devices are surface emitters the operation of which is based on the longitudinal injection of electrons and holes in the active region. These devices can be designed to be used as vertical cavity surface emitting laser or, as in this study, as a vertical cavity semiconductor optical amplifier (VCSOA). This study investigates the prospects for a Hellish VCSOA based on GaInNAs/GaAs material for operation in the 1.3-μm wavelength range. Hellish VCSOAs have increased functionality, and use undoped distributed Bragg reflectors; and this coupled with direct injection into the active region is expected to yield improvements in the gain and bandwidth. The design of the Hellish VCSOA is based on the transfer matrix method and the optical field distribution within the structure, where the determination of the position of quantum wells is crucial. A full assessment of Hellish VCSOAs has been performed in a device with eleven layers of Ga0.35In0.65N0.02As0.08/GaAs quantum wells (QWs) in the active region. It was characterised through I-V, L-V and by spectral photoluminescence, electroluminescence and electro-photoluminescence as a function of temperature and applied bias. Cavity resonance and gain peak curves have been calculated at different temperatures. Good agreement between experimental and theoretical results has been obtained. PMID:21711630

  3. Cavity ring-up spectroscopy for ultrafast sensing with optical microresonators

    NASA Astrophysics Data System (ADS)

    Rosenblum, Serge; Lovsky, Yulia; Arazi, Lior; Vollmer, Frank; Dayan, Barak

    2015-04-01

    Spectroscopy of whispering-gallery mode microresonators has become a powerful scientific tool, enabling the detection of single viruses, nanoparticles and even single molecules. Yet the demonstrated timescale of these schemes has been limited so far to milliseconds or more. Here we introduce a scheme that is orders of magnitude faster, capable of capturing complete spectral snapshots at nanosecond timescales--cavity ring-up spectroscopy. Based on sharply rising detuned probe pulses, cavity ring-up spectroscopy combines the sensitivity of heterodyne measurements with the highest-possible, transform-limited acquisition rate. As a demonstration, we capture spectra of microtoroid resonators at time intervals as short as 16 ns, directly monitoring submicrosecond dynamics of their optomechanical vibrations, thermorefractive response and Kerr nonlinearity. Cavity ring-up spectroscopy holds promise for the study of fast biological processes such as enzyme kinetics, protein folding and light harvesting, with applications in other fields such as cavity quantum electrodynamics and pulsed optomechanics.

  4. Two-dimensional infrared spectroscopy of vibrational polaritons of molecules in an optical cavity

    NASA Astrophysics Data System (ADS)

    Saurabh, Prasoon; Mukamel, Shaul

    2016-03-01

    Strong coupling of molecular vibrations to an infrared cavity mode affects their nature by creating dressed polariton states. We show how the single and double vibrational polariton manifolds may be controlled by varying the cavity coupling strength and probed by a time domain two-dimensional infrared (2DIR) technique, double quantum coherence. Applications are made to the amide-I (CO) and amide-II (CN) bond vibrations of N-methylacetamide.

  5. Two-dimensional infrared spectroscopy of vibrational polaritons of molecules in an optical cavity.

    PubMed

    Saurabh, Prasoon; Mukamel, Shaul

    2016-03-28

    Strong coupling of molecular vibrations to an infrared cavity mode affects their nature by creating dressed polariton states. We show how the single and double vibrational polariton manifolds may be controlled by varying the cavity coupling strength and probed by a time domain two-dimensional infrared (2DIR) technique, double quantum coherence. Applications are made to the amide-I (CO) and amide-II (CN) bond vibrations of N-methylacetamide. PMID:27036435

  6. Implementing a quantum cloning machine in separate cavities via the optical coherent pulse as a quantum communication bus

    NASA Astrophysics Data System (ADS)

    Zhu, Meng-Zheng; Ye, Liu

    2015-04-01

    An efficient scheme is proposed to implement a quantum cloning machine in separate cavities based on a hybrid interaction between electron-spin systems placed in the cavities and an optical coherent pulse. The coefficient of the output state for the present cloning machine is just the direct product of two trigonometric functions, which ensures that different types of quantum cloning machine can be achieved readily in the same framework by appropriately adjusting the rotated angles. The present scheme can implement optimal one-to-two symmetric (asymmetric) universal quantum cloning, optimal symmetric (asymmetric) phase-covariant cloning, optimal symmetric (asymmetric) real-state cloning, optimal one-to-three symmetric economical real-state cloning, and optimal symmetric cloning of qubits given by an arbitrary axisymmetric distribution. In addition, photon loss of the qubus beams during the transmission and decoherence effects caused by such a photon loss are investigated.

  7. Striped-double cavity fabry-perot interferometers using both glass and air cavities

    SciTech Connect

    Perry, S; Steinmetz, L

    1998-07-08

    We have used piezo-driven Fabry-Perot interferometers in the past far many continuous velocity-time measurements of fast moving surfaces. In order to avoid the annoying drift of some of these devices, we have developed and used inexpensive, solid glass, striped etalons with lengths up to 64 mm. Usable apertures are 35 mm by 80 mm with a finess of 25. A roundabout technique was devised for double cavity operation. We built a passive thermal housing for temperature stability, with tilt and height adjustments. We have also developed and used our first fixed etalon air-spaced cavity with a rotatable glass double- cavity insert. The rotation allows the referee cavity fractional order to be adjusted separately from that of the main cavity. It needs very little thermal protection, and eliminates the need for a roundabout scheme for double cavity operation, but is more costly than the solid glass version I

  8. Mode-cleaning and injection optics of the gravitational-wave detector GEO600

    NASA Astrophysics Data System (ADS)

    Goßler, S.; Casey, M. M.; Freise, A.; Grant, A.; Grote, H.; Heinzel, G.; Heurs, M.; Husman, M. E.; Kötter, K.; Leonhardt, V.; Lück, H.; Malec, M.; Mossavi, K.; Nagano, S.; McNamara, P. W.; Plissi, M. V.; Quetschke, V.; Robertson, D. I.; Robertson, N. A.; Rüdiger, A.; Schilling, R.; Skeldon, K. D.; Strain, K. A.; Torrie, C. I.; Ward, H.; Weiland, U.; Willke, B.; Winkler, W.; Hough, J.; Danzmann, K.

    2003-08-01

    The British-German interferometric gravitational-wave detector GEO600 uses two high-finesse triangular ring cavities of 8 m optical pathlength each, as an optical mode-cleaning system. The modecleaner system is housed in an ultrahigh-vacuum environment to avoid contamination of the optics and to minimize both the influence of refractive index variations of the air and acoustic coupling to the optics. To isolate the cavities from seismic noise, all optical components are suspended as double pendulums. These pendulums are damped at their resonance frequencies at the upper pendulum stage with magnet-coil actuators. A suspended reaction mass supports three coils matching magnets bonded onto the surface of one mirror of each cavity, allowing length control of the modecleaner cavities to maintain resonance with the laser light. A fully automated control system stabilizes the frequency of the slave laser to that of the master laser, the frequency of the master laser to the length of the first modecleaner and the length of the first to the length of the second modecleaner. The control system uses the Pound-Drever-Hall sideband technique and operates autonomously over long time periods with only infrequent human interaction. The duty cycle of the system was measured to be 99.7% during an 18 day period. The throughput of the whole modecleaner system is about 50%. In this article, we give an overview of the mechanical and optical setup and the achieved performance of the double modecleaner system.

  9. Optical-Fiber Thermal-Wave-Cavity Technique to Study Thermal Properties of Silver/Clay Nanofliuds

    NASA Astrophysics Data System (ADS)

    Noroozi, M.; Radiman, S.; Zakaria, A.; Shameli, K.; Deraman, M.; Soltaninejad, S.; Abedini, A.

    2014-10-01

    Thermal properties enhancement of nanofluids have varied strongly with synthesis technique, particle size and type, concentration and agglomeration with time. This study explores the possibility of changing the thermal wave signal of Ag/clay nanofluids into a thermal diffusivity measurement at well dispersion or aggregation of nanoparticles in the base fluid. Optical-Fiber Thermal-Wave-Cavity (OF-TWC) technique was achieved by using a small amount of nanofluid (only 0.2 mL) between fiber optic tip and the Pyroelectric detector and the cavity-length scan was performed. We established the accuracy and precision of this technique by comparing the thermal diffusivity of distilled water to values reported in the literature. Assuming a linear Pyroelectric signal response, the results show that adding clay reduced the thermal diffusivity of water, while increasing the Ag concentration from 1 to 5 wt.% increased the thermal diffusivity of the Ag nanofluid from 1.524×10-3 to 1.789×10-3 cm2/s. However, in particular, nanoparticles show the tendency to form aggregates over time that correlated with the performance change of thermal properties of nanofluid. Our results confirm the high sensitivity of OF-TWC technique raises the potential to be applied to measuring the optical and thermal properties of nanofluids. Furthermore, this technique allows the extraction of information not obtained using other traditional techniques.

  10. All-optical control of three-photon spectra and time asymmetry in a strongly coupled cavity polariton system

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Li, R.; Wu, Haibin

    2016-03-01

    Manipulating the nature of photons emission is one of the basic tasks in quantum optics and photonics. The ever growing list of quantum applications requires a robust means of controlling the strongly coupled coherent interaction of photons and matter. Here, we investigate three-photon transmission spectra in a strongly coupled cavity polariton system and show that the correlation functions and transmitted photon stream can be optically manipulated. The dynamics of single photons and photon pairs at the polariton resonances can be changed by light from a single external coupling laser. At the “dark-state polariton,” three-photon transmission is a perfectly coherent field in contrast to the strong photon-bunching behavior of a typical cavity quantum electrodynamics system. When the detuned probe light is tuned to the “bright polariton,” the light exhibits a dramatic photon antibunching effect. Remarkably, the Fano-resonant asymmetric three-photon transmission caused by the interference between the dressed states leads to a new quantum feature that is strongly nonclassical (the third-order correlation function g(3)(0, 0) ≪ 1) and has a wide and tunable bandwidth. The dependence of the intrinsic third-order correlation and time symmetry of the photon stream on the controlled parameters is also examined. Strongly nonclassical, all-optically controllable multi-photon dynamics are very important for future quantum devices and metrology.

  11. All-optical control of three-photon spectra and time asymmetry in a strongly coupled cavity polariton system

    PubMed Central

    Zhang, X.; Li, R.; Wu, Haibin

    2016-01-01

    Manipulating the nature of photons emission is one of the basic tasks in quantum optics and photonics. The ever growing list of quantum applications requires a robust means of controlling the strongly coupled coherent interaction of photons and matter. Here, we investigate three-photon transmission spectra in a strongly coupled cavity polariton system and show that the correlation functions and transmitted photon stream can be optically manipulated. The dynamics of single photons and photon pairs at the polariton resonances can be changed by light from a single external coupling laser. At the “dark-state polariton,” three-photon transmission is a perfectly coherent field in contrast to the strong photon-bunching behavior of a typical cavity quantum electrodynamics system. When the detuned probe light is tuned to the “bright polariton,” the light exhibits a dramatic photon antibunching effect. Remarkably, the Fano-resonant asymmetric three-photon transmission caused by the interference between the dressed states leads to a new quantum feature that is strongly nonclassical (the third-order correlation function g(3)(0, 0) ≪ 1) and has a wide and tunable bandwidth. The dependence of the intrinsic third-order correlation and time symmetry of the photon stream on the controlled parameters is also examined. Strongly nonclassical, all-optically controllable multi-photon dynamics are very important for future quantum devices and metrology. PMID:26936334

  12. All-optical control of three-photon spectra and time asymmetry in a strongly coupled cavity polariton system.

    PubMed

    Zhang, X; Li, R; Wu, Haibin

    2016-01-01

    Manipulating the nature of photons emission is one of the basic tasks in quantum optics and photonics. The ever growing list of quantum applications requires a robust means of controlling the strongly coupled coherent interaction of photons and matter. Here, we investigate three-photon transmission spectra in a strongly coupled cavity polariton system and show that the correlation functions and transmitted photon stream can be optically manipulated. The dynamics of single photons and photon pairs at the polariton resonances can be changed by light from a single external coupling laser. At the "dark-state polariton," three-photon transmission is a perfectly coherent field in contrast to the strong photon-bunching behavior of a typical cavity quantum electrodynamics system. When the detuned probe light is tuned to the "bright polariton," the light exhibits a dramatic photon antibunching effect. Remarkably, the Fano-resonant asymmetric three-photon transmission caused by the interference between the dressed states leads to a new quantum feature that is strongly nonclassical (the third-order correlation function g((3))(0, 0) ≪ 1) and has a wide and tunable bandwidth. The dependence of the intrinsic third-order correlation and time symmetry of the photon stream on the controlled parameters is also examined. Strongly nonclassical, all-optically controllable multi-photon dynamics are very important for future quantum devices and metrology. PMID:26936334

  13. Cavity enhanced terahertz modulation

    SciTech Connect

    Born, N.; Scheller, M.; Moloney, J. V.; Koch, M.

    2014-03-10

    We present a versatile concept for all optical terahertz (THz) amplitude modulators based on a Fabry-Pérot semiconductor cavity design. Employing the high reflectivity of two parallel meta-surfaces allows for trapping selected THz photons within the cavity and thus only a weak optical modulation of the semiconductor absorbance is required to significantly damp the field within the cavity. The optical switching yields to modulation depths of more than 90% with insertion efficiencies of 80%.

  14. High-power ultralow-noise semiconductor external cavity lasers based on low-confinement optical waveguide gain media

    NASA Astrophysics Data System (ADS)

    Juodawlkis, Paul W.; Loh, William; O'Donnell, Frederick J.; Brattain, Michael A.; Plant, Jason J.

    2010-02-01

    For the past several years, we have been developing a new class of high-power, low-noise semiconductor optical gain medium based on the slab-coupled optical waveguide (SCOW) concept. The key characteristics of the SCOW design are (i) large (> 5 x 5 μm), symmetric, fundamental-transverse-mode operation attained through a combination of coupledmode filtering and low index-contrast, (ii) very low optical confinement factor (Γ ~ 0.3-0.5%), and (iii) low excessoptical loss (αi ~ 0.5 cm-1). The large transverse mode and low confinement factor enables SCOW lasers (SCOWLs) and amplifiers (SCOWAs) having Watt-class output power. The low confinement factor also dictates that the waveguide length be very large (0.5-1 cm) to achieve useful gain, which provides the benefits of small ohmic and thermal resistance. In this paper, we review the operating principles and performance of the SCOW gain medium, and detail its use in 1550-nm single-frequency SCOW external cavity lasers (SCOWECLs). The SCOWECL consists of a doublepass, curved-channel InGaAlAs quantum-well SCOWA and a narrowband (2.5 GHz) fiber Bragg grating (FBG) external cavity. We investigate the impact of the cavity Q on SCOWECL performance by varying the FBG reflectivity. We show that a bench-top SCOWECL having a FBG reflectivity of R = 10% (R = 20%) has a maximum output power of 450 mW (400 mW), linewidth of 52 kHz (28 kHz), and RIN at 2-MHz offset frequency of -155 dB/Hz (-165 dB/Hz).

  15. Electro-optic harmonic conversion to switch a laser beam out of a cavity

    DOEpatents

    Haas, R.A.; Henesian, M.A.

    1984-10-19

    The present invention relates to switching laser beams out of laser cavities, and more particularly, it relates to the use of generating harmonics of the laser beam to accomplish the switching. When laser light is generatd in a laser cavity the problem arises of how to switch the laser light out of the cavity in order to make use of the resulting laser beam in a well known multitude of ways. These uses include range finding, communication, remote sensing, medical surgery, laser fusion applications and many more. The switch-out problem becomes more difficult as the size of the laser aperture grows such as in laser fusion applications. The final amplifier stages of the Nova and Novette lasers at Lawrence Livermore National Laboratory are 46 centimeters with the laser beam expanded to 74 centimeters thereafter. Larger aperture lasers are planned.

  16. Enhanced sensitivity of a passive optical cavity by an intracavity dispersive medium

    SciTech Connect

    Smith, David D.; Myneni, Krishna; Odutola, Jamiu A.; Diels, J. C.

    2009-07-15

    The pushing of the modes of a Fabry-Perot cavity by an intracavity rubidium cell is measured. The scale factor of the modes is increased by the anomalous dispersion and is inversely proportional to the sum of the effective group index and an additional cavity delay factor that arises from the variation of the Rb absorption over a free spectral range. This additional positive feedback further increases the effect of the anomalous dispersion and goes to zero at the lasing threshold. The mode width does not grow as fast as the scale factor as the intracavity absorption is increased resulting in enhanced measurement sensitivities. For absorptions larger than the scale factor pole, the atom-cavity response is multivalued and mode splitting occurs.

  17. Evanescent-wave comb spectroscopy of liquids with strongly dispersive optical fiber cavities

    NASA Astrophysics Data System (ADS)

    Avino, S.; Giorgini, A.; Salza, M.; Fabian, M.; Gagliardi, G.; De Natale, P.

    2013-05-01

    We demonstrate evanescent-wave fiber cavity-enhanced spectroscopy in the liquid phase using a near-infrared frequency comb. Exploiting strong fiber-dispersion effects, we show that liquid absorption spectra can be recorded without any external dispersive element. The fiber cavity is used both as sensor and spectrometer. The resonance modes are frequency locked to the comb teeth while the cavity photon lifetime is measured over 155 nm, from 1515 nm to 1670 nm, where absorption bands of liquid polyamines are detected as a proof of concept. Our fiber spectrometer lends itself to in situ, real-time chemical analysis in environmental monitoring, biomedical assays, and micro-opto-fluidic systems.

  18. Mitigating parametric instability in optical gravitational wave detectors

    NASA Astrophysics Data System (ADS)

    Matsko, Andrey B.; Poplavskiy, Mikhail V.; Yamamoto, Hiroaki; Vyatchanin, Sergey P.

    2016-04-01

    Achieving quantum limited sensitivity in a laser interferometric gravitational wave detector can be hindered by an optomechanical parametric instability of the interferometer. This instability is sustained by a large number of idle high-finesse Stokes modes supported by the system. We show that by optimizing the geometrical shape of the mirrors of the detector, one reduces the diffraction-limited finesse of unessential optical modes and effectively increases the instability threshold. Utilizing parameters of the Advanced LIGO system as a reference, we find that the proposed technique allows constructing a Fabry-Perot interferometer with round-trip diffraction loss of the fundamental mode not exceeding 5 ppm, whereas the loss of the first dipole as well as the other high-order modes exceeds 1000 ppm and 8000 ppm, respectively. This is 2 orders of magnitude higher if compared with a conventional Advanced LIGO interferometer. The optimization comes at the price of tighter tolerances on the mirror tilt stability, but it does not result in a significant modification of the optical beam profile and does not require changes in the gravity detector readout system. The cavity with proposed mirrors is also stable with respect to the slight modification of the mirror shape.

  19. An Optical Offgas Sensor Network Incorporating a HG Cavity Ringdown Spectrometer and IR Diode Lasers

    SciTech Connect

    George P. Miller

    2007-12-30

    A multi-element cavity ringdown system was evaluated with the objective of developing an intelligent sensor network to be incorporated into the control systems for advanced coal combustion facilities. Using a combination of a YAG-pumped dye laser and a tunable NIR/IR laser a dual cavity was constructed and a labview program was developed to provide multi-channel, real-time data to permit the real-time monitoring of typical exhaust emission gases, (for example: CO{sub 2}, SO{sub 2}, and mercury) of concern to the next generation of coal-powered facilities.

  20. Geometry Effects on Multipole Components and Beam Optics in High-Velocity Multi-Spoke Cavities

    SciTech Connect

    Hopper, Christopher S.; Deitrick, Kirsten E.; Delayen, Jean R.

    2013-12-01

    Velocity-of-light, multi-spoke cavities are being proposed to accelerate electrons in a compact light-source. There are strict requirements on the beam quality which require that the linac have only small non-uniformities in the accelerating field. Beam dynamics simulations have uncovered varying levels of focusing and defocusing in the proposed cavities, which is dependent on the geometry of the spoke in the vicinity of the beam path. Here we present results for the influence different spoke geometries have on the multipole components of the accelerating field and how these components, in turn, impact the simulated beam properties.

  1. Optical coherence tomography based imaging of dental demineralisation and cavity restoration in 840 nm and 1310 nm wavelength regions

    NASA Astrophysics Data System (ADS)

    Damodaran, Vani; Rao, Suresh Ranga; Vasa, Nilesh J.

    2016-08-01

    In this paper, a study of in-house built optical coherence tomography (OCT) system with a wavelength of 840 nm for imaging of dental caries, progress in demineralisation and cavity restoration is presented. The caries when imaged with the 840 nm OCT system showed minute demineralisation in the order of 5 μm. The OCT system was also proposed to study the growth of lesion and this was demonstrated by artificially inducing caries with a demineralisation solution of pH 4.8. The progress of carious lesion to a depth of about 50-60 μm after 60 hours of demineralisation was clearly observed with the 840 nm OCT system. The tooth samples were subjected to accelerated demineralisation condition at pH of approximately 2.3 to study the adverse effects and the onset of cavity formation was clearly observed. The restoration of cavity was also studied by employing different restorative materials (filled and unfilled). In the case of restoration without filler material (unfilled), the restoration boundaries were clearly observed. Overall, results were comparable with that of the widely used 1310 nm OCT system. In the case of restoration with filler material, the 1310 nm OCT imaging displayed better imaging capacity due to lower scattering than 840 nm imaging.

  2. Optical switching in bistable active cavity containing nonlinear absorber on bacteriorhodopsin

    NASA Astrophysics Data System (ADS)

    Bazhenov, Vladimir Y.; Taranenko, Victor B.; Vasnetsov, Mikhail V.

    1993-04-01

    The transverse nonlinear dynamics of switchings in an active system (laser with nonlinear saturable absorber on bacteriorhodopsin in a self-imaging cavity) is studied both experimentally and theoretically. The soliton-like light field structure formation and continuously cycled self-switching process are investigated.

  3. Cavity ring-up spectroscopy for ultrafast sensing with optical microresonators

    PubMed Central

    Rosenblum, Serge; Lovsky, Yulia; Arazi, Lior; Vollmer, Frank; Dayan, Barak

    2015-01-01

    Spectroscopy of whispering-gallery mode microresonators has become a powerful scientific tool, enabling the detection of single viruses, nanoparticles and even single molecules. Yet the demonstrated timescale of these schemes has been limited so far to milliseconds or more. Here we introduce a scheme that is orders of magnitude faster, capable of capturing complete spectral snapshots at nanosecond timescales—cavity ring-up spectroscopy. Based on sharply rising detuned probe pulses, cavity ring-up spectroscopy combines the sensitivity of heterodyne measurements with the highest-possible, transform-limited acquisition rate. As a demonstration, we capture spectra of microtoroid resonators at time intervals as short as 16 ns, directly monitoring submicrosecond dynamics of their optomechanical vibrations, thermorefractive response and Kerr nonlinearity. Cavity ring-up spectroscopy holds promise for the study of fast biological processes such as enzyme kinetics, protein folding and light harvesting, with applications in other fields such as cavity quantum electrodynamics and pulsed optomechanics. PMID:25873232

  4. Cavity ring-up spectroscopy for ultrafast sensing with optical microresonators.

    PubMed

    Rosenblum, Serge; Lovsky, Yulia; Arazi, Lior; Vollmer, Frank; Dayan, Barak

    2015-01-01

    Spectroscopy of whispering-gallery mode microresonators has become a powerful scientific tool, enabling the detection of single viruses, nanoparticles and even single molecules. Yet the demonstrated timescale of these schemes has been limited so far to milliseconds or more. Here we introduce a scheme that is orders of magnitude faster, capable of capturing complete spectral snapshots at nanosecond timescales-cavity ring-up spectroscopy. Based on sharply rising detuned probe pulses, cavity ring-up spectroscopy combines the sensitivity of heterodyne measurements with the highest-possible, transform-limited acquisition rate. As a demonstration, we capture spectra of microtoroid resonators at time intervals as short as 16 ns, directly monitoring submicrosecond dynamics of their optomechanical vibrations, thermorefractive response and Kerr nonlinearity. Cavity ring-up spectroscopy holds promise for the study of fast biological processes such as enzyme kinetics, protein folding and light harvesting, with applications in other fields such as cavity quantum electrodynamics and pulsed optomechanics. PMID:25873232

  5. Numerical analysis of optical bistability based on Fiber Bragg Grating cavity containing a high nonlinearity doped-fiber

    NASA Astrophysics Data System (ADS)

    Zang, Zhigang

    2012-03-01

    We demonstrate a new optical bistability devise by using two Fiber Bragg Gratings (FBG), in which an erbium-doped fiber (EDF) is inserted to form a nonlinear Fabry-Perot cavity (EDF FBG/F-P). The operation principle of this device is described by the resonant nonlinearity theory combining with the transfer matrix method. The optical bistability behaviors under different parameters are investigated. It shows that EDF FBG/F-P device has an evident merit in reducing the threshold switching power to 7 mW, resulting in a reduction about 6 orders, compared with that of single FBG device. Moreover, the ultra-fast response time about 35 ps is also confirmed.

  6. Circular polarization switching and bistability in an optically injected 1300 nm spin-vertical cavity surface emitting laser

    SciTech Connect

    Alharthi, S. S. Henning, I. D.; Adams, M. J.; Hurtado, A.; Korpijarvi, V.-M.; Guina, M.

    2015-01-12

    We report the experimental observation of circular polarization switching (PS) and polarization bistability (PB) in a 1300 nm dilute nitride spin-vertical cavity surface emitting laser (VCSEL). We demonstrate that the circularly polarized optical signal at 1300 nm can gradually or abruptly switch the polarization ellipticity of the spin-VCSEL from right-to-left circular polarization and vice versa. Moreover, different forms of PS and PB between right- and left-circular polarizations are observed by controlling the injection strength and the initial wavelength detuning. These results obtained at the telecom wavelength of 1300 nm open the door for novel uses of spin-VCSELs in polarization sensitive applications in future optical systems.

  7. Overview of NASA Finesse (Field Investigations to Enable Solar System Science and Exploration) Science and Exploration Project

    NASA Technical Reports Server (NTRS)

    Heldmann, J. L.; Lim, D.S.S.; Hughes, S.; Nawotniak, S. Kobs; Garry, B.; Sears, D.; Neish, C.; Osinski, G. R.; Hodges, K.; Downs, M.; Busto, J.; Cohen, B.; Caldwell, B.; Jones, A. J. P.; Johnson, S.; Kobayashi, L.; Colaprete, A.

    2016-01-01

    NASA's FINESSE (Field Investigations to Enable Solar System Science and Exploration) project was selected as a research team by NASA's Solar System Exploration Research Virtual Institute (SSERVI). SSERVI is a joint Institute supported by NASA's Science Mission Directorate (SMD) and Human Exploration and Operations Mission Directorate (HEOMD). As such, FINESSE is focused on a science and exploration field-based research program to generate strategic knowledge in preparation for human and robotic exploration of other planetary bodies including our Moon, Mars moons Phobos and Deimos, and near-Earth asteroids. FINESSE embodies the philosophy that "science enables exploration and exploration enables science".

  8. Theoretical modeling of optical properties of Ag8 and Ag14 silver clusters embedded in an LTA sodalite zeolite cavity.

    PubMed

    Cuong, Ngo Tuan; Nguyen, Hue Minh Thi; Nguyen, Minh Tho

    2013-10-01

    Optical properties of silver Ag(n) nanoclusters are demonstrated to be dependent on their size, structure and charge state. It is found that when being contained in the sodalite cavity of LTA zeolite the tetradecanuclear hexacation silver cluster Ag14(6+) is stable. Its lower-lying states and optical spectrum are theoretically determined using the quantum chemical TD-DFT method. Its ground state possesses an outer-shell electron configuration of A1g(2)T2g(6) mimicking the s(2)p(6) valence of noble gas atoms. These frontier orbitals are constructed from 5s,5p(Ag)-AOs with contributions from framework oxygen atoms. Light absorption of Ag14(6+) embedded in the sodalite cage which is characterized by strong peaks centered at 331 and 476 nm (transitions 5s,p(Ag) → 5s,p(Ag)) leads to much longer wavelength emission. The sodalite cage, as a container, stabilizes the central Ag14(6+) cluster by electrostatic attraction. The absorption spectrum of the isovalent neutral Ag8 cluster embedded inside the same sodalite cavity is also simulated using TD-DFT and CASPT2 methods. This absorption spectrum which is similar to that of the Ag14(6+) cluster has two absorption bands in the near UV and visible regions. PMID:23936902

  9. Measurement of refractive index and size of microparticles by optical traps generated by vertical cavity surface emitting lasers

    NASA Astrophysics Data System (ADS)

    Flynn, Richard A.

    Optical trapping is a powerful tool in the biological sciences for manipulating cells, bacteria, viruses and organelles within cells. Optical traps can measure tiny biological forces on the order of picoNewtons or less. Currently particle manipulation and force measurement are the two main applications of optical traps. Conventional optical traps are generated by large expensive lasers aligned to full sized laboratory microscopes. In this era lab-on-a-chip bioanalysis technologies, the trapping laser must be miniaturized while the analysis capabilities of optical traps should be expanded to address a larger span of applications. The research that forms the basis of this dissertation involves the use of Vertical Cavity Surface Emitting Lasers (VCSELs) that are compact and arrayable for optical trapping and toward the development of a new and parallel method to measure the refractive index and size of a particle within an optical trap. The current best technique for measuring refractive index of a microparticle, refractometry, requires changing the fluid composition of the sample. The proposed optical trap technique works with any transparent fluid, a significant advantage for biological analysis. VCSEL arrays are applied to create arrays of optical traps. VCSEL arrays offer a low cost, low power, compact and arrayable solution to creating many simultaneous optical traps in parallel. VCSEL traps are shown to manipulate 3x3 arrays of biological cells. Cell types manipulated include red blood cells, yeast cells, NIH 3T3 Murine fibroblasts and rat primary hepatocytes. Forces exerted by VCSEL traps are quantified. Scaling of the array size is analyzed. VCSEL traps are applied to creating a co-culture of fibroblasts and hepatocytes, enabling the study of intracellular communication. Finally, VCSELS are shown to cause negligible damage to hepatocytes after 5 min exposure. The counter-propagating optical trap measurement (COTM) system extends the capabilities of optical

  10. Periodic error characterization in commercial heterodyne interferometer using an external cavity diode laser based Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Zhu, Minhao; Wei, Haoyun; Li, Yan

    2014-07-01

    Periodic error is a main error source that limits the measurement accuracy in heterodyne laser interferometry. An external cavity diode laser (ECDL) based Fabry-Perot (F-P) interferometer referenced to an optical frequency comb (OFC) is proposed to characterize the periodic error in heterodyne interferometers. The Pound-Drever-Hall locking technique is employed to lock the tracking ECDL frequency to the resonance of a high finesse F-P cavity. The frequency of a reference ECDL is locked to a selected mode of an OFC to generate a stable single optical frequency. The frequency change of the tracking ECDL induced by the cavity displacement is measured by beating with the reference ECDL locked to the OFC. Experiments show that the F-P interferometer system has a displacement resolution of 1.96 pm. We compared the measurement results of our system with a commercial plane mirror heterodyne interferometer. The period if the periodic error is about half wavelength, with an error amplitude of 4.8 nm.

  11. Design study of an optical cavity for a future photon collider at ILC

    NASA Astrophysics Data System (ADS)

    Klemz, G.; Mönig, K.; Will, I.

    2006-08-01

    Hard photons well above 100 GeV have to be generated in a future photon collider which essentially will be based on the infrastructure of the planned International Linear Collider (ILC). The energy of near-infrared laser photons will be boosted by Compton backscattering against a high-energy relativistic electron beam. For high effectiveness, a very powerful laser system is required that exceeds today's state-of-the-art capabilities. In this paper a design of an auxiliary passive cavity is discussed that resonantly enhances the peak-power of the laser. The properties and prospects of such a cavity are addressed on the basis of the specifications for the European TeV Energy Superconducting Linear Accelerator (TESLA) proposal. Those of the ILC are expected to be similar.

  12. Experimental Demonstration of Frequency Autolocking an Optical Cavity Using a Time-Varying Kalman Filter

    NASA Astrophysics Data System (ADS)

    Schütte, Dirk; Hassen, S. Z. Sayed; Karvinen, Kai S.; Boyson, Toby K.; Kallapur, Abhijit G.; Song, Hongbin; Petersen, Ian R.; Huntington, Elanor H.; Heurs, Michèle

    2016-01-01

    We propose and demonstrate a new autolocking scheme using a three-mirror ring cavity consisting of a linear quadratic regulator and a time-varying Kalman filter. Our technique does not require a frequency scan to acquire resonance. We utilize the singular perturbation method to simplify our system dynamics and to permit the application of linear control techniques. The error signal combined with the transmitted power is used to estimate the cavity detuning. This estimate is used by a linear time-varying Kalman filter which enables the implementation of an optimal controller. The experimental results validate the controller design, and we demonstrate improved robustness to disturbances and a faster locking time than a traditional proportional-integral controller. More important, the time-varying Kalman filtering approach automatically reacquires lock for large detunings, where the error signal leaves its linear capture range, a feat which linear time-invariant controllers cannot achieve.

  13. Toward a broadband astro-comb: effects of nonlinear spectral broadening in optical fibers.

    PubMed

    Chang, Guoqing; Li, Chih-Hao; Phillips, David F; Walsworth, Ronald L; Kärtner, Franz X

    2010-06-01

    We propose and analyze a new approach to generate a broadband astro-comb by spectral broadening of a narrowband astro-comb inside a highly nonlinear optical fiber. Numerical modeling shows that cascaded four-wave-mixing dramatically degrades the input comb's side-mode suppression and causes side-mode amplitude asymmetry. These two detrimental effects can systematically shift the center-of-gravity of astro-comb spectral lines as measured by an astrophysical spectrograph with resolution approximately 100,000; and thus lead to wavelength calibration inaccuracy and instability. Our simulations indicate that this performance penalty, as a result of nonlinear spectral broadening, can be compensated by using a filtering cavity configured for double-pass. As an explicit example, we present a design based on an Yb-fiber source comb (with 1 GHz repetition rate) that is filtered by double-passing through a low finesse cavity (finesse = 208), and subsequent spectrally broadened in a 2-cm, SF6-glass photonic crystal fiber. Spanning more than 300 nm with 16 GHz line spacing, the resulting astro-comb is predicted to provide 1 cm/s (approximately 10 kHz) radial velocity calibration accuracy for an astrophysical spectrograph. Such extreme performance will be necessary for the search for and characterization of Earth-like extra-solar planets, and in direct measurements of the change of the rate of cosmological expansion. PMID:20588402

  14. Sensitive and Instantaneous Molecular Detection from Broadband Cavity-Enhanced Dual Comb Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bernhardt, B.; Ozawa, A.; Jacquey, M.; Jacquet, P.; Guelachvili, G.; Udem, T.; Holzwarth, R.; Kobayashi, Y.; Hänsch, T. W.; Picqué, N.

    2010-06-01

    Recent experiments have demonstrated that the precisely spaced spectral lines of a laser frequency comb can be harnessed for new techniques of multi-heterodyne Fourier transform spectroscopy (also called dual-comb spectroscopy) of molecules. In one such experiment, an absorbing molecular gas was placed inside an optical cavity that is matched to the laser resonator so that it is resonant for each comb line. The sensitivity for weak absorption is much enhanced, as in cavity ring-down spectroscopy. The light transmitted by the cavity is superimposed on a second frequency comb with slightly different repetition frequency. A single fast photodetector then produces an output signal with a comb of radio frequencies due to interference between pairs of optical comb lines. The optical spectrum is thus effectively mapped into the radio frequency regime, where it becomes accessible to fast digital signal processing. Experimental proof-of-principle is carried out in the near-infrared 1 μm region. An Yb-doped fiber frequency comb is coherently coupled to a passive resonator with a finesse of 1200, resulting in an effective interaction length between the light and the gas enhanced to 880m. The weak 3ν1 band of ammonia is rotationally resolved for the first time to our knowledge. Recording times of 18 μs are enough to span 220 cm-1 with a resolution of 0.15 cm-1. The signal to noise ratio of 380 leads to a minimum-detectable-absorption coefficient αmin of 3×10-8 cm-1 . B. Bernhardt, A. Ozawa, P. Jacquet, M. Jacquey, Y. Kobayashi, T. Udem, R. Holzwarth, G. Guelachvili, T.W. Hänsch, N. Picqué, Cavity-enhanced dual-comb spectroscopy, Nature Photonics 4, 55-57 (2010),

  15. Simulation of Optical Resonators for Vertical-Cavity Surface-Emitting Lasers (vcsel)

    NASA Astrophysics Data System (ADS)

    Mansour, Mohy S.; Hassen, Mahmoud F. M.; El-Nozahey, Adel M.; Hafez, Alaa S.; Metry, Samer F.

    2010-04-01

    Simulation and modeling of the reflectivity and transmissivity of the multilayer DBR of VCSEL, as well as inside the active region quantum well are analyzed using the characteristic matrix method. The electric field intensity distributions inside such vertical-cavity structure are calculated. A software program under MATLAB environment is constructed for the simulation. This study was performed for two specific Bragg wavelengths 980 nm and 370 nm for achieving a resonant periodic gain (RPG)

  16. Ring resonant cavities for spectroscopy

    DOEpatents

    Zare, Richard N.; Martin, Juergen; Paldus, Barbara A.; Xie, Jinchun

    1999-01-01

    Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS).

  17. Ring resonant cavities for spectroscopy

    DOEpatents

    Zare, R.N.; Martin, J.; Paldus, B.A.; Xie, J.

    1999-06-15

    Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS). 6 figs.

  18. Harmonic distortion dependent on optical feedback, temperature and injection current in a vertical cavity surface emitting laser

    NASA Astrophysics Data System (ADS)

    Nazhan, Salam; Ghassemlooy, Zabih; Busawon, Krishna

    2016-04-01

    In this paper, selective optical feedback is used to investigate the nonlinearity behaviours of a vertical cavity surface emitting laser (VCSEL) with the modulation signal. A single mode VCSEL with both parallel and orthogonal optical feedback (OF) signals modulated at 1 MHz frequency over a range of modulation depth is investigated. We also investigate the nonlinear characteristics of the orthogonal polarization modes XP and YP of the VCSEL by changing the injection current and temperature. The results show an enhancement in the harmonic distortions (HDs) of both XP and YP modes with parallel OF, and the total suppression of HDs with orthogonal OF. We show that for the VCSEL with orthogonal OF, the second and third harmonic components of the XP and YP modes decrease and reach the noise floor level of the output power spectrum. Additionally, peaks of second and third harmonic components change radically when varying the bias current and temperature. The results reveal that orthogonal OF can be employed as a new tool to improve the linear dynamic range and to control the nonlinear characteristics of the VCSEL, thus making these devices a promising optical source in present and future optical communication applications.

  19. Giant enhancement of optical high-order sideband generation and their control in a dimer of two cavities with gain and loss

    NASA Astrophysics Data System (ADS)

    Li, Jiahui; Li, Jiahua; Xiao, Qian; Wu, Ying

    2016-06-01

    Parity-time (PT ) symmetric systems, which rely on the balanced gain-loss condition and render the Hamiltonian non-Hermitian, have provided a new platform to engineer effective light-matter interactions in recent years. Here we explore the high-order sideband features of the output fields obtained from a PT -symmetric optical system consisting of a passive nonlinear cavity coupled to an active linear cavity. By employing a perturbation technique, we derive analytic formulas used to determine the nonlinear transmission coefficient of optical second-order sideband in this structure. Using experimentally achievable parameters, it is clearly shown that the efficiency of the second-order sideband generation can be greatly enhanced in the PT -symmetric dimer, extremely in the vicinity of the transition point from unbroken- to broken-PT regimes. Moreover, we further analyzed the influences of the system parameters, including the photon-tunneling rate between two cavities, Kerr nonlinearity strength, and optical detuning, on the second-order sideband generation. Subsequently we investigate the higher-order sideband output spectrum by numerical simulations, where the sideband amplitude also is largely enhanced in the PT -symmetric arrangement, compared with the passive-passive double-cavity system. Our obtained results provide a new avenue for acquiring optical high-order sidebands and operating light, which may inspire further applications in chip-scale optical communications and optical frequency combs.

  20. Optical Bragg, atomic Bragg and cavity QED detections of quantum phases and excitation spectra of ultracold atoms in bipartite and frustrated optical lattices

    SciTech Connect

    Ye, Jinwu; Zhang, K.Y.; Li, Yan; Chen, Yan; Zhang, W.P.

    2013-01-15

    Ultracold atoms loaded on optical lattices can provide unprecedented experimental systems for the quantum simulations and manipulations of many quantum phases and quantum phase transitions between these phases. However, so far, how to detect these quantum phases and phase transitions effectively remains an outstanding challenge. In this paper, we will develop a systematic and unified theory of using the optical Bragg scattering, atomic Bragg scattering or cavity QED to detect the ground state and the excitation spectrum of many quantum phases of interacting bosons loaded in bipartite and frustrated optical lattices. The physically measurable quantities of the three experiments are the light scattering cross sections, the atom scattered clouds and the cavity leaking photons respectively. We show that the two photon Raman transition processes in the three detection methods not only couple to the density order parameter, but also the valence bond order parameter due to the hopping of the bosons on the lattice. This valence bond order coupling is very sensitive to any superfluid order or any valence bond (VB) order in the quantum phases to be probed. These quantum phases include not only the well-known superfluid and Mott insulating phases, but also other important phases such as various kinds of charge density waves (CDW), valence bond solids (VBS), and CDW-VBS phases with both CDW and VBS orders unique to frustrated lattices, and also various kinds of supersolids. We analyze respectively the experimental conditions of the three detection methods to probe these various quantum phases and their corresponding excitation spectra. We also address the effects of a finite temperature and a harmonic trap. We contrast the three scattering methods with recent in situ measurements inside a harmonic trap and argue that the two kinds of measurements are complementary to each other. The combination of both kinds of detection methods could be used to match the combination of

  1. Cavity ring-down spectroscopy sensor for detection of hydrogen chloride

    NASA Astrophysics Data System (ADS)

    Hagen, C. L.; Lee, B. C.; Franka, I. S.; Rath, J. L.; VandenBoer, T. C.; Roberts, J. M.; Brown, S. S.; Yalin, A. P.

    2013-08-01

    A laser-based cavity ring-down spectroscopy (CRDS) sensor for measurement of hydrogen chloride (HCl) has been developed and characterized. The instrument uses light from a distributed-feedback diode laser at 1742 nm coupled to a high finesse optical cavity to make sensitive and quantifiable concentration measurements of HCl based on optical absorption. The instrument has a (1σ) limit of detection of < 20 pptv in 1 min and has high specificity to HCl. The measurement response time to changes in input HCl concentration is < 15 s. Validation studies with a previously calibrated permeation tube setup show an accuracy of better than 10%. The CRDS sensor was preliminarily tested in the field with two other HCl instruments (mist chamber and chemical ionization mass spectrometry), all of which were in broad agreement. The mist chamber and CRDS sensors both showed a 400 pptv plume within 50 pptv agreement. The sensor also allows simultaneous sensitive measurements of water and methane, and minimal hardware modification would allow detection of other near-infrared absorbers.

  2. Cavity ring-down spectroscopy sensor for detection of hydrogen chloride

    NASA Astrophysics Data System (ADS)

    Hagen, C. L.; Lee, B. C.; Franka, I. S.; Rath, J. L.; VandenBoer, T. C.; Roberts, J. M.; Brown, S. S.; Yalin, A. P.

    2014-02-01

    A laser-based cavity ring-down spectroscopy (CRDS) sensor for measurement of hydrogen chloride (HCl) has been developed and characterized. The instrument uses light from a distributed-feedback diode laser at 1742 nm coupled to a high finesse optical cavity to make sensitive and quantifiable concentration measurements of HCl based on optical absorption. The instrument has a (1σ) limit of detection of <20 pptv in 1 min and has high specificity to HCl. The measurement response time to changes in input HCl concentration is <15 s. Validation studies with a previously calibrated permeation tube setup show an accuracy of better than 10%. The CRDS sensor was preliminarily tested in the field with two other HCl instruments (mist chamber and chemical ionization mass spectrometry), all of which were in broad agreement. The mist chamber and CRDS sensors both showed a 400 pptv plume within 50 pptv agreement. The sensor also allows simultaneous sensitive measurements of water and methane, and minimal hardware modification would allow detection of other near-infrared absorbers.

  3. Frequency-switchable microwave generation based on a dual-wavelength single-longitudinal-mode fiber laser incorporating a high-finesse ring filter.

    PubMed

    Pan, Shilong; Yao, Jianping

    2009-07-01

    A wavelength-switchable single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber laser (EDFL) incorporating a novel high-finesse ring filter is proposed and demonstrated. The ring filter consists of two optical couplers and a section of pumped erbium-doped fiber (EDF). Thanks to the gain generated by the EDF, the ring filter has spectral response with a high finesse. The incorporation of the ring filter leads to the suppression of undesirable modes in the dual-wavelength EDFL. An experiment is carried out. Two SLM wavelengths are generated. The side mode suppression ratio is greater than 50 dB. The wavelength spacing of the two wavelengths is tunable with a tuning step of approximately 10 GHz. A frequency switchable microwave signal from approximately 10 to approximately 40 GHz is thus generated by beating the two wavelengths at a photodetector (PD). The spectral width of the generated microwave signal is measured to be less than 5 kHz. PMID:19582131

  4. Optical characterization of InGaN heterostructures for blue light emitters and vertical cavity lasers: Efficiency and recombination dynamics

    NASA Astrophysics Data System (ADS)

    Okur, Serdal

    This thesis explores radiative efficiencies and recombination dynamics in InGaN-based heterostructures and their applications as active regions in blue light emitters and particularly vertical cavities. The investigations focus on understanding the mechanism of efficiency loss at high injection as well as developing designs to mitigate it, exploring nonpolar and semipolar crystal orientations to improve radiative efficiency, integration of optimized active regions with high reflectivity dielectric mirrors in vertical cavity structures, and achieving strong exciton-photon coupling regime in these microcavities for potential polariton lasing. In regard to active regions, multiple double heterostructure (DH) designs with sufficiently thick staircase electron injection (SEI) layers, which act as electron coolers to reduce the overflow of hot electrons injected into the active region, were found to be more viable to achieve high efficiencies and to mitigate the efficiency loss at high injection. Such active regions were embedded in novel vertical cavity structure designs with full dielectric distributed Bragg reflectors (DBRs) through epitaxial lateral overgrowth (ELO), eliminating the problems associated with semiconductor bottom DBRs having narrow stopbands and the cumbersome substrate removal process. Moreover, the ELO technique allowed the injection of carriers only through the high quality regions with substantially reduced threading dislocation densities compared to regular GaN templates grown on sapphire. Reduced electron-hole wavefunction overlap in polar heterostructures was shown to hamper the efficiency of particularly thick active regions (thicker than 3 nm) possessing three-dimensional density of states needed for higher optical output. In addition, excitation density-dependent photoluminescence (PL) measurements showed superior optical quality of double heterostructure (3 nm InGaN wells) active regions compared to quantum wells (2 nm InGaN wells

  5. Frequency-feedback cavity enhanced spectrometer

    DOEpatents

    Hovde, David Christian; Gomez, Anthony

    2015-08-18

    A spectrometer comprising an optical cavity, a light source capable of producing light at one or more wavelengths transmitted by the cavity and with the light directed at the cavity, a detector and optics positioned to collect light transmitted by the cavity, feedback electronics causing oscillation of amplitude of the optical signal on the detector at a frequency that depends on cavity losses, and a sensor measuring the oscillation frequency to determine the cavity losses.

  6. Quality factor and finesse optimization in buried InGaAsP/InP ring resonators

    NASA Astrophysics Data System (ADS)

    Ciminelli, C.; Passaro, V. M. N.; Dell'Olio, F.; Armenise, M. N.

    2009-06-01

    Quality factor and finesse of buried In1 xGaxAsyP1 y / InP ring resonators have been optimized in this paper by a very general modelling technique. Limiting effect of propagation loss within the ring has been investigated using a three-dimensional (3D) highly accurate complex mode solver based on mode matching method to analyze bending loss dependence on ring radius and wavelength. Coupling between straight input/output (I/O) bus waveguides and ring resonator has been studied by 3D Beam Propagation Method (BPM), deriving coupling loss and coupling coefficient for a large range of ring radius and bus waveguides-ring distance values (for both polarizations). Ring resonator has been modelled by the transfer-matrix approach, while finesse and quality factor dependence on radius has been estimated for two resonator architectures (including one or two I/O bus waveguides) and for quasi-TE and quasi-TM modes. Guiding structure has been optimized to enhance resonator performance. The modelling approach has been validated by comparing results obtained by our algorithm with experimental data reported in literature. Influence of rejection (at resonance wavelength) at through port on quality factor and finesse has been widely discussed. A quality factor larger than 8105 has been predicted for the ring resonator employing only one I/O bus waveguide and having a radius of 400 mm. This resonator exhibits a rejection of -8 dB at through port.

  7. Evaluation of the aero-optical properties of the SOFIA cavity by means of computional fluid dynamics and a super fast diagnostic camera

    NASA Astrophysics Data System (ADS)

    Engfer, Christian; Pfüller, Enrico; Wiedemann, Manuel; Wolf, Jürgen; Lutz, Thorsten; Krämer, Ewald; Röser, Hans-Peter

    2012-09-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a 2.5 m reflecting telescope housed in an open cavity on board of a Boeing 747SP. During observations, the cavity is exposed to transonic flow conditions. The oncoming boundary layer evolves into a free shear layer being responsible for optical aberrations and for aerodynamic and aeroacoustic disturbances within the cavity. While the aero-acoustical excitation of an airborne telescope can be minimized by using passive flow control devices, the aero-optical properties of the flow are difficult to improve. Hence it is important to know how much the image seen through the SOFIA telescope is perturbed by so called seeing effects. Prior to the SOFIA science fights Computational Fluid Dynamics (CFD) simulations using URANS and DES methods were carried out to determine the flow field within and above the cavity and hence in the optical path in order to provide an assessment of the aero-optical properties under baseline conditions. In addition and for validation purposes, out of focus images have been taken during flight with a Super Fast Diagnostic Camera (SFDC). Depending on the binning factor and the sub-array size, the SFDC is able to take and to read out images at very high frame rates. The paper explains the numerical approach based on CFD to evaluate the aero-optical properties of SOFIA. The CFD data is then compared to the high speed images taken by the SFDC during flight.

  8. Microwave to optical state transfer with a cavity electro-opto-mechanical system

    NASA Astrophysics Data System (ADS)

    Andrews, Reed; Peterson, Robert; Purdy, Thomas; Cicak, Katarina; Simmonds, Raymond; Regal, Cindy; Lehnert, Konrad

    2014-03-01

    Quantum-coherent conversion between gigahertz-frequency ``microwave light'' and terahertz-frequency ``optical light'' would combine the processing power and scalability of superconducting qubits with the low-loss and long-distance distribution of optical fibers. Here we use an electro-opto-mechanical device to reversibly convert classical signals between microwave and optical light with an efficiency of ten percent. The frequency conversion is coherent and occurs over a 10 kHz bandwidth. This new type of converter opens new possibilities for generating and distributing entanglement, and is potentially capable of quantum-coherent frequency conversion.

  9. DWDM channel spacing tunable optical TDM carrier from a mode-locked weak-resonant-cavity Fabry-Perot laser diode based fiber ring.

    PubMed

    Peng, Guo-Hsuan; Chi, Yu-Chieh; Lin, Gong-Ru

    2008-08-18

    A novel optical TDM pulsed carrier with tunable mode spacing matching the ITU-T defined DWDM channels is demonstrated, which is generated from an optically injection-mode-locked weak-resonant-cavity Fabry-Perot laser diode (FPLD) with 10%-end-facet reflectivity. The FPLD exhibits relatively weak cavity modes and a gain spectral linewidth covering >33.5 nm. The least common multiple of the mode spacing determined by both the weak-resonant-cavity FPLD and the fiber-ring cavity can be tunable by adjusting length of the fiber ring cavity or the FPLD temperature to approach the desired 200GHz DWDM channel spacing of 1.6 nm. At a specific fiber-ring cavity length, such a least-common- multiple selection rule results in 12 lasing modes between 1532 and 1545 nm naturally and a mode-locking pulsewidth of 19 ps broadened by group velocity dispersion among different modes. With an additional intracavity bandpass filter, the operating wavelength can further extend from 1520 to 1553.5 nm. After channel filtering, each selected longitudinal mode gives rise to a shortened pulsewidth of 12 ps due to the reduced group velocity dispersion. By linear dispersion compensating with a 55-m long dispersion compensation fiber (DCF), the pulsewidth can be further compressed to 8 ps with its corresponding peak-to-peak chirp reducing from 9.7 to 4.3 GHz. PMID:18711579

  10. Chaos synchronization in vertical-cavity surface-emitting laser based on rotated polarization-preserved optical feedback

    NASA Astrophysics Data System (ADS)

    Nazhan, Salam; Ghassemlooy, Zabih; Busawon, Krishna

    2016-01-01

    In this paper, the influence of the rotating polarization-preserved optical feedback on the chaos synchronization of a vertical-cavity surface-emitting laser (VCSEL) is investigated experimentally. Two VCSELs' polarization modes (XP) and (YP) are gradually rotated and re-injected back into the VCSEL. The anti-phase dynamics synchronization of the two polarization modes is evaluated using the cross-correlation function. For a fixed optical feedback, a clear relationship is found between the cross-correlation coefficient and the polarization angle θp. It is shown that high-quality anti-phase polarization-resolved chaos synchronization is achieved at higher values of θp. The maximum value of the cross-correlation coefficient achieved is -0.99 with a zero time delay over a wide range of θp beyond 65° with a poor synchronization dynamic at θp less than 65°. Furthermore, it is observed that the antiphase irregular oscillation of the XP and YP modes changes with θp. VCSEL under the rotating polarization optical feedback can be a good candidate as a chaotic synchronization source for a secure communication system.

  11. Compositional and Optical Properties of Titan Haze Analogs Using Aerosol Mass Spectrometry, Photoacoustic Spectroscopy and Cavity Ring-Down Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ugelow, M.; Zarzana, K. J.; Tolbert, M. A.

    2015-12-01

    The organic haze that surrounds Saturn's moon Titan is formed through the photolysis and electron initiated dissociation of methane and nitrogen. The chemical pathways leading to haze formation and the resulting haze optical properties are still highly uncertain. Here we examine the compositional and optical properties of Titan haze aerosol analogs. By studying these properties together, the impact of haze on Titan's radiative balance can be better understood. The aerosol analogs studied are produced from different initial methane concentrations (0.1, 2 and 10% CH4) using spark discharge excitation. To determine the complex refractive index of the aerosol, we combine two spectroscopic techniques, one that measures absorption and one that measures extinction: photoacoustic spectroscopy coupled with cavity ring-down spectroscopy (PASCaRD). This technique provides the benefit of a high precision determination of the imaginary component of the refractive index (k), along with the highly sensitive determination of the real component of the refractive index (n). The refractive indices are retrieved at two wavelengths, 405 and 532 nm, using the PASCaRD system. To yield aerosol composition, quadrupole aerosol mass spectrometry is used. Compositional information is obtained from a technique that uses isotopically labeled and unlabeled methane gas. I will present preliminary data on the complex refractive indices of Titan aerosol analogs at both wavelengths, in conjunction with the aerosol composition as a percent by weight of carbon, nitrogen and hydrogen. The correlation of optical and chemical properties should be useful for remote sensing instruments probing Titan haze.

  12. External cavity based single mode Fabry-Pérot laser diode and its application towards all-optical digital circuits

    NASA Astrophysics Data System (ADS)

    Nakarmi, Bikash; Zhang, Xuping; Won, Yong Hyub

    2012-11-01

    We have proposed a novel approach of realizing all-optical logic gates and combinational circuit using external cavity based single mode Fabry-Pérot laser diodes (SMFP-LDs). Different techniques and critical parameters for injection locking the any one of the modes of SMFP-LDs are discussed. Taking consideration of wavelength detuning and input injected power, we have proposed and demonstrated multi-input injection locking, supporting beam injection locking with the conventional injection locking which are used for demonstrating different logic gates (NAND, AND, XNOR, XOR, NOT, NOR) and digital circuits (Half adder and Comparator). Since we have used SMFP-LDs, there is no requirement of additional probe beam and associated components as required by other optical technologies making the realization simple in configuration, cost effective and power efficient. Clear output waveforms, eye diagrams, risingfalling times and BER are presented to verify the proposed method. All-optical logic units and digital circuit are demonstrated at the data rate of 10 Gbps with the waveform of NRZ signal waveform and measured eye diagram and BER of the PRBS of 231-1 signal. The maximum power penalty among all demonstrated units is below 1.4 dB at the BER of 10-9.

  13. Laser Cooling and Trapping of Neutral Mercury Atoms Using an Optically-Pumped External-Cavity Semiconductor Laser

    NASA Astrophysics Data System (ADS)

    Paul, Justin; Lytle, Christian; Jones, R. Jason

    2011-05-01

    The level structure of the Hg atom is similar to other alkaline earth-like atoms, offering the possibility to realize an extremely high quality resonance factor (Q) on the ``clock'' transition (1S0- 3P0) when confined in an optical lattice at the Stark-shift free wavelength. A key feature of the Hg system is the reduced uncertainty due to black-body induced Stark shifts, making it an interesting candidate as an optical frequency standard. One challenge to laser-cooling neutral Hg atoms is finding a reliable source for cooling on the 1S0-3 P1 transition at 253.7 nm. We employ an optically pumped semiconductor laser (OPSEL) operating at 1015 nm, whose frequency is quadrupled in two external-cavity doubling stages to generate over 120 mW at 253.7 nm. With this new laser source we have trapped Hg199 from a background vapor in a standard MOT. We trap up to 2 × 106 atoms with a 1/e2 radius of our MOT of ~310 microns, corresponding to a density of 1.28 × 1010 atoms/cm3. We report on the progress of our Hg system and plans for precision lattice-based spectroscopy of the clock transition. Support for this work is supported through the U.S. Air Force Office of Scientific Research (AFOSR) through grant no. FA9550-09-1-0563.

  14. Prototype of an ultra-stable optical cavity for space applications.

    PubMed

    Argence, B; Prevost, E; Lévèque, T; Le Goff, R; Bize, S; Lemonde, P; Santarelli, G

    2012-11-01

    We report the main features and performances of a prototype of an ultra-stable cavity designed and realized by industry for space applications with the aim of space missions. The cavity is a 100 mm long cylinder rigidly held at its midplane by a engineered mechanical interface providing an efficient decoupling from thermal and vibration perturbations. Intensive finite element modeling was performed in order to optimize thermal and vibration sensitivities while getting a high fundamental resonance frequency. The system was designed to be transportable, acceleration tolerant (up to several g) and temperature range compliant [-33°C ; 73°C]. Thermal isolation is ensured by gold coated Aluminum shields inside a stainless steel enclosure for vacuum. The axial vibration sensitivity was evaluated at (4 ± 0.5) × 10(-11)/(m.s(-2)), while the transverse one is < 1 × 10(-11)/(m.s(-2)). The fractional frequency instability is

  15. Resonant cavity enhanced optical microsensor for molecular interactions based on porous silicon

    NASA Astrophysics Data System (ADS)

    de Stefano, Luca; Rea, Ilaria; Rendina, Ivo; Rotiroti, Lucia; Rossi, Mosè; D'Auria, Sabato

    2006-04-01

    The molecular binding between the glutamine binding-protein (GlnBP) from Escherichia coli and L-glutamine (Gln) is detected by means of an optical biosensor based on porous silicon technology. The binding event is optically transduced in the wavelength shift of the porous silicon optical microcavity (PSMC) reflectivity spectrum. The hydrophobic interaction links the GlnBP, which acts as a molecular probe for Gln, to the hydrogenated porous silicon surface area. We can thus avoid any preliminary surface functionalization process. The protein infiltrated PSMC results stable to oxidation at least for few cycles of wet measurements. The penetration of the proteins into the pores of the porous silicon matrix has been optimized: a strong base post-etch process increases the pore size and removes any nanostructure on top and inside the porous silicon multilayer while does not degrade the optical response and the quality of the microcavity.

  16. Effect of Pure Dephasing and Phonon Scattering on the Coupling of Semiconductor Quantum Dots to Optical Cavities.

    PubMed

    Jarlov, C; Wodey, É; Lyasota, A; Calic, M; Gallo, P; Dwir, B; Rudra, A; Kapon, E

    2016-08-12

    Using site-controlled semiconductor quantum dots (QDs) free of multiexcitonic continuum states, integrated with photonic crystal membrane cavities, we clarify the effects of pure dephasing and phonon scattering on exciton-cavity coupling in the weak-coupling regime. In particular, the observed QD-cavity copolarization and cavity mode feeding versus QD-cavity detuning are explained quantitatively by a model of a two-level system embedded in a solid-state environment. PMID:27563983

  17. Effect of Pure Dephasing and Phonon Scattering on the Coupling of Semiconductor Quantum Dots to Optical Cavities

    NASA Astrophysics Data System (ADS)

    Jarlov, C.; Wodey, É.; Lyasota, A.; Calic, M.; Gallo, P.; Dwir, B.; Rudra, A.; Kapon, E.

    2016-08-01

    Using site-controlled semiconductor quantum dots (QDs) free of multiexcitonic continuum states, integrated with photonic crystal membrane cavities, we clarify the effects of pure dephasing and phonon scattering on exciton-cavity coupling in the weak-coupling regime. In particular, the observed QD-cavity copolarization and cavity mode feeding versus QD-cavity detuning are explained quantitatively by a model of a two-level system embedded in a solid-state environment.

  18. Mid-infrared high-resolution absorption spectroscopy by use of a semimonolithic entangled-cavity optical parametric oscillator.

    PubMed

    Desormeaux, A; Lefebvre, M; Rosencher, E; Huignard, J P

    2004-12-15

    By recording low-pressure absorption lines of N2O around 3.9 microm, we fully qualify a pulsed entangled-cavity doubly resonant optical parametric oscillator as a power tool for high-resolution spectroscopy. This compact source runs at a high repetition rate (>10 kHz) with a low threshold of oscillation (<8 microJ), is mode-hop-free tunable over 5 cm(-1), and displays single-frequency Fourier-transformed-limited operation (linewidth <0.005 cm(-1)). A high potential for nonlinear spectroscopy is also expected given the high peak power (70 W) and the good quality (M2 < 2) of the output beam. PMID:15645813

  19. Development of narrow linewidth, micro-integrated extended cavity diode lasers for quantum optics experiments in space

    NASA Astrophysics Data System (ADS)

    Luvsandamdin, E.; Spießberger, S.; Schiemangk, M.; Sahm, A.; Mura, G.; Wicht, A.; Peters, A.; Erbert, G.; Tränkle, G.

    2013-05-01

    We present a micro-integrated extended cavity diode laser module for experiments on rubidium Bose-Einstein condensates and atom interferometry at 780.24 nm onboard a sounding rocket. The micro-integration concept is optimized for space application. The laser chip, micro-lenses, a volume holographic Bragg grating, micro-temperature sensors and a micro-thermoelectric cooler are integrated on an aluminium nitride ceramic micro-optical bench with a foot print of only 50 × 10 mm2. Moveable parts are omitted to allow for a very compact and robust design. The laser module provides an output power of more than 120 mW at a short term (170 μs) linewidth of 54 kHz, both full-width-at-half-maximum. The laser can be coarsely tuned by 44 GHz with a continuous tuning range of 31 GHz. The micro-integration technology presented here can be transferred to other wavelengths.

  20. Nonclassical Correlation Dynamics in a System of Mesoscopic Josephson Junction Coupled to Single-mode Optical Cavity

    NASA Astrophysics Data System (ADS)

    Xiang, Shao-Hua; Zhao, Yu-Jing; Zhu, Xi-Xiang; Song, Ke-Hui

    2015-08-01

    We investigate the time evolutions of the continuous-variable entanglement and Gaussian quantum discord in a system consisting of a mesoscopic Josephson junction coupled to a single-mode optical cavity field. We can obtain the time-dependent covariance matrix using known symplectic operation and local canonical transformations. We compare the dynamics of Gaussian quantum discord with that of entanglement. It is shown that the entanglement dynamics of two-mode squeezed thermal state is richer and undergoes three different features: periodical oscillation, sudden death and revival, and no-creation of entanglement, conditioned on the average number of thermal photons in each mode, whereas the Gaussian quantum discord can only exhibit a periodical oscillation behavior during the evolution.

  1. Quantum input-output theory for optical cavities with arbitrary coupling strength: Application to two-photon wave-packet shaping

    NASA Astrophysics Data System (ADS)

    Raymer, M. G.; McKinstrie, C. J.

    2013-10-01

    We develop quantum-optical input-output theory for resonators with arbitrary coupling strength, and for input fields whose spectrum can be wider than the cavity free-spectral range, while ensuring that the field-operator commutator relations in space-time variables are correct. The cavity-field commutator exhibits a series of space-time “echoes,” representing causal connections of certain space-time points by light propagation. We apply the theory to two-photon wave-packet shaping by cavity reflection, which displays a remarkable illustration of dispersion cancellation. We also show that the theory is amenable to inclusion of intracavity absorbing and emitting atoms, allowing, for example, dissipative losses within the cavity to be incorporated in a quantum mechanically correct way.

  2. The Microlaser: Study of Laser Oscillation with One Atom in AN Optical Resonator.

    NASA Astrophysics Data System (ADS)

    An, Kyungwon

    1995-01-01

    This thesis describes the first realization of one-atom laser, a laser oscillator with only one atom in an optical resonator. In our experiment a beam of ^{138}Ba atoms traverses a high -Q optical cavity with a finesse of 8times10 ^5. The atoms are excited from the ^1S_0 ground state to the ^3P_1 (m = 0) excited state by a pi-pulse before they enter the cavity. Laser oscillation at 791 nm (^3P_1--> ^1S_0 ) has been observed with the mean number of atoms inside the cavity mode varied between 0.1 and 1.0, resulting in the mean number of photons inside the cavity changing from 0.14 to 11. To understand the data quantitatively, two different theoretical approaches were taken. First a pendulum equation based on the Maxwell-Schrodinger equation provides physical insights on the evolution of the one -atom laser with limited success in predicting correct signal size. Second approach is based on a fully-quantized one -atom theory. In this approach, a new photon recursion relation for the field density matrix was derived. Combined with a simple modification needed for the standing wave nature of the cavity mode, the quantum theory is in good agreement with the experiment. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617 -253-5668; Fax 617-253-1690.).

  3. Low-photon-number optical switch and AND/OR logic gates based on quantum dot-bimodal cavity coupling system.

    PubMed

    Ma, Shen; Ye, Han; Yu, Zhong-Yuan; Zhang, Wen; Peng, Yi-Wei; Cheng, Xiang; Liu, Yu-Min

    2016-01-01

    We propose a new scheme based on quantum dot-bimodal cavity coupling system to realize all-optical switch and logic gates in low-photon-number regime. Suppression of mode transmission due to the destructive interference effect is theoretically demonstrated by driving the cavity with two orthogonally polarized pulsed lasers at certain pulse delay. The transmitted mode can be selected by designing laser pulse sequence. The optical switch with high on-off ratio emerges when considering one driving laser as the control. Moreover, the AND/OR logic gates based on photon polarization are achieved by cascading the coupling system. Both proposed optical switch and logic gates work well in ultra-low energy magnitude. Our work may enable various applications of all-optical computing and quantum information processing. PMID:26750557

  4. Low-photon-number optical switch and AND/OR logic gates based on quantum dot-bimodal cavity coupling system

    PubMed Central

    Ma, Shen; Ye, Han; Yu, Zhong-Yuan; Zhang, Wen; Peng, Yi-Wei; Cheng, Xiang; Liu, Yu-Min

    2016-01-01

    We propose a new scheme based on quantum dot-bimodal cavity coupling system to realize all-optical switch and logic gates in low-photon-number regime. Suppression of mode transmission due to the destructive interference effect is theoretically demonstrated by driving the cavity with two orthogonally polarized pulsed lasers at certain pulse delay. The transmitted mode can be selected by designing laser pulse sequence. The optical switch with high on-off ratio emerges when considering one driving laser as the control. Moreover, the AND/OR logic gates based on photon polarization are achieved by cascading the coupling system. Both proposed optical switch and logic gates work well in ultra-low energy magnitude. Our work may enable various applications of all-optical computing and quantum information processing. PMID:26750557

  5. Three-dimensional cavity cooling and trapping in an optical lattice

    SciTech Connect

    Murr, K.; Nussmann, S.; Puppe, T.; Hijlkema, M.; Weber, B.; Webster, S. C.; Kuhn, A.; Rempe, G.

    2006-06-15

    A robust scheme for trapping and cooling atoms is described. It combines a deep dipole-trap which localizes the atom in the center of a cavity with a laser directly exciting the atom. In that way one obtains three-dimensional cooling while the atom is dipole-trapped. In particular, we identify a cooling force along the large spatial modulations of the trap. A feature of this setup, with respect to a dipole trap alone, is that all cooling forces keep a constant amplitude if the trap depth is increased simultaneously with the intensity of the probe laser. No strong coupling is required, which makes such a technique experimentally attractive. Several analytical expressions for the cooling forces and heating rates are derived and interpreted by analogy to ordinary laser cooling.

  6. Optical design and optimization of parabolic dish solar concentrator with a cavity hybrid receiver

    NASA Astrophysics Data System (ADS)

    Blázquez, R.; Carballo, J.; Silva, M.

    2016-05-01

    One of the main goals of the BIOSTIRLING-4SKA project, funded by the European Commission, is the development of a hybrid Dish-Stirling system based on a hybrid solar-gas receiver, which has been designed by the Swedish company Cleanergy. A ray tracing study, which is part of the design of this parabolic dish system, is presented in this paper. The study pursues the optimization of the concentrator and receiver cavity geometry according to the requirements of flux distribution on the receiver walls set by the designer of the hybrid receiver. The ray-tracing analysis has been performed with the open source software Tonatiuh, a ray-tracing tool specifically oriented to the modeling of solar concentrators.

  7. Real Time Tracking and Trapping of Single Atoms in Cavity QED

    NASA Astrophysics Data System (ADS)

    Ye, Jun

    2000-06-01

    Cavity quantum electrodynamics offers a viable approach for significant advances in quantum information science. The unique advantages of cavity QED are manifested in the demonstrated utilities of strong coupling and in the proposed quantum networks by way of multiple, interconnected atom-cavity systems. Investigations of quantum dynamics for continuously observed open quantum systems are ideally suited in this strong coupling regime. The successful achievement of these scientific goals relies on the realization of controlled atom-localization within a cavity. Here we report our latest progresses in this quest. Strong coupling between the atomic internal degree of freedom and the quantized cavity field can exert strong influences on the external center-of-mass motion. The initial preparation of laser cooled atoms helps to monitor in real time the "trajectory" of an individual atom as well as to signify the influence of mechanical force on the atom by the field of single photons. For example, we have observed the atomic transit time through a small, high finesse optical cavity extended by a factor of 10, to ms scale, with single photons. With a further increase of the coherent coupling energy to about 5 mK, high-contrast variations in the cavity transmission are generated and can be used to reconstruct two-dimensional trajectories of a localized atom, revealing single atoms bound in orbit by single photons. To extend the trap lifetime we need to explore the use of an external conservative potential that does not compromise the cavity-QED interactions. The first experiment involves a far-off-resonance-trap (FORT) built along the same cavity axis. The real time monitoring capability permits precise timing control of the trap. Careful selections of various parameters of QED and FORT fields are important for both observation and cooling of atomic motions due to the composite eigenvalue structure associated with both fields. The observed lifetime for individual atoms

  8. ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS: Alternative Scheme for Generation of Atomic Schrödinger Cat States and Entangled Coherent States in an Optical Cavity

    NASA Astrophysics Data System (ADS)

    Lin, Xiu

    2010-05-01

    We propose an alternative scheme for generation of atomic Schrödinger cat states in an optical cavity. In the scheme the atoms are always populated in the two ground states and the cavity remains in the vacuum state. Therefore, the scheme is insensitive to the atomic spontaneous emission and cavity decay. The scheme may be generalized to the deterministic generation of entangled coherent states for two atomic samples. In contrast with the previously proposed schemes of [Commun. Theor. Phys. 40 (2003) 103 and Chin. Phys. B 18 (2009) 1045], the required interaction time in our scheme is greatly shortened and thus the decoherence can be effectively suppressed.

  9. Qualitative analysis of ultra-short optical dissipative solitary pulses in the actively mode-locked semiconductor heterolasers with an external fiber cavity

    NASA Astrophysics Data System (ADS)

    Shcherbakov, Alexandre S.; Campos Acosta, Joaquin; Moreno Zarate, Pedro; Pons Aglio, Alicia

    2011-02-01

    An advanced qualitative characterization of simultaneously existing various low-power trains of ultra-short optical pulses with an internal frequency modulation in a distributed laser system based on semiconductor heterostructure is presented. The scheme represents a hybrid cavity consisting of a single-mode heterolaser operating in the active mode-locking regime and an external long single-mode optical fiber exhibiting square-law dispersion, cubic Kerr nonlinearity, and linear optical losses. In fact, we consider the trains of optical dissipative solitons, which appear within double balance between the second-order dispersion and cubic-law nonlinearity as well as between the active-medium gain and linear optical losses in a hybrid cavity. Moreover, we operate on specially designed modulating signals providing non-conventional composite regimes of simultaneous multi-pulse active mode-locking. As a result, the mode-locking process allows shaping regular trains of picosecond optical pulses excited by multi-pulse independent on each other sequences of periodic modulations. In so doing, we consider the arranged hybrid cavity as a combination of a quasi-linear part responsible for the active mode-locking by itself and a nonlinear part determining the regime of dissipative soliton propagation. Initially, these parts are analyzed individually, and then the primarily obtained data are coordinated with each other. Within this approach, a contribution of the appeared cubically nonlinear Ginzburg-Landau operator is analyzed via exploiting an approximate variational procedure involving the technique of trial functions.

  10. High sensitivity detection of NO2 employing off-axis integrated cavity output spectroscopy coupled with multiple line integrated spectroscopy

    NASA Astrophysics Data System (ADS)

    Rao, Gottipaty N.; Karpf, Andreas

    2011-05-01

    We report on the development of a new sensor for NO2 with ultrahigh sensitivity of detection. This has been accomplished by combining off-axis integrated cavity output spectroscopy (OA-ICOS) (which can provide large path lengths of the order of several km in a small volume cell) with multiple line integrated absorption spectroscopy (MLIAS) (where we integrate the absorption spectra over a large number of rotational-vibrational transitions of the molecular species to further improve the sensitivity). Employing an external cavity tunable quantum cascade laser operating in the 1601 - 1670 cm-1 range and a high-finesse optical cavity, the absorption spectra of NO2 over 100 transitions in the R-band have been recorded. From the observed linear relationship between the integrated absorption vs. concentration of NO2, we report an effective sensitivity of detection of 10 ppt for NO2. To the best of our knowledge, this is among the most sensitive levels of detection of NO2 to date. A sensitive sensor for the detection of NO2 will be helpful to monitor the ambient air quality, combustion emissions from the automobiles, power plants, aircraft and for the detection of nitrate based explosives (which are commonly used in improvised explosives (IEDs)). Additionally such a sensor would be valuable for the study of complex chemical reactions that undergo in the atmosphere resulting in the formation of photochemical smog, tropospheric ozone and acid rain.

  11. Cooling and manipulation of a levitated nanoparticle with an optical fiber trap

    SciTech Connect

    Mestres, Pau; Berthelot, Johann; Spasenović, Marko; Gieseler, Jan; Novotny, Lukas; Quidant, Romain

    2015-10-12

    Accurate delivery of small targets in high vacuum is a pivotal task in many branches of science and technology. Beyond the different strategies developed for atoms, proteins, macroscopic clusters, and pellets, the manipulation of neutral particles over macroscopic distances still poses a formidable challenge. Here, we report an approach based on a mobile optical trap operated under feedback control that enables cooling and long range 3D manipulation of a silica nanoparticle in high vacuum. We apply this technique to load a single nanoparticle into a high-finesse optical cavity through a load-lock vacuum system. We foresee our scheme to benefit the field of optomechanics with levitating nano-objects as well as ultrasensitive detection and monitoring.

  12. Cooling and manipulation of a levitated nanoparticle with an optical fiber trap

    NASA Astrophysics Data System (ADS)

    Mestres, Pau; Berthelot, Johann; Spasenović, Marko; Gieseler, Jan; Novotny, Lukas; Quidant, Romain

    2015-10-01

    Accurate delivery of small targets in high vacuum is a pivotal task in many branches of science and technology. Beyond the different strategies developed for atoms, proteins, macroscopic clusters, and pellets, the manipulation of neutral particles over macroscopic distances still poses a formidable challenge. Here, we report an approach based on a mobile optical trap operated under feedback control that enables cooling and long range 3D manipulation of a silica nanoparticle in high vacuum. We apply this technique to load a single nanoparticle into a high-finesse optical cavity through a load-lock vacuum system. We foresee our scheme to benefit the field of optomechanics with levitating nano-objects as well as ultrasensitive detection and monitoring.

  13. Interference and dynamics of light from a distance-controlled atom pair in an optical cavity

    NASA Astrophysics Data System (ADS)

    Neuzner, A.; Körber, M.; Morin, O.; Ritter, S.; Rempe, G.

    2016-05-01

    Interference is central to quantum physics and occurs when indistinguishable paths exist, as in a double-slit experiment. Replacing the two slits with single atoms introduces optical nonlinearities for which non-trivial interference phenomena are predicted. Their observation, however, has been hampered by difficulties in preparing the required atomic distribution, controlling the optical phases and detecting the faint light. Here we overcome all of these experimental challenges by combining an optical lattice for atom localization, an imaging system with single-site resolution and an optical resonator for light steering. We observe resonator-induced saturation of resonance fluorescence for constructive interference and non-zero emission with huge photon bunching for destructive interference. The latter is explained by atomic saturation and photon-pair generation, similar to predictions for free-space atoms. Our experimental setting allows realization of the Tavis–Cummings model for any number of atoms and photons, exploration of fundamental aspects of light–matter interaction and implementation of new quantum information processing protocols.

  14. High-resolution and fast-response fiber-optic temperature sensor using silicon Fabry-Pérot cavity.

    PubMed

    Liu, Guigen; Han, Ming; Hou, Weilin

    2015-03-23

    We report a fiber-optic sensor based on a silicon Fabry-Pérot cavity, fabricated by attaching a silicon pillar on the tip of a single-mode fiber, for high-resolution and high-speed temperature measurement. The large thermo-optic coefficient and thermal expansion coefficient of the silicon material give rise to an experimental sensitivity of 84.6 pm/°C. The excellent transparency and large refractive index of silicon over the infrared wavelength range result in a visibility of 33 dB for the reflection spectrum. A novel average wavelength tracking method has been proposed and demonstrated for sensor demodulation with improved signal-to-noise ratio, which leads to a temperature resolution of 6 × 10⁻⁴ °C. Due to the high thermal diffusivity of silicon, a response time as short as 0.51 ms for a sensor with an 80-µm-diameter and 200-µm-long silicon pillar has been experimentally achieved, suggesting a maximum frequency of ~2 kHz can be reached, to address the needs for highly dynamic environmental variations such as those found in the ocean. PMID:25837068

  15. Upstream vertical cavity surface-emitting lasers for fault monitoring and localization in WDM passive optical networks

    NASA Astrophysics Data System (ADS)

    Wong, Elaine; Zhao, Xiaoxue; Chang-Hasnain, Connie J.

    2008-04-01

    As wavelength division multiplexed passive optical networks (WDM-PONs) are expected to be first deployed to transport high capacity services to business customers, real-time knowledge of fiber/device faults and the location of such faults will be a necessity to guarantee reliability. Nonetheless, the added benefit of implementing fault monitoring capability should only incur minimal cost associated with upgrades to the network. In this work, we propose and experimentally demonstrate a fault monitoring and localization scheme based on a highly-sensitive and potentially low-cost monitor in conjunction with vertical cavity surface-emitting lasers (VCSELs). The VCSELs are used as upstream transmitters in the WDM-PON. The proposed scheme benefits from the high reflectivity of the top distributed Bragg reflector (DBR) mirror of optical injection-locked (OIL) VCSELs to reflect monitoring channels back to the central office for monitoring. Characterization of the fault monitor demonstrates high sensitivity, low bandwidth requirements, and potentially low output power. The added advantage of the proposed fault monitoring scheme incurs only a 0.5 dB penalty on the upstream transmissions on the existing infrastructure.

  16. Frequency-induced polarization bistability in vertical-cavity surface-emitting lasers with orthogonal optical injection

    SciTech Connect

    Gatare, I.; Panajotov, K.; Sciamanna, M.

    2007-02-15

    We report theoretically on a pure frequency-induced polarization bistability in a vertical-cavity surface-emitting laser (VCSEL) subject to orthogonal optical injection, i.e., the master laser light polarization is orthogonal to that of the slave VCSEL. As the frequency detuning is scanned from negative to positive values and for a fixed injected power, the VCSEL exhibits two successive and possibly bistable polarization switchings. The first switching (from the slave laser polarization to the injected light polarization) exhibits a bistable region whose width is maximum for a given value of the injected power. Such a dependency of hysteresis width on the injected power is similar to that recently found experimentally by Hong et al.[Electron. Lett. 36, 2019 (2000)]. The bistability accompanying the second switching (from the injected light polarization back to the slave laser free-running polarization) exhibits, however, significantly different features related to the occurrence of optical chaos. Interestingly, the width of the bistable region can be tuned over a large range not only by modifying the injection parameters but also by modifying the device parameters, in particular the VCSEL linewidth enhancement factor.

  17. Approaching broadband quantum-limited displacement noise in a deformable optical cavity

    NASA Astrophysics Data System (ADS)

    Sankar, Shannon Reynier

    An outstanding goal of the optomechanics community, particularly in the field of gravitational wave detection, is to demonstrate a system with a broadband displacement sensitivity limited by quantum fluctuations of the probe field. This thesis presents significant progress in this direction, namely a means of achieving a sufficiently small off-resonant thermal noise of a deformable optomechanical cavity through the incorporation of a low mass, highly compliant, cryogenically cooled mirror structure with a sensitive motional readout. We conclusively demonstrate the mitigation of Brownian fluctuations in this system by the reduction of the thermal bath temperature, and our measurements are shown to be in close agreement with a finite element analysis of the device. This analysis has been utilized in devising improved oscillator geometries. This work provides a clear path towards the observation of quantum fluctuations in our system and demonstrates the Brownian properties of the crystalline multilayers which make them a promising technology for the realization of low-thermal-noise reflectors in the quantum regime.

  18. Photon storage in {lambda}-type optically dense atomic media. I. Cavity model

    SciTech Connect

    Gorshkov, Alexey V.; Andre, Axel; Lukin, Mikhail D.; Soerensen, Anders S.

    2007-09-15

    In a recent paper [Gorshkov et al., Phys. Rev. Lett. 98, 123601 (2007)], we used a universal physical picture to optimize and demonstrate equivalence between a wide range of techniques for storage and retrieval of photon wave packets in {lambda}-type atomic media in free space, including the adiabatic reduction of the photon group velocity, pulse-propagation control via off-resonant Raman techniques, and photon-echo-based techniques. In the present paper, we perform the same analysis for the cavity model. In particular, we show that the retrieval efficiency is equal to C/(1+C) independent of the retrieval technique, where C is the cooperativity parameter. We also derive the optimal strategy for storage and, in particular, demonstrate that at any detuning one can store, with the optimal efficiency of C/(1+C), any smooth input mode satisfying TC{gamma}>>1 and a certain class of resonant input modes satisfying TC{gamma}{approx}1, where T is the duration of the input mode and 2{gamma} is the transition linewidth. In the two subsequent papers of the series, we present the full analysis of the free-space model and discuss the effects of inhomogeneous broadening on photon storage.

  19. Multistable particle-field dynamics in cavity-generated optical lattices

    NASA Astrophysics Data System (ADS)

    Winterauer, Dominik J.; Niedenzu, Wolfgang; Ritsch, Helmut

    2015-05-01

    Polarizable particles trapped in a resonator-sustained optical-lattice potential generate strong position-dependent backaction on the intracavity field. In the quantum regime, particles in different energy bands are connected to different intracavity light intensities and optical-lattice depths. This generates a highly nonlinear coupled particle-field dynamics. For a given pump strength and detuning, a factorizing mean-field approach predicts several self-consistent stationary solutions of strongly distinct photon numbers and motional states. Quantum Monte Carlo wave-function simulations of the master equation confirm these predictions and reveal complex multimodal photon-number and particle-momentum distributions. Using larger nanoparticles in such a setup thus constitutes a well-controllable playground to study nonlinear quantum dynamics and the buildup of macroscopic quantum superpositions at the quantum-classical boundary.

  20. Phase shift multiplication effect of all-optical analog to electromagnetically induced transparency in two micro-cavities side coupled to a waveguide system

    SciTech Connect

    Wang, Boyun; Wang, Tao Tang, Jian; Li, Xiaoming; Dong, Chuanbo

    2014-01-14

    We propose phase shift multiplication effect of all-optical analog to electromagnetically induced transparency in two photonic crystal micro-cavities side coupled to a waveguide system through external optical pump beams. With dynamically tuning the propagation phase of the line waveguide, the phase shift of the transmission spectrum in two micro-cavities side coupled to a waveguide system is doubled along with the phase shift of the line waveguide. π-phase shift and 2π-phase shift of the transmission spectrum are obtained when the propagation phase of the line waveguide is tuned to 0.5π-phase shift and π-phase shift, respectively. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and the coupled-mode formalism. These results show a new direction to the miniaturization and the low power consumption of microstructure integration photonic devices in optical communication and quantum information processing.

  1. Possible influence of surface oxides on the optical response of high-purity niobium material used in the fabrication of superconducting radio frequency cavity

    NASA Astrophysics Data System (ADS)

    Singh, Nageshwar; Deo, M. N.; Roy, S. B.

    2016-09-01

    We have investigated the possible influence of surface oxides on the optical properties of a high-purity niobium (Nb) material for fabrication of superconducting radio frequency (SCRF) cavities. Various peaks in the infrared region were identified using Fourier transform infrared and Raman spectroscopy. Optical response functions such as complex refractive index, dielectric and conductivity of niobium were compared with the existing results on oxides free Nb and Cu. It was observed that the presence of a mixture of niobium-oxides, and probably near other surface impurities, appreciably influence the conducting properties of the material causing deviation from the typical metallic characteristics. In this way, the key result of this work is the observation, identification of vibrational modes of some of surface complexes and study of its influences on the optical responses of materials. This method of spectroscopic investigation will help in understanding the origin of degradation of performance of SCRF cavities.

  2. Optically tunable Fano resonance in a grating-based Fabry-Perot cavity-coupled microring resonator on a silicon chip.

    PubMed

    Zhang, Weifeng; Li, Wangzhe; Yao, Jianping

    2016-06-01

    A grating-based Fabry-Perot (FP) cavity-coupled microring resonator on a silicon chip is reported to demonstrate an all-optically tunable Fano resonance. In the device, an add-drop microring resonator (MRR) is employed, and one of the two bus waveguides is replaced by an FP cavity consisting of two sidewall Bragg gratings. By choosing the parameters of the gratings, the resonant mode of the FP cavity is coupled to one of the resonant modes of the MRR. Due to the coupling between the resonant modes, a Fano resonance with an asymmetric line shape resulted. Measurement results show a Fano resonance with an extinction ratio of 22.54 dB, and a slope rate of 250.4 dB/nm is achieved. A further study of the effect of the coupling on the Fano resonance is performed numerically and experimentally. Thanks to the strong light-confinement capacity of the MRR and the FP cavity, a strong two-photon absorption induced nonlinear thermal-optic effect resulted, which is used to tune the Fano resonance optically. PMID:27244392

  3. Coherent pulse stacking amplification using low-finesse Gires-Tournois interferometers.

    PubMed

    Zhou, Tong; Ruppe, John; Zhu, Cheng; Hu, I-Ning; Nees, John; Galvanauskas, Almantas

    2015-03-23

    We demonstrate a new technique of coherent pulse stacking (CPS) amplification to overcome limits on achievable pulse energies from optical amplifiers. CPS uses reflecting resonators without active cavity-dumpers to transform a sequence of phase- and amplitude-modulated optical pulses into a single output pulse. Experimental validation with a single reflecting resonator demonstrates a near-theoretical stacked peak-power enhancement factor of ~2.5 with 92% and 97.4% efficiency for amplified nanosecond and femtosecond pulses. We also show theoretically that large numbers of equal-amplitude pulses can be stacked using sequences of multiple reflecting resonators, thus providing a new path for generating very high-energy pulses from ultrashort pulse fiber amplifier systems. PMID:25837085

  4. Compact vibration isolation and suspension for Australian International Gravitational Observatory: performance in a 72 m Fabry Perot cavity.

    PubMed

    Barriga, P; Dumas, J C; Woolley, A A; Zhao, C; Blair, D G

    2009-11-01

    This paper describes the first demonstration of vibration isolation and suspension systems, which have been developed with view to application in the proposed Australian International Gravitational Observatory. In order to achieve optimal performance at low frequencies new components and techniques have been combined to create a compact advanced vibration isolator structure. The design includes two stages of horizontal preisolation and one stage of vertical preisolation with resonant frequencies approximately 100 mHz. The nested structure facilitates a compact design and enables horizontal preisolation stages to be configured to create a superspring configuration, where active feedback can enable performance close to the limit set by seismic tilt coupling. The preisolation stages are combined with multistage three-dimensional (3D) pendulums. Two isolators suspending mirror test masses have been developed to form a 72 m optical cavity with finesse approximately 700 in order to test their performance. The suitability of the isolators for use in suspended optical cavities is demonstrated through their ease of locking, long term stability, and low residual motion. An accompanying paper presents the local control system and shows how simple upgrades can substantially improve residual motion performance. PMID:19947743

  5. Circuit-tunable sub-wavelength THz resonators: hybridizing optical cavities and loop antennas.

    PubMed

    Paulillo, B; Manceau, J M; Degiron, A; Zerounian, N; Beaudoin, G; Sagnes, I; Colombelli, R

    2014-09-01

    We demonstrate subwavelength electromagnetic resonators operating in the THz spectral range, whose spectral properties and spatial/angular patterns can be engineered in a similar way to an electronic circuit. We discuss the device concept, and we experimentally study the tuning of the resonant frequency as a function of variable capacitances and inductances. We then elucidate the optical coupling properties. The radiation pattern, obtained by angle-resolved reflectance, reveals that the system mainly couples to the outside world via a magnetic dipolar interaction. PMID:25321509

  6. ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS: Quantum Information Processing in An Array of Fiber Coupled Cavities

    NASA Astrophysics Data System (ADS)

    Li, Jian; Zou, Jian; Shao, Bin

    2010-04-01

    We consider a fiber coupled cavity array. Each cavity is doped with a single two-level atom. By treating the atom-cavity systems as combined polaritonic qubits, we can transform it into a polaritonic qubit-qubit array in the dispersive regime. We show that the four fiber coupled cavity open chain and ring can both generate the four qubit W state and cluster state, and can both transfer one and two qubit arbitrary states. We also discuss the dynamical behaviors of the four fiber coupled cavity array with unequal couplings.

  7. Photothermal determination of optical coefficients of tissue phantoms using an optical fibre probe.

    PubMed

    Laufer, J G; Beard, P C; Walker, S P; Mills, T N

    2001-10-01

    The absorption and reduced scattering coefficients of turbid tissue phantoms have been determined from photothermal measurements made using an optical fibre probe. The thermal sensor was a thin polymer film positioned at the end of a multimode optical fibre. The film was illuminated by the output of a continuous-wave diode laser and formed the cavity of a low-finesse Fabry-Perot interferometer. Low energy laser pulses, launched into the fibre and passed through the film, produced an abrupt temperature rise in the target tissue, which was placed in contact with the film. The subsequent conduction of heat into the film caused a change in its optical thickness and hence the reflected intensity. The absorption and reduced scattering coefficients of gelatine tissue phantoms of known optical properties were determined from the measurements using a numerical model of photothermal signal generation and maximum a posteriori estimation. The determined optical coefficients were in good agreement with the known values. The results showed that the probe can be used for the determination of optical coefficients provided the thermal coefficients of the target tissue are known with low uncertainty. PMID:11686272

  8. Precise optical dosimetry in low-level laser therapy of soft tissues in oral cavity

    NASA Astrophysics Data System (ADS)

    Stoykova, Elena V.; Sabotinov, O.

    2004-06-01

    The new low level laser therapy (LLLT) is widely applied for treatment of diseases of the oral mucosa and parodont. Depending on indication, different optical tips and light-guides are used to create beams with a required shape. However, to the best of our knowledge, the developed irradiation geometries are usually proposed assuming validity of Bouger-Lambert law. This hardly corresponds to the real situation because of the dominating multiple scattering within 600-1200 nm range that destroys correlation between the emitted laser beam and the spatial distribution of the absorbed dose inside the tissue. The aim of this work is to base the dosimetry of the LLLT procedures of periodontal tissues on radiation transfer theory using a flexible Monte-Carlo code. We studied quantitatively the influence of tissue optical parameters (absorption and scattering coefficients, tissue refraction index, anisotropy factor) on decreasing of correlation between the emitted beam and the energy deposition for converging or diverging beams. We evaluated energy deposition for the developed by us LLLT system in a 3-D model of periodontal tissues created using a cross-sectional image of this region with internal structural information on the gingival and the tooth. The laser source is a CW diode laser emitting elliptical beam within 650-675 nm at output power 5-30 mW. To determine the geometry of the irradiating beam we used CCD camera Spiricon LBA 300.

  9. Tracking Optical and Electronic Behaviour of Quantum Contacts in Sub-Nanometre Plasmonic Cavities

    PubMed Central

    Sanders, A.; Bowman, R. W.; Baumberg, J. J.

    2016-01-01

    Plasmonic interactions between two metallic tips are dynamically studied in a supercontinuum dark-field microscope and the transition between coupled and charge-transfer plasmons is directly observed in the sub-nm regime. Simultaneous measurement of the dc current, applied force, and optical scattering as the tips come together is used to determine the effects of conductive pathways within the plasmonic nano-gap. Critical conductances are experimentally identified for the first time, determining the points at which quantum tunnelling and conductive charge transport begin to influence plasmon coupling. These results advance our understanding of the relationship between conduction and plasmonics, and the fundamental quantum mechanical behaviours of plasmonic coupling. PMID:27608825

  10. Tracking Optical and Electronic Behaviour of Quantum Contacts in Sub-Nanometre Plasmonic Cavities.

    PubMed

    Sanders, A; Bowman, R W; Baumberg, J J

    2016-01-01

    Plasmonic interactions between two metallic tips are dynamically studied in a supercontinuum dark-field microscope and the transition between coupled and charge-transfer plasmons is directly observed in the sub-nm regime. Simultaneous measurement of the dc current, applied force, and optical scattering as the tips come together is used to determine the effects of conductive pathways within the plasmonic nano-gap. Critical conductances are experimentally identified for the first time, determining the points at which quantum tunnelling and conductive charge transport begin to influence plasmon coupling. These results advance our understanding of the relationship between conduction and plasmonics, and the fundamental quantum mechanical behaviours of plasmonic coupling. PMID:27608825

  11. Low cost, high performance white-light fiber-optic hydrophone system with a trackable working point.

    PubMed

    Ma, Jinyu; Zhao, Meirong; Huang, Xinjing; Bae, Hyungdae; Chen, Yongyao; Yu, Miao

    2016-08-22

    A working-point trackable fiber-optic hydrophone with high acoustic resolution is proposed and experimentally demonstrated. The sensor is based on a polydimethylsiloxane (PDMS) cavity molded at the end of a single-mode fiber, acting as a low-finesse Fabry-Perot (FP) interferometer. The working point tracking is achieved by using a low cost white-light interferometric system with a simple tunable FP filter. By real-time adjusting the optical path difference of the FP filter, the sensor working point can be kept at its highest sensitivity point. This helps address the sensor working point drift due to hydrostatic pressure, water absorption, and/or temperature changes. It is demonstrated that the sensor system has a high resolution with a minimum detectable acoustic pressure of 148 Pa and superior stability compared to a system using a tunable laser. PMID:27557180

  12. Liquid laser cavities

    NASA Technical Reports Server (NTRS)

    Bjorklund, S.; Filipescu, N.; Kellermeyer, G. L.; Mc Avoy, N.

    1969-01-01

    Liquid laser cavities have plenum chambers at the ends of the capillary cell which are terminated in transparent optical flats. By use of these cavities, several new europium chelates and a terbium chelate can provide laser action in solution at room temperature.

  13. Cavity Enhanced Absorption Spectroscopy Using a Broadband Prism Cavity and a Supercontinuum Source

    NASA Astrophysics Data System (ADS)

    Johnston, Paul S.; Lehmann, Kevin K.

    2009-06-01

    The multiplex advantage of current cavity enhanced spectrometers is limited by the high reflectivity bandwidth of the mirrors used to construct the high finesse cavity. Previously, we reported the design and construction of a new spectrometer that circumvents this limitation by utilizing Brewster^{,}s angle prism retroreflectors. The prisms, made from fused silica and combined with a supercontinuum source generated by pumping a highly nonlinear photonic crystal fiber, yields a spectral window ranging from 500 nm to 1750 nm. Recent progress in the instruments development will be discussed, including work on modeling the prism cavity losses, alternative prism material for use in the UV and mid-IR spectral regions, and a new high power supercontinuum source based on mode-locked picosecond laser.

  14. Comparison of Optical Emission Spectroscopy and Cavity Ring-Down Spectroscopy in Large-Scaled Negative-Ion Source

    SciTech Connect

    Ikeda, K.; Nakano, H.; Tsumori, K.; Kaneko, O.; Kisaki, M.; Nagaoka, K.; Osakabe, M.; Takeiri, Y.; Fantz, U.

    2011-09-26

    Optical emission spectroscopy (OES) and cavity ring-down spectroscopy (CRDS) systems are installed in a 1/3-scaled negative hydrogen-ion source at the National Institute for Fusion Science testbed to investigate the dynamics of H{sup -} ions in the extraction region near the plasma grid. The signal form of the H{sup -} ion density rapidly drops after beam extraction on applying a low-bias voltage. A similar signal drop appears in the intensity of the hydrogen Balmer-line emission measured by OES and is caused by decreasing atomic hydrogen produced by mutual neutralization effects between H{sup -} and H{sup +}. Shot trend of the beam currents are similar to the H{sup -} density and H{sub {alpha}}/H{sub {beta}} in the extraction region, which increases twice as large immediately after Cs seeding. We observe a linear correlation between the H{sup -} density and the inclination of H{sub {alpha}}/H{sub {beta}} which allows for experimentally benchmarking the OES measurement with that of CRDS. Thus, this approach is used for estimating the H{sup -} density by OES in negative-ion sources for high-energy neutral beam injector.

  15. Non-intrusive tunable resonant microwave cavity for optical detected magnetic resonance of NV centres in nanodiamonds

    NASA Astrophysics Data System (ADS)

    Le Floch, Jean-Michel; Bradac, Carlo; Volz, Thomas; Tobar, Michael E.; Castelletto, Stefania

    2013-12-01

    Optically detected magnetic resonance (ODMR) in nanodiamond nitrogen-vacancy (NV) centres is usually achieved by applying a microwave field delivered by micron-size wires, strips or antennas directly positioned in very close proximity (~ μm) of the nanodiamond crystals. The microwave field couples evanescently with the ground state spin transition of the NV centre (2.87 GHz at zero magnetic field), which results in a reduction of the centre photoluminescence. We propose an alternative approach based on the construction of a dielectric resonator. We show that such a resonator allows for the efficient detection of NV spins in nanodiamonds without the constraints associated to the laborious positioning of the microwave antenna next to the nanodiamonds, providing therefore improved flexibility. The resonator is based on a tunable Transverse Electric Mode in a dielectric-loaded cavity, and we demonstrate that the resonator can detect single NV centre spins in nanodiamonds using less microwave power than alternative techniques in a non-intrusive manner. This method can achieve higher precision measurement of ODMR of paramagnetic defects spin transition in the micro to millimetre-wave frequency domain. Our approach would permit the tracking of NV centres in biological solutions rather than simply on the surface, which is desirable in light of the recently proposed applications of using nanodiamonds containing NV centres for spin labelling in biological systems with single spin and single particle resolution.

  16. Characteristics of optimized fibre-optic ultrasound receivers for minimally invasive photoacoustic detection

    NASA Astrophysics Data System (ADS)

    Zhang, Edward Z.; Beard, Paul C.

    2015-03-01

    A range of miniature (125μm o.d.) fibre optic ultrasound sensors based on the use of interferometric polymer optical cavities has been developed for minimally invasive photoacoustic imaging and sensing applications. It was observed that by careful selection of both the fibre tip and cavity geometry it is possible to achieve exceptional acoustic performance. Specifically, rounding the tip of the fibre to remove the presence of sharp diffractive boundaries enables a well behaved frequency response along with a near omnidirectional response at frequencies in the tens of MHz range to be achieved. The use of a plano-convex rather than a planar cavity provides high finesse and therefore detection sensitivity. Thus, by using a plano-convex cavity formed at the tip of radiused single mode fibre it was possible to realise a miniature ultrasound detector with a bandwidth of 80MHz, a noise-equivalent pressure of 40Pa (over a 20MHz measurement bandwidth) and a near omnidirectional response at frequencies as high as 30MHz. These characteristics suggest this type of sensor could find applications in interventional medicine for guiding needles or catheters, as mechanically scanned photoacoustic imaging probes or in laser scanning OR-PAM.

  17. In vivo wide-field reflectance/fluorescence imaging and polarization-sensitive optical coherence tomography of human oral cavity with a forward-viewing probe.

    PubMed

    Yoon, Yeoreum; Jang, Won Hyuk; Xiao, Peng; Kim, Bumju; Wang, Taejun; Li, Qingyun; Lee, Ji Youl; Chung, Euiheon; Kim, Ki Hean

    2015-02-01

    We report multimodal imaging of human oral cavity in vivo based on simultaneous wide-field reflectance/fluorescence imaging and polarization-sensitive optical coherence tomography (PS-OCT) with a forward-viewing imaging probe. Wide-field reflectance/fluorescence imaging and PS-OCT were to provide both morphological and fluorescence information on the surface, and structural and birefringent information below the surface respectively. The forward-viewing probe was designed to access the oral cavity through the mouth with dimensions of approximately 10 mm in diameter and 180 mm in length. The probe had field of view (FOV) of approximately 5.5 mm in diameter, and adjustable depth of field (DOF) from 2 mm to 10 mm by controlling numerical aperture (NA) in the detection path. This adjustable DOF was to accommodate both requirements for image-based guiding with high DOF and high-resolution, high-sensitivity imaging with low DOF. This multimodal imaging system was characterized by using a tissue phantom and a mouse model in vivo, and was applied to human oral cavity. Information of surface morphology and vasculature, and under-surface layered structure and birefringence of the oral cavity tissues was obtained. These results showed feasibility of this multimodal imaging system as a tool for studying oral cavity lesions in clinical applications. PMID:25780742

  18. In vivo wide-field reflectance/fluorescence imaging and polarization-sensitive optical coherence tomography of human oral cavity with a forward-viewing probe

    PubMed Central

    Yoon, Yeoreum; Jang, Won Hyuk; Xiao, Peng; Kim, Bumju; Wang, Taejun; Li, Qingyun; Lee, Ji Youl; Chung, Euiheon; Kim, Ki Hean

    2015-01-01

    We report multimodal imaging of human oral cavity in vivo based on simultaneous wide-field reflectance/fluorescence imaging and polarization-sensitive optical coherence tomography (PS-OCT) with a forward-viewing imaging probe. Wide-field reflectance/fluorescence imaging and PS-OCT were to provide both morphological and fluorescence information on the surface, and structural and birefringent information below the surface respectively. The forward-viewing probe was designed to access the oral cavity through the mouth with dimensions of approximately 10 mm in diameter and 180 mm in length. The probe had field of view (FOV) of approximately 5.5 mm in diameter, and adjustable depth of field (DOF) from 2 mm to 10 mm by controlling numerical aperture (NA) in the detection path. This adjustable DOF was to accommodate both requirements for image-based guiding with high DOF and high-resolution, high-sensitivity imaging with low DOF. This multimodal imaging system was characterized by using a tissue phantom and a mouse model in vivo, and was applied to human oral cavity. Information of surface morphology and vasculature, and under-surface layered structure and birefringence of the oral cavity tissues was obtained. These results showed feasibility of this multimodal imaging system as a tool for studying oral cavity lesions in clinical applications. PMID:25780742

  19. In vivo microvascular imaging of human oral and nasal cavities using swept-source optical coherence tomography with a single forward/side viewing probe

    NASA Astrophysics Data System (ADS)

    Choi, Woo June; Wang, Ruikang K.

    2015-03-01

    We report three-dimensional (3D) imaging of microcirculation within human cavity tissues in vivo using a high-speed swept-source optical coherence tomography (SS-OCT) at 1.3 μm with a modified probe interface. Volumetric structural OCT images of the inner tissues of oral and nasal cavities are acquired with a field of view of 2 mm x 2 mm. Two types of disposable and detachable probe attachments are devised and applied to the port of the imaging probe of OCT system, enabling forward and side imaging scans for selective and easy access to specific cavity tissue sites. Blood perfusion is mapped with OCT-based microangiography from 3D structural OCT images, in which a novel vessel extraction algorithm is used to decouple dynamic light scattering signals, due to moving blood cells, from the background scattering signals due to static tissue elements. Characteristic tissue anatomy and microvessel architectures of various cavity tissue regions of a healthy human volunteer are identified with the 3D OCT images and the corresponding 3D vascular perfusion maps at a level approaching capillary resolution. The initial finding suggests that the proposed method may be engineered into a promising tool for evaluating and monitoring tissue microcirculation and its alteration within a wide-range of cavity tissues in the patients with various pathological conditions.

  20. In vivo imaging of functional microvasculature within tissue beds of oral and nasal cavities by swept-source optical coherence tomography with a forward/side-viewing probe

    PubMed Central

    Choi, Woo June; Wang, Ruikang K.

    2014-01-01

    We report three-dimensional (3D) imaging of microcirculation within human cavity tissues in vivo using a high-speed swept-source optical coherence tomography (SS-OCT) at 1300 nm with a modified probe interface. Volumetric structural OCT images of the inner tissues of oral and nasal cavities are acquired with a field of view of 2 mm × 2 mm. Two types of disposable and detachable probe attachments are devised and applied to the port of the imaging probe of OCT system, enabling forward and side imaging scans for selective and easy access to specific cavity tissue sites. Blood perfusion is mapped with OCT-based microangiography from 3D structural OCT images, in which a novel vessel extraction algorithm is used to decouple dynamic light scattering signals, due to moving blood cells, from the background scattering signals due to static tissue elements. Characteristic tissue anatomy and microvessel architectures of various cavity tissue regions of a healthy human volunteer are identified with the 3D OCT images and the corresponding 3D vascular perfusion maps at a level approaching capillary resolution. The initial finding suggests that the proposed method may be engineered into a promising tool for evaluating and monitoring tissue microcirculation and its alteration within a wide-range of cavity tissues in the patients with various pathological conditions. PMID:25136490