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Sample records for state moderate optical

  1. Solid state optical microscope

    DOEpatents

    Young, Ian T.

    1983-01-01

    A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

  2. Solid state optical microscope

    DOEpatents

    Young, I.T.

    1983-08-09

    A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal. 2 figs.

  3. Confined Visible Optical Tamm States

    NASA Astrophysics Data System (ADS)

    Feng, F.; Ouaret, K.; Portalupi, S.; Lafosse, X.; Nasilovski, M.; de Marcillac, W. Daney; Frigerio, J.-M.; Schwob, C.; Dubertret, B.; Maître, A.; Senellart, P.; Coolen, L.

    2016-05-01

    Optical Tamm states are two-dimensional (2D) electromagnetic modes propagating at the interface between a Bragg mirror and a metallic film. When a thin (a few tens of nm) metallic micron-radius disk is deposited on a Bragg mirror, optical Tamm states can be confined below the disk surface, creating a Tamm-states cavity. We describe here the photoluminescence properties of colloidal semiconductor nanocrystals embedded in a Tamm cavity. Tamm states confinement effects are demonstrated and analysed as a function of the disk diameter, and compared with finite-elements simulations.

  4. Solid-state optical microscope

    DOEpatents

    Young, I.T.

    1981-01-07

    A solid state optical microscope is described wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. Means for scanning in one of two orthogonal directions are provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

  5. State of Ohio Curriculum Guide for Moderately Mentally Retarded Learners.

    ERIC Educational Resources Information Center

    Mays, Maxine.

    Provided is a curriculum guide based on the lifelong learning needs of moderately retarded persons. Behavioral objectives are identified at each of six levels of functioning which approximate the mental age levels of 1.5, 3.0, 5.0, 7.0, 8.0, and 8.0 + (adult) years. Sections cover the following persisting life problem areas: (1) developing the…

  6. State-Level Moderation of Genetic Tendencies to Smoke

    PubMed Central

    2009-01-01

    Objectives. I examined genetic influences on smoking among adolescents and differences in the heritability of smoking across states in the United States. Methods. With data from the National Longitudinal Study of Adolescent Health (participants aged 12–21 years), I used a multilevel twin- and sibling-pair (N = 2060 pairs) regression model. Results. Daily smoking (hereditability estimate [h2] = 0.54) and smoking onset (h2 = 0.42) were both highly heritable. Whereas the genetic influences on smoking onset were consistent across states, there was significant variation in these influences on daily smoking. Genetic influences on daily smoking were lower in states with relatively high taxes on cigarettes and in those with greater controls on the vending machines and cigarette advertising. Genetic influences were also negatively associated with rates of smoking among youths. Conclusions. At the state level, gene–environment interaction models are best characterized by the model of social control. State policies may influence genetic tendencies to smoke regularly, but they have not affected the genetic contributions to cigarette onset or experimentation. Future tobacco-control policies may emphasize the heritable endophenotypes that increase the likelihood that adolescents will initiate smoking. PMID:19150910

  7. Moderating effects of music on resting state networks.

    PubMed

    Kay, Benjamin P; Meng, Xiangxiang; Difrancesco, Mark W; Holland, Scott K; Szaflarski, Jerzy P

    2012-04-01

    Resting state networks (RSNs) are spontaneous, synchronous, low-frequency oscillations observed in the brains of subjects who are awake but at rest. A particular RSN called the default mode network (DMN) has been shown to exhibit changes associated with neurological disorders such as temporal lobe epilepsy or Alzheimer's disease. Previous studies have also found that differing experimental conditions such as eyes-open versus eyes-closed can produce measurable changes in the DMN. These condition-associated changes have the potential of confounding the measurements of changes in RSNs related to or caused by disease state(s). In this study, we use fMRI measurements of resting-state connectivity paired with EEG measurements of alpha rhythm and employ independent component analysis, undirected graphs of partial spectral coherence, and spatiotemporal regression to investigate the effect of music-listening on RSNs and the DMN in particular. We observed similar patterns of DMN connectivity in subjects who were listening to music compared with those who were not, with a trend toward a more introspective pattern of resting-state connectivity during music-listening. We conclude that music-listening is a valid condition under which the DMN can be studied. PMID:22365746

  8. Harmonic oscillator states in aberration optics

    NASA Technical Reports Server (NTRS)

    Wolf, Kurt Bernardo

    1993-01-01

    The states of the three-dimensional quantum harmonic oscillator classify optical aberrations of axis-symmetric systems due to the isomorphism between the two mathematical structures. Cartesian quanta and angular momentum classifications have their corresponding aberration classifications. The operation of concatenation of optical elements introduces a new operation between harmonic oscillator states.

  9. Optical coherence tomography and low-frequency mechanics: A moderated discussion

    SciTech Connect

    Freeman, Dennis M.; Ruggero, Mario A.

    2015-12-31

    The following is an edited transcript of a recorded discussion session on the topics of “Optical Coherence Tomography” and “Low-Frequency Mechanics”. The discussion, moderated by the authors, took place at the 12{sup th} International Workshop on the Mechanics of Hearing held at Cape Sounio, Greece, in June 2014. All participants knew that the session was being recorded. In view of both the spontaneous nature of the discussion and the editing, however, this transcript may not represent the considered or final views of the participants, and may not represent a consensus of experts in the field. The reader is advised to consult additional independent publications.

  10. Quantum state sharing using linear optical elements

    NASA Astrophysics Data System (ADS)

    Xia, Yan; Song, Jie; Song, He-Shan

    2008-10-01

    Motivated by protocols [G. Gordon, G. Rigolin, Phys. Rev. A 73 (2006) 062316] and [N.B. An, G. Mahler, Phys. Lett. A 365 (2007) 70], we propose a linear optical protocol for quantum state sharing of polarization entangled state in terms optical elements. Our protocol can realize a near-complete quantum state sharing of polarization entangled state with arbitrary coefficients, and it is possible to achieve unity fidelity transfer of the state if the parties collaborate. This protocol can also be generalized to the multi-party system.

  11. Moderate plasma treatment enhances the quality of optically detected magnetic resonance signals of nitrogen-vacancy centres in nanodiamonds

    NASA Astrophysics Data System (ADS)

    Sotoma, Shingo; Igarashi, Ryuji; Shirakawa, Masahiro

    2016-05-01

    We demonstrate that a moderate plasma treatment increases the quality of optically detected magnetic resonance (ODMR) signals from negatively charged nitrogen-vacancy centres in nanodiamonds (NDs). We measured the statistics of the ODMR spectra of 50-nm-size NDs before and after plasma treatment. We then evaluated each ODMR spectrum in terms of fluorescence and ODMR intensities, line width and signal-to-noise (SN) ratio. Our results showed that plasma treatment for more than 10 min contributes to higher-quality ODMR signals, i.e. signals that are brighter, stronger, sharper and have a higher SN ratio. We showed that such signal improvement is due to alteration of the surface chemical states of the NDs by the plasma treatment. Our study contributes to the advancement of biosensing applications using ODMR of NDs.

  12. Sequential quantum teleportation of optical coherent states

    SciTech Connect

    Yonezawa, Hidehiro; Furusawa, Akira; Loock, Peter van

    2007-09-15

    We demonstrate a sequence of two quantum teleportations of optical coherent states, combining two high-fidelity teleporters for continuous variables. In our experiment, the individual teleportation fidelities are evaluated as F{sub 1}=0.70{+-}0.02 and F{sub 2}=0.75{+-}0.02, while the fidelity between the input and the sequentially teleported states is determined as F{sup (2)}=0.57{+-}0.02. This still exceeds the optimal fidelity of one half for classical teleportation of arbitrary coherent states and almost attains the value of the first (unsequential) quantum teleportation experiment with optical coherent states.

  13. Cloning of Gaussian states by linear optics

    SciTech Connect

    Olivares, Stefano; Paris, Matteo G. A.; Andersen, Ulrik L.

    2006-06-15

    We analyze in details a scheme for cloning of Gaussian states based on linear optical components and homodyne detection recently demonstrated by Andersen et al. [Phys. Rev. Lett. 94, 240503 (2005)]. The input-output fidelity is evaluated for a generic (pure or mixed) Gaussian state taking into account the effect of nonunit quantum efficiency and unbalanced mode mixing. In addition, since in most quantum information protocols the covariance matrix of the set of input states is not perfectly known, we evaluate the average cloning fidelity for classes of Gaussian states with the degree of squeezing and the number of thermal photons being only partially known.

  14. Arbitrary unitary transformations on optical states using a quantum memory

    SciTech Connect

    Campbell, Geoff T.; Pinel, Olivier; Hosseini, Mahdi; Buchler, Ben C.; Lam, Ping Koy

    2014-12-04

    We show that optical memories arranged along an optical path can perform arbitrary unitary transformations on frequency domain optical states. The protocol offers favourable scaling and can be used with any quantum memory that uses an off-resonant Raman transition to reversibly transfer optical information to an atomic spin coherence.

  15. Efficient quantum optical state engineering and applications

    NASA Astrophysics Data System (ADS)

    McCusker, Kevin T.

    Over a century after the modern prediction of the existence of individual particles of light by Albert Einstein, a reliable source of this simple quantum state of one photon does not exist. While common light sources such as a light bulb, LED, or laser can produce a pulse of light with an average of one photon, there is (currently) no way of knowing the number of photons in that pulse without first absorbing (and thereby destroying) them. Spontaneous parametric down-conversion, a process in which one high-energy photon splits into two lower-energy photons, allows us to prepare a single-photon state by detecting one of the photons, which then heralds the existence of its twin. This process has been the workhorse of quantum optics, allowing demonstrations of a myriad of quantum processes and protocols, such as entanglement, cryptography, superdense coding, teleportation, and simple quantum computing demonstrations. All of these processes would benefit from better engineering of the underlying down-conversion process, but despite significant effort (both theoretical and experimental), optimization of this process is ongoing. The focus of this work is to optimize certain aspects of a down-conversion source, and then use this tool in novel experiments not otherwise feasible. Specifically, the goal is to optimize the heralding efficiency of the down-conversion photons, i.e., the probability that if one photon is detected, the other photon is also detected. This source is then applied to two experiments (a single-photon source, and a quantum cryptography implementation), and the detailed theory of an additional application (a source of Fock states and path-entangled states, called N00N states) is discussed, along with some other possible applications.

  16. Effects of transmission on Gaussian optical states.

    PubMed

    McKinstrie, C J; Marshall, K; Weedbrook, C

    2015-04-20

    The noise properties of phase-insensitive and phase-sensitive optical transmission links are described in detail, for Gaussian input signals. Formulas are derived for the quadrature covariance matrices of the output signals, which allow one to quantify the noise figures of the links and the fidelities of transmission. Another formula is derived, which relates the density operator of an output signal, in the number-state representation, to its covariance matrix. This density matrix allows one to quantify the decrease in coherence and changes in photon-number probabilities associated with transmission. Based on the aforementioned performance metrics, links with distributed phase-sensitive amplification perform significantly better than other links. PMID:25969122

  17. Self-awareness moderates the relation between maternal mental state language about desires and children's mental state vocabulary.

    PubMed

    Taumoepeau, Mele; Ruffman, Ted

    2016-04-01

    In this intervention study, we tested the differential effect of talking about children's desires versus talking about others' thoughts and knowledge on children's acquisition of mental state vocabulary for children who did and did not have mirror self-recognition. In a sample of 96 mother-toddler dyads, each mother was randomly assigned a specially constructed, interactive lift-the-flap book to read to her child three times a week for 4 weeks. In the child desire condition the story elicited comments regarding the child's desires, and in the cognitive condition the story elicited the mother's comments about her own thoughts and knowledge while reading the story. Children's mirror self-recognition and mental state vocabulary were assessed at pre- and post-test. Children in the condition that focused on the child's desires showed a significantly greater increase in their mental state vocabulary; however, this effect was moderated by their levels of self-awareness, with children benefitting more from the intervention if they also showed self-recognition at pre-test. We argue that the combination of specific types of maternal talk and children's prior insights facilitates gains in children's mental state vocabulary. PMID:26723013

  18. Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects

    PubMed Central

    2013-01-01

    Background Eurycoma longifolia is a medicinal plant commonly called tongkat ali (TA) and “Malaysian ginseng.” TA roots are a traditional “anti-aging” remedy and modern supplements are intended to improve libido, energy, sports performance and weight loss. Previous studies have shown properly-standardized TA to stimulate release of free testosterone, improve sex drive, reduce fatigue, and improve well-being. Methods We assessed stress hormones and mood state in 63 subjects (32 men and 31 women) screened for moderate stress and supplemented with a standardized hot-water extract of TA root (TA) or Placebo (PL) for 4 weeks. Analysis of variance (ANOVA) with significance set at p < 0.05 was used to determine differences between groups. Results Significant improvements were found in the TA group for Tension (−11%), Anger (−12%), and Confusion (−15%). Stress hormone profile (salivary cortisol and testosterone) was significantly improved by TA supplementation, with reduced cortisol exposure (−16%) and increased testosterone status (+37%). Conclusion These results indicate that daily supplementation with tongkat ali root extract improves stress hormone profile and certain mood state parameters, suggesting that this “ancient” remedy may be an effective approach to shielding the body from the detrimental effects of “modern” chronic stress, which may include general day-to-day stress, as well as the stress of dieting, sleep deprivation, and exercise training. PMID:23705671

  19. Use of Optical Fiber Imported Intra-Tissue Photodynamic Therapy for Treatment of Moderate to Severe Acne Vulgaris

    PubMed Central

    Wang, Qian; Yuan, Dan; Liu, Wei; Chen, Jin; Lin, Xinyu; Cheng, Shi; Li, Fumin; Duan, Xiling

    2016-01-01

    Background To treat moderate to severe acne vulgaris, we developed an optical fiber imported intra-tissue photodynamic therapy: the optical fiber irradiation 5-aminolevulinic acid photodynamic therapy (OFI-ALA-PDT). The aim of this study was to compare the treatment effect and tolerability of OFI-ALA-PDT versus traditional ALA-PDT in the treatment of moderate to severe acne vulgaris. Material/Methods 60 patients with facial acne enrolled into this study were randomly divided into an OFI-ALA-PDT group and a traditional ALA-PDT group, with 30 patients in each group. The difference between these 2 groups was the red light irradiation methods used. In the OFI-ALA-PDT group we used intra-tissue irradiation (import the red light directly into the target lesion with optical fiber) for 5 min, while the traditional ALA-PDT group received whole-face irradiation for 20 min. All patients received 1 irradiation every 7 to 10 days for a total of 6 irradiations. Treatment effects and adverse reactions were recorded after the 4th and 6th irradiation, and at 4, 8, 16 weeks after the entire treatment. Results After the 4th irradiation, significantly different effective rates were observed in these groups (90.0% for the OFI-ALA-PDT group and 66.7% for the control group). However, no significant difference in effective rate was recorded in the later observations. There were 182 adverse reactions in the OFI-ALA-PDT group and 497 in the control group, which showed a significant difference (P<0.05). Conclusions OFI-ALA-PDT showed improved treatment effective rate in the early stage of irradiation, and it had fewer adverse reactions. PMID:26839152

  20. Leucine-enriched essential amino acid supplementation during moderate steady state exercise enhances postexercise muscle protein synthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: The effects of essential amino acid (EAA) supplementation during moderate steady state (ie, endurance) exercise on postexercise skeletal muscle metabolism are not well described, and the potential role of supplemental leucine on muscle protein synthesis (MPS) and associated molecular re...

  1. Optical characterization of a precipitation event in a moderately hypersaline lake

    NASA Astrophysics Data System (ADS)

    Reifel, Kristen M.; Swan, Brandon K.; Ehrhardt, Christopher J.; Jones, Burton H.

    2010-11-01

    The role of mineral precipitation events in creating large patches of bright green water in the Salton Sea was investigated by comparing in situ inherent optical properties (IOPs) and constituent concentrations within and outside a green water region. While absorption was similar in both regions, scatter and backscatter were ˜2 and 3 times higher in green water, respectively. Ratios of scatter to absorption and backscatter to absorption had nearly identical spectral shapes but much higher magnitudes within green water. CIE chromaticity values were similar between stations, but luminance was 2.4 times greater in green water. Therefore, differences in observed water color were mostly due to increased brightness within green water. Further analyses of IOPs indicated that particles were small at both stations (average diameter ˜0.3 μm), but a larger proportion of particles present in green water were inorganic. Scanning electron microscopy analysis revealed the presence of small (up to 5 μm) particles consistent with gypsum. Because precipitated minerals only increase backscatter and do not by themselves affect water color, simple reflectance ratios will not always detect these events. Therefore, the magnitude of reflectance must be incorporated into analyses of precipitation events.

  2. Optical glass: standards - present state and outlook

    NASA Astrophysics Data System (ADS)

    Hartmann, Peter

    2015-10-01

    In 1996, the international organization for standardization ISO started the standards series ISO 10110 specifying indications in drawings of optical elements. Three parts cover material properties: part 2 (stress birefringence), 3 (bubbles and inclusions), and 4 (inhomogeneity and striae). Customers used to just send optical element drawings to glass manufacturers often leading to uncertainty, overspecification, and delivery problems. The raw glass standard ISO 12123 of 2010 allows direct addressing of raw glass specifications. Harmonizing ISO 10110 with ISO 12123 and progress in inspection methods require updating of the material specifying parts. A new part 18 containing all properties is under preparation and is meant to replace parts 2-4. ISO 12123 will be amended by introducing definitions for relative partial dispersions and reference normal lines and grade denominations for tolerance ranges. The working draft ISO/WD 10110 part 18 extends indication possibilities to allow relating to ISO 12123 while ensuring backward compatibility. Default optical glass quality and direct specification of raw glass simplify tolerancing considerably. Annexes support selection of appropriate quality classes referring to optical element size categories. Test and inspection standards on chemical resistances, hardness, stress birefringence, and optical homogeneity will be maintained. Standards for water resistance, refractive index, and striae inspection are being prepared.

  3. Visual and optical performance of silicone hydrogel contact lenses for moderate myopia

    PubMed Central

    Keir, Nancy; Simpson, Trefford; Fonn, Desmond

    2010-01-01

    Purpose To compare the short-term visual and optical performance of silicone hydrogel contact lenses for myopia ≥ −3.00D. Methods This was a short-term, non-dispense, double-masked, randomized study investigating Night&Day (ND), PureVision (PV), O2 Optix (O2), Biofinity (BF), Acuvue Advance (AA) and Acuvue OASYS for myopia ≥ −3.00D. Testing was conducted under scotopic conditions. Measures (one eye only) included: high- and low-contrast visual acuity (HCVA/LCVA), contrast sensitivity, subjective clarity of vision ratings (0-100 scale using reference images, with test image representing grade 50) and ocular aberrations (up to the 4th order, analyzed across individual scotopic pupil sizes). Results Three males and 27 females participated, with a mean (± SD) age of 24.9 ± 7.7 yrs (range 19 to 53 yrs), sphere of −5.30 ± 1.73D (range −3.00 to −10.75D) and cylinder −0.36 ± 0.23D (range 0 to −0.75D). Mean (± SEM) logMAR HCVA ranged from 0.06 (PV) to 0.10 (AA) (± 0.02), LCVA from 0.33 (BF) to 0.40 (AA) (± 0.02) and contrast sensitivity from 2.33 (BF) to 2.53 (ND) (± 0.15) (differences not statistically significant; all p > 0.05). Subjective ratings for the test image ranged from 59 (PV) to 64 (ND) (± 4) and 56 (AA) to 65 (ND) (± 4), for monochromatic and polychromatic reference images, respectively (all p > 0.05). There was a statistically significant impact on ocular aberrations with all study lenses compared to no lens. Between-lens differences were statistically significant for defocus (Z02), horizontal coma (Z 13) and spherical aberration (Z04). Conclusions Despite some differences in ocular aberrations, there were no significant differences in HCVA, LCVA, contrast sensitivity or subjective ratings across lenses.

  4. Solid state electro-optic color filter and iris

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Test results obtained have confirmed the practicality of the solid state electro-optic filters as an optical control element in a television system. Neutral-density control range in excess of 1000:1 has been obtained on sample filters. Test results, measurements in a complete camera system, discussions of problem areas, analytical comparisons, and recommendations for future investigations are included.

  5. Solid-state gadolinium{endash}magnesium hydride optical switch

    SciTech Connect

    Armitage, R.; Rubin, M.; Richardson, T.; OBrien, N.; Chen, Y.

    1999-09-01

    The optical switching properties of gadolinium{endash}magnesium hydride have been demonstrated in a solid-state electrochromic device. With positive polarization of the hydride electrode, the visible reflectance approaches 35{percent} with virtually zero transmission, while with negative polarization, the visible transmission exceeds 25{percent} at 650 nm. The switching is reversible, with intermediate optical properties between the transparent and reflecting states. {copyright} {ital 1999 American Institute of Physics.}

  6. Optical state-of-charge monitor for batteries

    DOEpatents

    Weiss, Jonathan D.

    1999-01-01

    A method and apparatus for determining the instantaneous state-of-charge of a battery in which change in composition with discharge manifests itself as a change in optical absorption. In a lead-acid battery, the sensor comprises a fiber optic system with an absorption cell or, alternatively, an optical fiber woven into an absorbed-glass-mat battery. In a lithium-ion battery, the sensor comprises fiber optics for introducing light into the anode to monitor absorption when lithium ions are introduced.

  7. A two-state Raman coupler for coherent atom optics.

    PubMed

    Debs, J E; Döring, D; Robins, N P; Figl, C; Altin, P A; Close, J D

    2009-02-16

    We present results on a Raman laser-system that resonantly drives a closed two-photon transition between two levels in different hyperfine ground states of (87)Rb. The coupler is based on a novel optical design for producing two phase-coherent optical beams to drive a Raman transition. Operated as an outcoupler, it produces an atom laser in a single internal atomic state, with the lower divergence and increased brightness typical of a Raman outcoupler. Due to the optical nature of the outcoupling, the two-state outcoupler is an ideal candidate for transferring photon correlations onto atom-laser beams. As our laser system couples just two hyperfine ground states, it has also been used as an internal state beamsplitter, taking the next major step towards free space Ramsey interferometry with an atom laser. PMID:19219134

  8. Effects of Moderate Aerobic Exercise on Cognitive Abilities and Redox State Biomarkers in Older Adults.

    PubMed

    Alghadir, Ahmad H; Gabr, Sami A; Al-Eisa, Einas S

    2016-01-01

    We used a moderate aerobic exercise program for 24 weeks to measure the positive impact of physical activity on oxidative stress and inflammatory markers and its association with cognitive performance in healthy older adults. A total of 100 healthy subjects (65-95 Yrs) were randomly classified into two groups: control group (n = 50) and exercise group (n = 50). Cognitive functioning, physical activity score, MDA, 8-OHdG, TAC, and hs-CRP were assessed using LOTCA battery, prevalidated PA questionnaire, and immunoassay techniques. LOTCA 7-set scores of cognitive performance showed a significant correlation with physical activity status and the regulation of both oxidative stress free radicals and inflammatory markers in all older subjects following 24 weeks of moderate exercise. Physically active persons showed a higher cognitive performance along with reduction in the levels of MDA, 8-OHdG, and hs-CRP and increase in TAC activity compared with sedentary participants. Cognitive performance correlated positively with the increase in TAC activity and physical fitness scores and negatively with MDA, 8-OHdG, and hs-CRP, respectively. There was a significant improvement in motor praxis, vasomotor organization, thinking operations, and attention and concentration among older adults. In conclusion, moderate aerobic training for 24 weeks has a positive significant effect in improving cognitive functions via modulating redox and inflammatory status of older adults. PMID:27195073

  9. Effects of Moderate Aerobic Exercise on Cognitive Abilities and Redox State Biomarkers in Older Adults

    PubMed Central

    Al-Eisa, Einas S.

    2016-01-01

    We used a moderate aerobic exercise program for 24 weeks to measure the positive impact of physical activity on oxidative stress and inflammatory markers and its association with cognitive performance in healthy older adults. A total of 100 healthy subjects (65–95 Yrs) were randomly classified into two groups: control group (n = 50) and exercise group (n = 50). Cognitive functioning, physical activity score, MDA, 8-OHdG, TAC, and hs-CRP were assessed using LOTCA battery, prevalidated PA questionnaire, and immunoassay techniques. LOTCA 7-set scores of cognitive performance showed a significant correlation with physical activity status and the regulation of both oxidative stress free radicals and inflammatory markers in all older subjects following 24 weeks of moderate exercise. Physically active persons showed a higher cognitive performance along with reduction in the levels of MDA, 8-OHdG, and hs-CRP and increase in TAC activity compared with sedentary participants. Cognitive performance correlated positively with the increase in TAC activity and physical fitness scores and negatively with MDA, 8-OHdG, and hs-CRP, respectively. There was a significant improvement in motor praxis, vasomotor organization, thinking operations, and attention and concentration among older adults. In conclusion, moderate aerobic training for 24 weeks has a positive significant effect in improving cognitive functions via modulating redox and inflammatory status of older adults. PMID:27195073

  10. Reduced Ventral Cingulum Integrity and Increased Behavioral Problems in Children with Isolated Optic Nerve Hypoplasia and Mild to Moderate or No Visual Impairment

    PubMed Central

    Clayden, Jonathan D.; Seunarine, Kiran K.; Dale, Naomi; Salt, Alison; Clark, Chris A.; Dattani, Mehul T.

    2013-01-01

    Objectives To assess the prevalence of behavioral problems in children with isolated optic nerve hypoplasia, mild to moderate or no visual impairment, and no developmental delay. To identify white matter abnormalities that may provide neural correlates for any behavioral abnormalities identified. Patients and Methods Eleven children with isolated optic nerve hypoplasia (mean age 5.9 years) underwent behavioral assessment and brain diffusion tensor imaging, Twenty four controls with isolated short stature (mean age 6.4 years) underwent MRI, 11 of whom also completed behavioral assessments. Fractional anisotropy images were processed using tract-based spatial statistics. Partial correlation between ventral cingulum, corpus callosum and optic radiation fractional anisotropy, and child behavioral checklist scores (controlled for age at scan and sex) was performed. Results Children with optic nerve hypoplasia had significantly higher scores on the child behavioral checklist (p<0.05) than controls (4 had scores in the clinically significant range). Ventral cingulum, corpus callosum and optic radiation fractional anisotropy were significantly reduced in children with optic nerve hypoplasia. Right ventral cingulum fractional anisotropy correlated with total and externalising child behavioral checklist scores (r = −0.52, p<0.02, r = −0.46, p<0.049 respectively). There were no significant correlations between left ventral cingulum, corpus callosum or optic radiation fractional anisotropy and behavioral scores. Conclusions Our findings suggest that children with optic nerve hypoplasia and mild to moderate or no visual impairment require behavioral assessment to determine the presence of clinically significant behavioral problems. Reduced structural integrity of the ventral cingulum correlated with behavioral scores, suggesting that these white matter abnormalities may be clinically significant. The presence of reduced fractional anisotropy in the optic radiations

  11. Laser action by optically depumping lower states

    DOEpatents

    Krupke, William F.

    1977-01-01

    A method and apparatus for obtaining laser action between an upper energy level and a lower energy level of a gaseous medium, which comprises populating the upper energy level to some degree (short of achieving a conventional inverted population) by any suitable pumping means, and thereafter establishing an inverted population by transiently and selectively depumping the lower energy level such as by exposing the medium to an intense source of radiation which selectively causes the transformation of the lower energy level species to some other energy level. Thus, a thermally pumped/optically depumped gas laser system is produced.

  12. Laser action by optically depumping lower states

    DOEpatents

    Krupke, W.F.

    1975-11-26

    A method and apparatus are described for obtaining laser action between an upper energy level and a lower energy level of a gaseous medium. The upper energy level is populated to some degree (short of achieving a conventional inverted population) by any suitable pumping means, and an inverted population is established by transiently and selectively depumping the lower energy level. The depumping may be done by exposing the medium to an intense source of radiation which selectively causes the transformation of the lower energy level species to some other energy level. Thus, a thermally pumped/optically depumped gas laser system is produced.

  13. Nonadditive Mixed State Phases in Neutron Optics

    SciTech Connect

    Klepp, J.; Sponar, S.; Filipp, S.; Lettner, M.; Badurek, G.; Hasegawa, Y.

    2009-03-10

    In a neutron polarimetry experiment mixed neutron spin phases are determined. We consider evolutions leading to purely geometric, purely dynamical and combined phases. It is experimentally demonstrated that the sum of the geometric and dynamical phases--both obtained in separate measurements--is not equal to the associated total phase as obtained from a third measurement, unless the system is in a pure state. In this sense, mixed state phases are not additive.

  14. Role of Beliefs About Hypnotic States as a Moderator Variable: A Reexamination of the Relationship Between Reactance and Hypnotizability.

    PubMed

    Shimizu, Takahiro

    2016-01-01

    The hypothesis that beliefs about hypnosis determine the amount of psychological reactance aroused was tested. Participants were administered a measure of trait reactance to therapist directives (Therapeutic Reactance Scale; TRS), the Beliefs about Hypnotic State Questionnaire (BHSQ-R), and behavioral and subjective scales concerning hypnotic response. Hierarchical multiple regressions revealed significant interactions between BHSQ-R subscales and TRS. The findings suggest that the arousal of psychological reactance to hypnosis is determined by individuals' trait reactance levels acting together with their interpretations of the hypnotic situation. The role of beliefs about hypnotic states as a moderator of the relationship between personality and hypnotizability was discussed. PMID:26894421

  15. Detecting multiatomic composite states in optical lattices

    NASA Astrophysics Data System (ADS)

    Kuklov, Anatoly; Moritz, Henning

    2007-01-01

    We propose and discuss methods for detecting quasimolecular complexes which are expected to form in strongly interacting optical lattice systems. Particular emphasis is placed on the detection of composite fermions forming in Bose-Fermi mixtures. We argue that, as an indirect indication of the composite fermions and a generic consequence of strong interactions, periodic correlations must appear in the atom shot noise of bosonic absorption images, similar to the bosonic Mott insulator [S. Fölling , Nature (London) 434, 481 (2005)]. The composites can also be detected directly and their quasimomentum distribution measured. This method—an extension of the technique of noise correlation interferometry [E. Altman , Phys. Rev. A 79, 013603 (2004)]—relies on measuring higher order correlations between the bosonic and fermionic shot noise in the absorption images. However, it fails above a certain number of the constituents due to a dramatic increase of uncorrelated noise.

  16. A new optical scheme for teleportation of entangled coherent state

    NASA Astrophysics Data System (ADS)

    Liao, Jie-Qiao; Kuang, Le-Man

    2006-10-01

    We propose a nearly perfect optical scheme for the quantum teleportation of entangled coherent states using optical devices such as nonlinear Kerr media, beam splitters, phase shifters, and photon detectors. Different from those previous schemes, our scheme needs only ``yes'' or `no' measurements of the photon number of the related modes, i.e. nonzero- and zero-photon measurements, while in previous schemes one has to exactly identify the even or odd parity character of the photon numbers detected by detectors.

  17. Optical pumping in solid state nuclear magnetic resonance

    SciTech Connect

    Tycko, R.; Reimer, J.A.

    1996-08-01

    An important current trend in solid state nuclear magnetic resonance (NMR) is the growing exploitation of optical pumping of nuclear spin polarizations as a means of enhancing and localizing NMR signals. Recent work has been concentrated in two areas, namely optically pumped NMR in semiconductors and optical pumping of noble gases. Progress in these two areas, including technical developments and new applications in physical chemistry, condensed matter physics, and biomedical sciences, is reviewed. Likely directions for future developments are suggested. 58 refs., 13 figs.

  18. Optical control of charged exciton states in tungsten disulfide

    NASA Astrophysics Data System (ADS)

    Currie, M.; Hanbicki, A. T.; Kioseoglou, G.; Jonker, B. T.

    2015-05-01

    A method is presented for optically preparing WS2 monolayers to luminescence from only the charged exciton (trion) state-completely suppressing the neutral exciton. When isolating the trion state, we observed changes in the Raman A1g intensity and an enhanced feature on the low energy side of the E12g peak. Photoluminescence and optical reflectivity measurements confirm the existence of the prepared trion state. This technique also prepares intermediate regimes with controlled luminescence amplitudes of the neutral and charged exciton. This effect is reversible by exposing the sample to air, indicating the change is mitigated by surface interactions with the ambient environment. This method provides a tool to modify optical emission energy and to isolate physical processes in this and other two-dimensional materials.

  19. Feasible logic Bell-state analysis with linear optics.

    PubMed

    Zhou, Lan; Sheng, Yu-Bo

    2016-01-01

    We describe a feasible logic Bell-state analysis protocol by employing the logic entanglement to be the robust concatenated Greenberger-Horne-Zeilinger (C-GHZ) state. This protocol only uses polarization beam splitters and half-wave plates, which are available in current experimental technology. We can conveniently identify two of the logic Bell states. This protocol can be easily generalized to the arbitrary C-GHZ state analysis. We can also distinguish two N-logic-qubit C-GHZ states. As the previous theory and experiment both showed that the C-GHZ state has the robustness feature, this logic Bell-state analysis and C-GHZ state analysis may be essential for linear-optical quantum computation protocols whose building blocks are logic-qubit entangled state. PMID:26877208

  20. Feasible logic Bell-state analysis with linear optics

    PubMed Central

    Zhou, Lan; Sheng, Yu-Bo

    2016-01-01

    We describe a feasible logic Bell-state analysis protocol by employing the logic entanglement to be the robust concatenated Greenberger-Horne-Zeilinger (C-GHZ) state. This protocol only uses polarization beam splitters and half-wave plates, which are available in current experimental technology. We can conveniently identify two of the logic Bell states. This protocol can be easily generalized to the arbitrary C-GHZ state analysis. We can also distinguish two N-logic-qubit C-GHZ states. As the previous theory and experiment both showed that the C-GHZ state has the robustness feature, this logic Bell-state analysis and C-GHZ state analysis may be essential for linear-optical quantum computation protocols whose building blocks are logic-qubit entangled state. PMID:26877208

  1. Feasible logic Bell-state analysis with linear optics

    NASA Astrophysics Data System (ADS)

    Zhou, Lan; Sheng, Yu-Bo

    2016-02-01

    We describe a feasible logic Bell-state analysis protocol by employing the logic entanglement to be the robust concatenated Greenberger-Horne-Zeilinger (C-GHZ) state. This protocol only uses polarization beam splitters and half-wave plates, which are available in current experimental technology. We can conveniently identify two of the logic Bell states. This protocol can be easily generalized to the arbitrary C-GHZ state analysis. We can also distinguish two N-logic-qubit C-GHZ states. As the previous theory and experiment both showed that the C-GHZ state has the robustness feature, this logic Bell-state analysis and C-GHZ state analysis may be essential for linear-optical quantum computation protocols whose building blocks are logic-qubit entangled state.

  2. Fault tolerance in parity-state linear optical quantum computing

    SciTech Connect

    Hayes, A. J. F.; Ralph, T. C.; Haselgrove, H. L.; Gilchrist, Alexei

    2010-08-15

    We use a combination of analytical and numerical techniques to calculate the noise threshold and resource requirements for a linear optical quantum computing scheme based on parity-state encoding. Parity-state encoding is used at the lowest level of code concatenation in order to efficiently correct errors arising from the inherent nondeterminism of two-qubit linear-optical gates. When combined with teleported error-correction (using either a Steane or Golay code) at higher levels of concatenation, the parity-state scheme is found to achieve a saving of approximately three orders of magnitude in resources when compared to the cluster state scheme, at a cost of a somewhat reduced noise threshold.

  3. Subwavelength optical lattices induced by position-dependent dark states

    SciTech Connect

    Sun Qingqing; Evers, Joerg; Kiffner, Martin; Zubairy, M. Suhail

    2011-05-15

    A method for the generation of subwavelength optical lattices based on multilevel dark states is proposed. The dark state is formed by a suitable combination of standing wave light fields, leading to position-dependent populations of the ground states. An additional field coupling dispersively to one of the ground states translates this position dependence into a subwavelength optical potential. We provide two semiclassical approaches to understand the involved physics, and demonstrate that they lead to identical results in a certain meaningful limit. Then we apply a Monte Carlo simulation technique to study the full quantum dynamics of the subwavelength trapping. Finally, we discuss the relevant time scales for the trapping, optimum conditions, and possible implementations.

  4. Optical Bistability And Hysteresis In A Solid State Ring Laser

    NASA Astrophysics Data System (ADS)

    Kornienko, L. S.; Kravtsov, N. S.; Shelaev, A. N.

    1985-01-01

    The phenomena of optical bistability, hysteresis and memory under the interaction of oppositely directed (OD) light waves in a CW YAG:Nd3+ solid state ring laser (SRL) have been experimentally discovered. The possibilities of spontaneous or forced (with modulated SRL parameters) commutation of the radiation direction without transients at the relaxation frequency (typical for solid state lasers) have been established both in the single-mode and in the mode-locking regimes with various feedback circuits. The mode-locking band was found to be substantially broadened by more than an order of magnitude when OD light waves primarily diffracted on a standing ultrasonic wave were returned into the acousto-optical modulator. With such acousto-optical feedback the mode-locking regime has been obtained using a modulator on a running ultrasonic wave.

  5. Optical control of charged exciton states in tungsten disulfide

    SciTech Connect

    Currie, M.; Hanbicki, A. T.; Jonker, B. T.; Kioseoglou, G.

    2015-05-18

    A method is presented for optically preparing WS{sub 2} monolayers to luminescence from only the charged exciton (trion) state–completely suppressing the neutral exciton. When isolating the trion state, we observed changes in the Raman A{sub 1g} intensity and an enhanced feature on the low energy side of the E{sup 1}{sub 2g} peak. Photoluminescence and optical reflectivity measurements confirm the existence of the prepared trion state. This technique also prepares intermediate regimes with controlled luminescence amplitudes of the neutral and charged exciton. This effect is reversible by exposing the sample to air, indicating the change is mitigated by surface interactions with the ambient environment. This method provides a tool to modify optical emission energy and to isolate physical processes in this and other two-dimensional materials.

  6. Assessment of Moderate- and High-Temperature Geothermal Resources of the United States

    USGS Publications Warehouse

    Williams, Colin F.; Reed, Marshall J.; Mariner, Robert H.; DeAngelo, Jacob; Galanis, S. Peter

    2008-01-01

    Scientists with the U.S. Geological Survey (USGS) recently completed an assessment of our Nation's geothermal resources. Geothermal power plants are currently operating in six states: Alaska, California, Hawaii, Idaho, Nevada, and Utah. The assessment indicates that the electric power generation potential from identified geothermal systems is 9,057 Megawatts-electric (MWe), distributed over 13 states. The mean estimated power production potential from undiscovered geothermal resources is 30,033 MWe. Additionally, another estimated 517,800 MWe could be generated through implementation of technology for creating geothermal reservoirs in regions characterized by high temperature, but low permeability, rock formations.

  7. United States Atlas of Optical Telescopes. [2nd Edition

    NASA Technical Reports Server (NTRS)

    Meszaros, Stephen Paul

    1987-01-01

    This atlas shows the locations of and gives information about optical telescopes used for astronomical research in the United States as of late 1986. Those instruments with mirror or lens diameters of 3/4 m (approx. 30 inches) and larger are included. These telescopes are concentrated in the Southwest, on the West Coast and on the island of Hawaii.

  8. Optomechanical design concept for GMACS: a wide-field multi-object moderate resolution optical spectrograph for the Giant Magellan Telescope (GMT)

    NASA Astrophysics Data System (ADS)

    Smee, Stephen A.; Prochaska, Travis; Shectman, Stephen A.; Hammond, Randolph P.; Barkhouser, Robert H.; DePoy, D. L.; Marshall, J. L.

    2012-09-01

    We describe the conceptual optomechanical design for GMACS, a wide-field, multi-object, moderate-resolution optical spectrograph for the Giant Magellan Telescope (GMT). GMACS is a candidate first-light instrument for the GMT and will be one of several instruments housed in the Gregorian Instrument Rotator (GIR) located at the Gregorian focus. The instrument samples a 9 arcminute x 18 arcminute field of view providing two resolution modes (i.e, low resolution, R ~ 2000, and moderate resolution, R ~ 4000) over a 3700 Å to 10200 Å wavelength range. To minimize the size of the optics, four fold mirrors at the GMT focal plane redirect the full field into four individual "arms", that each comprises a double spectrograph with a red and blue channel. Hence, each arm samples a 4.5 arcminute x 9 arcminute field of view. The optical layout naturally leads to three separate optomechanical assemblies: a focal plane assembly, and two identical optics modules. The focal plane assembly contains the last element of the telescope's wide-field corrector, slit-mask, tent-mirror assembly, and slit-mask magazine. Each of the two optics modules supports two of the four instrument arms and houses the aft-optics (i.e. collimators, dichroics, gratings, and cameras). A grating exchange mechanism, and articulated gratings and cameras facilitate multiple resolution modes. In this paper we describe the details of the GMACS optomechanical design, including the requirements and considerations leading to the design, mechanism details, optics mounts, and predicted flexure performance.

  9. Quantum communication with coherent states and linear optics

    NASA Astrophysics Data System (ADS)

    Arrazola, Juan Miguel; Lütkenhaus, Norbert

    2014-10-01

    We introduce a general mapping for encoding quantum communication protocols involving pure states of multiple qubits, unitary transformations, and projective measurements into another set of protocols that employ a coherent state of light in a linear combination of optical modes, linear-optics transformations, and measurements with single-photon threshold detectors. This provides a general framework for transforming protocols in quantum communication into a form in which they can be implemented with current technology. We explore the similarity between properties of the original qubit protocols and the coherent-state protocols obtained from the mapping and make use of the mapping to construct additional protocols in the context of quantum communication complexity and quantum digital signatures. Our results have the potential of bringing a wide class of quantum communication protocols closer to their experimental demonstration.

  10. Optical isolation in topological-edge-state photonic arrays.

    PubMed

    El-Ganainy, Ramy; Levy, Miguel

    2015-11-15

    We introduce a new type of optical isolator based on breaking time reversal symmetry in dissipative finite Su-Schrieffer-Heeger (SSH) waveguide arrays that support topological edge states at one end of the structure. In the forward propagation direction, light is launched into the edge waveguide to excite the localized topological midgap state. As a result, most of the input optical power is transmitted to the output port. On the other hand, backward reflected light encounters a propagation constant mismatch in that same channel which shifts the otherwise midgap state into one of the bands and hence becomes delocalized over the whole array. We show that under these conditions, a judicious spatial distribution of the optical dissipation across the structure can produce an isolation ratio of -50 dB. The required nonreciprocal phase shift is introduced by depositing a magnetic garnet film only on the edge waveguide and, thus, the required magnetic field can be generated by an integrated micromagnet. Similar concepts can also be applied to SSH arrays made from optical resonators. PMID:26565853

  11. Solid-state optical refrigeration to sub-100 Kelvin regime

    DOE PAGESBeta

    Melgaard, Seth D.; Albrecht, Alexander R.; Hehlen, Markus P.; Sheik-Bahae, Mansoor

    2016-02-05

    We report that since the first demonstration of net cooling twenty years ago, optical refrigeration of solids has progressed to outperform all other solid-state cooling processes. It has become the first and only solid-state refrigerator capable of reaching cryogenic temperatures, and now the first solid-state cooling below 100 K. Such substantial progress required a multi-disciplinary approach of pump laser absorption enhancement, material characterization and purification, and thermal management. Here we present the culmination of two decades of progress, the record cooling to ≈91K from room temperature.

  12. Solid-state optical refrigeration to sub-100 Kelvin regime

    NASA Astrophysics Data System (ADS)

    Melgaard, Seth D.; Albrecht, Alexander R.; Hehlen, Markus P.; Sheik-Bahae, Mansoor

    2016-02-01

    Since the first demonstration of net cooling twenty years ago, optical refrigeration of solids has progressed to outperform all other solid-state cooling processes. It has become the first and only solid-state refrigerator capable of reaching cryogenic temperatures, and now the first solid-state cooling below 100 K. Such substantial progress required a multi-disciplinary approach of pump laser absorption enhancement, material characterization and purification, and thermal management. Here we present the culmination of two decades of progress, the record cooling to ≈ 91 K from room temperature.

  13. Solid-state optical refrigeration to sub-100 Kelvin regime.

    PubMed

    Melgaard, Seth D; Albrecht, Alexander R; Hehlen, Markus P; Sheik-Bahae, Mansoor

    2016-01-01

    Since the first demonstration of net cooling twenty years ago, optical refrigeration of solids has progressed to outperform all other solid-state cooling processes. It has become the first and only solid-state refrigerator capable of reaching cryogenic temperatures, and now the first solid-state cooling below 100 K. Such substantial progress required a multi-disciplinary approach of pump laser absorption enhancement, material characterization and purification, and thermal management. Here we present the culmination of two decades of progress, the record cooling to ≈ 91 K from room temperature. PMID:26847703

  14. Solid-state optical refrigeration to sub-100 Kelvin regime

    PubMed Central

    Melgaard, Seth D.; Albrecht, Alexander R.; Hehlen, Markus P.; Sheik-Bahae, Mansoor

    2016-01-01

    Since the first demonstration of net cooling twenty years ago, optical refrigeration of solids has progressed to outperform all other solid-state cooling processes. It has become the first and only solid-state refrigerator capable of reaching cryogenic temperatures, and now the first solid-state cooling below 100 K. Such substantial progress required a multi-disciplinary approach of pump laser absorption enhancement, material characterization and purification, and thermal management. Here we present the culmination of two decades of progress, the record cooling to ≈ 91 K from room temperature. PMID:26847703

  15. 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.

  16. All-optical reconstruction of atomic ground-state population

    NASA Astrophysics Data System (ADS)

    London, P.; Firstenberg, O.; Shuker, M.; Ron, A.

    2010-04-01

    The population distribution within the ground state of an atomic ensemble is of great significance in a variety of quantum-optics processes. We present a method to reconstruct the detailed population distribution from a set of absorption measurements with various frequencies and polarizations, by utilizing the differences between the dipole matrix elements of the probed transitions. The technique is experimentally implemented on a thermal rubidium vapor, demonstrating a population-based analysis in two optical-pumping examples. The results are used to verify and calibrate an elaborated numerical model, and the limitations of the reconstruction scheme, which result from the symmetry properties of the dipole matrix elements, are discussed.

  17. Introducing single-crystal scattering and optical potentials into MCNPX: Predicting neutron emission from a convoluted moderator

    NASA Astrophysics Data System (ADS)

    Gallmeier, F. X.; Iverson, E. B.; Lu, W.; Baxter, D. V.; Muhrer, G.; Ansell, S.

    2016-04-01

    Neutron transport simulation codes are indispensable tools for the design and construction of modern neutron scattering facilities and instrumentation. Recently, it has become increasingly clear that some neutron instrumentation has started to exploit physics that is not well-modeled by the existing codes. In particular, the transport of neutrons through single crystals and across interfaces in MCNP(X), Geant4, and other codes ignores scattering from oriented crystals and refractive effects, and yet these are essential phenomena for the performance of monochromators and ultra-cold neutron transport respectively (to mention but two examples). In light of these developments, we have extended the MCNPX code to include a single-crystal neutron scattering model and neutron reflection/refraction physics. We have also generated silicon scattering kernels for single crystals of definable orientation. As a first test of these new tools, we have chosen to model the recently developed convoluted moderator concept, in which a moderating material is interleaved with layers of perfect crystals to provide an exit path for neutrons moderated to energies below the crystal's Bragg cut-off from locations deep within the moderator. Studies of simple cylindrical convoluted moderator systems of 100 mm diameter and composed of polyethylene and single crystal silicon were performed with the upgraded MCNPX code and reproduced the magnitude of effects seen in experiments compared to homogeneous moderator systems. Applying different material properties for refraction and reflection, and by replacing the silicon in the models with voids, we show that the emission enhancements seen in recent experiments are primarily caused by the transparency of the silicon and void layers. Finally we simulated the convoluted moderator experiments described by Iverson et al. and found satisfactory agreement between the measurements and the simulations performed with the tools we have developed.

  18. Reversible Dehydrogenation of Magnesium Borohydride to Magnesium Triborane in the Solid State Under Moderate Conditions

    SciTech Connect

    Chong, Marina; Karkamkar, Abhijeet J.; Autrey, Thomas; Orimo, Shin-ichi; Jalisatgi, Satish; Jensen, Craig M.

    2011-02-17

    Thermal decomposition of magnesium borohydride, Mg(BH4)2, in the solid state was studied by a combination of PCT, TGA/MS and NMR spectroscopy. Dehydrogenation of Mg(BH4)2 at 200 °C, results in the highly selective formation of magnesium triborane, Mg(B3H8)2. This process is reversible at 250 °C under 120 atm H2. Dehydrogenation at higher temperature, > 300 °C, produces a complex mixture of polyborane species. Solution phase 11B NMR spectra of the hydrolyzed decomposition products reveals the formation of the B3H8 anion, boric acid from hydrolysis of the unstable polyboranes (BnHx) (n = 3-11, x >8), and the closoborane B12H12 dianion as a minor product. A BH condensation mechanism involving metal hydride formation is proposed to explain the limited reversible hydrogen storage in magnesium borohydride.

  19. Combining anatomical, diffusion, and resting state functional magnetic resonance imaging for individual classification of mild and moderate Alzheimer's disease

    PubMed Central

    Schouten, Tijn M.; Koini, Marisa; de Vos, Frank; Seiler, Stephan; van der Grond, Jeroen; Lechner, Anita; Hafkemeijer, Anne; Möller, Christiane; Schmidt, Reinhold; de Rooij, Mark; Rombouts, Serge A.R.B.

    2016-01-01

    Magnetic resonance imaging (MRI) is sensitive to structural and functional changes in the brain caused by Alzheimer's disease (AD), and can therefore be used to help in diagnosing the disease. Improving classification of AD patients based on MRI scans might help to identify AD earlier in the disease's progress, which may be key in developing treatments for AD. In this study we used an elastic net classifier based on several measures derived from the MRI scans of mild to moderate AD patients (N = 77) from the prospective registry on dementia study and controls (N = 173) from the Austrian Stroke Prevention Family Study. We based our classification on measures from anatomical MRI, diffusion weighted MRI and resting state functional MRI. Our unimodal classification performance ranged from an area under the curve (AUC) of 0.760 (full correlations between functional networks) to 0.909 (grey matter density). When combining measures from multiple modalities in a stepwise manner, the classification performance improved to an AUC of 0.952. This optimal combination consisted of grey matter density, white matter density, fractional anisotropy, mean diffusivity, and sparse partial correlations between functional networks. Classification performance for mild AD as well as moderate AD also improved when using this multimodal combination. We conclude that different MRI modalities provide complementary information for classifying AD. Moreover, combining multiple modalities can substantially improve classification performance over unimodal classification. PMID:26909327

  20. Selective cloning of Gaussian states by linear optics

    SciTech Connect

    Olivares, Stefano

    2007-08-15

    We investigate the performance of a selective cloning machine based on linear optical elements and Gaussian measurements, which allows one to clone at will one of the two incoming input states. This machine is a complete generalization of a 1{yields}2 cloning scheme demonstrated by Andersen et al. [Phys. Rev. Lett. 94, 240503 (2005)]. The input-output fidelity is studied for a generic Gaussian input state, and the effect of nonunit quantum efficiency is also taken into account. We show that, if the states to be cloned are squeezed states with known squeezing parameter, then the fidelity can be enhanced using a third suitable squeezed state during the final stage of the cloning process. A binary communication protocol based on the selective cloning machine is also discussed.

  1. Experimental Implementation of a Quantum Optical State Comparison Amplifier

    NASA Astrophysics Data System (ADS)

    Donaldson, Ross J.; Collins, Robert J.; Eleftheriadou, Electra; Barnett, Stephen M.; Jeffers, John; Buller, Gerald S.

    2015-03-01

    We present an experimental demonstration of a practical nondeterministic quantum optical amplification scheme that employs two mature technologies, state comparison and photon subtraction, to achieve amplification of known sets of coherent states with high fidelity. The amplifier uses coherent states as a resource rather than single photons, which allows for a relatively simple light source, such as a diode laser, providing an increased rate of amplification. The amplifier is not restricted to low amplitude states. With respect to the two key parameters, fidelity and the amplified state production rate, we demonstrate significant improvements over previous experimental implementations, without the requirement of complex photonic components. Such a system may form the basis of trusted quantum repeaters in nonentanglement-based quantum communications systems with known phase alphabets, such as quantum key distribution or quantum digital signatures.

  2. Moderators and mediators of the stress-aggression relationship: executive function and state anger.

    PubMed

    Sprague, Jenessa; Verona, Edelyn; Kalkhoff, Will; Kilmer, Ashley

    2011-02-01

    The present study examined the effects of executive function (i.e., EF) and anger/hostility on the relationship between stress (across individual stress domains, as well as at the aggregate level) and aggression. Two independent groups of participants-a college sample and a low-income community sample-were administered a battery of self-report measures concerning the subjective experience of stress, aggressive behaviors, and feelings of state anger and hostility in the last month, along with a battery of well-validated neuropsychological tests of EF. Across both samples, the stress domains that demonstrated the strongest associations with aggression were those involving chronic strains of daily living (e.g., job, financial, health) versus interpersonal stressors (e.g., family, romantic). In the community sample, analyses also revealed a significant interaction between perceived stress (aggregated across domains) and EF in predicting aggressive behavior. Specifically, participants with relatively low EF abilities, across different EF processes, showed a stronger relationship between different domains of stress and aggression in the last month. Similar effects were demonstrated in the college sample, although the interaction was not significant. In both samples, experiences of anger and hostility in the last month mediated the relationship between perceived stress (aggregate) and aggressive behavior among those low, but not high, in EF. These findings highlight the importance of higher-order cognitive processes in regulating appropriate affective and behavioral responses across different types of individuals, particularly among those experiencing high levels of stress. PMID:21401226

  3. Improving accuracy of Eutrophication State Index estimation in Chaohu Lake by moderate resolution remote sensing data driven method

    NASA Astrophysics Data System (ADS)

    Xiang, Bo; Song, Jing-Wei; Wang, Xin-Yuan; Zhen, Jing; Gao, Rui

    2014-11-01

    Trophic Level Index (TLI) calculated from several water quality monitoring indicators is often used to assess the general eutrophication state of inland-lake. In this paper, we proposed a data driven inland-lake eutrophication mapping method by using artificial neural network (ANN) to build relationship from remote sensing data and in-situ TLI sampling. Low spatial resolution remote sensing data (MODIS, 250-m and 500-m) and moderate spatial resolution remote sensing data (OLI, 30-m) together with in-situ observations are acquired to train the net. Result demonstrates that TLI obtained from medium-resolution remote sensing images is more accurate than which from low resolution remote sensing data, and more accurate than TLI calculated from the water quality factors retrieved from remote sensing images. This method provides an efficient way of mapping the TLI spatial distribution in-inland lake.

  4. Optical Conductivity of Topological Surface States with Emergent Supersymmetry.

    PubMed

    Witczak-Krempa, William; Maciejko, Joseph

    2016-03-11

    Topological states of electrons present new avenues to explore the rich phenomenology of correlated quantum matter. Topological insulators (TIs) in particular offer an experimental setting to study novel quantum critical points (QCPs) of massless Dirac fermions, which exist on the sample's surface. Here, we obtain exact results for the zero- and finite-temperature optical conductivity at the semimetal-superconductor QCP for these topological surface states. This strongly interacting QCP is described by a scale invariant theory with emergent supersymmetry, which is a unique symmetry mixing bosons and fermions. We show that supersymmetry implies exact relations between the optical conductivity and two otherwise unrelated properties: the shear viscosity and the entanglement entropy. We discuss experimental considerations for the observation of these signatures in TIs. PMID:27015463

  5. Optical Conductivity of Topological Surface States with Emergent Supersymmetry

    NASA Astrophysics Data System (ADS)

    Witczak-Krempa, William; Maciejko, Joseph

    2016-03-01

    Topological states of electrons present new avenues to explore the rich phenomenology of correlated quantum matter. Topological insulators (TIs) in particular offer an experimental setting to study novel quantum critical points (QCPs) of massless Dirac fermions, which exist on the sample's surface. Here, we obtain exact results for the zero- and finite-temperature optical conductivity at the semimetal-superconductor QCP for these topological surface states. This strongly interacting QCP is described by a scale invariant theory with emergent supersymmetry, which is a unique symmetry mixing bosons and fermions. We show that supersymmetry implies exact relations between the optical conductivity and two otherwise unrelated properties: the shear viscosity and the entanglement entropy. We discuss experimental considerations for the observation of these signatures in TIs.

  6. Tunable rubidium excited state Voigt atomic optical filter.

    PubMed

    Yin, Longfei; Luo, Bin; Xiong, Junyu; Guo, Hong

    2016-03-21

    A tunable rubidium excited state Voigt atomic optical filter working at optical communication wavelength (1.5 μm) is realized. The filter achieves a peak transmittance of 57.6% with a double-peak structure, in which each one has a bandwidth of 600 MHz. Benefiting from the Voigt type structure, the magnetic field of the filter can be tuned from 0 to 1600 gauss, and a peak transmittance tunability of 1.6 GHz can thus be realized. Different from the excited state Faraday type filter, the pump efficiency in the Voigt filter is affected a lot by the pump polarization. Measured absorption results of the pump laser and transmittances of the signal laser both prove that the vertical linear polarization pumping is the most efficient in the Voigt filter. PMID:27136803

  7. Yeast metabolic state identification using micro-fiber optics spectroscopy

    NASA Astrophysics Data System (ADS)

    Silva, J. S.; Castro, C. C.; Vicente, A. A.; Tafulo, P.; Jorge, P. A. S.; Martins, R. C.

    2011-05-01

    Saccharomyces cerevisiae morphology is known to be dependent on the cell physiological state and environmental conditions. On their environment, wild yeasts tend to form complex colonies architectures, such as stress response and pseudohyphal filaments morphologies, far away from the ones found inside bioreactors, where the regular cell cycle is observed under controlled conditions (e.g. budding and flocculating colonies). In this work we explore the feasibility of using micro-fiber optics spectroscopy to classify Saccharomyces cerevisiae S288C colony structures in YPD media, under different growth conditions, such as: i) no alcohol; ii) 1 % (v/v) Ethanol; iii) 1 % (v/v) 1-butanol; iv) 1 % (v/v) Isopropanol; v) 1 % (v/v) Tert-Amyl alcohol (2 Methyl-2-butanol); vi) 0,2 % (v/v) 2-Furaldehyde; vii) 5 % (w/v) 5 (Hydroxymethyl)-furfural; and viii) 1 % (w/v) (-)-Adenosine3', 5'cyclic monophosphate. The microscopy system includes a hyperspectral camera apparatus and a micro fiber (sustained by micro manipulator) optics system for spectroscopy. Results show that micro fiber optics system spectroscopy has the potential for yeasts metabolic state identification once the spectral signatures of colonies differs from each others. This technique associated with others physico-chemical information can benefit the creation of an information system capable of providing extremely detailed information about yeast metabolic state that will aid both scientists and engineers to study and develop new biotechnological products.

  8. Push-Pull Optical Pumping of Pure Superposition States

    NASA Astrophysics Data System (ADS)

    Jau, Y.-Y.; Miron, E.; Post, A. B.; Kuzma, N. N.; Happer, W.

    2004-10-01

    A new optical pumping method, “push-pull pumping,” can produce very nearly pure, coherent superposition states between the initial and the final sublevels of the important field-independent 0-0 clock resonance of alkali-metal atoms. The key requirement for push-pull pumping is the use of D1 resonant light which alternates between left and right circular polarization at the Bohr frequency of the state. The new pumping method works for a wide range of conditions, including atomic beams with almost no collisions, and atoms in buffer gases with pressures of many atmospheres.

  9. State dissociation moderates response to dialectical behavior therapy for posttraumatic stress disorder in women with and without borderline personality disorder

    PubMed Central

    Kleindienst, Nikolaus; Priebe, Kathlen; Görg, Nora; Dyer, Anne; Steil, Regina; Lyssenko, Lisa; Winter, Dorina; Schmahl, Christian; Bohus, Martin

    2016-01-01

    dissociation during psychotherapeutic sessions moderates the success of an established treatment for PTSD. Patients were much more likely to substantially improve with respect to PTSD symptomatology if state dissociation during psychotherapeutic sessions was low. The article suggests that the relation between low dissociation and good response in highly symptomatic patients is stronger than previously thought. Future studies investigating the extent to which outcome might be improved when treating dissociation more vigorously than usually are necessary. PMID:27396380

  10. Moderate Resolution Jet Cooled Cavity Ringdown Spectra of the tilde{A} State of NO_3 Radical

    NASA Astrophysics Data System (ADS)

    Codd, Terrance J.; Chen, Ming-Wei; Roudjane, Mourad; Miller, Terry A.

    2012-06-01

    The tilde{A}-tilde{X} spectrum of NO_3 has been previously observed using cavity ringdown spectroscopy (CRDS) by Andrei Deev et. al under ambient conditions. There the authors assigned a number of vibronic bands in the spectrum. However, under these conditions, hot-bands may be present and the spectrum becomes very congested at frequencies higher than ˜8700 cm-1 due to the density of vibronic states and the overlap of their rotational contours. In order to obtain more information about the tilde{A} state of NO_3 we recently obtained spectra from 7550 cm-1 to over 10000 cm-1 using our moderate resolution (≃ 0.05 cm-1) jet cooled CRDS apparatus. Jet cooling in our apparatus reduces the rotational temperature to <30 K and eliminates vibrational hot bands greatly simplifying the spectrum. We are able to resolve and assign more than 15 vibronic features including a new assignment of the 31_0 band. Analysis of the ν_4 progression shows weak Jahn-Teller coupling in this mode. Anomalous band contours and anharmonic spacings are observed for the ν_1ν_4 combination bands and the cause is being investigated. We also see some features that could belong to vibronically forbidden transitions which may be magnetic dipole allowed. A. Deev, J. Sommar, and M. Okumura, J. Chem. Phys. 122, 224305 (2005)

  11. The moderating role of state inhibitory control in the effect of evaluative conditioning on temptation and unhealthy snacking.

    PubMed

    Haynes, Ashleigh; Kemps, Eva; Moffitt, Robyn

    2015-12-01

    The current study sought to test the effect of a brief evaluative conditioning intervention on experienced temptation to indulge, and consumption of, unhealthy snack foods. We expected that a training task associating unhealthy food with negative affect would result in lower experienced temptation across the sample, but would lead to lower snack consumption only among individuals with low state inhibitory control. Undergraduate women (N=134) aged 17-25 years were randomised to complete an evaluative conditioning procedure pairing unhealthy food with either positive or negative affect. Snack consumption was subsequently assessed using a taste-test procedure which offered four snack foods for ad libitum consumption. Participants also reported the strength of their experienced temptation to indulge in the foods presented. Additionally, they completed a Stop Signal Task as a measure of state inhibitory control. As predicted, participants in the food negative condition ate less than those in the food positive condition, but this effect was only observed among individuals with low inhibitory control. The same moderation pattern was observed for the effect of evaluative conditioning on temptation: only participants with low inhibitory control reported feeling less tempted by the snack foods in the food negative condition compared to the food positive condition. In addition, temptation mediated the effect of evaluative conditioning on intake for individuals with low inhibitory control. Findings suggest that evaluative conditioning of unhealthy food stimuli could be especially useful for reducing temptation and consumption of unhealthy snacks in situations where individuals experience low inhibitory control capacity. PMID:26409213

  12. Magneto-optical controlled transmittance alteration of PbS quantum dots by moderately applied magnetic fields at room temperature

    SciTech Connect

    Singh, Akhilesh K.; Barik, Puspendu; Ullrich, Bruno E-mail: bruno.ullrich@yahoo.com

    2014-12-15

    We observed changes of the transmitted monochromatic light passing through a colloidal PbS quantum dot film on glass owing to an applied moderate (smaller than 1 T) magnetic field under ambient conditions. The observed alterations show a square dependence on the magnetic field increase that cannot be achieved with bulk semiconductors. The findings point to so far not recognized application potentials of quantum dots.

  13. Exciton states and optical properties of carbon nanotubes.

    PubMed

    Ajiki, Hiroshi

    2012-12-01

    Exciton states and related optical properties of a single-walled carbon nanotube are reviewed, primarily from a theoretical viewpoint. The energies and wavefunctions of excitons are discussed using a screened Hartree-Fock approximation with an effective-mass or k·p approximation. The close relationship between a long-range electron-hole exchange interaction and a depolarization effect is clarified. I discuss optical properties including the radiative lifetime of excitons, absorption spectra and radiation force. To describe these properties in a unified scheme, a self-consistent method is introduced for calculating the scattering light and induced current density due to excitons. I also briefly review experimental results on the Aharonov-Bohm effect in excitons and quasi-dark excitons excited by light polarized perpendicular to the tube axis. PMID:23139202

  14. Solid state electro-optic color filter and iris

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A pair of solid state electro-optic filters (SSEF) in a binocular holder were designed and fabricated for evaluation of field sequential stereo TV applications. The electronic circuitry for use with the stereo goggles was designed and fabricated, requiring only an external video input. A polarizing screen suitable for attachment to various size TV monitors for use in conjunction with the stereo goggles was designed and fabricated. An improved engineering model 2 filter was fabricated using the bonded holder technique developed previously and integrated to a GCTA color TV camera. An engineering model color filter was fabricated and assembled using PLZT control elements. In addition, a ruggedized holder assembly was designed, fabricated and tested. This assembly provides electrical contacts, high voltage protection, and support for the fragile PLZT disk, and also permits mounting and optical alignment of the associated polarizers.

  15. Quantum amplification and quantum optical tapping with squeezed states and correlated quantum states

    NASA Technical Reports Server (NTRS)

    Ou, Z. Y.; Pereira, S. F.; Kimble, H. J.

    1994-01-01

    Quantum fluctuations in a nondegenerate optical parametric amplifier (NOPA) are investigated experimentally with a squeezed state coupled into the internal idler mode of the NOPA. Reductions of the inherent quantum noise of the amplifier are observed with a minimum noise level 0.7 dB below the usual noise level of the amplifier with its idler mode in a vacuum state. With two correlated quantum fields as the amplifier's inputs and proper adjustment of the gain of the amplifier, it is shown that the amplifier's intrinsic quantum noise can be completely suppressed so that noise-free amplification is achieved. It is also shown that the NOPA, when coupled to either a squeezed state or a nonclassically correlated state, can realize quantum tapping of optical information.

  16. Imaging of spatiotemporal coincident states by DC optical tomography.

    PubMed

    Graber, Harry L; Pei, Yaling; Barbour, Randall L

    2002-08-01

    The utility of optical tomography as a practical imaging modality has, thus far, been limited by its intrinsically low spatial resolution and quantitative accuracy. Recently, we have argued that a broad range of physiological phenomena might be accurately studied by adopting this technology to investigate dynamic states (Schmitz et al., 2000; Barbour et al., 2000; Graber et al., 2000; Barbour et aL, 2001; and Barbour et aL, 1999). One such phenomenon holding considerable significance is the dynamics of the vasculature, which has been well characterized as being both spatially and temporally heterogeneous. In this paper, we have modeled such heterogeneity in the limiting case of spatiotemporal coincident behavior involving optical contrast features, in an effort to define the expected limits with which dynamic states can be characterized using two newly described reconstruction methods that evaluate normalized detector data: the normalized difference method (NDM) and the normalized constraint method (NCM). Influencing the design of these studies is the expectation that spatially coincident temporal variations in both the absorption and scattering properties of tissue can occur in vivo. We have also chosen to model dc illumination techniques, in recognition of their favorable performance and cost for practical systems. This choice was made with full knowledge of theoretical findings arguing that separation of the optical absorption and scattering coefficients under these conditions is not possible. Results obtained show that the NDM algorithm provides for good spatial resolution and excellent characterization of the temporal behavior of optical properties but is subject to interparameter crosstalk. The NCM algorithm, while also providing excellent characterization of temporal behavior, provides for improved spatial resolution, as well as for improved separation of absorption and scattering coefficients. A discussion is provided to reconcile these findings with

  17. Group transformations and entangled-state quantum gates with directionally unbiased linear-optical multiports

    NASA Astrophysics Data System (ADS)

    Simon, David S.; Fitzpatrick, Casey A.; Sergienko, Alexander V.

    2016-04-01

    The concept of directionally unbiased optical multiports is introduced, in which photons may reflect back out the input direction. A linear-optical implementation is described, and the simplest three-port version studied. Symmetry arguments demonstrate potential for unusual quantum information processing applications. The devices impose group structures on two-photon entangled Bell states and act as universal Bell-state processors to implement probabilistic quantum gates acting on state symmetries. These multiports allow optical scattering experiments to be carried out on arbitrary undirected graphs via linear optics and raise the possibility of linear-optical information processing using group structures formed by optical qudit states.

  18. Comparison of Coincident Multiangle Imaging Spectroradiometer and Moderate Resolution Imaging Spectroradiometer Aerosol Optical Depths over Land and Ocean Scenes Containing Aerosol Robotic Network Sites

    NASA Technical Reports Server (NTRS)

    Abdou, Wedad A.; Diner, David J.; Martonchik, John V.; Bruegge, Carol J.; Kahn, Ralph A.; Gaitley, Barbara J.; Crean, Kathleen A.; Remer, Lorraine A.; Holben, Brent

    2005-01-01

    The Multiangle Imaging Spectroradiometer (MISR) and the Moderate Resolution Imaging Spectroradiometer (MODIS), launched on 18 December 1999 aboard the Terra spacecraft, are making global observations of top-of-atmosphere (TOA) radiances. Aerosol optical depths and particle properties are independently retrieved from these radiances using methodologies and algorithms that make use of the instruments corresponding designs. This paper compares instantaneous optical depths retrieved from simultaneous and collocated radiances measured by the two instruments at locations containing sites within the Aerosol Robotic Network (AERONET). A set of 318 MISR and MODIS images, obtained during the months of March, June, and September 2002 at 62 AERONET sites, were used in this study. The results show that over land, MODIS aerosol optical depths at 470 and 660 nm are larger than those retrieved from MISR by about 35% and 10% on average, respectively, when all land surface types are included in the regression. The differences decrease when coastal and desert areas are excluded. For optical depths retrieved over ocean, MISR is on average about 0.1 and 0.05 higher than MODIS in the 470 and 660 nm bands, respectively. Part of this difference is due to radiometric calibration and is reduced to about 0.01 and 0.03 when recently derived band-to-band adjustments in the MISR radiometry are incorporated. Comparisons with AERONET data show similar patterns.

  19. Simultaneous retrieval of total ozone column amounts and cloud/aerosol optical depths from multi-channel, moderate bandwidth filter instruments

    NASA Astrophysics Data System (ADS)

    Stamnes, Knut; Fan, Lingling; Li, Wei; Dahlback, Arne; Stamnes, Jakob; Stamnes, Snorre

    2015-04-01

    A new method is presented based on using neural networks (NN) to analyze ultraviolet (UV) irradiance data recorded by multi-channel, moderate bandwidth filter instruments. Application of the NN method to three years of data obtained by a NILU-UV multi-channel, moderate bandwidth filter instrument, revealed that compared to a traditional look-up table (LUT) method, the NN method yielded better agreement against the Ozone Monitoring Instrument (OMI) with a 1% decrease in relative difference and a significant increase in the correlation of total ozone column (TOC) values. Furthermore, this new method resulted in larger number of valid retrievals (daily average values within a meaningful range of 200-500 DU) than the LUT method. Compared with NN retrievals based on NILU-UV irradiance measurements, TOC values obtained from OMI were underestimated under cloudy conditions. Cloud optical depth (COD) values derived by the NN method were more reliable than corresponding results derived by the LUT method, the latter results were less accurate for heavy cloud cover, broken cloud situations or snow-covered ground. The potential for retrieving aerosol optical depth (AOD) values under cloud-free conditions will be discussed. The cloud-aerosol information obtained by irradiance instruments such as the NILU-UV can be used in conjunction with a radiative transfer model to estimate cloud/aerosol radiative forcing and hence the impact of clouds and aerosols on the radiative energy balance. Deployment of multi-channel, moderate bandwidth filter instruments at AERONET sites and analysis of such data in conjunction with AERONET and satellite remote sensing data can provide crucial information needed for the assessment of the influence of ozone, clouds, and aerosols on climate.

  20. Optical Properties of a Vibrationally Modulated Solid State Mott Insulator

    PubMed Central

    Kaiser, S.; Clark, S. R.; Nicoletti, D.; Cotugno, G.; Tobey, R. I.; Dean, N.; Lupi, S.; Okamoto, H.; Hasegawa, T.; Jaksch, D.; Cavalleri, A.

    2014-01-01

    Optical pulses at THz and mid-infrared frequencies tuned to specific vibrational resonances modulate the lattice along chosen normal mode coordinates. In this way, solids can be switched between competing electronic phases and new states are created. Here, we use vibrational modulation to make electronic interactions (Hubbard-U) in Mott-insulator time dependent. Mid-infrared optical pulses excite localized molecular vibrations in ET-F2TCNQ, a prototypical one-dimensional Mott-insulator. A broadband ultrafast probe interrogates the resulting optical spectrum between THz and visible frequencies. A red-shifted charge-transfer resonance is observed, consistent with a time-averaged reduction of the electronic correlation strength U. Secondly, a sideband manifold inside of the Mott-gap appears, resulting from a periodically modulated U. The response is compared to computations based on a quantum-modulated dynamic Hubbard model. Heuristic fitting suggests asymmetric holon-doublon coupling to the molecules and that electron double-occupancies strongly squeeze the vibrational mode. PMID:24448171

  1. Optical nanoscopy of transient states in condensed matter

    NASA Astrophysics Data System (ADS)

    Kuschewski, F.; Kehr, S. C.; Green, B.; Bauer, Ch.; Gensch, M.; Eng, L. M.

    2015-07-01

    Recently, the fundamental and nanoscale understanding of complex phenomena in materials research and the life sciences, witnessed considerable progress. However, elucidating the underlying mechanisms, governed by entangled degrees of freedom such as lattice, spin, orbit, and charge for solids or conformation, electric potentials, and ligands for proteins, has remained challenging. Techniques that allow for distinguishing between different contributions to these processes are hence urgently required. In this paper we demonstrate the application of scattering-type scanning near-field optical microscopy (s-SNOM) as a novel type of nano-probe for tracking transient states of matter. We introduce a sideband-demodulation technique that allows for probing exclusively the stimuli-induced change of near-field optical properties. We exemplify this development by inspecting the decay of an electron-hole plasma generated in SiGe thin films through near-infrared laser pulses. Our approach can universally be applied to optically track ultrafast/-slow processes over the whole spectral range from UV to THz frequencies.

  2. Quantum Optics in the Solid State with Diamond Nanophotonics

    NASA Astrophysics Data System (ADS)

    de Leon, Nathalie; Evans, Ruffin; de Greve, Kristiaan; Goldman, Michael; High, Alex; Markham, Matthew; Stacey, Alastair; Twitchen, Daniel; Loncar, Marko; Park, Hongkun; Lukin, Mikhail

    2015-05-01

    Large-scale quantum networks will require efficient interfaces between photons and stationary quantum bits. Nitrogen-vacancy (NV) centers in diamond are a promising candidate for quantum information processing because they are optically addressable, have spin degrees of freedom with long coherence times, and as solid-state entities, can be integrated into nanophotonic devices. An enabling feature of the NV center is its zero-phonon line (ZPL), which acts as an atom-like cycling transition that can be used for coherent optical manipulation and read-out of the spin. However, the ZPL only accounts for 3-5% of the total emission, and previously demonstrated methods of producing high densities of NV centers yield unstable ZPLs. We have developed techniques to fabricate high quality factor, small mode volume photonic crystal cavities directly out of diamond, and to deterministically position these photonic crystal cavities so that a stable NV center sits at the maximum electric field. We observe an enhancement of the spontaneous emission at the cavity resonance by a factor of up to 100. Crucially, we are able to control the NV center precisely using both microwave and resonant optical manipulation. These nanophotonic elements in diamond will provide key building blocks for quantum information processing such as single photon transistors, enabling distribution of entanglement over quantum networks.

  3. Optical nanoscopy of transient states in condensed matter

    PubMed Central

    Kuschewski, F.; Kehr, S.C.; Green, B.; Bauer, Ch.; Gensch, M.; Eng, L.M.

    2015-01-01

    Recently, the fundamental and nanoscale understanding of complex phenomena in materials research and the life sciences, witnessed considerable progress. However, elucidating the underlying mechanisms, governed by entangled degrees of freedom such as lattice, spin, orbit, and charge for solids or conformation, electric potentials, and ligands for proteins, has remained challenging. Techniques that allow for distinguishing between different contributions to these processes are hence urgently required. In this paper we demonstrate the application of scattering-type scanning near-field optical microscopy (s-SNOM) as a novel type of nano-probe for tracking transient states of matter. We introduce a sideband-demodulation technique that allows for probing exclusively the stimuli-induced change of near-field optical properties. We exemplify this development by inspecting the decay of an electron-hole plasma generated in SiGe thin films through near-infrared laser pulses. Our approach can universally be applied to optically track ultrafast/-slow processes over the whole spectral range from UV to THz frequencies. PMID:26215769

  4. Remote state preparation of three-dimensional optical vortices.

    PubMed

    Su, Ming; Chen, Lixiang

    2014-05-01

    We propose a feasible scheme to remotely prepare three-dimensional (3D) optical vortex lines. Our scheme relies on the complete description of high-dimensional orbital angular momentum (OAM) entanglement in terms of the Laguerre-Gaussian modes. It is theoretically demonstrated that by simply changing the pump beam waist, we can remotely prepare the target photons in the vortex states of 3D interesting morphology, appearing as twisted vortex strands, separated vortex loops, and vortex link or knot. Furthermore, we employ the biphoton Klyshko picture to illustrate the conservation law of the OAM index ℓ and the spreading effect of the radial mode index p, where the Schmidt numbers are calculated to show the high-dimensional capacity of the quantum channels involved in the present remote state preparation. PMID:24921788

  5. DEMOS: state-of-the-art application software for design, evaluation, and modeling of optical systems

    NASA Astrophysics Data System (ADS)

    Gan, Michael A.; Zhdanov, Dmitriy D.; Novoselskiy, Vadim V.; Ustinov, Sergey I.; Fedorov, Alexander O.; Potyemin, Igor S.

    1992-04-01

    A new version of the DEMOS program is presented. DEMOS (design, evaluation, and modeling of optical systems) is integrated dialog software for automatic modeling to estimate and design optical systems with conventional and hologram optical elements. The theoretical principles and the current state of the primary possibilities and application principles of the DEMOS program for optical systems design and simulation on computers are discussed.

  6. Online technique for detecting state of onboard fiber optic gyroscope

    NASA Astrophysics Data System (ADS)

    Miao, Zhiyong; Xu, Dingjie; He, Kunpeng; Pang, Shuwan; Tian, Chunmiao

    2015-02-01

    Although angle random walk (ARW) of fiber optic gyroscope (FOG) has been well modeled and identified before being integrated into the high-accuracy attitude control system of satellite, aging and unexpected failures can affect the performance of FOG after launch, resulting in the variation of ARW coefficient. Therefore, the ARW coefficient can be regarded as an indicator of "state of health" for FOG diagnosis in some sense. The Allan variance method can be used to estimate ARW coefficient of FOG, however, it requires a large amount of data to be stored. Moreover, the procedure of drawing slope lines for estimation is painful. To overcome the barriers, a weighted state-space model that directly models the ARW to obtain a nonlinear state-space model was established for FOG. Then, a neural extended-Kalman filter algorithm was implemented to estimate and track the variation of ARW in real time. The results of experiment show that the proposed approach is valid to detect the state of FOG. Moreover, the proposed technique effectively avoids the storage of data.

  7. Online technique for detecting state of onboard fiber optic gyroscope.

    PubMed

    Miao, Zhiyong; Xu, Dingjie; He, Kunpeng; Pang, Shuwan; Tian, Chunmiao

    2015-02-01

    Although angle random walk (ARW) of fiber optic gyroscope (FOG) has been well modeled and identified before being integrated into the high-accuracy attitude control system of satellite, aging and unexpected failures can affect the performance of FOG after launch, resulting in the variation of ARW coefficient. Therefore, the ARW coefficient can be regarded as an indicator of "state of health" for FOG diagnosis in some sense. The Allan variance method can be used to estimate ARW coefficient of FOG, however, it requires a large amount of data to be stored. Moreover, the procedure of drawing slope lines for estimation is painful. To overcome the barriers, a weighted state-space model that directly models the ARW to obtain a nonlinear state-space model was established for FOG. Then, a neural extended-Kalman filter algorithm was implemented to estimate and track the variation of ARW in real time. The results of experiment show that the proposed approach is valid to detect the state of FOG. Moreover, the proposed technique effectively avoids the storage of data. PMID:25725877

  8. Online technique for detecting state of onboard fiber optic gyroscope

    SciTech Connect

    Miao, Zhiyong; He, Kunpeng Pang, Shuwan; Xu, Dingjie; Tian, Chunmiao

    2015-02-15

    Although angle random walk (ARW) of fiber optic gyroscope (FOG) has been well modeled and identified before being integrated into the high-accuracy attitude control system of satellite, aging and unexpected failures can affect the performance of FOG after launch, resulting in the variation of ARW coefficient. Therefore, the ARW coefficient can be regarded as an indicator of “state of health” for FOG diagnosis in some sense. The Allan variance method can be used to estimate ARW coefficient of FOG, however, it requires a large amount of data to be stored. Moreover, the procedure of drawing slope lines for estimation is painful. To overcome the barriers, a weighted state-space model that directly models the ARW to obtain a nonlinear state-space model was established for FOG. Then, a neural extended-Kalman filter algorithm was implemented to estimate and track the variation of ARW in real time. The results of experiment show that the proposed approach is valid to detect the state of FOG. Moreover, the proposed technique effectively avoids the storage of data.

  9. Noninvasive optical cytochrome c oxidase redox state measurements using diffuse optical spectroscopy

    NASA Astrophysics Data System (ADS)

    Lee, Jangwoen; Kim, Jae G.; Mahon, Sari B.; Mukai, David; Yoon, David; Boss, Gerry R.; Patterson, Steven E.; Rockwood, Gary; Isom, Gary; Brenner, Matthew

    2014-05-01

    A major need exists for methods to assess organ oxidative metabolic states in vivo. By contrasting the responses to cyanide (CN) poisoning versus hemorrhage in animal models, we demonstrate that diffuse optical spectroscopy (DOS) can detect cytochrome c oxidase (CcO) redox states. Intermittent decreases in inspired O2 from 100% to 21% were applied before, during, and after CN poisoning, hemorrhage, and resuscitation in rabbits. Continuous DOS measurements of total hemoglobin, oxyhemoglobin, deoxyhemoglobin, and oxidized and reduced CcO from muscle were obtained. Rabbit hemorrhage was accomplished with stepwise removal of blood, followed by blood resuscitation. CN treated rabbits received 0.166 mg/min NaCN infusion. During hemorrhage, CcO redox state became reduced concurrently with decreases in oxyhemoglobin, resulting from reduced tissue oxygen delivery and hypoxia. In contrast, during CN infusion, CcO redox state decreased while oxyhemoglobin concentration increased due to CN binding and reduction of CcO with resultant inhibition of the electron transport chain. Spectral absorption similarities between hemoglobin and CcO make noninvasive spectroscopic distinction of CcO redox states difficult. By contrasting physiological perturbations of CN poisoning versus hemorrhage, we demonstrate that DOS measured CcO redox state changes are decoupled from hemoglobin concentration measurement changes.

  10. Noninvasive optical cytochrome c oxidase redox state measurements using diffuse optical spectroscopy

    PubMed Central

    Lee, Jangwoen; Kim, Jae G.; Mahon, Sari B.; Mukai, David; Yoon, David; Boss, Gerry R.; Patterson, Steven E.; Rockwood, Gary; Isom, Gary; Brenner, Matthew

    2014-01-01

    Abstract. A major need exists for methods to assess organ oxidative metabolic states in vivo. By contrasting the responses to cyanide (CN) poisoning versus hemorrhage in animal models, we demonstrate that diffuse optical spectroscopy (DOS) can detect cytochrome c oxidase (CcO) redox states. Intermittent decreases in inspired O2 from 100% to 21% were applied before, during, and after CN poisoning, hemorrhage, and resuscitation in rabbits. Continuous DOS measurements of total hemoglobin, oxyhemoglobin, deoxyhemoglobin, and oxidized and reduced CcO from muscle were obtained. Rabbit hemorrhage was accomplished with stepwise removal of blood, followed by blood resuscitation. CN treated rabbits received 0.166  mg/min NaCN infusion. During hemorrhage, CcO redox state became reduced concurrently with decreases in oxyhemoglobin, resulting from reduced tissue oxygen delivery and hypoxia. In contrast, during CN infusion, CcO redox state decreased while oxyhemoglobin concentration increased due to CN binding and reduction of CcO with resultant inhibition of the electron transport chain. Spectral absorption similarities between hemoglobin and CcO make noninvasive spectroscopic distinction of CcO redox states difficult. By contrasting physiological perturbations of CN poisoning versus hemorrhage, we demonstrate that DOS measured CcO redox state changes are decoupled from hemoglobin concentration measurement changes. PMID:24788369

  11. Optoelectronic device simulation: Optical modeling for semiconductor optical amplifiers and solid state lighting

    NASA Astrophysics Data System (ADS)

    Wang, Dong-Xue (Michael)

    2006-07-01

    transparency carrier densities; the differential gain is assumed constant accordingly. This assumption is only valid for wavelengths close to the gain peak wavelength. As a result, high accuracy for wideband wavelength conversion is not guaranteed. We proposed a steady state numerical model of wavelength converters based on cross-gain modulation in semiconductor optical amplifiers. In this model, a new model of the gain coefficient developed by Connelly was applied, which also includes the internal loss variation with the electron carrier density. Each physical variable, such as the carrier density, gain coefficient, differential gain, and internal loss, spatially varies across the SOA cavity and is numerically calculated throughout the device. This model can predicts wavelength-dependent characteristics of a wavelength converter of the SOA in both large and small signal regimes. Some key performance factors of SOA wavelength converters, such as selection of pump and probe wavelengths and power, length of SOA cavities, conversion efficiency and bandwidth, system performance difference between up and down conversions can be modeled and optimized using this numerical model. Most LED modeling techniques are based on optical ray tracing to predict the light extraction efficiency, and the light extraction efficiency is a critical parameter to evaluate LEDs. Here, we proposed a hybrid method to simulate the lighting efficiency of LED chips, where both guided wave theory and geometric optical ray tracing are applied. Guided wave optics is used to identify guided modes and leakage modes inside the LED active layer, and its device structure can be optimized to increase leakage modes so that the lighting extraction efficiency is improved. On the other hand, Monte Carlo optical ray tracing is used to quantitatively determine optical extraction efficiency. Moreover, this method can model the light distribution and far-field illumination pattern. Both single wavelength LEDs and dual

  12. Optical Properties and Electronic States Specific to Solid Fullerene

    NASA Astrophysics Data System (ADS)

    Minami, Nobutsugu; Kazaoui, Said; Wen, Ching-Ju; Byrne, Hugh J.

    1996-03-01

    One of the most intriguing aspects of the fullerene research is to ask what specific phenomena will occur when the soccer-ball shaped molecules aggregate and make a solid. Seeking this question is crucial for the realization of any photonic and electronic application of this new type of carbon allotrope. We have been working on this theme by the study of optical and electrical properties of C60 thin film. An important result is the demonstration of a distinct intermolecular charge transfer excited state (CT exciton) originating from intermolecular electronic interaction specific to the spherical pai conjugation system. This has been shown by the coincidence in the threshold energy of 2.3eV for absorption, luminescence efficiency, field induced luminescence quenching, and photoconductivity. We also found an evidence of the interconnection between optical properties and the structural phase transition at 260K. Moreover, a composite film containing C60 is demonstrated to show intense luminescence under 10mW laser irradiation.

  13. Quantum states of p-band bosons in optical lattices

    SciTech Connect

    Collin, A.; Larson, J.; Martikainen, J.-P.

    2010-02-15

    We study a gas of repulsively interacting bosons in the first excited band of an optical lattice. We explore this p-band physics both within the framework of a standard mean-field theory as well as with the more accurate generalized Gutzwiller ansatz. We find the phase diagrams for two- and three-dimensional systems and characterize the first Mott-states which typically possess an integer or half-integer vortex structure. Furthermore, we find that even though the p-band model has strongly anisotropic kinetic energies and interflavor interaction terms are missing in the lowest band theory, the mean-field theory becomes useful quite rapidly once the transition from the Mott insulator to the superfluid is crossed.

  14. Pre-seizure state identified by diffuse optical tomography

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Zhou, Junli; Jiang, Ruixin; Yang, Hao; Carney, Paul R.; Jiang, Huabei

    2014-01-01

    In epilepsy it has been challenging to detect early changes in brain activity that occurs prior to seizure onset and to map their origin and evolution for possible intervention. Here we demonstrate using a rat model of generalized epilepsy that diffuse optical tomography (DOT) provides a unique functional neuroimaging modality for noninvasively and continuously tracking such brain activities with high spatiotemporal resolution. We detected early hemodynamic responses with heterogeneous patterns, along with intracranial electroencephalogram gamma power changes, several minutes preceding the electroencephalographic seizure onset, supporting the presence of a ``pre-seizure'' state. We also observed the decoupling between local hemodynamic and neural activities. We found widespread hemodynamic changes evolving from local regions of the bilateral cortex and thalamus to the entire brain, indicating that the onset of generalized seizures may originate locally rather than diffusely. Together, these findings suggest DOT represents a powerful tool for mapping early seizure onset and propagation pathways.

  15. Pre-seizure state identified by diffuse optical tomography

    PubMed Central

    Zhang, Tao; Zhou, Junli; Jiang, Ruixin; Yang, Hao; Carney, Paul R.; Jiang, Huabei

    2014-01-01

    In epilepsy it has been challenging to detect early changes in brain activity that occurs prior to seizure onset and to map their origin and evolution for possible intervention. Here we demonstrate using a rat model of generalized epilepsy that diffuse optical tomography (DOT) provides a unique functional neuroimaging modality for noninvasively and continuously tracking such brain activities with high spatiotemporal resolution. We detected early hemodynamic responses with heterogeneous patterns, along with intracranial electroencephalogram gamma power changes, several minutes preceding the electroencephalographic seizure onset, supporting the presence of a “pre-seizure” state. We also observed the decoupling between local hemodynamic and neural activities. We found widespread hemodynamic changes evolving from local regions of the bilateral cortex and thalamus to the entire brain, indicating that the onset of generalized seizures may originate locally rather than diffusely. Together, these findings suggest DOT represents a powerful tool for mapping early seizure onset and propagation pathways. PMID:24445927

  16. Wavelets and the squeezed states of quantum optics

    NASA Technical Reports Server (NTRS)

    Defacio, B.

    1992-01-01

    Wavelets are new mathematical objects which act as 'designer trigonometric functions.' To obtain a wavelet, the original function space of finite energy signals is generalized to a phase-space, and the translation operator in the original space has a scale change in the new variable adjoined to the translation. Localization properties in the phase-space can be improved and unconditional bases are obtained for a broad class of function and distribution spaces. Operators in phase space are 'almost diagonal' instead of the traditional condition of being diagonal in the original function space. These wavelets are applied to the squeezed states of quantum optics. The scale change required for a quantum wavelet is shown to be a Yuen squeeze operator acting on an arbitrary density operator.

  17. Optical Properties of Moderately-Absorbing Organic and Mixed Organic/Inorganic Particles at Very High Humidities

    SciTech Connect

    Bond, Tami C; Rood, Mark J; Brem, Benjamin T; Mena-Gonzalez, Francisco C; Chen, Yanju

    2012-04-16

    Relative humidity (RH) affects the water content of an aerosol, altering its ability to scatter and absorb light, which is important for aerosol effects on climate and visibility. This project involves in situ measurement and modeling of aerosol optical properties including absorption, scattering and extinction at three visible wavelengths (467, 530, 660 nm), for organic carbon (OC) generated by pyrolysis of biomass, ammonium sulfate and sodium chloride, and their mixtures at controlled RH conditions. Novel components of this project include investigation of: (1) Changes in all three of these optical properties at scanned RH conditions; (2) Optical properties at RH values up to 95%, which are usually extrapolated instead of measured; and (3) Examination of aerosols generated by the pyrolysis of wood, which is representative of primary atmospheric organic carbon, and its mixture with inorganic aerosol. Scattering and extinction values were used to determine light absorption by difference and single scattering albedo values. Extensive instrumentation development and benchmarking with independently measured and modeled values were used to obtain and evaluate these new results. The single scattering albedo value for a dry absorbing polystyrene microsphere benchmark agreed within 0.02 (absolute value) with independently published results at 530 nm. Light absorption by a nigrosin (sample light-absorbing) benchmark increased by a factor of 1.24 +/-0.06 at all wavelengths as RH increased from 38 to 95%. Closure modeling with Mie theory was able to reproduce this increase with the linear volume average (LVA) refractive index mixing rule for this water soluble compound. Absorption by biomass OC aerosol increased by a factor of 2.1 +/- 0.7 and 2.3 +/- 1.2 between 32 and 95% RH at 467 nm and 530 nm, but there was no detectable absorption at 660 nm. Additionally, the spectral dependence of absorption by OC that was observed with filter measurements was confirmed qualitatively

  18. Remote sensing-based Information for crop monitoring: contribution of SAR and Moderate resolution optical data on Asian rice production

    NASA Astrophysics Data System (ADS)

    Boschetti, Mirco; Holectz, Francesco; Manfron, Giacinto; Collivignarelli, Francesco; Nelson, Andrew

    2013-04-01

    Updated information on crop typology and status are strongly required to support suitable action to better manage agriculture production and reduce food insecurity. In this field, remote sensing has been demonstrated to be a suitable tool to monitor crop condition however rarely the tested system became really operative. The ones today available, such as the European Commission MARS, are mainly based on the analysis of NDVI time series and required ancillary external information like crop mask to interpret the seasonal signal. This condition is not always guarantied worldwide reducing the potentiality of the remote sensing monitoring. Moreover in tropical countries cloud contamination strongly reduce the possibility of using optical remote sensing data for crop monitoring. In this framework we focused our analysis on the rice production monitoring in Asian tropical area. Rice is in fact the staple food for half of the world population (FAO 2004), in Asia almost 90% of the world's rice is produced and consumed and Rice and poverty often coincide. In this contest the production of reliable rice production information is of extreme interest. We tried to address two important issue in terms of required geospatial information for crop monitoring: rice crop detection (rice map) and seasonal dynamics analysis (phenology). We use both SAR and Optical data in order to exploit the potential complementarity of this system. Multi-temporal ASAR Wide Swath data are in fact the best option to deal with cloud contamination. SAR can easily penetrate the clouds providing information on the surface target. Temporal analysis of archive ASAR data allowed to derived accurate map, at 100m spatial resolution, of permanent rice cultivated areas. On the other and high frequency revisiting optical data, in this case MODIS, have been used to extract seasonal information for the year under analysis. MOD09A1 Surface Reflectance 8-Day L3 Global 500m have been exploited to derive time series of

  19. Optical state engineering, quantum communication, and robustness of entanglement promiscuity in three-mode Gaussian states

    NASA Astrophysics Data System (ADS)

    Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio

    2007-03-01

    We present a novel, detailed study on the usefulness of three-mode Gaussian states for realistic processing of continuous variable (CV) quantum information, with a particular emphasis on the possibilities opened up by their genuine tripartite entanglement. We describe practical schemes to engineer several classes of pure and mixed three-mode states that stand out for their informational and/or entanglement properties. In particular, we introduce a simple procedure—based on passive optical elements—to produce pure three-mode Gaussian states with arbitrary entanglement structure (upon availability of an initial two-mode squeezed state). We analyse in depth the properties of distributed entanglement and the origin of its sharing structure, showing that the promiscuity of entanglement sharing is a feature peculiar to symmetric Gaussian states that survives even in the presence of significant degrees of mixedness and decoherence. Next, we discuss the suitability of the considered tripartite entangled states to the implementation of quantum information and communication protocols with CVs. This will lead to a feasible experimental proposal to test the promiscuous sharing of CV tripartite entanglement, in terms of the optimal fidelity of teleportation networks with Gaussian resources. We finally focus on the application of three-mode states to symmetric and asymmetric telecloning, and single out the structural properties of the optimal Gaussian resources for the latter protocol in different settings. Our analysis aims to lay the basis for a practical quantum communication with CVs beyond the bipartite scenario.

  20. Solid-state detector and optical system for microchip analyzers

    DOEpatents

    Mathies, Richard A.; Kamei, Toshihiro; Scherer, James R.; Street, Robert A.

    2005-03-15

    A miniaturized optical excitation and detector system is described for detecting fluorescently labeled analytes in electrophoretic microchips and microarrays. The system uses miniature integrated components, light collection, optical fluorescence filtering, and an amorphous a-Si:H detector for detection. The collection of light is accomplished with proximity gathering and/or a micro-lens system. Optical filtering is accomplished by integrated optical filters. Detection is accomplished utilizing a-Si:H detectors.

  1. Spontaneous Facial Mimicry Is Enhanced by the Goal of Inferring Emotional States: Evidence for Moderation of “Automatic” Mimicry by Higher Cognitive Processes

    PubMed Central

    Murata, Aiko; Saito, Hisamichi; Schug, Joanna; Ogawa, Kenji; Kameda, Tatsuya

    2016-01-01

    A number of studies have shown that individuals often spontaneously mimic the facial expressions of others, a tendency known as facial mimicry. This tendency has generally been considered a reflex-like “automatic” response, but several recent studies have shown that the degree of mimicry may be moderated by contextual information. However, the cognitive and motivational factors underlying the contextual moderation of facial mimicry require further empirical investigation. In this study, we present evidence that the degree to which participants spontaneously mimic a target’s facial expressions depends on whether participants are motivated to infer the target’s emotional state. In the first study we show that facial mimicry, assessed by facial electromyography, occurs more frequently when participants are specifically instructed to infer a target’s emotional state than when given no instruction. In the second study, we replicate this effect using the Facial Action Coding System to show that participants are more likely to mimic facial expressions of emotion when they are asked to infer the target’s emotional state, rather than make inferences about a physical trait unrelated to emotion. These results provide convergent evidence that the explicit goal of understanding a target’s emotional state affects the degree of facial mimicry shown by the perceiver, suggesting moderation of reflex-like motor activities by higher cognitive processes. PMID:27055206

  2. All-optical control of a solid-state spin using coherent dark states.

    PubMed

    Yale, Christopher G; Buckley, Bob B; Christle, David J; Burkard, Guido; Heremans, F Joseph; Bassett, Lee C; Awschalom, David D

    2013-05-01

    The study of individual quantum systems in solids, for use as quantum bits (qubits) and probes of decoherence, requires protocols for their initialization, unitary manipulation, and readout. In many solid-state quantum systems, these operations rely on disparate techniques that can vary widely depending on the particular qubit structure. One such qubit, the nitrogen-vacancy (NV) center spin in diamond, can be initialized and read out through its special spin-selective intersystem crossing, while microwave electron spin resonance techniques provide unitary spin rotations. Instead, we demonstrate an alternative, fully optical approach to these control protocols in an NV center that does not rely on its intersystem crossing. By tuning an NV center to an excited-state spin anticrossing at cryogenic temperatures, we use coherent population trapping and stimulated Raman techniques to realize initialization, readout, and unitary manipulation of a single spin. Each of these techniques can be performed directly along any arbitrarily chosen quantum basis, removing the need for extra control steps to map the spin to and from a preferred basis. Combining these protocols, we perform measurements of the NV center's spin coherence, a demonstration of this full optical control. Consisting solely of optical pulses, these techniques enable control within a smaller footprint and within photonic networks. Likewise, this unified approach obviates the need for both electron spin resonance manipulation and spin addressability through the intersystem crossing. This method could therefore be applied to a wide range of potential solid-state qubits, including those which currently lack a means to be addressed. PMID:23610403

  3. Long-term monitoring of PKS 2155-304 with ATOM and H.E.S.S.: investigation of optical/γ-ray correlations in different spectral states

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E. O.; Backes, M.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Carrigan, S.; Casanova, S.; Chadwick, P. M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Grondin, M.-H.; Grudzińska, M.; Hadsch, D.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Morå, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Odaka, H.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2014-11-01

    In this paper we report on the analysis of all the available optical and very high-energy γ-ray (>200 GeV) data for the BL Lac object PKS 2155-304, collected simultaneously with the ATOM and H.E.S.S. telescopes from 2007 until 2009. This study also includes X-ray (RXTE, Swift) and high-energy γ-ray (Fermi-LAT) data. During the period analysed, the source was transitioning from its flaring to quiescent optical states, and was characterized by only moderate flux changes at different wavelengths on the timescales of days and months. A flattening of the optical continuum with an increasing optical flux can be noted in the collected dataset, but only occasionally and only at higher flux levels. We did not find any universal relation between the very high-energy γ-ray and optical flux changes on the timescales from days and weeks up to several years. On the other hand, we noted that at higher flux levels the source can follow two distinct tracks in the optical flux-colour diagrams, which seem to be related to distinct γ-ray states of the blazar. The obtained results therefore indicate a complex scaling between the optical and γ-ray emission of PKS 2155-304, with different correlation patterns holding at different epochs, and a γ-ray flux depending on the combination of an optical flux and colour rather than a flux alone.

  4. Minimal-excitation states for electron quantum optics using levitons

    NASA Astrophysics Data System (ADS)

    Dubois, J.; Jullien, T.; Portier, F.; Roche, P.; Cavanna, A.; Jin, Y.; Wegscheider, W.; Roulleau, P.; Glattli, D. C.

    2013-10-01

    The on-demand generation of pure quantum excitations is important for the operation of quantum systems, but it is particularly difficult for a system of fermions. This is because any perturbation affects all states below the Fermi energy, resulting in a complex superposition of particle and hole excitations. However, it was predicted nearly 20 years ago that a Lorentzian time-dependent potential with quantized flux generates a minimal excitation with only one particle and no hole. Here we report that such quasiparticles (hereafter termed levitons) can be generated on demand in a conductor by applying voltage pulses to a contact. Partitioning the excitations with an electronic beam splitter generates a current noise that we use to measure their number. Minimal-excitation states are observed for Lorentzian pulses, whereas for other pulse shapes there are significant contributions from holes. Further identification of levitons is provided in the energy domain with shot-noise spectroscopy, and in the time domain with electronic Hong-Ou-Mandel noise correlations. The latter, obtained by colliding synchronized levitons on a beam splitter, exemplifies the potential use of levitons for quantum information: using linear electron quantum optics in ballistic conductors, it is possible to imagine flying-qubit operation in which the Fermi statistics are exploited to entangle synchronized electrons emitted by distinct sources. Compared with electron sources based on quantum dots, the generation of levitons does not require delicate nanolithography, considerably simplifying the circuitry for scalability. Levitons are not limited to carrying a single charge, and so in a broader context n-particle levitons could find application in the study of full electron counting statistics. But they can also carry a fraction of charge if they are implemented in Luttinger liquids or in fractional quantum Hall edge channels; this allows the study of Abelian and non-Abelian quasiparticles in the

  5. Optical Control of Mammalian Endogenous Transcription and Epigenetic States

    PubMed Central

    Trevino, Alexandro; Hsu, Patrick D.; Heidenreich, Matthias; Cong, Le; Platt, Randall J.; Scott, David A.; Church, George M.; Zhang, Feng

    2013-01-01

    The dynamic nature of gene expression enables cellular programming, homeostasis, and environmental adaptation in living systems. Dissection of causal gene functions in cellular and organismal processes therefore necessitates approaches that enable spatially and temporally precise modulation of gene expression. Recently, a variety of microbial and plant-derived light-sensitive proteins have been engineered as optogenetic actuators, enabling high precision spatiotemporal control of many cellular functions1-11. However, versatile and robust technologies that enable optical modulation of transcription in the mammalian endogenous genome remain elusive. Here, we describe the development of Light-Inducible Transcriptional Effectors (LITEs), an optogenetic two-hybrid system integrating the customizable TALE DNA-binding domain12-14 with the light-sensitive cryptochrome 2 protein and its interacting partner CIB1 from Arabidopsis thaliana. LITEs do not require additional exogenous chemical co-factors, are easily customized to target many endogenous genomic loci, and can be activated within minutes with reversibility3,4,6,7,15. LITEs can be packaged into viral vectors and genetically targeted to probe specific cell populations. We have applied this system in primary mouse neurons, as well as in the brain of awake mice in vivo to mediate reversible modulation of mammalian endogenous gene expression as well as targeted epigenetic chromatin modifications. The LITE system establishes a novel mode of optogenetic control of endogenous cellular processes and enables direct testing of the causal roles of genetic and epigenetic regulation in normal biological processes and disease states. PMID:23877069

  6. Bright and black paired soliton states in birefringent optical fibers

    NASA Astrophysics Data System (ADS)

    Chen, Yijiang

    1996-08-01

    It is shown that a bright stationary light pulse evolving along the slow axis of a birefringent fiber in the anomalous dispersion regime can be locked to move in the same group velocity together with a black-soliton pulse trapped along the fast axis in the normal dispersion regime despite each individual pulse's, in the absence of the other, propagating at different group velocities. Such a stationary copropagation of the bright and the black soliton pulses with the same group velocity in coherent trapping can sustain up to a finite distance owing to polarization modulation instability of the black-pulse background that breaks the stationary evolution into radiation. In incoherent trapping the bright-black paired soliton state also disintegrates with propagation distance, and the disintegration is accompanied by emission of bright and gray solitons that has potential for ultrafast optical switching. On the other hand, it is found that the two black-soliton pulses polarized along the principal axes of the birefringent fiber in the normal dispersion regime can evolve stably, in contrast to the paired spatial black solitons of different frequencies and parametric black solitons that break up with propagation distance owing to modulational instability of the cw backgrounds.

  7. Optically triggered solid state driver for shock wave therapy

    NASA Astrophysics Data System (ADS)

    Duryea, Alexander P.; Roberts, William W.; Cain, Charles A.; Hall, Timothy L.

    2012-10-01

    Shock wave lithotripsy (SWL) represents one of several first-line therapies for the treatment of stones located in the kidneys and ureters. Additional applications for shock wave therapy are also under exploration, including non-urinary calculi, orthopedics, and neovascularization. Except for the elimination of a large water bath in which the treatment is performed, current procedures remain largely unchanged, with one of the original commercial devices (the Dornier HM3) still considered a gold standard for comparison. To accelerate research in this area, Coleman, et al. published an experimental electrohydraulic shock wave generator capable of simulating the acoustic field generated by the HM3. We propose a further update of this system, replacing the triggered spark gap with an optically triggered solid state switch. The new system has better reliability, a wider operating range, and reduced timing jitter allowing synchronization with additional acoustic sources under exploration for improving efficacy and reducing injury. Originally designed for exciting electrohydraulic spark electrodes, the system can also be adapted for driving piezoelectric and electromagnetic sources.

  8. Steady-state heating of active fibres under optical pumping

    SciTech Connect

    Gainov, V V; Shaidullin, R I; Ryabushkin, Oleg A

    2011-07-31

    We have measured the temperature in the core of rare-earth-doped optical fibres under lasing conditions at high optical pump powers using a fibre Mach - Zehnder interferometer and probe light of wavelength far away from the absorption bands of the active ions. From the observed heating kinetics of the active medium, the heat transfer coefficient on the polymer cladding - air interface has been estimated. The temperature of the active medium is shown to depend on the thermal and optical properties of the polymer cladding. (fiber and integrated optics)

  9. The effects of advertisements that sexually objectify women on state body dissatisfaction and judgments of women: The moderating roles of gender and internalization.

    PubMed

    Krawczyk, Ross; Thompson, J Kevin

    2015-09-01

    Experimental studies have demonstrated that exposure to idealized images of women increases state body image disturbance. However, little work has experimentally examined the effects of exposure to images that sexually objectify women, especially as it relates to women and men's state body dissatisfaction and judgments of women. In the current study, 437 women and men were randomly assigned to view advertisements that sexually objectify women and portray appearance ideals, or to view non-appearance-related advertisements. Results indicated that state body dissatisfaction increased for women and men exposed to advertisements that sexually objectified women, although this effect was larger for women. Trait internalization of appearance ideals moderated this effect, indicating that women and men with higher internalization exhibited greater state body dissatisfaction after viewing women sexually objectified in advertisements. Exposure to women sexually objectified in advertisements did not affect women's or men's attractiveness or competence ratings of women in university advertisements. PMID:26363356

  10. A novel experimental setup for energy loss and charge state measurements in dense moderately coupled plasma using laser-heated hohlraum targets

    NASA Astrophysics Data System (ADS)

    Ortner, A.; Schumacher, D.; Cayzac, W.; Frank, A.; Basko, M. M.; Bedacht, S.; Blazevic, A.; Faik, S.; Kraus, D.; Rienecker, T.; Schaumann, G.; Tauschwitz, An.; Wagner, F.; Roth, M.

    2016-03-01

    We report on a new experimental setup for ion energy loss measurements in dense moderately coupled plasma which has recently been developed and tested at GSI Darmstadt. A partially ionized, moderately coupled carbon plasma (ne ≤ 0.8• 1022 cm-3, Te = 15 eV, z = 2.5, Γ = 0.5) is generated by volumetrical heating of two thin carbon foils with soft X-rays. This plasma is then probed by a bunched heavy ion beam. For that purpose, a special double gold hohlraum target of sub-millimeter size has been developed which efficiently converts intense laser light into thermal radiation and guarantees a gold-free interaction path for the ion beam traversing the carbon plasma. This setup allows to do precise energy loss measurements in non-ideal plasma at the level of 10 percent solid-state density.

  11. Experimental generation of tripartite polarization entangled states of bright optical beams

    NASA Astrophysics Data System (ADS)

    Wu, Liang; Yan, Zhihui; Liu, Yanhong; Deng, Ruijie; Jia, Xiaojun; Xie, Changde; Peng, Kunchi

    2016-04-01

    The multipartite polarization entangled states of bright optical beams directly associating with the spin states of atomic ensembles are one of the essential resources in the future quantum information networks, which can be conveniently utilized to transfer and convert quantum states across a network composed of many atomic nodes. In this letter, we present the experimental demonstration of tripartite polarization entanglement described by Stokes operators of optical field. The tripartite entangled states of light at the frequency resonant with D1 line of Rubidium atoms are transformed into the continuous variable polarization entanglement among three bright optical beams via an optical beam splitter network. The obtained entanglement is confirmed by the extended criterion for polarization entanglement of multipartite quantized optical modes.

  12. Quantum Coherent Feedback Control for Generation System of Optical Entangled State

    PubMed Central

    Zhou, Yaoyao; Jia, Xiaojun; Li, Fang; Yu, Juan; Xie, Changde; Peng, Kunchi

    2015-01-01

    The non-measurement based coherent feedback control (CFC) is a control method without introducing any backaction noise into the controlled system, thus is specially suitable to manipulate various quantum optical systems for preparing nonclassical states of light. By simply tuning the transmissivity of an optical controller in a CFC loop attached to a non-degenerate optical parametric amplifier (NOPA), the quantum entanglement degree of the output optical entangled state of the system is improved. At the same time, the threshold pump power of the NOPA is reduced also. The experimental results are in reasonable agreement with the theoretical expectation. PMID:26047357

  13. Switching between ground and excited states by optical feedback in a quantum dot laser diode

    SciTech Connect

    Virte, Martin; Breuer, Stefan; Sciamanna, Marc; Panajotov, Krassimir

    2014-09-22

    We demonstrate switching between ground state and excited state emission in a quantum-dot laser subject to optical feedback. Even though the solitary laser emits only from the excited state, we can trigger the emission of the ground state by optical feedback. We observe recurrent but incomplete switching between the two emission states by variation of the external cavity length in the sub-micrometer scale. We obtain a good qualitative agreement of experimental results with simulation results obtained by a rate equation that accounts for the variations of the feedback phase.

  14. Violation of the Bell-Clauser-Horne-Shimony-Holt inequality using imperfect photodetectors with optical hybrid states

    NASA Astrophysics Data System (ADS)

    Kwon, Hyukjoon; Jeong, Hyunseok

    2013-11-01

    We show that a Bell inequality test using an optical hybrid state between a polarized single photon and a coherent field can be highly robust against detection inefficiency. The Bell violation occurs until the efficiency becomes as low as 67% even though its degree becomes small as the detection efficiency degrades. We consider on/off and photon number parity measurements, respectively, for the Bell test and they result in similar conditions. If the detection efficiency is higher than 98.68%, parity measurements give larger Bell violations close to Cirel'son's bound, while on/off measurements give larger but moderate violations for realistic values of detector efficiency. Experimental realization of our proposal seems feasible in the near future for the implementation of a loophole-free Bell inequality test.

  15. Optical Field-Strength Polarization of Two-Mode Single-Photon States

    ERIC Educational Resources Information Center

    Linares, J.; Nistal, M. C.; Barral, D.; Moreno, V.

    2010-01-01

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of…

  16. Transient state of polarization in optical ground wire caused by lightning and impulse current

    NASA Astrophysics Data System (ADS)

    Kurono, Masahiro; Isawa, K.; Kuribara, Masayuki

    1996-08-01

    This paper describes a transient state of polarization in an optical ground wire (OPGW) theoretically, experimentally and with field measurements in lightning conditions, which is considered one of the fastest phenomena of polarization fluctuations in the natural environment. These characteristics will be required for optical coherent communication for utilities in future and for application to sensing of lightning with OPGW.

  17. The Development of Replicated Optical Integral Field Spectrographs and their Application to the Study of Lyman-alpha Emission at Moderate Redshifts

    NASA Astrophysics Data System (ADS)

    Chonis, Taylor Steven

    volume phase holographic (VPH) diffraction gratings for VIRUS is presented, which highlights the challenge and success associated with producing of a very large number of highly customized optical elements whose performance is crucial to meeting the efficiency requirements of the spectrograph system. To accommodate VIRUS, the HET is undergoing a substantial wide-field upgrade to increase its field of view to 22' in diameter. The previous HET facility Low Resolution Spectrograph (LRS), which was directly fed by the telescope's previous spherical aberration corrector, must be removed from the prime focus instrument package as a result of the telescope upgrades and instead be fiber-coupled to the telescope focal plane. For a similar cost as modifying LRS to accommodate these changes, a new second generation instrument (LRS2) will be based on the VIRUS unit spectrograph. The design, operational concept, construction, and laboratory testing and characterization of LRS2 is the primary focus of this dissertation, which highlights the benefits of leveraging the large engineering investment, economies of scale, and laboratory and observatory infrastructure associated with the massively replicated VIRUS instrument. LRS2 will provide integral field spectroscopy for a seeing-limited field of 12" x 6". The multiplexed VIRUS framework facilitates broad wavelength coverage from 370 nm to 1.0 mum spread between two dual-channel spectrographs at a moderate spectral resolving power of R ≈ 2000. The design departures from VIRUS are presented, including the novel integral field unit, VPH grism dispersers, and various optical changes for accommodating the broadband wavelength coverage. Laboratory testing has verified that LRS2 largely meets its image quality specification and is nearly ready for delivery to the HET where its final verification and validation tasks will be executed. LRS2 will enable the continuation of most legacy LRS science programs and provide improved capability for

  18. Affect and State Dysregulation as Moderators of the Relationship between Childhood Sexual Abuse and Nonsuicidal Self-Injury

    ERIC Educational Resources Information Center

    Bolen, Rebecca M.; Ramseyer Winter, Virginia; Hodges, Liz

    2013-01-01

    Nonsuicidal self-injury (NSSI) is a significant problem in both clinical and nonclinical populations. Affect and state dysregulation are frequently observed in survivors of childhood sexual abuse and in those who engage in NSSI. Both have been found to predict NSSI, and affect regulation has also been modeled as a mediator of NSSI. This study…

  19. Energy shift and state mixing of Rydberg atoms in ponderomotive optical traps

    NASA Astrophysics Data System (ADS)

    Wang, Xiao; Robicheaux, F.

    2016-08-01

    We present a degenerate perturbation analysis in the spin–orbit coupled basis for Rydberg atoms in an optical trap. The perturbation matrix is found to be nearly the same for two states with the same total angular momentum j, and orbital angular momentum number l differing by 1, The same perturbation matrices result in the same state-mixing and energy shift. We also study the dependence of state mixing and energy shift on the periodicity and symmetry of the ponderomotive potentials induced by different optical traps. State mixing in a one-dimensional lattice formed with two counterpropagating Gaussian beams is studied and yields a state-dependent trap depth. We also calculate the state-mixing in an optical trap formed by four parallel, separated and highly focused Gaussian beams.

  20. Quantum optics. Quantum harmonic oscillator state synthesis by reservoir engineering.

    PubMed

    Kienzler, D; Lo, H-Y; Keitch, B; de Clercq, L; Leupold, F; Lindenfelser, F; Marinelli, M; Negnevitsky, V; Home, J P

    2015-01-01

    The robust generation of quantum states in the presence of decoherence is a primary challenge for explorations of quantum mechanics at larger scales. Using the mechanical motion of a single trapped ion, we utilize reservoir engineering to generate squeezed, coherent, and displaced-squeezed states as steady states in the presence of noise. We verify the created state by generating two-state correlated spin-motion Rabi oscillations, resulting in high-contrast measurements. For both cooling and measurement, we use spin-oscillator couplings that provide transitions between oscillator states in an engineered Fock state basis. Our approach should facilitate studies of entanglement, quantum computation, and open-system quantum simulations in a wide range of physical systems. PMID:25525161

  1. Pump-probe quantum state tomography in a semiconductor optical amplifier.

    PubMed

    Grosse, N B; Owschimikow, N; Aust, R; Lingnau, B; Koltchanov, A; Kolarczik, M; Lüdge, K; Woggon, U

    2014-12-29

    Pump-probe quantum state tomography was applied to the transmission of a coherent state through an In(Ga)As based quantum dot optical amplifier during the interaction with an optical pump pulse. The Wigner function and the statistical moments of the field were extracted and used to determine the degree of population inversion and the signal-to-noise ratio in a sub-picosecond time window. PMID:25607214

  2. Optics program in the physics department at San Jose State University

    NASA Astrophysics Data System (ADS)

    Bahuguna, Ramendra D.; Arya, Karamjeet; Becker, Joseph F.; Gruber, John B.; Lakkaraju, H. Sarma; Wharton, Kenneth B.; Williams, Gareth T.

    2002-05-01

    The San Jose State University Physics Department, located in Silicon Valley, provides students with a high quality education in optics and provides local high-tech industry and government laboratories with a partner for optics- related research and development projects. There are approximately 50 undergraduate majors and 20 graduate (M.S.) students in the Department. Core courses leading to the B.S. in Physics are offered with upper division courses in Modern Optics, Lasers and Applications, Advanced Optics Lab, Advanced Instrumentation Lab, and Individual Studies as well as graduate courses in Electro-optics, Graduate Optics, Optical Metrology, and Laser Spectroscopy. Graduates are well prepared to enter the lasers and optics industry or go onto graduate school. A 4000 square-foot lab in the Science Building houses the Institute for Modern Optics, an organized research unit in the College of Science. One of the major goals of the Institute is to facilitate collaborative research between the local optics industry and the faculty and students at SJSU. The Department is presently developing a new biophotonics lab for single molecule studies with a dual beam optical tweezers already operational. A National Science Foundation Research Experience for Undergraduates Program grant provides research support for undergraduates.

  3. Optical State-of-Change Monitor for Lead-Acid Batteries

    SciTech Connect

    Weiss, Jonathan D.

    1998-07-24

    A method and apparatus for determining the instantaneous state-of-charge of a battery in which change in composition with discharge manifests itself as a change in optical absorption. In a lead-acid battery, the sensor comprises a fiber optic system with an absorption cdl or, alternatively, an optical fiber woven into an absorbed-glass-mat battery. In a lithium-ion battery, the sensor comprises fiber optics for introducing light into the anode to monitor absorption when lithium ions are introduced.

  4. Solid state electro-optic color filter and iris

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The electro-optic properties of lanthanum-modified lead zirconate titanate (PLZT) ferroelectric ceramic material are evaluated when utilized as a variable density and/or spectral filter in conjunction with a television scanning system. Emphasis was placed on the development of techniques and procedures for processing the PLZT disks and for applying efficient electrode structures. A number of samples were processed using different combinations of cleaning, electrode material, and deposition process. Best overall performance resulted from the direct evaporation of gold over chrome electrodes. A ruggedized mounting holder assembly was designed, fabricated, and tested. The assembly provides electrical contacts, high voltage protection, and support for the fragile PLZT disk, and permits mounting and optical alignment of the associated polarizers. Operational measurements of a PLZT sample mounted in the holder assembly were performed in conjunction with a television camera and the associated drive circuits. The data verified achievement of the elimination of the observed white-line effect.

  5. IUE and optical observations of MV Lyrae at intermediate and low states

    NASA Technical Reports Server (NTRS)

    Szkody, P.; Downes, R. A.

    1982-01-01

    Ultraviolet observations of MV Lyrae were obtained with the aid of the International Ultraviolet Explorer (IUE) spacecraft on 1979 December 2 when MV Lyr was at a normal low state and on 1980 December 8. The optical observations were obtained at Kitt Peak, Lick Observatory, and the University of Washington Observatory with various image-tube scanners and photometers. The photometric colors were found to be very blue at the very low state and at the normal low state. Robinson et al. (1981) have identified three components in their very low-state optical spectra. The significance of the observations is discussed.

  6. Multiplexing OAM states in an optical fiber: Increase bandwidth of quantum communication and QKD applications

    NASA Astrophysics Data System (ADS)

    Gupta, Manish Kumar; Dowling, Jonathan P.

    2015-05-01

    We propose a noble method for multiplexing OAM states to increase bandwidth of communication in a birefringent single-mode optical fiber for quantum communication and QKD applications by minimizing the decoherence. We analytically derive and show that the rate of decoherence for OAM state in a birefringent optical fiber is proportional to l2. We also show numerically that decoherence can be minimized with CPMG pulse sequence to preserve the state with > 90 % fidelity for smaller values of l to allow for high-bandwidth communication. Louisiana State University, Baton Rouge, Louisiana 70803, USA.

  7. Optical indication for evaluation ecological state of water areas

    SciTech Connect

    Surin, V.G.; Goloudin, R.I.

    1996-11-01

    The results of spectral measurements of reed, leaves by using a two kinds or the spectrometers at the Neva Bay and in the east part of the Gulf of Finland are discussed. It is shown that the optical properties of the coastal-aqueous vegetation depend on the presence of heavy metals in them. Key words: ecology, spectral reflectance, pollution, aqueous vegetation, remote sensing, spectrometer. 7 refs., 4 figs., 2 tabs.

  8. What Students Think They Feel Differs from What They Really Feel – Academic Self-Concept Moderates the Discrepancy between Students’ Trait and State Emotional Self-Reports

    PubMed Central

    Bieg, Madeleine; Goetz, Thomas; Lipnevich, Anastasiya A.

    2014-01-01

    This study investigated whether there is a discrepancy pertaining to trait and state academic emotions and whether self-concept of ability moderates this discrepancy. A total of 225 secondary school students from two different countries enrolled in grades 8 and 11 (German sample; n = 94) and grade 9 (Swiss sample; n = 131) participated. Students’ trait academic emotions of enjoyment, pride, anger, and anxiety in mathematics were assessed with a self-report questionnaire, whereas to assess their state academic emotions experience-sampling method was employed. The results revealed that students’ scores on the trait assessment of emotions were generally higher than their scores on the state assessment. Further, as expected, students’ academic self-concept in the domain of mathematics was shown to partly explain the discrepancy between scores on trait and state emotions. Our results indicate that there is a belief-driven discrepancy between what students think they feel (trait assessment) and what they really feel (state assessment). Implications with regard to the assessment of self-reported emotions in future studies and practical implications for the school context are discussed. PMID:24647760

  9. Infant Negative Affect and Maternal Interactive Behavior During the Still-Face Procedure: The Moderating Role of Adult Attachment States of Mind

    PubMed Central

    Haltigan, John D.; Leerkes, Esther M.; Supple, Andrew J.; Calkins, Susan D.

    2013-01-01

    The current study examined associations between attachment state of mind measured prenatally (N = 259) and maternal behavior in the reunion episode of the still-face procedure when infants were six months of age both as a main effect and in conjunction with infant negative affect. Using a dimensional approach to adult attachment measurement, dismissing and preoccupied states of mind were negatively associated with maternal sensitivity, and each correlated with distinct parenting behaviors. Positive associations were found between dismissing states of mind and maternal monitoring and preoccupied states of mind and maternal withdraw. Maternal preoccupation moderated associations between infant negative affect and maternal intrusive, withdrawn, and monitoring behaviors, supporting the notion that maternal attachment influences parenting behavior via a modulatory process in which infant distress cues are selectively filtered and responded to. Analyses using a traditional AAI scale and classification approach also provided evidence for distinct parenting behavior correlates of insecure adult attachment representations. The importance of measuring global and stylistic differences in maternal behavior in contexts which allow for the activation of the entire range of infant affective states is discussed. PMID:24329015

  10. Aerosol optical properties over the midcontinental United States

    NASA Technical Reports Server (NTRS)

    Halthore, Rangasayi N.; Markham, Brian L.; Ferrare, Richard A.; Aro, Theo. O.

    1992-01-01

    Solar and sky radiation measurements were analyzed to obtain aerosol properties such as the optical thickness and the size distribution. The measurements were conducted as part of the First International Satellite Land Surface Climatology Project Field Experiment during the second intensive field campaign (IFC) from June 25 to July 14, 1987, and the fifth IFC from July 25 to August 12, 1989, on the Konza Prairie near Manhattan, Kansas. Correlations with climatological and meteorological parameters show that during the period of observations in 1987, two types of air masses dominated the area: an air mass with low optical thickness and low temperature air associated with a northerly breeze, commonly referred to as the continental air, and an air mass with a higher optical thickness and higher temperature air associated with a southerly wind which we call 'Gulf air'. The size distributions show a predominance of the larger size particles in 'Gulf air'. Because of the presence of two contrasting air masses, correlations with parameters such as relative humidity, specific humidity, pressure, temperature, and North Star sky radiance reveal some interesting aspects. In 1989, clear distinctions between continental and Gulf air cannot be made; the reason for this will be discussed.

  11. Effect of rotational-state-dependent molecular alignment on the optical dipole force

    NASA Astrophysics Data System (ADS)

    Kim, Lee Yeong; Lee, Ju Hyeon; Kim, Hye Ah; Kwak, Sang Kyu; Friedrich, Bretislav; Zhao, Bum Suk

    2016-07-01

    The properties of molecule-optical elements such as lenses or prisms based on the interaction of molecules with optical fields depend in a crucial way on the molecular quantum state and its alignment created by the optical field. Herein, we consider the effects of state-dependent alignment in estimating the optical dipole force acting on the molecules and, to this end, introduce an effective polarizability which takes proper account of molecular alignment and is directly related to the alignment-dependent optical dipole force. We illustrate the significance of including molecular alignment in the optical dipole force by a trajectory study that compares previously used approximations with the present approach. The trajectory simulations were carried out for an ensemble of linear molecules subject to either propagating or standing-wave optical fields for a range of temperatures and laser intensities. The results demonstrate that the alignment-dependent effective polarizability can serve to provide correct estimates of the optical dipole force, on which a state-selection method applicable to nonpolar molecules could be based. We note that an analogous analysis of the forces acting on polar molecules subject to an inhomogeneous static electric field reveals a similarly strong dependence on molecular orientation.

  12. Preparation of stable excited states in an optical lattice via sudden quantum quench

    SciTech Connect

    Wang, Li; Chen, Shu; Hao, Yajiang

    2010-06-15

    We study how stable excited many-body states of the Bose-Hubbard model, including both the gaslike state for strongly attractive bosons and bound cluster state for repulsive bosons, can be produced with cold bosonic atoms in an one-dimensional optical lattice. Starting from the initial ground states of strongly interacting bosonic systems, we can achieve stable excited states of the systems with opposite interaction strength by suddenly switching the interaction to the opposite limit. By exactly solving dynamics of the Bose-Hubbard model, we demonstrate that the produced excited state can be a very stable dynamic state. This allows the experimental study of excited state properties of ultracold atoms system in optical lattices.

  13. Optical control, diagnostic and power supply system for a solid state induction modulator

    SciTech Connect

    Saethre, R.; Kirbie, H.; Hickman, B.; Lee, B.; Ollis, C.

    1997-06-01

    A new high speed optical control, diagnostic and power supply system has been developed for a solid state induction modulator. The modulator consists of a large array of field effect transistors (FETs) that switch a high-voltage pulse across a tape-wound magnetic core. The FETs within the modulator are mounted on numerous circuit boards that are stacked in series for high-voltage operation. The new optical system overcomes the issue of voltage isolation by supplying each circuit board with optically coupled control power and high bandwidth signal information. An optical fiber is used to transmit laser light to a custom photovoltaic cell that provides dc power to the on-board control circuits. Optical fiber technology is again used to convey a pulse that contains detailed analog features to the FET gate controls. Diagnostic data and status information are also obtained from each board by similar optical methods. 8 refs., 6 figs., 1 tab.

  14. Optical description of solid-state dye-sensitized solar cells. I. Measurement of layer optical properties

    SciTech Connect

    Moule, Adam J.; Snaith, Henry J.; Kaiser, Markus; Klesper, Heike; Meerholz, Klaus; Huang, David M.; Graetzel, Michael

    2009-10-01

    The efficiency of a photovoltaic device is limited by the portion of solar energy that can be captured. We discuss how to measure the optical properties of the various layers in solid-state dye-sensitized solar cells (SDSC). We use spectroscopic ellipsometry to determine the complex refractive index of each of the various layers in a SDSC. Each of the ellipsometry fits is used to calculate a transmission spectrum that is compared to a measured transmission spectrum. The complexities of pore filling on the fitting of the ellipsometric data are discussed. Scanning electron microscopy and energy dispersive x-ray spectroscopy is shown to be an effective method for determining pore filling in SDSC layers. Accurate effective medium optical constants for each layer are presented and the material limits under which these optical constants can be used are discussed.

  15. Continuous Optical Production of Ultracold Vibronic Ground State Polar Molecules

    NASA Astrophysics Data System (ADS)

    Bruzewicz, Colin David

    We present recent results on the formation of ultracold polar molecules via photoassociation. Beginning with pre-cooled samples of Rb and Cs atoms, we produce electronically-excited molecules that inherit the ultracold temperature of their atomic precursors. In order to create large samples of ultracold molecules in their vibrational and rotational X 1Sigma+(upsilon=J=0) ground state, we study two different photoassociative regimes. In the first, molecules are created in a particular highly vibrationally-excited molecular state and decay strongly to a weakly-bound vibrational level in the ground a3Sigma + state. To study a possible population transfer scheme from this state to the X1Sigma+(upsilon=J=0) ground state, we present high-resolution depletion spectroscopy of the a 3Sigma+ c3Sigma+ transition for use in the first stage of a proposed Stimulated Raman Adiabatic Passage (STIRAP) transfer. In the second photoassociative regime, molecules are created in deeply-bound, electronically-excited vibrational levels that decay directly to the X1Sigma+(upsilon=0) state, obviating the need for population transfer. Through theoretical analysis and subsequent experimental verification, we demonstrate continuous formation of X 1Sigma+(upsilon=0) RbCs molecules at rates in excess of 103/s. We then conclude with detailed calculations of a method to purify the molecular sample of unwanted excited molecular states, based on inelastic scattering with ultracold Cs atoms.

  16. Optical solid-state detection of organophosphates using organophosphorus hydrolase.

    PubMed

    White, Brandy J; Harmon, H James

    2005-04-15

    We have developed a sensor surface for optical detection of organophosphates based on reversible inhibition of organophosphorus hydrolase (OPH) by copper complexed meso-tri(4-sulfonato phenyl) mono(4-carboxy phenyl) porphyrin (CuC1TPP). OPH immobilized onto glass microscope slides retains catalytic activity for more than 232 days. CuC1TPP is a reversible, competitive inhibitor of OPH, binding at the active site of the immobilized enzyme. The absorbance spectrum of the porphyrin-enzyme complex is measured via planar waveguide evanescent wave absorbance spectroscopy using a blue LED as a light source and an Ocean Optics USB2000 as the spectrophotometer. The characteristics of the absorbance spectrum of CuC1TPP are specific and different when the porphyrin is bound to the enzyme or is bound non-specifically to the surface of the slide. Addition of a substrate of OPH such as one of the organophosphates paraoxon, coumaphos, diazinon, or malathion displaces the porphyrin from the enzyme resulting in reduced absorbance intensity at 412 nm. Absorbance changes at 412 nm show log-linear dependence on substrate concentration. Paraoxon concentrations between 7 parts per trillion (ppt) and 14 parts per million (ppm) were investigated and a 3:1 S/N detection limit of 7 ppt was determined. Concentrations of 700 ppt to 40 ppm were investigated for diazinon, malathion, and coumaphos with detection limits of 800 ppt, 1 part per billion, and 250 ppt, respectively. This optical technique does not require the addition of reagents or solutions other than the sample and absorbance spectra can be collected in less than 6 s. PMID:15741066

  17. Hermite polynomial excited squeezed vacuum as quantum optical vortex states

    NASA Astrophysics Data System (ADS)

    Li, Ya-Zhou; Jia, Fang; Zhang, Hao-Liang; Huang, Jie-Hui; Hu, Li-Yun

    2015-11-01

    We introduce theoretically a kind of Hermite polynomial excited squeezed vacuum by extending the wave-packet states with a vortex structure to a general case. Its normalised factor is found to be the Legendre polynomial and the condition converting the general case to a special one is achieved. Then we consider its statistical properties according to the photon number distribution and the Wigner function. As an application, we investigate the performance of the teleportation of the coherent state. It is shown that these parameters in the generalised state can modulate all the above properties including the vortex structure.

  18. Moderate variations of mood/emotional states related to alterations in cochlear otoacoustic emissions and tinnitus onset in young normal hearing subjects exposed to gun impulse noise.

    PubMed

    Job, Agnès; Cian, Corinne; Esquivié, Dominique; Leifflen, Daniel; Trousselard, Marion; Charles, Corinne; Nottet, Jean-Bertrand

    2004-07-01

    This study was designed to test whether under impulse noise exposure mood and emotional states could play a role in the onset of tinnitus and/or could modify cochlear sensitivity objectively measured with distortion product otoacoustic emissions (DPOAEs). The experimental design consisted in a short follow-up study of 54 young military subjects (20+/-2 years old), psychologically normal, with normal hearing, during two consecutive days of target practice rounds. Data collection included an abbreviated version of the profile of mood states (POMSs) inventory [Profile of Mood States, Educational and Industrial Testing Service, San Diego, 1971], questionnaires on tinnitus perception (previous history and after shooting) and DPOAEs measurements before and after shooting. Higher scores of tension-anxiety were found in subjects having previous history of tinnitus. Association between tinnitus previous history and tinnitus after shooting was found significant. Perception of tinnitus after target practice rounds was associated with significantly lower DPOAEs at 3 kHz. The most tense-anxious subjects were found to have DPOAEs decreases of 3.35+/-6 dB at 3 kHz after shooting. This study clearly shows that, in young healthy population, psychologically normal and with normal hearing, moderate variations in mood and emotional states were related to tinnitus onset and DPOAEs alterations. It is possible that stronger variations in mood and/or emotional condition would increase risks of tinnitus and alterations of cochlear sensitivity. PMID:15219318

  19. Tailoring Cyanine Dark States for Improved Optically Modulated Fluorescence Recovery

    PubMed Central

    Mahoney, Daniel P.; Owens, Eric A.; Fan, Chaoyang; Hsiang, Jung-Cheng; Henary, Maged M.; Dickson, Robert M.

    2016-01-01

    Cyanine dyes are well known for their bright fluorescence and utility in biological imaging. Yet, cyanines also readily photoisomerize to produce non-emissive dark states. Co-illumination with a secondary, red-shifted light source on-resonance with the longer wavelength absorbing dark state reverses the photoisomerization and returns the cyanine dye to the fluorescent manifold, increasing steady-state fluorescence intensity. Modulation of this secondary light source dynamically alters emission intensity, drastically improving detection sensitivity and facilitating fluorescence signals to be recovered from otherwise overwhelming background. Red and near-IR emitting cyanine derivatives have been synthesized with varying alkyl chain lengths and halogen substituents to alter dual-laser fluorescence enhancement. Photophysical properties and enhancement with dual laser modulation were coupled with density functional calculations to characterize substituent effects on dark state photophysics, potentially improving detection in high background biological environments. PMID:25763888

  20. Magneto-optical contrast in liquid-state optically detected NMR spectroscopy.

    PubMed

    Pagliero, Daniela; Meriles, Carlos A

    2011-12-01

    We use optical Faraday rotation (OFR) to probe nuclear spins in real time at high-magnetic field in a range of diamagnetic sample fluids. Comparison of OFR-detected NMR spectra reveals a correlation between the relative signal amplitude and the fluid Verdet constant, which we interpret as a manifestation of the variable detuning between the probe beam and the sample optical transitions. The analysis of chemical-shift-resolved, optically detected spectra allows us to set constraints on the relative amplitudes of hyperfine coupling constants, both for protons at chemically distinct sites and other lower-gyromagnetic-ratio nuclei including carbon, fluorine, and phosphorous. By considering a model binary mixture we observe a complex dependence of the optical response on the relative concentration, suggesting that the present approach is sensitive to the solvent-solute dynamics in ways complementary to those known in inductive NMR. Extension of these experiments may find application in solvent suppression protocols, sensitivity-enhanced NMR of metalloproteins in solution, the investigation of solvent-solute interactions, or the characterization of molecular orbitals in diamagnetic systems. PMID:22100736

  1. Electronic states and optical properties of porphyrins in van der Waals contact: Th{sup IV} sandwich complexes

    SciTech Connect

    Bilsel, O.; Rodriguez, J.; Holten, D.

    1992-07-29

    Ground-state and time-resolved excited-state absorption spectra and fluorescence and phosphorescence spectra of three Th{sup IV} sandwich complexes, Th{sup IV}(TPP){sub 2}, Th{sup IV}(OEP){sub 2}, and Th{sup IV}(OEP)(TPP), are reported (OEP = 2,3,7,8,12,13,17,18-octaethylporphyrinate, TPP = 5,10,15,20-tetraphenylporphyrinate). These complexes, in which the nitrogen planes of the two porphyrin macrocycles are {approximately}2.9 {Angstrom} apart, exhibit a number of prominent optical characteristics: (1) monoporphyrin-like Q and B absorption bands, (2) a new absorption between the Q and B bands, (3) a weak, low-energy absorption that is substantially red-shifted relative to the Q bands of analogous monoporphyrin complexes, (4) fluorescence and phosphorescence emission bands that are even further red-shifted relative to typical emission bands from porphyrin monomers, and (5) a moderately intense near-infrared {sup 3}({pi},{pi}*) excited-state absorption not observed in monomeric porphyrins. These characteristic optical properties of the sandwich complexes are all accounted for by a relatively simple molecular orbital configuration-interaction model. Additionally, the spectral data and molecular orbital model identify the energies of charge-transfer configurations and delineate their contribution to the electronic states of these strongly-coupled {pi} systems. These results provide insights into the interactions that can take place between other pairs of chromophores brought within van der Waals contact, such as the bacteriochlorophyll dimer of the photosynthetic reaction center. 49 refs., 9 figs., 1 tab.

  2. Nonclassical states of the second optical harmonic in the presence of self-action

    NASA Technical Reports Server (NTRS)

    Chirkin, A. S.; Korolkova, N. V.

    1993-01-01

    The quantum theory of coherent radiation frequency doubling in crystals with quadratic and cubic optical nonlinearities is developed. The possibility of producing the quadrature-squeezed state of the second harmonic (SH) field is shown. The nonclassical SH states arise due to self-action effect.

  3. Extrinsic optical recombination in pentacene single crystals: Evidence of gap states

    NASA Astrophysics Data System (ADS)

    He, Rui; Chi, X.; Pinczuk, Aron; Lang, D. V.; Ramirez, A. P.

    2005-11-01

    Two luminescence bands observed in pentacene single crystals with different degrees of purity are identified as due to extrinsic optical emissions. A band at 1.49 eV remains in the crystal with the highest purity. Its redshift of about 0.3 eV from the free exciton optical recombination suggests that the extrinsic transitions could involve gap states recently discovered in pentacene transistors. Absence of resonance Raman scattering when photon energies overlap the extrinsic recombination suggests that the gap states are likely due to impurities. The temperature dependence of luminescence intensities is interpreted by activated decay of excitons to radiative and nonradiative states.

  4. Arbitrarily complete Bell-state measurement using only linear optical elements

    SciTech Connect

    Grice, W. P.

    2011-10-15

    A complete Bell-state measurement is not possible using only linear-optic elements, and most schemes achieve a success rate of no more than 50%, distinguishing, for example, two of the four Bell states but returning degenerate results for the other two. It is shown here that the introduction of a pair of ancillary entangled photons improves the success rate to 75%. More generally, the addition of 2{sup N}-2 ancillary photons yields a linear-optic Bell-state measurement with a success rate of 1-1/2{sup N}.

  5. All-optical generation of states for "Encoding a qubit in an oscillator".

    PubMed

    Vasconcelos, H M; Sanz, L; Glancy, S

    2010-10-01

    Most quantum computation schemes propose encoding qubits in two-level systems. Others exploit the use of an infinite-dimensional system. In "Encoding a qubit in an oscillator" [Phys. Rev. A 64, 012310 (2001)], Gottesman, Kitaev, and Preskill (GKP) combined these approaches when they proposed a fault-tolerant quantum computation scheme in which a qubit is encoded in the continuous position and momentum degrees of freedom of an oscillator. One advantage of this scheme is that it can be performed by use of relatively simple linear optical devices, squeezing, and homodyne detection. However, we lack a practical method to prepare the initial GKP states. Here we propose the generation of an approximate GKP state by using superpositions of optical coherent states (sometimes called "Schrödinger cat states"), squeezing, linear optical devices, and homodyne detection. PMID:20890353

  6. Possibility of triple magic trapping of clock and Rydberg states of divalent atoms in optical lattices

    NASA Astrophysics Data System (ADS)

    Topcu, T.; Derevianko, A.

    2016-07-01

    We predict the possibility of ‘triply magic’ optical lattice trapping of neutral divalent atoms. In such a lattice, the {}1{{{S}}}0 and {}3{{{P}}}0 clock states and an additional Rydberg state experience identical optical potentials, fully mitigating detrimental effects of the motional decoherence. In particular, we show that this triply magic trapping condition can be satisfied for Yb atom at optical wavelengths and for various other divalent systems (Ca, Mg, Hg and Sr) in the UV region. We assess the quality of triple magic trapping conditions by estimating the probability of excitation out of the motional ground state as a result of the excitations between the clock and the Rydberg states. We also calculate trapping laser-induced photoionization rates of divalent Rydberg atoms at magic frequencies. We find that such rates are below the radiative spontaneous-emission rates, due to the presence of Cooper minima in photoionization cross-sections.

  7. Effects of low-impact, moderate-intensity exercise training with and without wrist weights on functional capacities and mood states in older adults.

    PubMed

    Engels, H J; Drouin, J; Zhu, W; Kazmierski, J F

    1998-01-01

    This study examined the effects of low-impact, moderate-intensity exercise training with and without wrist weights (0.68 kg.wrist-1) on functional capacities and mood states in older adults (age 68.6 +/- 5.6, mean +/- SD). Twenty-three senior citizens residing in the community were randomly assigned to wrist weight (WW; n = 12) and no-wrist weight (NW; n = 11) exercise groups while 11 matched subjects served as non-exercise controls (NE). Exercise training was performed for 10 weeks, 3 days/week, for 60 min/session and consisted of low-impact aerobic dance (50-70% of maximal heart rate) combined with exercises to promote muscular fitness, flexibility, and balance. Before and after the intervention, each participant's aerobic fitness, muscular strength, flexibility, static and dynamic balance, skinfold thickness, and psychological mood states were assessed under standardized testing conditions. Exercise training resulted in significant improvements in peak oxygen uptake, lower extremity muscle strength, and psychological vigor (p < 0.05) but did not affect other fitness components (p > 0.05). There were no differences between the WW and NW exercise groups for any of the same variables studied (p > 0.05). No significant pre- to post-test changes were found for the NE control group (p > 0.05). It is concluded that 10 weeks of low-impact, moderate-intensity exercise training of the type that can be considered well-rounded in nature provides a sufficient stimulus to augment aerobic fitness, beneficially affects leg strength, and increases feelings of vigor in older adults. The present observations indicate that the use of light wrist weights has no beneficial or adverse effects on the measured training outcomes. PMID:9657086

  8. Optical properties of tetravalent uranium in the solid state

    SciTech Connect

    Edelstein, N.

    1987-04-01

    The optical spectra are fit to the parameters of a phenomenological Hamiltonian from which a calculated spectrum is obtained. The goodness of fit is determined by the value of sigma (cm/sup -1/), the rms deviation. The sigma and crystal field are tabulated for U/sup 4 +/ in various host crystals, Pr/sup 3 +/ or Nd/sup 3 +/ in various crystals, and the free ion U/sup 4 +/. The rms deviation sigma for the U/sup 4 +/ compounds is much worse on the average than for the Pr/Nd examples. There appears to be a correlation between a poor fit and a large sigma, and a large crystal field. 28 refs., 1 tab. (DLC)

  9. Effect of additional optical pumping injection into the ground-state ensemble on the gain and the phase recovery acceleration of quantum-dot semiconductor optical amplifiers

    NASA Astrophysics Data System (ADS)

    Kim, Jungho

    2014-02-01

    The effect of additional optical pumping injection into the ground-state ensemble on the ultrafast gain and the phase recovery dynamics of electrically-driven quantum-dot semiconductor optical amplifiers is numerically investigated by solving 1088 coupled rate equations. The ultrafast gain and the phase recovery responses are calculated with respect to the additional optical pumping power. Increasing the additional optical pumping power can significantly accelerate the ultrafast phase recovery, which cannot be done by increasing the injection current density.

  10. Optical Synthesis of Large-Amplitude Squeezed Coherent-State Superpositions with Minimal Resources.

    PubMed

    Huang, K; Le Jeannic, H; Ruaudel, J; Verma, V B; Shaw, M D; Marsili, F; Nam, S W; Wu, E; Zeng, H; Jeong, Y-C; Filip, R; Morin, O; Laurat, J

    2015-07-10

    We propose and experimentally realize a novel versatile protocol that allows the quantum state engineering of heralded optical coherent-state superpositions. This scheme relies on a two-mode squeezed state, linear mixing, and a n-photon detection. It is optimally using expensive non-Gaussian resources to build up only the key non-Gaussian part of the targeted state. In the experimental case of a two-photon detection based on high-efficiency superconducting nanowire single-photon detectors, the freely propagating state exhibits a 67% fidelity with a squeezed even coherent-state superposition with a size |α|(2)=3. The demonstrated procedure and the achieved rate will facilitate the use of such superpositions in subsequent protocols, including fundamental tests and optical hybrid quantum information implementations. PMID:26207468

  11. Quasi-optical solid-state power combining for millimeter-wave active seeker applications

    NASA Astrophysics Data System (ADS)

    Halladay, R. H.; Terrill, S. D.; Bowling, D. R.; Gagnon, D. R.

    1992-05-01

    Consideration is given to quasi-optical power combining techniques, state-of-the-art demonstrated performance, and system issues as they apply to endoatmospheric homing seeker insertion. Quasi-optical power combining is based on combining microwave and millimeter-wave solid-state device power in space through the use of antennas and lenses. It is concluded that quasi-optical power combining meets the severe electrical requirements and packaging constraints of active MMW seekers for endoatmospheric hit-to-kill missiles. The approach provides the possibility of wafer-scale integration of major components for low cost production and offers high reliability. Critical issues include thermal loading and system integration, which must be resolved before the quasi-optical power combining technology will be applied to an active MMW seeker.

  12. Quasi-optical solid-state power combining for millimeter-wave active seeker applications

    SciTech Connect

    Halladay, R.H.; Terrill, S.D.; Bowling, D.R.; Gagnon, D.R. U.S. Navy, Naval Air Warfare Center, China Lake, CA )

    1992-05-01

    Consideration is given to quasi-optical power combining techniques, state-of-the-art demonstrated performance, and system issues as they apply to endoatmospheric homing seeker insertion. Quasi-optical power combining is based on combining microwave and millimeter-wave solid-state device power in space through the use of antennas and lenses. It is concluded that quasi-optical power combining meets the severe electrical requirements and packaging constraints of active MMW seekers for endoatmospheric hit-to-kill missiles. The approach provides the possibility of wafer-scale integration of major components for low cost production and offers high reliability. Critical issues include thermal loading and system integration, which must be resolved before the quasi-optical power combining technology will be applied to an active MMW seeker. 18 refs.

  13. Role of photonic angular momentum states in nonreciprocal diffraction from magneto-optical cylinder arrays

    SciTech Connect

    Guo, Tian-Jing; Wu, Li-Ting; Yang, Mu; Guo, Rui-Peng; Cui, Hai-Xu; Chen, Jing

    2014-07-15

    Optical eigenstates in a concentrically symmetric resonator are photonic angular momentum states (PAMSs) with quantized optical orbital angular momentums (OAMs). Nonreciprocal optical phenomena can be obtained if we lift the degeneracy of PAMSs. In this article, we provide a comprehensive study of nonreciprocal optical diffraction of various orders from a magneto-optical cylinder array. We show that nonreciprocal diffraction can be obtained only for these nonzero orders. Role of PAMSs, the excitation of which is sensitive to the directions of incidence, applied magnetic field, and arrangement of the cylinders, are studied. Some interesting phenomena such as a dispersionless quasi-omnidirectional nonreciprocal diffraction and spikes associated with high-OAM PAMSs are present and discussed.

  14. An investigation of optical feedback to extend the frequency response of solid-state detector systems

    NASA Technical Reports Server (NTRS)

    Katzberg, S. J.

    1972-01-01

    A primary limitation of many solid-state photodetectors used in electro-optical systems such as the facsimile camera is their slow response in converting light intensities into electrical signals. An optical feedback technique is presented which can extend the frequency response of systems that use these detectors by orders of magnitude without significantly degrading their signal-to-noise performance. This technique is analyzed to predict improvement, implemented, and evaluated to verify analytical results.

  15. State reversals of optically induced tilt and torsional eye movements

    NASA Technical Reports Server (NTRS)

    Finke, R. A.; Held, R.

    1978-01-01

    Alternations of the state of apparent self-motion during observation of a large visual display rotating about the line of sight are associated with alternations in the magnitude of induced tilt and torsional eye rotation. In one experiment, shifts in visually induced tilt during these state alternations are found to be in the opposite direction to corresponding shifts in induced ocular torsion. In a second experiment, the reversals of self-motion perception are shown to be an intravisual phenomenon, independent of competing inputs provided by the vestibular system. These results emphasize the importance of distinguishing between visual and vestibular processes in tilt perception and ocular rotation during human orientation to gravitational vertical.

  16. State-of-the-art survey of multimode fiber optic wavelength division multiplexing

    NASA Technical Reports Server (NTRS)

    Spencer, J. L.

    1983-01-01

    Optical wavelength division multiplexing (WDM) systems, with signals transmitted on different wavelengths through a single fiber, can have increased information capacity and fault isolation properties over single wavelength optical systems. This paper describes a typical WDM system. Also, a state-of-the-art survey of optical multimode components which could be used to implement the system is made. The components to be surveyed are sources, multiplexers, and detectors. Emphasis is given to the demultiplexer techniques which are the major development components in the WDM system.

  17. The nature of the 2014-2015 dim state of RW Aurigae revealed by X-ray, optical, and near-IR observations

    NASA Astrophysics Data System (ADS)

    Schneider, P. C.; Günther, H. M.; Robrade, J.; Facchini, S.; Hodapp, K. W.; Manara, C. F.; Perdelwitz, V.; Schmitt, J. H. M. M.; Skinner, S.; Wolk, S. J.

    2015-12-01

    The binary system RW Aur consists of two classical T Tauri stars (CTTSs). The primary recently underwent its second observed major dimming event (ΔV ~ 2 mag). We present new, resolved Chandra X-ray and UKIRT near-IR (NIR) data as well as unresolved optical photometry obtained in the dim state to study the gas and dust content of the absorber causing the dimming. The X-ray data show that the absorbing column density increased from NH< 0.1 × 1022cm-2 during the bright state to ≈2 × 1022cm-2 in the dim state. The brightness ratio between dim and bright state at optical to NIR wavelengths shows only a moderate wavelength dependence and the NIR color-color diagram suggests no substantial reddening. Taken together, this indicates gray absorption by large grains (≳1 μm) with a dust mass column density of ≳2 × 10-4 g cm-2. Comparison with NH shows that an absorber responsible for the optical/NIR dimming and the X-ray absorption is compatible with the ISM's gas-to-dust ratio, i.e., that grains grow in the disk surface layers without largely altering the gas-to-dust ratio. Lastly, we discuss a scenario in which a common mechanism can explain the long-lasting dimming in RW Aur and recently in AA Tau. Appendix A is available in electronic form at http://www.aanda.org

  18. Optical control of nonlinearly dressed states in an individual quantum dot

    NASA Astrophysics Data System (ADS)

    Ardelt, P.-L.; Koller, M.; Simmet, T.; Hanschke, L.; Bechtold, A.; Regler, A.; Wierzbowski, J.; Riedl, H.; Finley, J. J.; Müller, K.

    2016-04-01

    We report nonlinear resonance fluorescence of an individual semiconductor quantum dot. By driving a single semiconductor quantum dot via a two-photon transition, we probe the linewidth of two-photon excitation processes and show that, similar to their single-photon counterparts, they are close to being Fourier limited at low temperatures. The evolution of the population of excitonic states with increasing Rabi energy exhibits a clear S-shaped behavior, indicative of the nonlinear response via the two-photon excitation process. Numerical calculations of the nonlinear response using a four-level atomic system representing the manifold of excitonic and biexcitonic states in the quantum dot are in excellent agreement with our experiments and reveal the effect of interactions with LA phonons in the solid-state environment. Finally, we demonstrate the formation of dressed states emerging from a nonlinear two-photon interaction between the quantum dot and the optical excitation field. The nonlinear optical dressing induces a mixing of all four excitonic states that allows direct optical tuning of the polarization selection rules and energies of the dressed states in the artificial atom. We expect our results to play a pivotal role for the generation of nonclassical photon pairs desired for applications in quantum communication and fundamental experiments on quantum optical properties of photons.

  19. Observation of Defect States in PT-Symmetric Optical Lattices

    NASA Astrophysics Data System (ADS)

    Regensburger, Alois; Miri, Mohammad-Ali; Bersch, Christoph; Näger, Jakob; Onishchukov, Georgy; Christodoulides, Demetrios N.; Peschel, Ulf

    2013-05-01

    We provide the first experimental demonstration of defect states in parity-time (PT) symmetric mesh-periodic potentials. Our results indicate that these localized modes can undergo an abrupt phase transition in spite of the fact that they remain localized in a PT-symmetric periodic environment. Even more intriguing is the possibility of observing a linearly growing radiation emission from such defects provided their eigenvalue is associated with an exceptional point that resides within the continuum part of the spectrum. Localized complex modes existing outside the band-gap regions are also reported along with their evolution dynamics.

  20. A State-of-the-Science Overview of Randomized Controlled Trials Evaluating Acute Management of Moderate-to-Severe Traumatic Brain Injury.

    PubMed

    Bragge, Peter; Synnot, Anneliese; Maas, Andrew I; Menon, David K; Cooper, D James; Rosenfeld, Jeffrey V; Gruen, Russell L

    2016-08-15

    Moderate-to-severe traumatic brain injury (TBI) remains a major global challenge, with rising incidence, unchanging mortality and lifelong impairments. State-of-the-science reviews are important for research planning and clinical decision support. This review aimed to identify randomized controlled trials (RCTs) evaluating interventions for acute management of moderate/severe TBI, synthesize key RCT characteristics and findings, and determine their implications on clinical practice and future research. RCTs were identified through comprehensive database and other searches. Key characteristics, outcomes, risk of bias, and analysis approach were extracted. Data were narratively synthesized, with a focus on robust (multi-center, low risk of bias, n > 100) RCTs, and three-dimensional graphical figures also were used to explore relationships between RCT characteristics and findings. A total of 207 RCTs were identified. The 191 completed RCTs enrolled 35,340 participants (median, 66). Most (72%) were single center and enrolled less than 100 participants (69%). There were 26 robust RCTs across 18 different interventions. For 74% of 392 comparisons across all included RCTs, there was no significant difference between groups. Positive findings were broadly distributed with respect to RCT characteristics. Less than one-third of RCTs demonstrated low risk of bias for random sequence generation or allocation concealment, less than one-quarter used covariate adjustment, and only 7% employed an ordinal analysis approach. Considerable investment of resources in producing 191 completed RCTs for acute TBI management has resulted in very little translatable evidence. This may result from broad distribution of research effort, small samples, preponderance of single-center RCTs, and methodological shortcomings. More sophisticated RCT design, large multi-center RCTs in priority areas, increased focus on pre-clinical research, and alternatives to RCTs, such as comparative

  1. Controlled production of subradiant states of a diatomic molecule in an optical lattice.

    PubMed

    Takasu, Yosuke; Saito, Yutaka; Takahashi, Yoshiro; Borkowski, Mateusz; Ciuryło, Roman; Julienne, Paul S

    2012-04-27

    We report the successful production of subradiant states of a two-atom system in a three-dimensional optical lattice starting from doubly occupied sites in a Mott insulator phase of a quantum gas of atomic ytterbium. We can selectively produce either a subradiant 1(g) state or a superradiant 0(u) state by choosing the excitation laser frequency. The inherent weak excitation rate for the subradiant 1(g) state is overcome by the increased atomic density due to the tight confinement in a three-dimensional optical lattice. Our experimental measurements of binding energies, linewidth, and Zeeman shift confirm the observation of subradiant levels of the 1(g) state of the Yb(2) molecule. PMID:22680859

  2. The local density of optical states of a metasurface

    PubMed Central

    Lunnemann, Per; Koenderink, A. Femius

    2016-01-01

    While metamaterials are often desirable for near-field functions, such as perfect lensing, or cloaking, they are often quantified by their response to plane waves from the far field. Here, we present a theoretical analysis of the local density of states near lattices of discrete magnetic scatterers, i.e., the response to near field excitation by a point source. Based on a pointdipole theory using Ewald summation and an array scanning method, we can swiftly and semi-analytically evaluate the local density of states (LDOS) for magnetoelectric point sources in front of an infinite two-dimensional (2D) lattice composed of arbitrary magnetoelectric dipole scatterers. The method takes into account radiation damping as well as all retarded electrodynamic interactions in a self-consistent manner. We show that a lattice of magnetic scatterers evidences characteristic Drexhage oscillations. However, the oscillations are phase shifted relative to the electrically scattering lattice consistent with the difference expected for reflection off homogeneous magnetic respectively electric mirrors. Furthermore, we identify in which source-surface separation regimes the metasurface may be treated as a homogeneous interface, and in which homogenization fails. A strong frequency and in-plane position dependence of the LDOS close to the lattice reveals coupling to guided modes supported by the lattice. PMID:26868601

  3. Optical Characterization of Deep-Space Object Rotation States

    NASA Astrophysics Data System (ADS)

    Hall, D.; Kervin, P.

    2014-09-01

    Analysis of time-series data can yield remarkably accurate estimates of the frequency of a satellites brightness modulations. These apparent or synodic frequencies can vary in time, differing from the actual rotation rate of the object by an amount that depends on the relative angular motion between the satellite, illuminator, and observer for reflected light measurements (or between the satellite and observer for thermal emission measurements). When detected with sufficient accuracy, such synodic frequency variations can be exploited to characterize an objects rotation state, using an analysis that does not require any a priori knowledge of the objects shape. For instance, this shape-independent analysis method can be used to derive spin-axis orientations and sidereal rotation rates for spinning objects. Remotely determining such rotation parameters can be useful in many circumstances, such as when performing anomaly resolution of satellites that have lost stabilization. Unfortunately, synodic variations cannot be detected by ground-based observers for many deep-space objects due to low rates of relative angular motion. This is especially true for objects in geosynchronous orbit. In these cases, deriving spin-axis orientations can be accomplished using a shape-dependent method that employs a model of the shape and reflectance characteristics of the object. Our analysis indicates that a simple cylinder model can often suffice to characterize rotation states for upper-stage rocket bodies.

  4. The local density of optical states of a metasurface.

    PubMed

    Lunnemann, Per; Koenderink, A Femius

    2016-01-01

    While metamaterials are often desirable for near-field functions, such as perfect lensing, or cloaking, they are often quantified by their response to plane waves from the far field. Here, we present a theoretical analysis of the local density of states near lattices of discrete magnetic scatterers, i.e., the response to near field excitation by a point source. Based on a pointdipole theory using Ewald summation and an array scanning method, we can swiftly and semi-analytically evaluate the local density of states (LDOS) for magnetoelectric point sources in front of an infinite two-dimensional (2D) lattice composed of arbitrary magnetoelectric dipole scatterers. The method takes into account radiation damping as well as all retarded electrodynamic interactions in a self-consistent manner. We show that a lattice of magnetic scatterers evidences characteristic Drexhage oscillations. However, the oscillations are phase shifted relative to the electrically scattering lattice consistent with the difference expected for reflection off homogeneous magnetic respectively electric mirrors. Furthermore, we identify in which source-surface separation regimes the metasurface may be treated as a homogeneous interface, and in which homogenization fails. A strong frequency and in-plane position dependence of the LDOS close to the lattice reveals coupling to guided modes supported by the lattice. PMID:26868601

  5. The local density of optical states of a metasurface

    NASA Astrophysics Data System (ADS)

    Lunnemann, Per; Koenderink, A. Femius

    2016-02-01

    While metamaterials are often desirable for near-field functions, such as perfect lensing, or cloaking, they are often quantified by their response to plane waves from the far field. Here, we present a theoretical analysis of the local density of states near lattices of discrete magnetic scatterers, i.e., the response to near field excitation by a point source. Based on a pointdipole theory using Ewald summation and an array scanning method, we can swiftly and semi-analytically evaluate the local density of states (LDOS) for magnetoelectric point sources in front of an infinite two-dimensional (2D) lattice composed of arbitrary magnetoelectric dipole scatterers. The method takes into account radiation damping as well as all retarded electrodynamic interactions in a self-consistent manner. We show that a lattice of magnetic scatterers evidences characteristic Drexhage oscillations. However, the oscillations are phase shifted relative to the electrically scattering lattice consistent with the difference expected for reflection off homogeneous magnetic respectively electric mirrors. Furthermore, we identify in which source-surface separation regimes the metasurface may be treated as a homogeneous interface, and in which homogenization fails. A strong frequency and in-plane position dependence of the LDOS close to the lattice reveals coupling to guided modes supported by the lattice.

  6. Resource-efficient generation of linear cluster states by linear optics with postselection

    DOE PAGESBeta

    Uskov, D. B.; Alsing, P. M.; Fanto, M. L.; Kaplan, L.; Kim, R.; Szep, A.; Smith, A. M.

    2015-01-30

    Here we report on theoretical research in photonic cluster-state computing. Finding optimal schemes of generating non-classical photonic states is of critical importance for this field as physically implementable photon-photon entangling operations are currently limited to measurement-assisted stochastic transformations. A critical parameter for assessing the efficiency of such transformations is the success probability of a desired measurement outcome. At present there are several experimental groups that are capable of generating multi-photon cluster states carrying more than eight qubits. Separate photonic qubits or small clusters can be fused into a single cluster state by a probabilistic optical CZ gate conditioned on simultaneousmore » detection of all photons with 1/9 success probability for each gate. This design mechanically follows the original theoretical scheme of cluster state generation proposed more than a decade ago by Raussendorf, Browne, and Briegel. The optimality of the destructive CZ gate in application to linear optical cluster state generation has not been analyzed previously. Our results reveal that this method is far from the optimal one. Employing numerical optimization we have identified that the maximal success probability of fusing n unentangled dual-rail optical qubits into a linear cluster state is equal to 1/2n-1; an m-tuple of photonic Bell pair states, commonly generated via spontaneous parametric down-conversion, can be fused into a single cluster with the maximal success probability of 1/4m-1.« less

  7. Resource-efficient generation of linear cluster states by linear optics with postselection

    SciTech Connect

    Uskov, D. B.; Alsing, P. M.; Fanto, M. L.; Kaplan, L.; Kim, R.; Szep, A.; Smith, A. M.

    2015-01-30

    Here we report on theoretical research in photonic cluster-state computing. Finding optimal schemes of generating non-classical photonic states is of critical importance for this field as physically implementable photon-photon entangling operations are currently limited to measurement-assisted stochastic transformations. A critical parameter for assessing the efficiency of such transformations is the success probability of a desired measurement outcome. At present there are several experimental groups that are capable of generating multi-photon cluster states carrying more than eight qubits. Separate photonic qubits or small clusters can be fused into a single cluster state by a probabilistic optical CZ gate conditioned on simultaneous detection of all photons with 1/9 success probability for each gate. This design mechanically follows the original theoretical scheme of cluster state generation proposed more than a decade ago by Raussendorf, Browne, and Briegel. The optimality of the destructive CZ gate in application to linear optical cluster state generation has not been analyzed previously. Our results reveal that this method is far from the optimal one. Employing numerical optimization we have identified that the maximal success probability of fusing n unentangled dual-rail optical qubits into a linear cluster state is equal to 1/2n-1; an m-tuple of photonic Bell pair states, commonly generated via spontaneous parametric down-conversion, can be fused into a single cluster with the maximal success probability of 1/4m-1.

  8. Resource-Efficient Generataion of Linear Cluster States by Linear Optics with postselection

    DOE PAGESBeta

    Uskov, Dmitry B; Alsing, Paul; Fanto, Michael; Kaplan, Lev; Kim, R; Szep, Atilla; Smith IV, Amos M

    2015-01-01

    We report on theoretical research in photonic cluster-state computing. Finding optimal schemes of generating non-classical photonic states is of critical importance for this field as physically implementable photon-photon entangling operations are currently limited to measurement-assisted stochastic transformations. A critical parameter for assessing the efficiency of such transformations is the success probability of a desired measurement outcome. At present there are several experimental groups that are capable of generating multi-photon cluster states carrying more than eight qubits. Separate photonic qubits or small clusters can be fused into a single cluster state by a probabilistic optical CZ gate conditioned on simultaneous detectionmore » of all photons with 1/9 success probability for each gate. This design mechanically follows the original theoretical scheme of cluster state generation proposed more than a decade ago by Raussendorf, Browne, and Briegel. The optimality of the destructive CZ gate in application to linear optical cluster state generation has not been analyzed previously. Our results reveal that this method is far from the optimal one. Employing numerical optimization we have identified that the maximal success probability of fusing n unentangled dual-rail optical qubits into a linear cluster state is equal to 1/2^n-1; an m-tuple of photonic Bell pair states, commonly generated via spontaneous parametric down-conversion, can be fused into a single cluster with the maximal success probability of 1/4^m-1.« less

  9. Identifying topological edge states in 2D optical lattices using light scattering

    NASA Astrophysics Data System (ADS)

    Goldman, Nathan; Beugnon, Jérôme; Gerbier, Fabrice

    2013-02-01

    We recently proposed in a Letter [Phys. Rev. Lett. 108, 255303] a novel scheme to detect topological edge states in an optical lattice, based on a generalization of Bragg spectroscopy. The scope of the present article is to provide a more detailed and pedagogical description of the system - the Hofstadter optical lattice - and probing method. We first show the existence of topological edge states, in an ultra-cold gas trapped in a 2D optical lattice and subjected to a synthetic magnetic field. The remarkable robustness of the edge states is verified for a variety of external confining potentials. Then, we describe a specific laser probe, made from two lasers in Laguerre-Gaussian modes, which captures unambiguous signatures of these edge states. In particular, the resulting Bragg spectra provide the dispersion relation of the edge states, establishing their chiral nature. In order to make the Bragg signal experimentally detectable, we introduce a "shelving method", which simultaneously transfers angular momentum and changes the internal atomic state. This scheme allows to directly visualize the selected edge states on a dark background, offering an instructive view on topological insulating phases, not accessible in solid-state experiments.

  10. State estimation Kalman filter using optical processings Noise statistics known

    NASA Technical Reports Server (NTRS)

    Jackson, J.; Casasent, D.

    1984-01-01

    Reference is made to a study by Casasent et al. (1983), which gave a description of a frequency-multiplexed acoustooptic processor and showed how it was capable of performing all the individual operations required in Kalman filtering. The data flow and organization of all required operations however, were not detailed in that study. Consideration is given here to a simpler Kalman filter state estimation problem. Equally spaced time-sampled intervals (k times T sub s, with k the iterative time index) are assumed. It is further assumed that the system noise vector w and the measurement noise vector v are uncorrelated and Gaussian distributed and that the noise statistics (Q and R) and the system model (Phi, Gamma, H) are known. The error covariance matrix P and the extrapolated error covariance matrix M can thus be precomputed and the Kalman gain matrix K sub k can be precomputed and stored for each input time sample.

  11. Multipass diode-pumped solid-state optical amplifier

    NASA Technical Reports Server (NTRS)

    Plaessmann, Henry; Re, Sean A.; Alonis, Joseph J.; Vecht, David L.; Grossman, William M.

    1993-01-01

    A new diode-pumped solid-state multipass amplifier produced 38-dB small-signal gain at 1.047 micron in Nd:YLF with 1.6-W pump power and 37 percent extraction efficiency near saturation. The amplifier had a 1:1 confocally reimaging multipass design that generated both high gain and high efficiency. The same amplifier design with 13 W of pump power was tested with Nd:YAG at 1.064 micron, which gave 38-dB small-signal gain and 3.2 W of output power, and with Nd:YVO4, also at 1.064 micron, which gave greater than 50-dB small-signal gain and 4.3 W of output power.

  12. Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

    PubMed Central

    Morin, Olivier; Liu, Jianli; Huang, Kun; Barbosa, Felippe; Fabre, Claude; Laurat, Julien

    2014-01-01

    Engineering non-classical states of the electromagnetic field is a central quest for quantum optics1,2. Beyond their fundamental significance, such states are indeed the resources for implementing various protocols, ranging from enhanced metrology to quantum communication and computing. A variety of devices can be used to generate non-classical states, such as single emitters, light-matter interfaces or non-linear systems3. We focus here on the use of a continuous-wave optical parametric oscillator3,4. This system is based on a non-linear χ2 crystal inserted inside an optical cavity and it is now well-known as a very efficient source of non-classical light, such as single-mode or two-mode squeezed vacuum depending on the crystal phase matching. Squeezed vacuum is a Gaussian state as its quadrature distributions follow a Gaussian statistics. However, it has been shown that number of protocols require non-Gaussian states5. Generating directly such states is a difficult task and would require strong χ3 non-linearities. Another procedure, probabilistic but heralded, consists in using a measurement-induced non-linearity via a conditional preparation technique operated on Gaussian states. Here, we detail this generation protocol for two non-Gaussian states, the single-photon state and a superposition of coherent states, using two differently phase-matched parametric oscillators as primary resources. This technique enables achievement of a high fidelity with the targeted state and generation of the state in a well-controlled spatiotemporal mode. PMID:24961685

  13. Chromophore Deprotonation State Alters the Optical Properties of Blue Chromoprotein

    PubMed Central

    Chiang, Cheng-Yi; Lee, Cheng-Chung; Lo, Shin-Yi; Wang, Andrew H.-J.; Tsai, Huai-Jen

    2015-01-01

    Chromoproteins (CPs) have unique colors and can be used in biological applications. In this work, a novel blue CP with a maximum absorption peak (λmax) at 608 nm was identified from the carpet anemone Stichodactyla gigantea (sgBP). In vivo expression of sgBP in zebrafish would change the appearance of the fishes to have a blue color, indicating the potential biomarker function. To enhance the color properties, the crystal structure of sgBP at 2.25 Å resolution was determined to allow structure-based protein engineering. Among the mutations conducted in the Gln-Tyr-Gly chromophore and chromophore environment, a S157C mutation shifted the λmax to 604 nm with an extinction coefficient (ε) of 58,029 M-1·cm-1 and darkened the blue color expression. The S157C mutation in the sgBP chromophore environment could affect the color expression by altering the deprotonation state of the phenolic group in the chromophore. Our results provide a structural basis for the blue color enhancement of the biomarker development. PMID:26218063

  14. Chromophore Deprotonation State Alters the Optical Properties of Blue Chromoprotein.

    PubMed

    Chiang, Cheng-Yi; Lee, Cheng-Chung; Lo, Shin-Yi; Wang, Andrew H-J; Tsai, Huai-Jen

    2015-01-01

    Chromoproteins (CPs) have unique colors and can be used in biological applications. In this work, a novel blue CP with a maximum absorption peak (λmax) at 608 nm was identified from the carpet anemone Stichodactyla gigantea (sgBP). In vivo expression of sgBP in zebrafish would change the appearance of the fishes to have a blue color, indicating the potential biomarker function. To enhance the color properties, the crystal structure of sgBP at 2.25 Å resolution was determined to allow structure-based protein engineering. Among the mutations conducted in the Gln-Tyr-Gly chromophore and chromophore environment, a S157C mutation shifted the λmax to 604 nm with an extinction coefficient (ε) of 58,029 M-1·cm-1 and darkened the blue color expression. The S157C mutation in the sgBP chromophore environment could affect the color expression by altering the deprotonation state of the phenolic group in the chromophore. Our results provide a structural basis for the blue color enhancement of the biomarker development. PMID:26218063

  15. Quantum ground state of self-organized atomic crystals in optical resonators

    SciTech Connect

    Fernandez-Vidal, Sonia; De Chiara, Gabriele; Larson, Jonas; Morigi, Giovanna

    2010-04-15

    Cold atoms, driven by a laser and simultaneously coupled to the quantum field of an optical resonator, may self-organize in periodic structures. These structures are supported by the optical lattice, which emerges from the laser light they scatter into the cavity mode and form when the laser intensity exceeds a threshold value. We study theoretically the quantum ground state of these structures above the pump threshold of self-organization by mapping the atomic dynamics of the self-organized crystal to a Bose-Hubbard model. We find that the quantum ground state of the self-organized structure can be the one of a Mott insulator, depending on the pump strength of the driving laser. For very large pump strengths, where the intracavity-field intensity is maximum and one would expect a Mott-insulator state, we find intervals of parameters where the phase is compressible. These states could be realized in existing experimental setups.

  16. Robust Light State by Quantum Phase Transition in Non-Hermitian Optical Materials

    NASA Astrophysics Data System (ADS)

    Zhao, Han; Longhi, Stefano; Feng, Liang

    2015-11-01

    Robust light transport is the heart of optical information processing, leading to the search for robust light states by topological engineering of material properties. Here, it is shown that quantum phase transition, rather than topology, can be strategically exploited to design a novel robust light state. We consider an interface between parity-time (PT) symmetric media with different quantum phases and use complex Berry phase to reveal the associated quantum phase transition and topological nature. While the system possesses the same topological order within different quantum phases, phase transition from PT symmetry to PT breaking across the interface in the synthetic non-Hermitian metamaterial system facilitates novel interface states, which are robust against a variety of gain/loss perturbations and topological impurities and disorder. The discovery of the robust light state by quantum phase transition may promise fault-tolerant light transport in optical communications and computing.

  17. Analysis of All-Optical State Generator for ``Encoding a Qubit in an Oscillator''

    NASA Astrophysics Data System (ADS)

    Policarpo, S. C.; Vasconcelos, H. M.

    2016-06-01

    The fault-tolerant quantum computation scheme proposed by Gottesman (Phys. Rev. A 64, 012310 (2001)) can be performed using relatively simple linear optical resources and provides a natural protection against arbitrary small errors. On the other hand, preparing the initial GKP states is a difficult task. A few proposals to generate GKP states have been done over the last years. Our objective here is to analyze the performance of a particular GKP generator that uses cat states, linear optical devices, squeezing, and homodyne detection. We use numerical simulations to study the behavior of the fidelity between the generated and the ideal states and show that the proposal in consideration is indeed a promising scheme.

  18. Analysis of All-Optical State Generator for "Encoding a Qubit in an Oscillator"

    NASA Astrophysics Data System (ADS)

    Policarpo, S. C.; Vasconcelos, H. M.

    2016-06-01

    The fault-tolerant quantum computation scheme proposed by Gottesman (Phys. Rev. A 64, 012310 (2001)) can be performed using relatively simple linear optical resources and provides a natural protection against arbitrary small errors. On the other hand, preparing the initial GKP states is a difficult task. A few proposals to generate GKP states have been done over the last years. Our objective here is to analyze the performance of a particular GKP generator that uses cat states, linear optical devices, squeezing, and homodyne detection. We use numerical simulations to study the behavior of the fidelity between the generated and the ideal states and show that the proposal in consideration is indeed a promising scheme.

  19. Analysis of All-Optical State Generator for "Encoding a Qubit in an Oscillator"

    NASA Astrophysics Data System (ADS)

    Policarpo, S. C.; Vasconcelos, H. M.

    2016-03-01

    The fault-tolerant quantum computation scheme proposed by Gottesman (Phys. Rev. A 64, 012310 (2001)) can be performed using relatively simple linear optical resources and provides a natural protection against arbitrary small errors. On the other hand, preparing the initial GKP states is a difficult task. A few proposals to generate GKP states have been done over the last years. Our objective here is to analyze the performance of a particular GKP generator that uses cat states, linear optical devices, squeezing, and homodyne detection. We use numerical simulations to study the behavior of the fidelity between the generated and the ideal states and show that the proposal in consideration is indeed a promising scheme.

  20. Robust Light State by Quantum Phase Transition in Non-Hermitian Optical Materials

    PubMed Central

    Zhao, Han; Longhi, Stefano; Feng, Liang

    2015-01-01

    Robust light transport is the heart of optical information processing, leading to the search for robust light states by topological engineering of material properties. Here, it is shown that quantum phase transition, rather than topology, can be strategically exploited to design a novel robust light state. We consider an interface between parity-time (PT) symmetric media with different quantum phases and use complex Berry phase to reveal the associated quantum phase transition and topological nature. While the system possesses the same topological order within different quantum phases, phase transition from PT symmetry to PT breaking across the interface in the synthetic non-Hermitian metamaterial system facilitates novel interface states, which are robust against a variety of gain/loss perturbations and topological impurities and disorder. The discovery of the robust light state by quantum phase transition may promise fault-tolerant light transport in optical communications and computing. PMID:26592765

  1. Optically thick cascade to the O I 3s 3S state in the Earth's thermosphere

    NASA Technical Reports Server (NTRS)

    Cotton, Daniel M.; Chakrabarti, Supriya; Gladstone, G. Randall

    1993-01-01

    The electron impact excitation cross section for the O I (1304 A) emission is enhanced in the terrestrial thermosphere owing to an optically thick cascade mechanism. Values for the contribution of the cascade have been calculated and deduced from measured 1304-A airglow emissions to between o and 200%. We have developed a model to calculate a large portion of the optically thick cascade contribution, including contributions from the radiative entrapment of the O I (1040, 1027, and 989 A) lines. High-resolution spectroscopic data from a sounding rocket experiment are analyzed using this model. The optically thick cascade contribution for the three lower lying states was evaluated to be 24.5% and compares well with recent calculations. The data, however, support a total contribution of 40%. The 15.5% difference is likely due to the contribution from higher Rydberg states.

  2. Pulse-mode quantum projection synthesis: Effects of mode mismatch on optical state truncation and preparation

    SciTech Connect

    Oezdemir, Sahin Kaya; Koashi, Masato; Miranowicz, Adam; Imoto, Nobuyuki

    2002-11-01

    Quantum projection synthesis can be used for phase-probability-distribution measurement and optical-state truncation and preparation. The method relies on interfering optical light beams, which is a major challenge in experiments performed by pulsed light sources. In the pulsed regime, the time frequency overlap of the interfering light beams has a major impact on the efficiency of the method. In this paper, the pulse-mode projection-synthesis approach is developed, the mode structures of interfering light beams are characterized, and the effect of this overlap on the fidelity of optical-state truncation and preparation is investigated. By introducing the positive-operator-valued measure for the detection events in the scheme, the effect of mode mismatch between the photon-counting detectors and the incident light beams is also presented.

  3. Generation of Symmetric Dicke States of Remote Qubits with Linear Optics

    SciTech Connect

    Thiel, C.; Zanthier, J. von; Bastin, T.; Solano, E.; Agarwal, G. S.

    2007-11-09

    We propose a method for generating all symmetric Dicke states, either in the long-lived internal levels of N massive particles or in the polarization degrees of freedom of photonic qubits, using linear optical tools only. By means of a suitable multiphoton detection technique, erasing Welcher-Weg information, our proposed scheme allows the generation and measurement of an important class of entangled multiqubit states.

  4. 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.

  5. Quantum teleportation of an arbitrary two-mode coherent state using only linear optics elements

    NASA Astrophysics Data System (ADS)

    Phien, Ho Ngoc; An, Nguyen Ba

    2008-04-01

    We propose a linear optics scheme to teleport an arbitrary two-mode coherent state. The devices used are beam-splitters, phase-shifters and ideal photo-detectors capable of distinguishing between even and odd photon numbers. The scheme achieves faithful teleportation with a probability of 1/4. However, with additional use of an appropriate displacement operator, the teleported state can always be made near-faithful.

  6. Generating single-photon catalyzed coherent states with quantum-optical catalysis

    NASA Astrophysics Data System (ADS)

    Xu, Xue-xiang; Yuan, Hong-chun

    2016-07-01

    We theoretically generate single-photon catalyzed coherent states (SPCCSs) by means of quantum-optical catalysis based on the beam splitter (BS) or the parametric amplifier (PA). These states are obtained in one of the BS (or PA) output channels if a coherent state and a single-photon Fock state are present in two input ports and a single photon is registered in the other output port. The success probabilities of the detection (also the normalization factors) are discussed, which is different for BS and PA catalysis. In addition, we prove that the generated states catalyzed by BS and PA devices are actually the same quantum states after analyzing photon number distribution of the SPCCSs. The quantum properties of the SPCCSs, such as sub-Poissonian distribution, anti-bunching effect, quadrature squeezing effect, and the negativity of the Wigner function are investigated in detail. The results show that the SPCCSs are non-Gaussian states with an abundance of nonclassicality.

  7. All-optical formation of coherent dark states of silicon-vacancy spins in diamond.

    PubMed

    Pingault, Benjamin; Becker, Jonas N; Schulte, Carsten H H; Arend, Carsten; Hepp, Christian; Godde, Tillmann; Tartakovskii, Alexander I; Markham, Matthew; Becher, Christoph; Atatüre, Mete

    2014-12-31

    Spin impurities in diamond can be versatile tools for a wide range of solid-state-based quantum technologies, but finding spin impurities that offer sufficient quality in both photonic and spin properties remains a challenge for this pursuit. The silicon-vacancy center has recently attracted much interest because of its spin-accessible optical transitions and the quality of its optical spectrum. Complementing these properties, spin coherence is essential for the suitability of this center as a spin-photon quantum interface. Here, we report all-optical generation of coherent superpositions of spin states in the ground state of a negatively charged silicon-vacancy center using coherent population trapping. Our measurements reveal a characteristic spin coherence time, T2*, exceeding 45 nanoseconds at 4 K. We further investigate the role of phonon-mediated coupling between orbital states as a source of irreversible decoherence. Our results indicate the feasibility of all-optical coherent control of silicon-vacancy spins using ultrafast laser pulses. PMID:25615329

  8. Projective measurement of the two-photon polarization state: Linear optics approach

    SciTech Connect

    Grudka, Andrzej; Wojcik, Antoni

    2002-12-01

    We present a method of implementation of general projective measurement of the two-photon polarization state with the use of linear optics elements only. The scheme presented succeeds with a probability of at least 1/16. For some specific measurements (e.g., parity measurement) this probability reaches 1/4.

  9. Multiplexing free-space optical signals using superimposed collinear orbital angular momentum states

    NASA Astrophysics Data System (ADS)

    Lin, J.; Yuan, X.-C.; Tao, S. H.; Burge, R. E.

    2007-07-01

    As a proof of concept, we experimentally demonstrate multiplexing of free-space optical signals in multiple channels labeled with different states of orbital angular momentum. The multiplexing process is carried out by a dynamic liquid-crystal spatial light modulator, while the phase function is calculated by an iterative algorithm. A binary amplitude computer-generated hologram serves as a demultiplexer.

  10. Driven-dissipative many-body pairing states for cold fermionic atoms in an optical lattice

    NASA Astrophysics Data System (ADS)

    Yi, W.; Diehl, S.; Daley, A. J.; Zoller, P.

    2012-05-01

    We discuss the preparation of many-body states of cold fermionic atoms in an optical lattice via controlled dissipative processes induced by coupling the system to a reservoir. Based on a mechanism combining Pauli blocking and phase locking between adjacent sites, we construct complete sets of jump operators describing coupling to a reservoir that leads to dissipative preparation of pairing states for fermions with various symmetries in the absence of direct inter-particle interactions. We discuss the uniqueness of these states, and demonstrate it with small-scale numerical simulations. In the late-time dissipative dynamics, we identify a ‘dissipative gap’ that persists in the thermodynamic limit. This gap implies exponential convergence of all many-body observables to their steady-state values. We then investigate how these pairing states can be used as a starting point for the preparation of the ground state of the Fermi-Hubbard Hamiltonian via an adiabatic state preparation process also involving the parent Hamiltonian of the pairing state. We also provide a proof-of-principle example for implementing these dissipative processes and the parent Hamiltonians of the pairing states, based on 171Yb atoms in optical lattice potentials.

  11. Proton-detected solid-state NMR spectroscopy of fully protonated proteins at slow to moderate magic-angle spinning frequencies

    NASA Astrophysics Data System (ADS)

    Mote, Kaustubh R.; Madhu, Perunthiruthy K.

    2015-12-01

    1H -detection offers a substitute to the sensitivity-starved experiments often used to characterize biomolecular samples using magic-angle spinning solid-state NMR spectroscopy (MAS-ssNMR). To mitigate the effects of the strong 1H -1H dipolar coupled network that would otherwise severely broaden resonances, high MAS frequencies (>40 kHz) are often employed. Here, we have explored the alternative of stroboscopic 1H -detection at moderate MAS frequencies of 5-30 kHz using windowed version of supercycled-phase-modulated Lee-Goldburg homonuclear decoupling. We show that improved resolution in the 1H dimension, comparable to that obtainable at high spinning frequencies of 40-60 kHz without homonuclear decoupling, can be obtained in these experiments for fully protonated proteins. Along with detailed analysis of the performance of the method on the standard tri-peptide f-MLF, experiments on micro-crystalline GB1 and amyloid- β aggregates are used to demonstrate the applicability of these pulse-sequences to challenging biomolecular systems. With only two parameters to optimize, broadbanded performance of the homonuclear decoupling sequence, linear dependence of the chemical-shift scaling factor on resonance offset and a straightforward implementation under experimental conditions currently used for many biomolecular studies (viz. spinning frequencies and radio-frequency amplitudes), we expect these experiments to complement the current 13C -detection based methods in assignments and characterization through chemical-shift mapping.

  12. Ground-state magneto-optical resonances in cesium vapor confined in an extremely thin cell

    NASA Astrophysics Data System (ADS)

    Andreeva, C.; Atvars, A.; Auzinsh, M.; Blush, K.; Cartaleva, S.; Petrov, L.; Slavov, D.

    2007-12-01

    Experimental and theoretical studies are presented related to the ground-state magneto-optical resonance observed in cesium vapor confined in an extremely thin cell (ETC), with thickness equal to the wavelength of the irradiating light. It is shown that utilization of the ETC allows one to examine the formation of a magneto-optical resonance on the individual hyperfine transitions, thus distinguishing processes resulting in dark (reduced absorption) or bright (enhanced absorption) resonance formation. We report experimental evidence of bright magneto-optical resonance sign reversal in Cs atoms confined in an ETC. A theoretical model is proposed based on the optical Bloch equations that involves the elastic interaction processes of atoms in the ETC with its walls, resulting in depolarization of the Cs excited state, which is polarized by the exciting radiation. This depolarization leads to the sign reversal of the bright resonance. Using the proposed model, the magneto-optical resonance amplitude and width as a function of laser power are calculated and compared with the experimental ones. The numerical results are in good agreement with those of experiment.

  13. Brief state-of-the-art review on optical communications for the NASA ISES workshop

    NASA Technical Reports Server (NTRS)

    Hendricks, Herbert D.

    1990-01-01

    The current state of the art of optical communications is briefly reviewed. This review covers NASA programs, DOD and other government agency programs, commercial aerospace programs, and foreign programs. Included is a brief summary of a recent NASA workshop on optical communications. The basic conclusions from all the program reviews is that optical communications is a technology ready to be accepted but needed to be demonstrated. Probably the most advanced and sophisticated optical communications system is the Laser Intersatellite Transmission Experiment (LITE) system developed for flight on the Advanced Communications Technology Satellite (ACTS). Optical communications technology is available for the applications of data communications at data rates in the under 300 MBits/sec for nearly all applications under 2 times GEO distances. Applications for low-earth orbiter (LEO) to ground will allow data rates in the multi-GBits/sec range. Higher data rates are limited by currently available laser power. Phased array lasers offer technology which should eliminate this problem. The major problem of cloud coverage can probably be eliminated by look ahead pointing, multiple ground stations, and knowledge of weather conditions to control the pointing. Most certainly, optical communications offer a new spectral region to relieve the RF bands and very high data communications rates that will be required in less than 10 years to solve the communications problems on Earth.

  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. Mixing nonclassical pure states in a linear-optical network almost always generates modal entanglement

    NASA Astrophysics Data System (ADS)

    Jiang, Zhang; Lang, Mattihas; Caves, Carlton; CenterQuantum Information and Control Collaboration

    2014-03-01

    In quantum optics a pure state is considered classical, relative to the statistics of photodetection, if and only if it is a coherent state. A different and newer notion of nonclassicality is based on modal entanglement. One example that relates these two notions is the Hong-Ou-Mandel effect, where modal entanglement is generated by a beamsplitter from the nonclassical photon-number state | 1 > ⊗ | 1 > . This suggests the beamsplitter or, more generally, linear-optical networks as a mediator of the two notions of nonclassicality. We show the following: Given a nonclassical pure product state input to an N-port linear-optical network, the output is almost always mode entangled; the only exception is a product of squeezed states, all with the same squeezing strength, input to a network that does not mix the squeezed and anti-squeezed quadratures. Our work thus gives a necessary and sufficient condition for a linear network to generate modal entanglement from pure product inputs, a result that is of immediate relevance to the boson sampling problem.

  16. Mixing nonclassical pure states in a linear-optical network almost always generates modal entanglement

    NASA Astrophysics Data System (ADS)

    Jiang, Zhang; Lang, Matthias D.; Caves, Carlton M.

    2013-10-01

    In quantum optics a pure state is considered classical, relative to the statistics of photodetection, if and only if it is a coherent state. A different and newer notion of nonclassicality is based on modal entanglement. One example that relates these two notions is the Hong-Ou-Mandel effect, where modal entanglement is generated by a beamsplitter from the nonclassical photon-number state |1>⊗|1>. This suggests that beamsplitters or, more generally, linear-optical networks are mediators of the two notions of nonclassicality. In this Brief Report, we show the following: Given a nonclassical pure-product-state input to an N-port linear-optical network, the output is almost always mode entangled; the only exception is a product of squeezed states, all with the same squeezing strength, input to a network that does not mix the squeezed and antisqueezed quadratures. Our work thus gives a necessary and sufficient condition for a linear network to generate modal entanglement from pure-product inputs, a result that is of immediate relevance to the boson-sampling problem.

  17. Controlling the volatility of the written optical state in electrochromic DNA liquid crystals

    NASA Astrophysics Data System (ADS)

    Liu, Kai; Varghese, Justin; Gerasimov, Jennifer Y.; Polyakov, Alexey O.; Shuai, Min; Su, Juanjuan; Chen, Dong; Zajaczkowski, Wojciech; Marcozzi, Alessio; Pisula, Wojciech; Noheda, Beatriz; Palstra, Thomas T. M.; Clark, Noel A.; Herrmann, Andreas

    2016-05-01

    Liquid crystals are widely used in displays for portable electronic information display. To broaden their scope for other applications like smart windows and tags, new material properties such as polarizer-free operation and tunable memory of a written state become important. Here, we describe an anhydrous nanoDNA-surfactant thermotropic liquid crystal system, which exhibits distinctive electrically controlled optical absorption, and temperature-dependent memory. In the liquid crystal isotropic phase, electric field-induced colouration and bleaching have a switching time of seconds. Upon transition to the smectic liquid crystal phase, optical memory of the written state is observed for many hours without applied voltage. The reorientation of the DNA-surfactant lamellar layers plays an important role in preventing colour decay. Thereby, the volatility of optoelectronic state can be controlled simply by changing the phase of the material. This research may pave the way for developing a new generation of DNA-based, phase-modulated, photoelectronic devices.

  18. Cs 728 nm excited state Faraday anomalous dispersion optical filter with indirect pump

    NASA Astrophysics Data System (ADS)

    Tao, Zhiming; Zhang, Xiaogang; Chen, Mo; Liu, Zhongzheng; Zhu, Chuanwen; Liu, Zhiwen; Chen, Jingbiao

    2016-06-01

    We demonstrate a Cs excited state Faraday anomalous dispersion optical filter (ESFADOF) operating at 728 nm using a novel pump method, by which the pump beam and the probe beam in the ESFADOF realized here have no a common energy level. Using this method, the ESFADOF achieves a transmission of 2.39% with a bandwidth of 22.52 MHz, which can be applied to both laser frequency stabilization and future four-level active optical clocks. Under the 455 nm laser pump, in addition to 52D5/2, other states such as 72S1/2, 72P3/2, 62P3/2, 62P1/2 and 52D3/2 have also been populated effectively. Meanwhile, multiple wavelength filters exploiting atomic transitions to these states can be realized.

  19. Modeling and design of a new core-moderator assembly and neutron beam ports for the Penn State Breazeale Nuclear Reactor (PSBR)

    NASA Astrophysics Data System (ADS)

    Ucar, Dundar

    This study is for modeling and designing a new reactor core-moderator assembly and new neutron beam ports that aimed to expand utilization of a new beam hall of the Penn State Breazeale Reactor (PSBR). The PSBR is a part of the Radiation Science and Engineering Facility (RSEC) and is a TRIGA MARK III type research reactor with a movable core placed in a large pool and is capable to produce 1MW output. This reactor is a pool-type reactor with pulsing capability up to 2000 MW for 10-20 msec. There are seven beam ports currently installed to the reactor. The PSBR's existing core design limits the experimental capability of the facility, as only two of the seven available neutron beam ports are usable. The finalized design features an optimized result in light of the data obtained from neutronic and thermal-hydraulics analyses as well as geometrical constraints. A new core-moderator assembly was introduced to overcome the limitations of the existing PSBR design, specifically maximizing number of available neutron beam ports and mitigating the hydrogen gamma contamination of the neutron beam channeled in the beam ports. A crescent-shaped moderator is favored in the new PSBR design since it enables simultaneous use of five new neutron beam ports in the facility. Furthermore, the crescent shape sanctions a coupling of the core and moderator, which reduces the hydrogen gamma contamination significantly in the new beam ports. A coupled MURE and MCNP5 code optimization analysis was performed to calculate the optimum design parameters for the new PSBR. Thermal-hydraulics analysis of the new design was achieved using ANSYS Fluent CFD code. In the current form, the PSBR is cooled by natural convection of the pool water. The driving force for the natural circulation of the fluid is the heat generation within the fuel rods. The convective heat data was generated at the reactor's different operating powers by using TRIGSIMS, the fuel management code of the PSBR core. In the CFD

  20. Variable pulse repetition frequency output from an optically injected solid state laser.

    PubMed

    Kane, D M; Toomey, J P

    2011-02-28

    An optically injected solid state laser (OISSL) system is known to generate complex nonlinear dynamics within the parameter space of varying the injection strength of the master laser and the frequency detuning between the master and slave lasers. Here we show that within these complex nonlinear dynamics, a system which can be operated as a source of laser pulses with a pulse repetition frequency (prf) that can be continuously varied by a single control, is embedded. Generation of pulse repetition frequencies ranging from 200 kHz up to 4 MHz is shown to be achievable for an optically injected Nd:YVO4 solid state laser system from analysis of prior experimental and simulation results. Generalizing this to other optically injected solid state laser systems, the upper bound on the repetition frequency is of order the relaxation oscillation frequency for the lasers. The system is discussed in the context of prf versatile laser systems more generally. Proposals are made for the next generation of OISSLs that will increase understanding of the variable pulse repetition frequency operation, and determine its practical limitations. Such variable prf laser systems; both low powered, and, higher powered systems achieved using one or more optical power amplifier stages; have many potential applications from interrogating resonance behaviors in microscale structures, through sensing and diagnostics, to laser processing. PMID:21369300

  1. Proposal for the creation and optical detection of spin cat states in Bose-Einstein condensates.

    PubMed

    Lau, Hon Wai; Dutton, Zachary; Wang, Tian; Simon, Christoph

    2014-08-29

    We propose a method to create "spin cat states," i.e., macroscopic superpositions of coherent spin states, in Bose-Einstein condensates using the Kerr nonlinearity due to atomic collisions. Based on a detailed study of atom loss, we conclude that cat sizes of hundreds of atoms should be realistic. The existence of the spin cat states can be demonstrated by optical readout. Our analysis also includes the effects of higher-order nonlinearities, atom number fluctuations, and limited readout efficiency. PMID:25215963

  2. Unconventional optical Tamm states in metal-terminated three-dimensional photonic crystals

    NASA Astrophysics Data System (ADS)

    Korovin, Alexander V.; Romanov, Sergei G.

    2016-03-01

    Unconventional optical Tamm surface states have been demonstrated in transmission and reflectance spectra of three-dimensional opal photonic crystals coated by thin metal films. These states appear in registry with diffraction resonances and localize the electromagnetic energy in asymmetric resonators formed by stacks of lattice planes and metal semishells. Tamm defect states provide the bypass for light at the edges of the Bragg diffraction resonances and thus reduce the diffraction efficiency. Despite the hidden nature of this effect, its magnitude is comparable to the extraordinary transmission associated with the surface-plasmon polaritons that are simultaneously excited at the surfaces of the corrugated metal films.

  3. 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

  4. Direct optical state preparation of the dark exciton in a quantum dot

    NASA Astrophysics Data System (ADS)

    Lüker, S.; Kuhn, T.; Reiter, D. E.

    2015-11-01

    Because of their weak coupling to the electromagnetic field, dark excitons in semiconductor quantum dots possess extremely long lifetimes, which makes them attractive candidates for quantum information processing. On the other hand, the preparation and manipulation of dark states is challenging, because commonly used optical excitation mechanisms are not applicable. We propose an efficient mechanism for the deterministic preparation of the dark exciton exploiting the application of a tilted magnetic field and the optical excitation with a chirped, i.e., frequency modulated, laser pulse.

  5. Self-injection locking and phase-locked states in microresonator-based optical frequency combs.

    PubMed

    Del'Haye, Pascal; Beha, Katja; Papp, Scott B; Diddams, Scott A

    2014-01-31

    Microresonator-based optical frequency combs have been a topic of extensive research during the last few years. Several theoretical models for the comb generation have been proposed; however, they do not comprehensively address experimental results that show a variety of independent comb generation mechanisms. Here, we present frequency-domain experiments that illuminate the transition of microcombs into phase-locked states, which show characteristics of injection locking between ensembles of comb modes. In addition, we demonstrate the existence of equidistant optical frequency combs that are phase stable but have nondeterministic phase relationships between individual comb modes. PMID:24580454

  6. Self-Injection Locking and Phase-Locked States in Microresonator-Based Optical Frequency Combs

    NASA Astrophysics Data System (ADS)

    Del'Haye, Pascal; Beha, Katja; Papp, Scott B.; Diddams, Scott A.

    2014-01-01

    Microresonator-based optical frequency combs have been a topic of extensive research during the last few years. Several theoretical models for the comb generation have been proposed; however, they do not comprehensively address experimental results that show a variety of independent comb generation mechanisms. Here, we present frequency-domain experiments that illuminate the transition of microcombs into phase-locked states, which show characteristics of injection locking between ensembles of comb modes. In addition, we demonstrate the existence of equidistant optical frequency combs that are phase stable but have nondeterministic phase relationships between individual comb modes.

  7. Lasing effect enhanced by optical Tamm state with in-plane lattice plasmon

    NASA Astrophysics Data System (ADS)

    Zhang, Zhenqing; Li, Yunhui; Liu, Wenxing; Sun, Yong; Jiang, Haitao; Chen, Hong

    2016-02-01

    A new type of surface-emitting laser based on in-plane lattice plasmons (LPs) and optical Tamm states (OTSs) is proposed, with arrays of metallic micro-disks followed by a photonic crystal. Due to the presence of LP modes, the reflection properties of the combined LP-OTS structure, including the spectrum linewidth, Q-factor and electromagnetic field, can be optimized for better lasing behavior. When the combined LP-OTS structure with a gain medium is optically pumped, a much lower lasing threshold and higher emission intensity can be achieved simultaneously, compared with the individual LP structure. This phenomenon successfully demonstrates the enhancement of the lasing efficiency.

  8. Aerosol optical properties and mixing state of black carbon in the Pearl River Delta, China

    NASA Astrophysics Data System (ADS)

    Tan, Haobo; Liu, Li; Fan, Shaojia; Li, Fei; Yin, Yan; Cai, Mingfu; Chan, P. W.

    2016-04-01

    Aerosols contribute the largest uncertainty to the total radiative forcing estimate, and black carbon (BC) that absorbs solar radiation plays an important role in the Earth's energy budget. This study analysed the aerosol optical properties from 22 February to 18 March 2014 at the China Meteorological Administration Atmospheric Watch Network (CAWNET) station in the Pearl River Delta (PRD), China. The representative values of dry-state particle scattering coefficient (σsp), hemispheric backscattering coefficient (σhbsp), absorption coefficient (σabsp), extinction coefficient (σep), hemispheric backscattering fraction (HBF), single scattering albedo (SSA), as well as scattering Ångström exponent (α) were presented. A comparison between a polluted day and a clean day shows that the aerosol optical properties depend on particle number size distribution, weather conditions and evolution of the mixing layer. To investigate the mixing state of BC at the surface, an optical closure study of HBF between measurements and calculations based on a modified Mie model was employed for dry particles. The result shows that the mixing state of BC might be between the external mixture and the core-shell mixture. The average retrieved ratio of the externally mixed BC to the total BC mass concentration (rext-BC) was 0.58 ± 0.12, and the diurnal pattern of rext-BC can be found. Furthermore, considering that non-light-absorbing particles measured by a Volatility-Tandem Differential Mobility Analyser (V-TDMA) exist independently with core-shell and homogenously internally mixed BC particles, the calculated optical properties were just slightly different from those based on the assumption that BC exist in each particle. This would help understand the influence of the BC mixing state on aerosol optical properties and radiation budget in the PRD.

  9. State-projective scheme for generating pair coherent states in traveling-wave optical fields

    SciTech Connect

    Gerry, Christopher C.; Mimih, Jihane; Birrittella, Richard

    2011-08-15

    The pair coherent states of a two-mode quantized electromagnetic field introduced by Agarwal [Phys. Rev. Lett. 57, 827 (1986)] have yet to be generated in the laboratory. The states can mathematically be obtained from a product of ordinary coherent states via projection onto a subspace wherein identical photon number states of each mode are paired. We propose a scheme by which this projection can be engineered. The scheme requires relatively weak cross-Kerr nonlinearities, the ability to perform a displacement operation on a beam mode, and photon detection ability able to distinguish between zero and any other number of photons. These requirements can be fulfilled with currently available technology or technology that is on the horizon.

  10. Quantum optics with quantum gases: Controlled state reduction by designed light scattering

    SciTech Connect

    Mekhov, Igor B.; Ritsch, Helmut

    2009-07-15

    Cavity-enhanced light scattering from an ultracold gas in an optical lattice constitutes a quantum measurement with a controllable form of the measurement backaction. Time-resolved counting of scattered photons alters the state of the atoms without particle loss implementing a quantum nondemolition measurement. The conditional dynamics is given by the interplay between photodetection events (quantum jumps) and no-count processes. The class of emerging atomic many-body states can be chosen via the optical geometry and light frequencies. Light detection along the angle of a diffraction maximum (Bragg angle) creates an atom-number-squeezed state, while light detection at diffraction minima leads to the macroscopic superposition states (Schroedinger cat states) of different atom numbers in the cavity mode. A measurement of the cavity transmission intensity can lead to atom-number-squeezed or macroscopic superposition states depending on its outcome. We analyze the robustness of the superposition with respect to missed counts and find that a transmission measurement yields more robust and controllable superposition states than the ones obtained by scattering at a diffraction minimum.

  11. Continuous Variable Cluster State Generation over the Optical Spatial Mode Comb

    SciTech Connect

    Pooser, Raphael C.; Jing, Jietai

    2014-10-20

    One way quantum computing uses single qubit projective measurements performed on a cluster state (a highly entangled state of multiple qubits) in order to enact quantum gates. The model is promising due to its potential scalability; the cluster state may be produced at the beginning of the computation and operated on over time. Continuous variables (CV) offer another potential benefit in the form of deterministic entanglement generation. This determinism can lead to robust cluster states and scalable quantum computation. Recent demonstrations of CV cluster states have made great strides on the path to scalability utilizing either time or frequency multiplexing in optical parametric oscillators (OPO) both above and below threshold. The techniques relied on a combination of entangling operators and beam splitter transformations. Here we show that an analogous transformation exists for amplifiers with Gaussian inputs states operating on multiple spatial modes. By judicious selection of local oscillators (LOs), the spatial mode distribution is analogous to the optical frequency comb consisting of axial modes in an OPO cavity. We outline an experimental system that generates cluster states across the spatial frequency comb which can also scale the amount of quantum noise reduction to potentially larger than in other systems.

  12. Continuous Variable Cluster State Generation over the Optical Spatial Mode Comb

    DOE PAGESBeta

    Pooser, Raphael C.; Jing, Jietai

    2014-10-20

    One way quantum computing uses single qubit projective measurements performed on a cluster state (a highly entangled state of multiple qubits) in order to enact quantum gates. The model is promising due to its potential scalability; the cluster state may be produced at the beginning of the computation and operated on over time. Continuous variables (CV) offer another potential benefit in the form of deterministic entanglement generation. This determinism can lead to robust cluster states and scalable quantum computation. Recent demonstrations of CV cluster states have made great strides on the path to scalability utilizing either time or frequency multiplexingmore » in optical parametric oscillators (OPO) both above and below threshold. The techniques relied on a combination of entangling operators and beam splitter transformations. Here we show that an analogous transformation exists for amplifiers with Gaussian inputs states operating on multiple spatial modes. By judicious selection of local oscillators (LOs), the spatial mode distribution is analogous to the optical frequency comb consisting of axial modes in an OPO cavity. We outline an experimental system that generates cluster states across the spatial frequency comb which can also scale the amount of quantum noise reduction to potentially larger than in other systems.« less

  13. Aerosol optical properties in the southeastern United States in summer - Part 2: Sensitivity of aerosol optical depth to relative humidity and aerosol parameters

    NASA Astrophysics Data System (ADS)

    Brock, Charles A.; Wagner, Nicholas L.; Anderson, Bruce E.; Beyersdorf, Andreas; Campuzano-Jost, Pedro; Day, Douglas A.; Diskin, Glenn S.; Gordon, Timothy D.; Jimenez, Jose L.; Lack, Daniel A.; Liao, Jin; Markovic, Milos Z.; Middlebrook, Ann M.; Perring, Anne E.; Richardson, Matthews S.; Schwarz, Joshua P.; Welti, Andre; Ziemba, Luke D.; Murphy, Daniel M.

    2016-04-01

    Aircraft observations of meteorological, trace gas, and aerosol properties were made between May and September 2013 in the southeastern United States (US). Regionally representative aggregate vertical profiles of median and interdecile ranges of the measured parameters were constructed from 37 individual aircraft profiles made in the afternoon when a well-mixed boundary layer with typical fair-weather cumulus was present (Wagner et al., 2015). We use these 0-4 km aggregate profiles and a simple model to calculate the sensitivity of aerosol optical depth (AOD) to changes in dry aerosol mass, relative humidity, mixed-layer height, the central diameter and width of the particle size distribution, hygroscopicity, and dry and wet refractive index, while holding the other parameters constant. The calculated sensitivity is a result of both the intrinsic sensitivity and the observed range of variation in these parameters. These observationally based sensitivity studies indicate that the relationship between AOD and dry aerosol mass in these conditions in the southeastern US can be highly variable and is especially sensitive to relative humidity (RH). For example, calculated AOD ranged from 0.137 to 0.305 as the RH was varied between the 10th and 90th percentile profiles with dry aerosol mass held constant. Calculated AOD was somewhat less sensitive to aerosol hygroscopicity, mean size, and geometric standard deviation, σg. However, some chemistry-climate models prescribe values of σg substantially larger than we or others observe, leading to potential high biases in model-calculated AOD of ˜ 25 %. Finally, AOD was least sensitive to observed variations in dry and wet aerosol refractive index and to changes in the height of the well-mixed surface layer. We expect these findings to be applicable to other moderately polluted and background continental air masses in which an accumulation mode between 0.1-0.5 µm diameter dominates aerosol extinction.

  14. Thermal hydraulic analysis of two-phase closed thermosyphon cooling system for new cold neutron source moderator of Breazeale research reactor at Penn State

    NASA Astrophysics Data System (ADS)

    Habte, Melaku

    A cold neutron source cooling system is required for the Penn State's next generation cold neutron source facility that can accommodate a variable heat load up to about ˜10W with operating temperature of about 28K. An existing cold neutron source cooling system operating at the University of Texas Cold Neutron Source (TCNS) facility failed to accommodate heat loads upwards of 4W with the moderator temperature reaching a maximum of 44K, which is the critical temperature for the operating fluid neon. The cooling system that was used in the TCNS cooling system was a two-phase closed thermosyphon with a reservoir (TPCTR). The reservoir containing neon gas is kept at room temperature. In this study a detailed thermal analysis of the fundamental operating principles of a TPCTR were carried out. A detailed parametric study of the various geometric and thermo-physical factors that affect the limits of the operational capacity of the TPCTR investigated. A CFD analysis is carried out in order to further refine the heat transfer analysis and understand the flow structure inside the thermosyphon and the two-phase nucleate boiling in the evaporator section of the thermosyphon. In order to help the new design, a variety of ways of increasing the operating range and heat removal capacity of the TPCTR cooling system were analyzed so that it can accommodate the anticipated heat load of 10W or more. It is found, for example, that doubling the pressure of the system will increase the capacity index zeta by 50% for a system with an initial fill ratio FR of 1. A decrease in cryorefrigeration performance angle increases the capacity index. For example taking the current condition of the TCNS system and reducing the angle from the current value of ˜700 by half (˜350) will increase the cooling power 300%. Finally based on detailed analytic and CFD analysis the best operating condition were proposed.

  15. Differential Stark shift measurement of clock states of Yb+ using an optical frequency comb

    NASA Astrophysics Data System (ADS)

    Quraishi*, Qudsia; Hayes, David; Hucul, David; Matsukevich, Dzmitry; Debnath, Shantanu; Clark, Susan; Monroe, Chris

    2011-03-01

    Quantum information processing with trapped ions has traditionally involved state preparation, manipulation (eg. quantum gates) and detection using CW lasers. Quantum gates implemented with ions typically involve optical Raman transitions between two atomic levels. An optical frequency comb, emitted by a pulsed laser, is an excellent tool for bridging atomic frequency differences. Previously, we demonstrated quantum gates and separately, ultrafast spin manipulation, using pulsed lasers [1,2]. Unlike the CW case, employing pulsed lasers has the marked advantage of both low spontaneous emission and low AC Stark shifts, because the high powers available from pulsed lasers allow for larger detunings from optical resonance. Here, we show both experimentally and theoretically the scaling of the differential Stark shift with detuning (6 THz to 20 THz) of the Raman fields, achieving values of 10-3 of the Rabi frequency.

  16. Boundary conditions in the research of stress-strain state by optical tomography method

    SciTech Connect

    Patrikeyev, I.; Shakhurdin, V.

    1994-12-31

    Mechanical stresses appear in the elastic body under the influence of external loading. In these conditions optical isotropic medium becomes optical anisotropic and behaves itself as a crystal. In photoelasticity on the analogy with a classification of natural crystal anisotropy three problems of the stress strain state can be distinguished. The tasks in which the stress strain state is caused by a uniform compression or expansion belong to the first problem. It is the most common case. The plane problems belong to the second group of problems. In this case stress strain state is described by the tensor of the second order with three or four components not equal to zero. All the rest problems belong to the third group. The stress strain state of the medium is described by the second order tensor with six components different from zero. The investigation of such problems required new transillumination schemes and algorithms for the treatment of experimental results which radically differ from the classical tomography schemes and methods. The role of boundary conditions for the correct formulation photoelasticity problems based on the restoration of tensor fields by means of optical tomography is presented in this article.

  17. A Single Intravitreal Injection of Ranibizumab Provides No Neuroprotection in a Nonhuman Primate Model of Moderate-to-Severe Nonarteritic Anterior Ischemic Optic Neuropathy

    PubMed Central

    Miller, Neil R.; Johnson, Mary A.; Nolan, Theresa; Guo, Yan; Bernstein, Steven L.

    2015-01-01

    Purpose Ranibizumab, a vascular endothelial growth factor-antagonist, is said to be neuroprotective when injected intravitreally in patients with nonarteritic anterior ischemic optic neuropathy (NAION). We evaluated the efficacy of a single intravitreal (IVT) injection of ranibizumab in a nonhuman primate model of NAION (pNAION). Methods We induced pNAION in one eye of four adult male rhesus monkeys using a laser-activated rose Bengal induction method. We then immediately injected the eye with either ranibizumab or normal saline (NS) intravitreally. We performed a clinical assessment, optical coherence tomography, electrophysiological testing, fundus photography, and fluorescein angiography in three of the animals (one animal developed significant retinal hemorrhages and, therefore, could not be analyzed completely) prior to induction, 1 day and 1, 2, and 4 weeks thereafter. Following the 4-week analysis of the first eye, we induced pNAION in the contralateral eye and then injected either ranibizumab or NS, whichever substance had not been injected in the first eye. We euthanized all animals 5 to 12 weeks after the final assessment of the second eye and performed both immunohistochemical and light and electron microscopic analyses of the retina and optic nerves of both eyes. Results A single IVT dose of ranibizumab administered immediately after induction of pNAION resulted in no significant reduction of clinical, electrophysiological, or histologic damage compared with vehicle-injected eyes. Conclusions A single IVT dose of ranibizumab is not neuroprotective when administered immediately after induction of pNAION. PMID:26624498

  18. 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.

  19. Excited-State Absorption from Real-Time Time-Dependent Density Functional Theory: Optical Limiting in Zinc Phthalocyanine.

    PubMed

    Fischer, Sean A; Cramer, Christopher J; Govind, Niranjan

    2016-04-01

    Optical-limiting materials are capable of attenuating light to protect delicate equipment from high-intensity light sources. Phthalocyanines have attracted a lot of attention for optical-limiting applications due to their versatility and large nonlinear absorption. With excited-state absorption (ESA) being the primary mechanism for optical limiting behavior in phthalocyanines, the ability to tune the optical absorption of ground and excited states in phthalocyanines would allow for the development of advanced optical limiters. We recently developed a method for the calculation of ESA based on real-time time-dependent density functional theory propagation of an excited-state density. In this work, we apply the approach to zinc phthalocyanine, demonstrating the ability of our method to efficiently identify the optical limiting potential of a molecular complex. PMID:27007445

  20. All-Optical Switching in Bacteriorhodopsin Based on Excited-State Absorption

    NASA Astrophysics Data System (ADS)

    Roy, Sukhdev

    2008-03-01

    Switching light with light is of tremendous importance for both fundamental and applied science. The advent of nano-bio-photonics has led to the design, synthesis and characterization of novel biomolecules that exhibit an efficient nonlinear optical response, which can be utilized for designing all-optical biomolecular switches. Bacteriorhodopsin (bR) protein found in the purple membrane of Halobacterium halobium has been the focus of intense research due to its unique properties that can also be tailored by physical, chemical and genetic engineering techniques to suit desired applications. The talk would focus on our recent results on all-optical switching in bR and its mutants, based on excited-state absorption, using the pump-probe technique. We would discuss the all-optical control of various features of the switching characteristics such as switching contrast, switching time, switching pump intensity, switched probe profile and phase, and relative phase-shift. Optimized conditions for all-optical switching that include optimized values of the small-signal absorption coefficient (for cw case), the pump pulse width and concentration for maximum switching contrast (for pulsed case), would be presented. We would discuss the desired optimal spectral and kinetic properties for device applications. We would also discuss the application of all-optical switching to design low power all-optical computing devices, such as, spatial light modulators, logic gates and multiplexers and compare their performance with other natural photoreceptors such as pharaonis phoborhodopsin, proteorhodopsin, photoactive yellow protein and the blue light plant photoreceptor phototropin.

  1. Loading Bose-Einstein-condensed atoms into the ground state of an optical lattice

    SciTech Connect

    Julienne, P. S.; Williams, C. J.; Band, Y. B.; Trippenbach, Marek

    2005-11-15

    We optimize the turning on of a one-dimensional optical potential, V{sub L}(x,t)=S(t)V{sub 0} cos{sup 2}(kx) to obtain the optimal turn-on function S(t) so as to load a Bose-Einstein condensate into the ground state of the optical lattice of depth V{sub 0}. Specifically, we minimize interband excitations at the end of the turn-on of the optical potential at the final ramp time t{sub r}, where S(t{sub r})=1, given that S(0)=0. Detailed numerical calculations confirm that a simple unit cell model is an excellent approximation when the turn-on time t{sub r} is long compared with the inverse of the band excitation frequency and short in comparison with nonlinear time ({Dirac_h}/2{pi})/{mu} where {mu} is the chemical potential of the condensate. We demonstrate using the Gross-Pitaevskii equation with an optimal turn-on function S(t) that the ground state of the optical lattice can be loaded with no significant excitation even for times t{sub r} on the order of the inverse band excitation frequency.

  2. Molecular states in double quantum wells: nanochemistry for metatmaterials with new optical properties

    NASA Astrophysics Data System (ADS)

    Gutierrez, Rafael M.; Castañeda, Arcesio

    2009-08-01

    Quantum mechanics explains the existence and properties of the chemical bond responsible for the formation of molecules from isolated atoms. In this work we study quantum states of Double Quantum Wells, DQW, formed from isolated Single Quantum Wells, SQWs, that can be considered metamaterials. Using the quantum chemistry definition of the covalent bond, we discuss molecular states in DQW as a kind of nanochemistry of metamaterials with new properties, in particular new optical properties. An important particularity of such nanochemistry, is the possible experimental control of the geometrical parameters and effective masses characterizing the semiconductor heterostructures represented by the corresponding DQW. This implies a great potential for new applications of the controlled optical properties of the metamaterials. The use of ab initio methods of intensive numerical calculations permits to obtain macroscopic optical properties of the metamaterials from the fundamental components: the spatial distribution of the atoms and molecules constituting the semiconductor layers. The metamaterial new optical properties emerge from the coexistence of many body processes at atomic and molecular level and complex quantum phenomena such as covalent-like bonds at nanometric dimensions.

  3. Through-wafer optical probe characterization for microelectromechanical systems positional state monitoring and feedback control

    NASA Astrophysics Data System (ADS)

    Dawson, Jeremy M.; Chen, Jingdong; Brown, Kolin S.; Famouri, Parviz F.; Hornak, Lawrence A.

    2000-12-01

    Implementation of closed-loop microelectromechanical system (MEMS) control enables mechanical microsystems to adapt to the demands of the environment that they are actuating, opening a broad range of new opportunities for future MEMS applications. Integrated optical microsystems have the potential to enable continuous in situ optical interrogation of MEMS microstructure position fully decoupled from the means of mechanical actuation that is necessary for realization of feedback control. We present the results of initial research evaluating through-wafer optical microprobes for surface micromachined MEMS integrated optical position monitoring. Results from the through-wafer free-space optical probe of a lateral comb resonator fabricated using the multiuser MEMS process service (MUMPS) indicate significant positional information content with an achievable return probe signal dynamic range of up to 80% arising from film transmission contrast. Static and dynamic deflection analysis and experimental results indicate a through-wafer probe positional signal sensitivity of 40 mV/micrometers for the present setup or 10% signal change per micrometer. A simulation of the application of nonlinear sliding control is presented illustrating position control of the lateral comb resonator structure given the availability of positional state information.

  4. Portable, solid state, fiber optic coupled Doppler interferometer system for detonation and shock diagnostics

    SciTech Connect

    Fleming, K.J.; Crump, O.B.

    1994-03-01

    VISAR (Velocity Interferometer System for Any Reflector) is a specialized Doppler interferometer system that is gaining world-wide acceptance as the standard for shock phenomena analysis. The VISAR`s large power and cooling requirements, and the sensitive and complex nature of the interferometer cavity have restricted the traditional system to the laboratory. This paper describes the new portable VISAR, its peripheral sensors, and the role it played in optically measuring ground shock of an underground nuclear detonation. The solid State VISAR uses a prototype diode pumped ND:YAG laser and solid state detectors that provide a suitcase-size system with low power requirements. A special window and sensors were developed for fiber optic coupling (1 kilometer long) to the VISAR. The system has proven itself as a reliable, easy to use instrument that is capable of field test use and rapid data reduction using only a notebook personal computer (PC).

  5. Portable, solid state, fiber optic coupled Doppler interferometer system for detonation and shock diagnostics

    NASA Astrophysics Data System (ADS)

    Fleming, K. J.; Crump, O. B.

    1993-05-01

    VISAR (Velocity Interferometer System for Any Reflector) is a specialized Doppler interferometer system that is gaining world-wide acceptance as the standard for shock phenomena analysis. The VISAR's large power and cooling requirements, and the sensitive and complex nature of the interferometer cavity, has restricted the traditional system to the laboratory. This paper describes the new portable VISAR, its peripheral sensors, and the role it played in optically measuring ground shock of an underground nuclear detonation (UGT). The Solid State VISAR uses a prototype diode pumped ND:YAG laser and solid state detectors that provide a suitcase-size system with low power requirements. A special window and sensor was developed for fiber optic coupling (1 kilometer long) to the VISAR. The system has proven itself as a reliable, easy-to-use instrument that is capable of field test use and rapid data reduction employing only a personal computer (PC).

  6. Ultrasensitive optical absorption in graphene based on bound states in the continuum

    PubMed Central

    Zhang, Mingda; Zhang, Xiangdong

    2015-01-01

    We have designed a sphere-graphene-slab structure so that the electromagnetic wave can be well confined in the graphene due to the formation of a bound state in a continuum (BIC) of radiation modes. Based on such a bound state, we have realized strong optical absorption in the monolayer graphene. Such a strong optical absorption exhibits many advantages. It is ultrasensitive to the wavelength because the Q factor of the absorption peak can be more than 2000. By taking suitable BICs, the selective absorption for S and P waves has not only been realized, but also all-angle absorption for the S and P waves at the same time has been demonstrated. We have also found that ultrasensitive strong absorptions can appear at any wavelength from mid-infrared to far-infrared band. These phenomena are very beneficial to biosensing, perfect filters and waveguides. PMID:25652437

  7. Portable, solid state, fiber optic coupled Doppler interferometer system for detonation and shock diagnostics

    NASA Technical Reports Server (NTRS)

    Fleming, K. J.; Crump, O. B.

    1994-01-01

    VISAR (Velocity Interferometer System for Any Reflector) is a specialized Doppler interferometer system that is gaining world-wide acceptance as the standard for shock phenomena analysis. The VISAR's large power and cooling requirements, and the sensitive and complex nature of the interferometer cavity have restricted the traditional system to the laboratory. This paper describes the new portable VISAR, its peripheral sensors, and the role it played in optically measuring ground shock of and underground nuclear detonation. The Solid State VISAR uses a prototype diode pumped Nd:YAG laser and solid state detectors that provide a suitcase-size system with low power requirements. A special window and sensors were developed for fiber optic coupling (1 kilometer long) to the VISAR. The system has proven itself as a reliable, easy to use instrument that is capable of field test use and rapid data reduction using only a notebook personal computer (PC).

  8. Fast ground state manipulation of neutral atoms in microscopic optical traps.

    PubMed

    Yavuz, D D; Kulatunga, P B; Urban, E; Johnson, T A; Proite, N; Henage, T; Walker, T G; Saffman, M

    2006-02-17

    We demonstrate Rabi flopping at MHz rates between ground hyperfine states of neutral 87Rb atoms that are trapped in two micron sized optical traps. Using tightly focused laser beams we demonstrate high fidelity, site specific Rabi rotations with cross talk on neighboring sites separated by 8 microm at the level of 10(-3). Ramsey spectroscopy is used to measure a dephasing time of 870 micros, which is approximately 5000 longer than the time for a pi/2 pulse. PMID:16605988

  9. Production of a Quantum Gas of Rovibronic Ground-State Molecules in AN Optical Lattice

    NASA Astrophysics Data System (ADS)

    Danzl, Johann G.; Mark, Manfred J.; Haller, Elmar; Gustavsson, Mattias; Hart, Russell; Nägerl, Hanns-Christoph

    2010-02-01

    Recent years have seen tremendous progress in the field of cold and ultracold molecules. A central goal in the field is currently the realization of stable rovibronic ground-state molecular samples in the regime of quantum degeneracy, e.g. in the form of molecular Bose-Einstein condensates, molecular degenerate Fermi gases, or, when an optical lattice is present, molecular Mott-insulator phases. However, molecular samples are not readily cooled to the extremely low temperatures at which quantum degeneracy occurs. In particular, laser cooling, the 'workhorse' for the field of atomic quantum gases, is generally not applicable to molecular samples. Here we take an important step beyond previous work1 and provide details on the realization of an ultracold quantum gas of ground-state dimer molecules trapped in an optical lattice as recently reported in Ref. 2. We demonstrate full control over all internal and external quantum degrees of freedom for the ground-state molecules by deterministically preparing the molecules in a single quantum state, i.e. in a specific hyperfine sublevel of the rovibronic ground state, while the molecules are trapped in the motional ground state of the individual lattice wells. We circumvent the problem of cooling by associating weakly-bound molecules out of a zero-temperature atomic Mott-insulator state and by transferring these to the absolute ground state in a four-photon STIRAP process. Our preparation procedure directly leads to a long-lived, lattice-trapped molecular many-body state, which we expect to form the platform for many of the envisioned future experiments with molecular quantum gases, e.g. on precision molecular spectroscopy, quantum information science, and dipolar quantum systems.

  10. Optical phase information writing and storage in populations of metastable quantum states

    SciTech Connect

    Djotyan, G. P.; Sandor, N.; Bakos, J. S.; Soerlei, Zs.

    2009-10-15

    We propose a scheme for robust writing and storage of optical phase information in populations of metastable states of the atoms with a tripod structure of levels by using frequency-chirped laser pulses. The method provides much longer storage times compared with the schemes based on the collective atomic spin coherences. A negligible excitation of the atom provides immunity to decoherence induced by decay of the excited states. The method is robust against small-to-medium variations in the laser pulse intensity and speed of the chirp and, being insensitive to resonance conditions, it is effective both in homogeneously and inhomogeneously broadened media.

  11. Optical isolation in the LIGO gravitational wave laser detector in transient states

    SciTech Connect

    Soloviev, A A; Khazanov, Efim A

    2012-04-30

    This paper presents a numerical analysis of the degree of optical isolation of the laser source by the Faraday isolator in transient states of the laser interferometer gravitational wave observatory (LIGO) detector. This system may be in transient states where the power of the light reflected from the detector to the laser source can exceed many times the power of the source. The present results can be used to analyse the need for installing an additional active mechanical isolation of the source and to evaluate its response time.

  12. High-fidelity rapid ground-state loading of an ultracold gas into an optical lattice.

    PubMed

    Masuda, Shumpei; Nakamura, Katsuhiro; del Campo, Adolfo

    2014-08-01

    A protocol is proposed for the rapid coherent loading of a Bose-Einstein condensate into the ground state of an optical lattice, without residual excitation associated with the breakdown of adiabaticity. The driving potential required to assist the rapid loading is derived using the fast-forward technique, and generates the ground state in any desired short time. We propose an experimentally feasible loading scheme using a bichromatic lattice potential, which approximates the fast-forward driving potential with high fidelity. PMID:25148323

  13. Near-deterministic discrimination of all Bell states with linear optics.

    PubMed

    Pavičić, Mladen

    2011-08-19

    For a reliable implementation of quantum teleportation, a near-deterministic (close to 100%) discrimination of all four Bell states of entangled qubits is required. One can carry it out with linear optical elements only if conditional dynamics are allowed. Here we present a setup in which we repeatedly disentangle and reentangle photons in three of four states, so as to separate photons in one of them, conditioned on keeping the other two at bay. The efficiency of a realistic implementation of our setup with current technology is over 90% for an ideal source of photons on demand. PMID:21929149

  14. Excited state Faraday anomalous dispersion optical filters based on indirect laser pumping.

    PubMed

    Yin, Longfei; Luo, Bin; Chen, Zhongjie; Zhong, Lei; Guo, Hong

    2014-02-15

    The direct pump method now used in excited state Faraday anomalous dispersion optical filters (ES-FADOFs) requires that the transition between the target and the ground state is an electric dipole allowed transition and that a laser that operates at the exact pump wavelength is available. This is not always satisfied in practice. An indirect laser pump method for ES-FADOF is proposed and experimentally realized. Compared with the commonly used direct pump method, this indirect pump method can reach the same performance using lasers at very different wavelengths. This method can greatly extend the wavelength range of FADOF and provide a novel scheme for ES-FADOF design. PMID:24562221

  15. Two-point attack on the two nonorthogonal states QKD protocol over a fiber optic channel

    NASA Astrophysics Data System (ADS)

    Yang, Li; Wu, Ling-An

    2005-01-01

    We suggest here a two-point eavesdropping strategy aimed at a two nonorthogonal states protocol of quantum key distribution over a fiber-optic channel. When the single-photon sources and detectors of Alice, Bob and the two Eve are all ideal, the two-point attack can break the two nonorthogonal states protocol if the distance between Alice and Bob is longer than 30 km. However, Bennett's original multi-photon protocol is secure against both two-point and beam splitting attacks, though the protocol is realized with a weak pulsed source.

  16. Characters of basic steady state solutions for superfluid Fermi gas in Bessel optical lattices

    NASA Astrophysics Data System (ADS)

    Zhang, Ke-Zhi; Chen, Yan; He, Yong-Lin; Liu, Zheng-Lai

    2015-08-01

    We consider a dynamical model for superfluid Fermi gas, trapped in the central well of an axially symmetric Bessel optical lattice potential. The equation includes nonlinear power-law form of the chemical potential μ(n) = C|ψ|2γ, for γ = 2 3, which accounts for Fermi pressure. Reducing the equation to two-dimensional (2D) form, we obtain the basic steady state solutions of the system along the Bose-Einstein condensation (BEC) side to Bardeen-Cooper-Schrieffer (BCS) side by employing the energy balance condition, which are guided by the variational approximation. It is found that the strength ɛ and the radial scale r of the Bessel optical lattice have an extreme effect on the characters of basic steady state solution. Analytically, we deduce the atomic density distribution, the average atom number and the average energy of basic steady state, where the atom distribution of the system presents on periodic change with r, and increases faster at unitarity than in the BEC limit. Furthermore, because of the Fermi pressure, the atomic density distribution at the unitarity is more extensive than that in the BEC limit. In particular, there exist very interesting changes, the average energy intends to collapse state with r, however it emerges as a stable state with varying L both in the BEC limit and at unitarity.

  17. Optical pumping and readout of bismuth hyperfine states in silicon for atomic clock applications

    PubMed Central

    Saeedi, K.; Szech, M.; Dluhy, P.; Salvail, J.Z.; Morse, K.J.; Riemann, H.; Abrosimov, N.V.; Nötzel, N.; Litvinenko, K.L.; Murdin, B.N.; Thewalt, M.L.W.

    2015-01-01

    The push for a semiconductor-based quantum information technology has renewed interest in the spin states and optical transitions of shallow donors in silicon, including the donor bound exciton transitions in the near-infrared and the Rydberg, or hydrogenic, transitions in the mid-infrared. The deepest group V donor in silicon, bismuth, has a large zero-field ground state hyperfine splitting, comparable to that of rubidium, upon which the now-ubiquitous rubidium atomic clock time standard is based. Here we show that the ground state hyperfine populations of bismuth can be read out using the mid-infrared Rydberg transitions, analogous to the optical readout of the rubidium ground state populations upon which rubidium clock technology is based. We further use these transitions to demonstrate strong population pumping by resonant excitation of the bound exciton transitions, suggesting several possible approaches to a solid-state atomic clock using bismuth in silicon, or eventually in enriched 28Si. PMID:25990870

  18. Electro-optic control of atom-light interactions using Rydberg dark-state polaritons

    NASA Astrophysics Data System (ADS)

    Bason, M. G.; Mohapatra, A. K.; Weatherill, K. J.; Adams, C. S.

    2008-03-01

    We demonstrate a multiphoton Rydberg dark resonance where a Λ system is coupled to a Rydberg state. This N -type level scheme combines the ability to slow and store light pulses associated with long-lived ground-state superpositions with the strongly interacting character of Rydberg states. For the nd5/2 Rydberg state in R87b (with n=26 or 44) and a beam size of 1 mm, we observe a resonance linewidth of less than 100 kHz in a room-temperature atomic ensemble limited by transit-time broadening. The resonance is switchable with an electric field of order 1Vcm-1 . Applications in electro-optic switching and photonic phase gates are discussed.

  19. Two novel schemes for probabilistic remote state preparation and the physical realization via the linear optics

    NASA Astrophysics Data System (ADS)

    Wei, Jiahua; Dai, Hong-Yi; Zhang, Ming; Yang, Le; Kuang, Jingsong

    2016-05-01

    In this paper, we put forward two novel schemes for probabilistic remote preparation of an arbitrary quantum state with the aid of appropriate local unitary operations when the sender and the receiver only have partial information of non-maximally entangled state, respectively. The concrete implementation procedures of the novel proposals are given in detail. Additionally, the physical realizations of our proposals are discussed based on the linear optics. Because of that neither the sender nor the receiver need to know fully the information of the partially entangled state, our schemes are useful to not only expand the application range of quantum entanglement, but also enlarge the research field of probabilistic remote state preparation (RSP).

  20. Electro-optical parameters in excited states of some spectrally active molecules

    NASA Astrophysics Data System (ADS)

    Benchea, Andreea Celia; Closca, Valentina; Rusu, Cristina Marcela; Morosanu, Cezarina; Dorohoi, Dana Ortansa

    2014-08-01

    The spectral shifts measured in different solvents are expressed as functions of the solvent macroscopic parameters. The value of the correlation coefficient multiplying the functions of electric permittivity was determined by statistical means. The correlation coefficient depends on the electric dipole moment of the spectrally active molecules. The electro-optical parameters in the ground state of the solute molecules can be approximated by molecular modeling. The excited state parameters are usually estimated using the results obtained both by HyperChem Programme and solvatochromic study. The importance of this approximate method is that it offers information about of the excited state of solute molecule for which our measuring possibilities are very restrictive. The information about the excited electronic state is affected by the limits in which the theories of liquid solutions are developed. Our results refer to two molecules of vitamins from B class, namely B3 and B6.

  1. A quantum gas of ground state molecules in an optical lattice

    NASA Astrophysics Data System (ADS)

    Danzl, Johann; Mark, Manfred; Haller, Elmar; Gustavsson, Mattias; Hart, Russell; Nägerl, Hanns-Christoph

    2009-05-01

    Ultracold samples of molecules are ideally suited for fundamental studies in physics and chemistry. For many of the proposed experiments full molecular state control and high phase space densities are needed. We create a dense quantum gas of ground state Cs2 molecules trapped at the wells of a 3D optical lattice, i.e. a molecular Mott-insulator-like state with ground state molecules with vibrational quantum number v = 0. We first efficiently produce weakly bound molecules with v 155 on a Feshbach resonance out of an atomic Mott-insulator state that is obtained from a Bose-Einstein condensate (BEC) of Cs atoms. These molecules are then (coherently) transferred to the ground state by two sequential two-photon STIRAP processes via the intermediate vibrational level v 73 ^1. The molecule production efficiency and the single-step STIRAP transfer efficiency reach 50% and 80%, respectively. We discuss the stability of the system and our progress towards the creation of a BEC of ground state molecules, which is expected to form when the molecular Mott-like state is ``melted'' upon lowering the lattice depth and releasing the molecules from the wells into a large volume trap. ^1J. G. Danzl, E. Haller, M. Gustavsson, M. Mark, R. Hart, N. Bouloufa, O. Dulieu, H. Ritsch, H.-C. Nägerl, Science 321, 1062 (2008).

  2. Comparison of Intensive Versus Moderate Lipid-Lowering Therapy on Fibrous Cap and Atheroma Volume of Coronary Lipid-Rich Plaque Using Serial Optical Coherence Tomography and Intravascular Ultrasound Imaging.

    PubMed

    Hou, Jingbo; Xing, Lei; Jia, Haibo; Vergallo, Rocco; Soeda, Tsunerari; Minami, Yoshiyasu; Hu, Sining; Yang, Shuang; Zhang, Shaosong; Lee, Hang; Yu, Bo; Jang, Ik-Kyung

    2016-03-01

    Despite marked clinical benefit, reduction in atheroma volume with statin therapy is minimal. Changes in plaque composition may explain this discrepancy. We aimed in the present study to assess the effect of statin therapy on coronary plaque composition and plaque volume using serial multimodality imaging. From an open-label, single-blinded study, patients with angiographically mild-to-moderate lesion were randomized to receive atorvastatin 60 (AT 60) mg or atorvastatin 20 (AT 20) mg for 12 months. Optical coherence tomography was used to assess fibrous cap thickness (FCT) and intravascular ultrasound to assess atheroma burden at 3 time points: baseline, at 6 months, and at 12 months. Thirty-six lipid-rich plaques in 27 patients with AT 60 mg and 30 lipid-rich plaques in 19 patients with AT 20 mg were enrolled in this study. Low-density lipoprotein cholesterol level was significantly decreased at 6 months without further reduction at 12 months. AT 60 mg induced greater reduction in low-density lipoprotein cholesterol compared with AT 20 mg. Optical coherence tomography revealed continuous increase in FCT from baseline to 6 months and to 12 months in both groups. AT 60 mg induced greater increase in FCT compared with AT 20 mg at both follow-up points. The prevalence of thin-cap fibroatheroma and the presence of macrophage at 6 months were significantly lower in AT 60 mg compared with AT 20 mg. Plaque burden did not change significantly in both groups. In conclusion, both intensive and moderate statin therapy stabilizes coronary plaques, with a greater benefit in the intensive statin group. However, no significant changes in plaque volume were observed over time regardless of the intensity of statin therapy. PMID:26778524

  3. Optical evidence for a Weyl semimetal state in pyrochlore Eu2 Ir2 O7

    NASA Astrophysics Data System (ADS)

    Sushkov, Andrei; Hofmann, Johannes; Jenkins, Gregory; Drew, Dennis; Ishikawa, Jun; Nakatsuji, Satoru

    Possible realization of a Weyl semimetallic state with the broken time-reversal symmetry in pyrochlore iridates is still under debate. In the absense of ARPES and neutron data, optical evidence become very important. We found that the THz optical conductivity and temperature dependence of the free carrier response in pyrochlore Eu2Ir2O7 match the predictions for a Weyl semimetal and suggest novel Dirac liquid behavior. The interband optical conductivity vanishes continuously at low frequencies signifying a semimetal. The metal-semimetal transition at TN = 110 K is manifested in the Drude spectral weight, which is independent of temperature in the metallic phase, and which decreases smoothly in the ordered phase. The temperature dependence of the free carrier weight below TN is in good agreement with theoretical predictions for a Weyl semimetal. The fit of experimental Drude weight yields a Fermi velocity 4x107 cm/s, a logarithmic renormalization scale ΛL ~ 600 K, and require a Fermi temperature of 100 K associated with residual unintentional doping to account for the low temperature optical response and dc resistivity. This work was supported by Grants: NSF DMR-1104343 and 1066293, DOE ER46741-SC0005436, LPS-MPO-CMTC, the Japanese Society for the Promotion of Science R2604, and Grants-in-Aid for Scientific Research 25707030.

  4. Space-bound optical source for satellite-ground decoy-state quantum key distribution.

    PubMed

    Li, Yang; Liao, Sheng-Kai; Chen, Xie-Le; Chen, Wei; Cheng, Kun; Cao, Yuan; Yong, Hai-Lin; Wang, Tao; Yang, Hua-Qiang; Liu, Wei-Yue; Yin, Juan; Liang, Hao; Peng, Cheng-Zhi; Pan, Jian-Wei

    2014-11-01

    Satellite-ground quantum key distribution has embarked on the stage of engineering implementation, and a global quantum-secured network is imminent in the foreseeable future. As one payload of the quantum-science satellite which will be ready before the end of 2015, we report our recent work of the space-bound decoy-state optical source. Specialized 850 nm laser diodes have been manufactured and the integrated optical source has gotten accomplished based on these LDs. The weak coherent pulses produced by our optical source feature a high clock rate of 100 MHz, intensity stability of 99.5%, high polarization fidelity of 99.7% and phase randomization. A series of space environment tests have been conducted to verify the optical source's performance and the results are satisfactory. The emulated final secure keys are about 120 kbits during one usable pass of the low Earth orbit satellite. This work takes a significant step forward towards satellite-ground QKD and the global quantum-secured network. PMID:25401878

  5. Effect of Aerosol Size and Hygroscopicity on Aerosol Optical Depth in the Southeastern United States

    NASA Astrophysics Data System (ADS)

    Brock, Charles; Wagner, Nick; Gordon, Timothy

    2016-04-01

    Aerosol optical depth (AOD) is affected by the size, optical characteristics, and hygroscopicity of particles, confounding attempts to link remote sensing observations of AOD to measured or modeled aerosol mass concentrations. In situ airborne observations of aerosol optical, chemical, microphysical and hygroscopic properties were made in the southeastern United States in the daytime in summer 2013. We use these observations to constrain a simple model that is used to test the sensitivity of AOD to the various measured parameters. As expected, the AOD was found to be most sensitive to aerosol mass concentration and to aerosol water content, which is controlled by aerosol hygroscopicity and the ambient relative humidity. However, AOD was also fairly sensitive to the mean particle diameter and the width of the size distribution. These parameters are often prescribed in global models that use simplified modal parameterizations to describe the aerosol, suggesting that the values chosen could substantially bias the calculated relationship between aerosol mass and optical extinction, AOD, and radiative forcing.

  6. 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.

  7. Mercury in fish tissue of Idaho lakes vs. those of the Northeastern United States as it relates to the moderating effects of selenium

    EPA Science Inventory

    The primary methyl-mercury (MeHg) exposure mode to wildlife and humans is through the consumption of aquatic organisms, particulary fish. Selenium has been demonstrated to moderate the toxicity of MeHg in every test animal type examined to date. A molar ratio of Se:Hg >1 appear...

  8. Optimal mode transformations for linear-optical cluster-state generation

    SciTech Connect

    Uskov, Dmitry B.; Lougovski, Pavel; Alsing, Paul M.; Fanto, Michael L.; Kaplan, Lev; Smith, Amos Matthew

    2015-06-15

    In this paper, we analyze the generation of linear-optical cluster states (LOCSs) via sequential addition of one and two qubits. Existing approaches employ the stochastic linear-optical two-qubit controlled-Z (CZ) gate with success rate of 1/9 per operation. The question of optimality of the CZ gate with respect to LOCS generation has remained open. We report that there are alternative schemes to the CZ gate that are exponentially more efficient and show that sequential LOCS growth is indeed globally optimal. We find that the optimal cluster growth operation is a state transformation on a subspace of the full Hilbert space. Finally, we show that the maximal success rate of postselected entangling n photonic qubits or m Bell pairs into a cluster is (1/2)n-1 and (1/4)m-1, respectively, with no ancilla photons, and we give an explicit optical description of the optimal mode transformations.

  9. Optimal mode transformations for linear-optical cluster-state generation

    DOE PAGESBeta

    Uskov, Dmitry B.; Lougovski, Pavel; Alsing, Paul M.; Fanto, Michael L.; Kaplan, Lev; Smith, Amos Matthew

    2015-06-15

    In this paper, we analyze the generation of linear-optical cluster states (LOCSs) via sequential addition of one and two qubits. Existing approaches employ the stochastic linear-optical two-qubit controlled-Z (CZ) gate with success rate of 1/9 per operation. The question of optimality of the CZ gate with respect to LOCS generation has remained open. We report that there are alternative schemes to the CZ gate that are exponentially more efficient and show that sequential LOCS growth is indeed globally optimal. We find that the optimal cluster growth operation is a state transformation on a subspace of the full Hilbert space. Finally,more » we show that the maximal success rate of postselected entangling n photonic qubits or m Bell pairs into a cluster is (1/2)n-1 and (1/4)m-1, respectively, with no ancilla photons, and we give an explicit optical description of the optimal mode transformations.« less

  10. Wave packet interferometry and quantum state reconstruction by acousto-optic phase modulation

    NASA Astrophysics Data System (ADS)

    Tekavec, Patrick F.; Dyke, Thomas R.; Marcus, Andrew H.

    2006-11-01

    Studies of wave packet dynamics often involve phase-selective measurements of coherent optical signals generated from sequences of ultrashort laser pulses. In wave packet interferometry (WPI), the separation between the temporal envelopes of the pulses must be precisely monitored or maintained. Here we introduce a new (and easy to implement) experimental scheme for phase-selective measurements that combines acousto-optic phase modulation with ultrashort laser excitation to produce an intensity-modulated fluorescence signal. Synchronous detection, with respect to an appropriately constructed reference, allows the signal to be simultaneously measured at two phases differing by 90°. Our method effectively decouples the relative temporal phase from the pulse envelopes of a collinear train of optical pulse pairs. We thus achieve a robust and high signal-to-noise scheme for WPI applications, such as quantum state reconstruction and electronic spectroscopy. The validity of the method is demonstrated, and state reconstruction is performed, on a model quantum system—atomic Rb vapor. Moreover, we show that our measurements recover the correct separation between the absorptive and dispersive contributions to the system susceptibility.