bluuebunny/crossref_metadata_2025 huggingface dataset:
Coherent amplification without inversion of femtosecond optical pulses
Authors: Sweetser John , Dunn Thomas J. , Walmsley Ian. A.
Published: February 2023

Recent progress has been made in the theoretical and experimental study of the amplification of optical signals without population inversion (AWI) of the participating electronic levels. Induced coherence among appropriate levels in the active medium is the necessary condition for obtaining AWI. Similarly, the generation of wave packet states in atoms and molecules also relies on the coherent superposition of several states. It is feasible, therefore, that AWI is possible in a system which has been excited into a wave packet state. We have thus demonstrated experimentally such amplification in an extended sample of sodium dimers and we term this process wave packet amplification (WPA). An important characteristic of WPA is that the gain is doubly phase-sensitive—it is modulated at both the wave packet oscillation period and the optical period. The former time-dependence is a result of the periodic revivals of the pump-induced electronic polarization and the latter optical phase-sensitivity is a manifestation of the coherent nature of the molecular wave packet. The experiments to be described use a time-resolved upconversion method to detect the change in energy of a 50 fs probe pulse after it passes through a sodium heat pipe that has been pumped with another 50 fs pulse. The maximum saturated energy gain in this system is four and corresponds to all of the available energy being transferred from the wave packet to the probe pulse.
Lasing without inversion through population trapping in the sodium D1 line
Authors: Li Xingfu , Padmabandu G. G. , Wang Ching , Fry Edward S. , Scully Marian O.
Published: February 2023

Atomic coherence effects are shown to lead to the suppression of optical pumping, to the switching of light on and off when the coherence effects are turned on and off, and especially to lasing without inversion.
Electromagnetically enhanced two-photon gain and absorption
Authors: Gauthier Daniel J.
Published: February 2023

Recent research has shown that the interaction between an atom and an electromagnetic field can be modified favorably by illuminating the atom by an intense, auxiliary laser field.
Scale-invariant matched-filter generation by simulated annealing
Authors: Wilkinson T. D. , O’Brien D. C. , Mears R. J.
Published: February 2023

This paper outlines the implementation of a scale invariant binary phase-only matched filter using a 128x128 ferroelectric spatial light modulator.
Performance analysis of the amplitude- modulated, phase-only filter
Authors: Iftekharuddin K. M. , Karim M. A. , Awwal A. A. S.
Published: February 2023

An optical pattern or character recognition operation may consist of matching either amplitudes, or both amplitudes and phases, or only phases. More recently, amplitude-modulated-phase-only-filter (AMPOF) has been proposed [2], which effectively utilizes both amplitude and phase information to obtain a narrower and larger autocorrelation peak between images.
High-voltage electrical circuitry for fast-switching VLSI/FLC spatial light modulators
Authors: Mao C. C. , Johnson K. M. , Huang Z. Y.
Published: February 2023

Very-large-scale-integration-ferroelectric-liquid-crystal (VLSI/FLC) devices have many applications, including image display, optical correlation, and neural networks.1,2 With typical CMOS transistors, the VLSI circuitry can provide 0 V or 5 V to switch the liquid crystals.
Numerical-inequality detection using a smart detector array
Authors: Seyfou S. , Athale R.A.
Published: February 2023

Optical database machines are important because of the high readout rates available from parallel-access optical storage.1 However, the high throughput rates are limited by the bottle-neck created at the electronic host processor interface which has a much lower rate.
GaAs optoelectronic neuron circuits fabricated through MOSIS
Authors: Grot Annette C. , Psaltis Demetri , Shenoy Krishna V. , Fonstad Clifton G.
Published: February 2023

GaAs MESFET (Metal-Semiconductor-Field-Effect Transistors) circuits available through the MOSIS service have been shown to be stable with no significant change in the Schottky gate or ohmic contact properties after 3 hours at 525°C ± 10°C. This allows one to build high density complex electronic circuitry with optical inputs and optical outputs by using lowered temperature MBE regrowth for the optical sources.
Photon superposition states in a cavity through adiabatic transfer of Zeeman coherence
Authors: Parkins A. S. , Marte P. , Zoller P. , Kimble H. J.
Published: February 2023

We propose a novel scheme to prepare Fock states and photon superposition states in a cavity. It is based on the fact that the ground state Zeeman coherence of an atom which is passed through a cavity can be transferred on-to-one to a (coherent) superposition of photon number states of the cavity mode.
Toward nonlinear atom optics
Authors: Meystre Pierre
Published: February 2023

The last few years have witnessed considerable advances in atom optics and atom interferometry. In a parallel development, novel atomic cooling techniques have broken the recoil limit, so that atomic temperatures in the nanoKelvin and sub-nanoKelvin ranges are now possible.
High-speed infrared imaging polarimeter
Authors: McClain Stephen C. , Chipman Russell A.
Published: February 2023

A high speed imaging polarimeter has been constructed to measure the polarization of time-dependent sources in the infrared.
Multiplexing Fabry-Perot interferometer for remote-sensing applications
Authors: Cook William B. , Snell Hilary E. , Hays Paul B.
Published: February 2023

Typically a Fabry-Perot interferometer (FPI) is designed as a high resolution instrument for studying a very narrow spectral bandpass region.
Effect of the low-earth-orbit environment on coated polyvinylidene fluoride pyroelectric detectors
Authors: La Delfe Peter C. , Goeller Roy M. , Springer R. W. , Murray Hugh S. , Reeves Gary A.
Published: February 2023

An array of polyvinylidene fluoride, pyroelectric detectors with various selective absorber coatings was included in the Evaluation of Oxygen Interaction with Materials (EOIM-3) experiment which flew aboard the shuttle Atlantis in August, 1992.
Algorithm for approximate matching of patterns of point intensities
Authors: Scholl Marija S.
Published: February 2023

An algorithm for approximate matching of a distribution of point intensities to a reference distribution has been developed for identification of star fields detected with the CCD-based imaging cameras.
Theoretical study on remote sensing of cirrus-cloud microphysical properties from VAS IR soundings
Authors: Xu Lisheng , Zhang Jianyun
Published: February 2023

A technique for inferring microphysics and the optical thickness of cirrus clouds is developed in this study.
A new single shot linear diagnostic method
Authors: Zhao Xin Miao , Diddams Scott A. , Diels Jean-Claude
Published: February 2023

A pulse spectrum provides the amplitude of a Fourier transformed pulse |ℰ(Ω)|2.
Study of frequency-modulation effects in a laser-pumped rubidium maser
Authors: Tremblay Pierre , Beaubien Jean , Michaud Alain , Cauchon Éric
Published: February 2023

The laser-pumped 87Rb maser showed many new experimental features.1 A precise understanding of the maser behavior is obtained by considering a simple three-level atom, located inside a microwave cavity, interacting with a frequency-modulated laser. This simple model is based on the density operator formalism within a semi-classical approach. We show that moderately rapid modulation of the laser frequency results in sustained large hyperfine coherence, thus high gain, due to reduced light broadening, even for a high intensity pump. This is optimally achieved with a given modulation depth which is proportional to the light intensity. This last result has also been obtained when considering only the maximization of the population inversion.2 On the other hand the modulation greatly decreases the dependence of the maser frequency upon the laser frequency (through the variation of the light shift), therefore reducing the requirements for the mid- and the long-term frequency stability of the pumping laser. Finally the maser frequency suffers a small modulation, relatively insensitive to the modulation depth, which becomes negligible for sufficiently high modulation frequencies.
Intracavity entangled coherent states and local realism
Authors: Sanders Barry C. , Wielinga Bruce , Mann Ady
Published: February 2023

The generation of entangled coherent states in two coupled cavities is considered. The coupling is provided by a fast variable reflectivity beamsplitter and a nonlinear medium is placed in each of the two cavities. A coherent state in one cavity is split between the two cavities and is subjected to a nonlinear evolution in each cavity and evolves into a superposition of the coherent field with itself 180° out of phase. Two types of nonlinear media are considered: (1) a nonlinear Kerr medium and (2) a medium with large χ(2) and χ(3) nonlinearities. Medium (2) permits an entanglement with variable weighting between approximate coherent states. The two cavities are coupled together again and the result is described as an entangled coherent state.
Genetic algorithms in adaptive signal processing
Authors: Johnson Eric G. , Abushagur Mustafa A. G.
Published: February 2023

Adaptive signal processing is used widely in a variety of application such as filtering, beam forming, and interference canceling.
Some special optical techniques in the TW laser facility
Authors: Qiu Yue , Fan Dianyuan , Deng Ximing
Published: February 2023

The TW Nd: glass laser facility is the greatest laser system in China. Some special optics technique were developed for laser fusion and x-ray laser researches. One of them is adaptive optics equipments which consisted of deformable mirror and Hartmann wavefront sensor. They can detect and compensate laser beam aberrations induced by thermal distortion of amplifier and imperfections of the surfaces and materials. Another is lens array technique. It can provide a flat-top focal spot of diameter 400 pm and has been successfully used for high pressure shock wave experiments. A novel line focus system composed of an aspherical lens and a pair of cylinder lens arrays have been suggested for x-ray laser research. The length of the line focus is continuously variable by tuning the distance between the two cylinder lens arrays. The arrays can eliminate the nonuniformities induced by the incident beam. The focus lengths of element lenses are a little different from each other, so that the lengths of the sub-lines are random, this will further smooth the diffraction nonuniformity and enable to obtain a more uniform line.
Measuring distance by using a narrow cw laser beam
Authors: Aruga Tadashi , Toyoda Masahiro
Published: February 2023

Conventional distance measurement techniques using laser are mainly the so-called laser ranging by pulsed laser or by cw laser, e.g., using quasi-random modulation.
Symmetrical and asymmetrical modes in a dielectric film bounded by two identical nonlinear media
Authors: Li Yi-Fan , Iizuka Keigo
Published: February 2023

Comparing with the analysis of the linear waveguides, the analysis of the guiding properties of the nonlinear waveguides has been neither complete nor detailed.
Even and odd waves in a symmetrical three-layer planar waveguide with a nonlinear film
Authors: Li Yi-Fan , Iizuka Keigo
Published: February 2023

Unified expressions for the eigenvalue equation, field distribution and total power flow for symmetrical even and odd TE modes in a symmetrical waveguide comprising a nonlinear film are obtained for all possible linear dielectric profiles with both self-focusing and self-defocusing nonlinearities.
Submillimeter rectification and frequency doubling in semiconductor quantum wells
Authors: Shore K. A.
Published: February 2023

The central issue in the optimization of quantum well structures for optical processing is the design of structures whose electronic wave-functions maximize the appropriate nonlinear optical coefficient.
Singular-value decomposition using the bimodal optical computer
Authors: Atashi Adel , Abushagur Mustafa A. G.
Published: February 2023

Bimodal optical computer is a hybrid algebraic processor capable of solving linear and nonlinear algebraic problems.
Harmonic oscillator fiducials for Hermite–Gaussian laser beams
Authors: Steely S. L.
Published: February 2023

This paper illustrates the similarity of the functional forms of quantum mechanical harmonic oscillators and the modes of Hermite–Gaussian laser beams. This functional similarity provides a direct correlation to investigate the spot size of large-order mode Hermite–Gaussian laser beams.1
Spatial bilinear transformations in pattern recognition
Authors: Bouzid Ahmed , Abushagur Mustafa A. G.
Published: February 2023

Fourier transform techniques are vital to the design of optical correlators. Bilinear transformations, on the other hand, are useful to many other applications such as the design of digital HR filters.
Response time of color perception at the periphery
Authors: Takase Masanori
Published: February 2023

Response time from turning on a stimulus to switching on in an instant of light- or color-perception was measured. Test stimulus was presented at one aperture of nine loci in the viewing horizontal meridian. Luminance of the test stimulus and the surround one (size of 110°, N5 gray mat) was 45 nt.
Study of biological objects with new laser holographic microscope
Authors: Karpov Vladimir B.
Published: February 2023

The results of investigation of new holographic laser microscope are presented. The instrument involves following main components: Ar-laser (wave-length 0.514 mcm) as a source of linearly polarized high coherent radiation, the Mach-Zender scheme optical setup producing the dark field Fourier hologram of investigated object tissue, 1024 x 1024 pixels 18 mm x 18 mm CCD detector of the hologram field distribution, Stardent Workstation supercomputer allowing numerical reconstruction of the object image from the heliogram based on the original “stigmatic” program.
Computer-controlled laser illumination for use in medicine and biology
Authors: Ozolinsh Maris , Viesturs Ansis
Published: February 2023

A portable and convenient in use set-up is developed on the base of transparent electrooptic PLZT (lead-lanthanum zirconate-titanate) ceramics. Maximum of simplicity, possibility to use a computer for the laser beam intensity control, the broad spectrum range from visible (He-Ne, Ar++, Cr++) to near infrared (solid state lasers) regions allows to broad the area of application of laser illumination.
Photochemistry of metals and the role of hot-electron cascades
Authors: Hasselbrink Eckart
Published: February 2023

It has been experimentally observed that the surface photochemistry of chemisorbed molecular oxygen exhibits a dependence on photon energy characterized by a monotonous, exponential increase over the range from hv = 3.5 to 6.4 eV. Similar observations have also been made for other systems.
Evaluating OH desorption rates from Pt using spatially resolved imaging of Laser-induced fluorescence
Authors: Fridell Erik , Elg Alf-Peter , Kasemo Bengt , Rosén Arne
Published: February 2023

A question of central importance in this contest is to what extent the OH-LIF intensity can be assumed to be proportional to the OH desorption rate. It is demonstrated in this work, that this assumption is not generally valid in the pressure regimes where measurements have been performed.
Precision figure metrology at the National Institute of Standards and Technology
Authors: Evans Chris J.
Published: February 2023

Metrologists frequently invoke the “gauge maker’s rule” where the measuring instrument has a factor of at least four (and preferably ten) greater accuracy than the component or dimension to be measured. The optician, by contrast, frequently uses interferometers no more accurate than the part being made.
Comparison of phase-encoded and angular multiplexing in volume-holgraphic media
Authors: Bashaw M. C. , Aharoni A. , Walkup J. F.
Published: February 2023

Multiple holograms may be stored in volume holographic media through angular, phase-encoded, or wavelength multiplexing.1 We compare the cross-talk for angular and phase-encoded multiplexing.
Volume holographic storage in spiropyrans
Authors: Tarkka Richard M. , Brady David J. , Schuster Gary B.
Published: February 2023

Interconversion between metastable states of photochromic molecules can modulate the absorption and refractive index of doped polymer media. We describe the diffraction efficiency, sensitivity, and response times of holograms written with 633-nm light and erased with incoherent ultra-violet light using the commercially available benzospiropyran 1′,3′-dihydro-1′,3′,3′-trimethyl-6-nitrospiro[2H-1-benzopyran-2,2′-(2H)-indole] in various polymer hosts.
Writing laser scanners
Authors: Kessler David
Published: February 2023

The emphasis of this tutorial is on high performance continuous and half-tone writers. Issues such as design tradeoffs, deflector limitations, and print artifacts sources are discussed.
New business development in the turbulent 1990’s
Authors: Blum Fred A.
Published: February 2023

Creating and developing new high technology business whether entrepreneurial or intrapreneurial takes on a new complexity in the face of forces such as economic recession, industrial restructuring, declining defense budgets, globalization of markets, and changing capital markets. What succeeds in turbulence?
Structure and function of the visual system
Authors: Lennie Peter
Published: February 2023

This tutorial examines the structure and function of the visual system from the retina through the visual cortex. The talk touches briefly on the techniques available for probing the system and it reviews the signal transformations that are undertaken at different levels in the visual pathway, relating these operations to perceptual function possible.
MATLAB for spatial-vision modeling, data analysis, and image processing
Authors: Klein Stanley A.
Published: February 2023

Progress in vision research has been hampered by the difficulty that researchers have in using each other’s models. One typically develops models to explain one’s own data. It would be much better to use someone else’s model to explain one’s data since that would provide an independent test of the model.
Adiabatic and diabatic evolution during multiphoton ionization
Authors: Story J.G. , Duncan D.I. , Gallagher T. F.
Published: February 2023

When exposed to intense light of ~ 580 nm, the ground state of K shifts up in energy, passing through two photon resonances with Rydberg states and finally crossing the two photon ionization limit.
Local Fourier descriptors for a radial-basis-function image classifier that uses diffractive lenslet arrays
Authors: Raj K. , Athale R. A.
Published: February 2023

Global image statistics represent average behavior of the input image while local statistics are confined to certain regions.
Two-part technique for detection of optical-correlation signals
Authors: Crowe W.M. , Hanson A.C. , Taylor Travis
Published: February 2023

Optical correlators operating against low contrast targets in cluttered backgrounds often produce correlation signals which are difficult to detect.
Optical modulation through the combined interaction of spatially separate ultrasonic waves operating in different diffraction regimes
Authors: Larson D. A. , Black T. D.
Published: February 2023

An optical beam incident on two dynamic gratings, one formed by a surface acoustic wave (SAW) and the other formed by a bulk acoustic wave (BAW) is temporally modulated.
A Michelson interferometer for ground-based measurements of upper atmospheric winds
Authors: Gault William A. , Brown Stephen , Moise Avygdor , Liang Dongyu , Shepherd Gordon G.
Published: February 2023

The E Region Wind INterferometer (ERWIN) was designed specifically to measure winds in the cold (200 K) region of the earth’s atmosphere near the mesopause (85–100 km altitude) by detecting the Doppler shifts of the faint airglow emissions occuring there.
Short-term prediction of atmospherically distorted wave fronts
Authors: Jorgenson Mark B. , Aitken George J. M.
Published: February 2023

Accurate short-term prediction of atmospherically-distorted wavefronts could reduce the detrimental effects of the delays inherent in adaptive-optics control systems.
The optimization of bandwidth in adaptive optics telescope
Authors: Dazun Zhao , Xin Yu
Published: February 2023

The wavefront compensation residual error with frequency response adaptive optics telescope is mainly depended on two factors: one is the error caused from lack of compensating high frequency front detection error, the former will increase with the decrease of bandwidth, inversely, the latter will increase with the increase use of bandwidth, so that in the opinion of minimizing residual error, there is an optimization of bandwidth.
Critical issues for fiber-optic sensing systems within advanced composite materials
Authors: Measures R.M.
Published: February 2023

Implementation of Smart Structure technology will require a number of major challenges to be addressed.
Hologram recordings in dye-doped dichromated colloid films
Authors: Couture Jean J.A.
Published: February 2023

In a near future conventional optical elements will be replaced by holographic optical elements (HOEs). Those HOEs will play a key role in the optical processing and optical computing circuits as well as in non destructive holographic testing studies. The fabrication of such HOEs require high quality recording films; in the search of such a recording material, we studied photocrosslinking colloid systems as simple as dichromated polyvinyl alcohol films (DCPVAL). Those films gave volume holograms having a maximum diffraction efficiency value (MDE) of 18% at 488 nm; at 442 nm, we obtained MDE values between 40% and 55%. When adding a xanthene dye, the MDE value may be increased. All of those results were obtained in real-time holography and the recording films were free of any chemical development and repositioning before playing back the recorded information. Moreover, in the present communication we will introduce many new results on hologram recordings in dye doped dichromated casein films (DC-CAS). The knowledge of holographic properties of such dye dc-colloid films will permit to focus on “How they will be usable for imaging of 3-D objects and engineering applications.”
Lensless imaging through electronic holography
Authors: Arons Eric , Sun P.C.
Published: February 2023

We will describe a lensless imaging system which utilizes the advantages of electronic processing to produce high quality images. The principle behind the lensless imaging system is based on the mutual coherence function. When spatially broad, spectrally coherent light is used in an interferometer, interference will only occur at those point in the hologram plane where the object and reference beam’s coherence functions match. If the object is placed the prober distance from the hologram plane, a point to point mapping of the object to the hologram can be made. Thus the object is “imaged” to the hologram plane. The use of electronic holography affords many advantages over more conventional methods, including the ability to accumulate images both coherently and incoherently resulting in an increased signal-to-noise ratio. The limited spatial resolution of a CCD camera causes a degradation in image resolution when a spatial carrier is used to record the hologram. This problem can be overcome by introducing a temporal carrier. By changing the phase of the reference beam, object information can be extracted from the varying intensity patterns on the hologram plane. This technology will be applicable to areas ranging from metrology to imaging through inhomogeneities.
Results of atom-interferometry experiments with potassium
Authors: Clauser J. F. , Reinsch M. W. , Li S.
Published: February 2023

Results of high flux atom interferometry experiments with potassium in generalized Talbot-vonLau configurations are presented. The interferometer consists of a sequence of three planar vacuum slit diffraction gratings, microfabricated from silicon nitride membranes. Interference fringes are sensed by measuring the transmission of atoms on a hot-wire as a function of grating relative position. Different spatial Fourier components (up to fifth) in the diffraction pattern are resonant in the interferometer at different atomic velocities. When a laser cooled slow beam is incident, various different diffraction patterns are observed as a function of atomic velocity, selected via the tuning of D2 cooling lasers. In an alternative “Heisenberg Microscope” configuration an incident thermal beam produces a velocity average over different fringe Fourier components. Fringe patterns for each HFS component are revealed by their selective destruction by AC modulated weak Dl laser light passing through the interferometer near the middle grating. Since imaging of the fluorescent light could determine which slit an atom passes, the laser removes the fringe pattern contribution by Doppler shifted atoms at its wavelength. That contribution is thus AC modulated and detected. Shifts of the patterns by gravity and rotation are evident when the vacuum chamber is tilted.
Fiber speckle sensing using variation in mean absolute speckle intensity
Authors: Pan Kun , Uang Chii-Maw , Cheng Feng , Yu F. T. S.
Published: February 2023

In this paper, we present a fiber sensing technique which detects the mean absolute speckle intensity variation between the up-dated and the reference speckle patterns, by which the mean absolute intensity variation of the fiber output due to external perturbation gives rise to the change of the modal phase differences. This system can be used for displacement, temperature, pressure, and acoustic wave sensing in an environment where other conventional sensing techniques are difficult to be employed. We have shown that the proposed system is highly sensitive to the modal phase variation from a multimode sensing fiber and the operation of the sensing system is rather simple. One of the major advantages of the proposed system is that it can perform a real-time fast response dynamic measurement by using the off-the-shelf electronic hardware. From our experimental demonstration we have shown that this technique can be used for sub-micro displacement sensing, with a measurement sensitivity as high as 0.1 μm. By updating the reference pattern, the dynamic range of the proposed system can be extended. Experiment for temperature measurement is also provided, in which we have shown that the sensitivity can be as high as 0.1 °C.
Lasing without inversion—gain enhancement with a colored pump
Authors: Vemuri Gautam , Agarwal G. S. , Mossberg T. W.
Published: February 2023

Most models of lasing without inversion utilize incoherent pumping of the upper state of the transition on which lasing occurs. We suggest replacing incoherent pumping by a color pump (i.e. laser with a finite bandwidth) for selective pumping of the upper state, where one can also take advantage of the tunability of the laser. A three-level ladder system is considered with the upper two levels providing the lasing transition. We reduce the density matrix equations for this system to a set of eight coupled Langevin equations with multiplicative noise. These equations are solved using Monte-Carlo methods to obtain the gain as a function of various atom and field parameters. The use of the color pump leads to a significant enhancement in gain. Using a dressed states formalism, an explanation of the possible physical mechanism behind this gain enhancement is provided.
General formulation of methods for measuring the phase of ultrashort pulses
Authors: Walmsley I. A. , Wong V.
Published: February 2023

A long-standing problem in ultrafast optics is that of measuring the electrical field of a light pulse whose duration is shorter than the response time of a photodetector. We analyze a general scheme that uses an arbitrary combination of linear filters, interferometers and nonlinear detectors, and elucidate the properties that allow determination of the temporal or spectral phase of the pulse. In particular we discuss the possibility of phase determination via a linear interferometer and a square-law detector, and derive general conditions on the speed of the detector that allow us to identify the limitations of certain measurement schemes.
Visible-wave-band kinoform in a simple optical sight
Authors: Evans Clinton , de Carteret Harvey
Published: February 2023

A typical optical sight comprises a cemented doublet objective, an erecting prism, a graticule and an eyepiece. We are interested in using kinoforms in these devices for cost and weight reduction. To this end, we have replaced the objective in one of our rifle sights with a diamond-machined acrylic kinoform, so that we can evaluate the performance trade-offs.
Small-angle scattering in the ocean: who cares?
Authors: Gordon Howard R.
Published: February 2023

Using Monte Carlo simulations of radiative transfer in the ocean, I show that measurements of the absorption coefficient and the volume scattering function for scattering angles > 15 degrees of ocean water are sufficient for predicting the transport of irradiance in the ocean. Thus, the difficult-to-measure small angle scattering is not necessary in many applications. Furthermore, irrelevance of small-angle scattering suggests the irrelevance of the scattering coefficient and the routinely-measured beam attenuation coefficient in many radiative transfer problems. Finally, these observations provide a method for determining the adequacy of instruments employing small sampling volumes (~ few cm3), for predicting irradiance attenuation and diffuse reflection, which sample very large volumes (~ 10-105 m3).
Approximating fully complex spatial modulation with pseudorandom phase-only modulation
Authors: Cohn Robert W. , Liang Minhua
Published: February 2023

Diffractive optics are used to produce far-field patterns as predicted by the Fourier transform. Because typical diffractive elements do not modulate amplitude many design procedures have been developed that iteratively search for the optimal transform pair under the constraint of phase-only modulation. We have instead identified a non-iterative design procedure for approximating any pre-specified Fourier plane pattern with phase-only modulation across the input plane.
Absolute frequency measurement of a single-ion optical transition: the 24-THz excited-state transition in Ba+
Authors: Madej A. A. , Whitford B. G. , Siemsen K.J. , Sankey J. D.
Published: February 2023

A single, laser cooled ion held in a radio-frequency trap is a near ideal system for high resolution spectroscopy and for new optical frequency standards. We report the first absolute frequency measurement of a single ion optical transition using a frequency chain referenced to a primary frequency standard. The D-D excited state, fine structure transition at 24 THz of a single, laser cooled ion was probed using an electro-optic shifted, frequency sideband from an optically pumped ammonia laser operating on the sP (8,6) line. By recording the ion quantum jump rate as a function of laser detuning, single ion lineshapes were obtained free of any Doppler broadening. Measurements of the ion motional temperature gave estimates below 15 mK and a time dilation shift below 2 × 1017. A phase-locked, optical frequency synthesis chain starting from a primary cesium standard to the 24.029 THz ammonia probe laser frequency has been constructed and can provide accuracies of 1013. Simultaneous measurement of the ammonia probe laser frequency and the shifted sideband frequency have enabled an absolute frequency determination with an uncertainty below the kilohertz level at the optical probe frequency of 24 THz limited by the current linewidth and stability of the ammonia probe laser.
Difference-frequency generation in AgGaS2 by using single-mode diode-laser pump sources
Authors: Simon Ulrich , Miller Charles E. , Curl Robert F. , Tittel Frank K.
Published: February 2023

Recent advances in the development of high-power single-mode III-V diode laser technology now offer the possibility of using diode lasers as pump sources in difference frequency generation (DFG). Because of the compact size and direct electric excitation of diode lasers, a robust, portable diode laser based DFG spectrometer especially suitable for applications in environmental monitoring of trace species can be constructed. We report the mixing of a red single-mode III-V diode laser with a tunable single-frequency Ti:Sapphire laser in AgGaSs. For 1 W of Ti:Sapphire laser power and 12.1 mW of diode laser power up to 1.4 μW of cw tunable, infrared (λ5=μm), narrow band coherent radiation has been generated using Type I noncritical phase-matching. The applicability of this novel laser source to high resolution molecular spectroscopy has been demonstrated by obtaining a test spectrum. The effect of the non-Gaussian diode laser beam on the DFG conversion efficiency has been investigated. The feasibility of a compact, all-solid-state cw laser spectrometer based on the mixing of two diode lasers (808 and 690 nm) as pump sources in AgGaS2 has also been shown. With 12 mW of total diode laser input power more than 3 nW of infrared radiation could be generated to date. This research was supported by the Department of Energy, the Natural Science Foundation and the Robert A. Welch Foundation.
Small-signal analysis of semiconductor-laser dynamics in complicated cavities
Authors: Dods Steven R. A.
Published: February 2023

Sometimes the rate equations are inadequate even for a small-signal (linearized) analysis of semiconductor laser dynamics. A vertical cavity surface emitting laser with a vertically integrated and slightly detuned resonant cavity is an example. Because of the wavelength sensitivity of the multilayer structure, changes in refractive index inside the resonant cavity lead to large changes in photon life-time, which in turn modulate the intensity of the laser output (Q-switching). However a structure that has such a strong wavelength sensitivity violates one of the assumptions of the rate equation model: that the optical spatial mode pattern is independent of modulation frequency and that its contribution can be reduced to a single valued parameter such as cavity Q (or equivalently, photon lifetime). In the above example, and for other lasers having significant optical wavelength selectivity, it is better to replace the photonic rate equations (those beginning with dS/dt =) by a more basic electromagnetic analysis. This is done by considering the modulated light to be a sum of optical sidebands, and performing a transfer matrix analysis on each sideband separately, thus accounting for the wavelength dependence (1). The transfer matrix approach is convenient for numerical calculations, and results for the above structure will be shown.
Closed-form approximate analysis of the fundamental and higher-order modes in rectangular-channel and planar-slab dielectric waveguides
Authors: Erteza Ireena A. , Goodman Joseph W.
Published: February 2023

In previous work, we have addressed the problem of describing the fundamental guided mode in a dielectric waveguiding structure using variational principles. Using this method, the value of the propagation constant and a Gaussian wavefield approximation for the fundamental mode are determined using variational arguments based on the scalar wave equation. In this paper, we present the extension of this method to include higher order modes. In this extension, the higher order modes are approximated by Hermite Gaussian functions. We will present results of the higher order analysis, along with the sets of equations used to describe the higher order modes. The structures of interest are planar slab dielectric waveguides and rectangular channel dielectric waveguides. The variational method is computationally fast, and good agreement is seen with other methods of analysis. Ways to increase accuracy will also be briefly discussed.
Soliton interactions in long-distance communication systems
Authors: Evangelides Stephen G.
Published: February 2023

The sliding frequency filter has, by suppressing the Gordon-Haus arrival time jitter and the amplitude noise in both the “1”s and the “0”s, made possible soliton transmission over significantly longer distances and at higher bit rates. Higher bit rates are achieved by decreasing the soliton width. Since σG-H can be kept small the detection window needed for a BER of 10-9 is significantly less than the soliton soliton spacing of 5 τ. One would like to decrease the soliton spacing in order to further increase the bit rate. The limit on the soliton spacing will now be determined by the strength of the soliton soliton interaction. Using numerical simulation, we have studied how the sliding filters modify the solitons-soliton interaction. Simulations with copolarized solitons τ = 20 ps., η= 0.6 (filter curvature) and a sliding rate of +1.4 GHz/zc a soliton spacing of 3 τ show the interaction is completely suppressed over a distance of at least 12,000 km. This translates to a 60% increase in the bit rate. For many reasons it is attractiave to do polarization multiplexing of solitons. We have studied the interaction of orthogonally polarized solitons in a fiber with polarization mode dispersion (PMD) and sliding frequency guiding filters. Here the nearest neighbor interaction for solitons, spaced closer than ~3 τ, is modified by the time delay induced by the fiber birefringence. This can have a profound effect, depending on the amount of PMD, on the basic interaction. We will show the effect the sliding filter has on suppressing the soliton soliton interaction for orthogonally polarized solitons.
Nonlinear longitudinal modes in intracavity second-harmonic generation
Authors: Banerjee Partha P. , Pliszka Pawel
Published: February 2023

The two-point boundary value problem for interaction between the fundamental and second harmonic inside a ring resonator filled with a χ(2) medium is analyzed.
Magneto-optic trap for on-line capture of radioactive atoms
Authors: Gwinner Gerald , Behr John A. , Cahn Sidney B. , Ghosh Anindita , Xu Fei , Sprouse Gene D. , Orozco Luis A.
Published: February 2023

In order to perform laser spectroscopy of radioactive atoms, we have designed and tested a system that produces, transports, and injects them into a magneto-optic trap in a glass cell.1
Roles of optics in parallel computing
Authors: Louri Ahmed
Published: February 2023

The purpose of this tutorial is to highlight the roles of optics in parallel computing.
Passive range detection with incoherent optical systems
Authors: Dowski Edward R. , Cathey W. Thomas
Published: February 2023

We have devised a new model for describing the impulse response of sampled incoherent linear optical systems.
Evaporative cooling of magnetically trapped hydrogen
Authors: Doyle John M.
Published: February 2023

Cooling by evaporation occurs by the preferential removal of high energy particles followed by rethermalization of the remaining gas.
Equivalent-particle theory for soliton and optical-soliton interaction
Authors: Chen Lu-Jun , Liang Chang-Hong , Wu Hong-Shi
Published: February 2023

As an example, the soliton interaction in optical fiber is analyzed by this theory and the conclusions which are strictly in keeping with the results obtained by the inverse scattering technique and the variational perturbation theory are achieved.
Single-mode diode-pumped Nd lasers
Authors: Dawes Judith M. , Knowles David S. , Dekker Peter , Mendes Ingrid , Willis A. Peter , Piper James A.
Published: February 2023

The noise spectra of several Nd lasers including both microchips and rods in short (7 cm) end-pumped laser cavities have been studied. In most cases, an etalon was used to restrict the laser to a single longitudinal mode.
Time-dependent temperature profiles and birefringence in end-pumped laser rods: noncircular pump cross section
Authors: Farrukh Usamah O. , Barnes Norman P.
Published: February 2023

The impact of birefringence is relevant to the quality of laser beams. Circular pump beams of Gaussian or constant profiles causes position dependent birefringence. Noncircular end-pumped beams will produce noncircular temperature contours.
Depolarization measurements of an integrating sphere
Authors: McClain Stephen C. , Bartlett Chanda , Pezzaniti J. Larry , Chipman Russell A.
Published: February 2023

Using a rotating retarder Mueller matrix polarimeter, we have measured the depolarization properties of a commercially available integrating sphere.
Modeling waveguide illumination systems by using nonimaging optics
Authors: Hillman Lloyd W. , Hough Thomas A. , Van Derlofske John F.
Published: February 2023

The dashboard is the information center of an automobile. At night, it must be uniformly illuminated for aesthetic and safety reasons.
Studies of clusters by using ZEKE spectroscopy on anions
Authors: Arnold Caroline C. , Zhao Yuexing , Reiser Georg , Yourshaw Ivan , Neumark Daniel M.
Published: February 2023

Using zero-electron-kinetic-energy (ZEKE) spectroscopy of mass-selected negative ions allows us to combine the high electron energy resolution of this method with the mass selectivity inherent in ion beam experiments.
Simulation of the radial energy distribution of a laser beam propagating through a medium with multistep photoionization
Authors: Akaoka Katsuaki , Maruyama Yoichiro , Arisawa Takashi
Published: February 2023

In the Atomic Vapor Laser Isotope Separation process with large volume of photon-atom interaction, multi-color laser beam travels through the atomic vapor as long as several hundreds of meters.
Quantum noise in pulsed optical-fiber amplifiers
Authors: Kahraman Gokalp , Saleh Bahaa E. A.
Published: February 2023

We consider the amplification of an optical pulse by an erbium-doped fiber, including photon statistics and population dynamics.
Optical in-situ monitoring techniques for optical and semiconductor coatings
Authors: Sankur Haluk
Published: February 2023

Summary not available.
Integrated photoreceiver and transmitter arrays for optical-data-link application
Authors: Dutta N. K.
Published: February 2023

Parallel optical interconnection is an important technology for computing and switching systems.
Integrated CMOS photodetectors for optical interconnects
Authors: Childers J. E. , Morris J. E. , Feldman M. R.
Published: February 2023

An optically interconnected multi-chip module is currently under development at UNC-Charlotte. The module consists of a transparent substrate and a planar mirror.
Diffractive optics fabricated by direct write with electron beam on analog resists
Authors: Lee Sing H.
Published: February 2023

To achieve high diffraction efficiencies, it is necessary for diffractive optics to have multi-level phases. With conventional methods of diffractive optics fabrication, n photolithographic masks and etching steps are required to produce 2n phase levels.
Basic analogies in advanced resonators for high-power and femtosecond lasers
Authors: Magni Vittorio
Published: February 2023

A strict formal analogy exists between the description and the properties of resonators used for high power solid-state and femtosecond lasers.
Squeezing
Authors: Carmichael Howard J.
Published: February 2023

The tutorial will explain quantum trajectory theory, a theory that uses stochastic wavefunctions to describe the time-dependent state of a quantum source of light.
High-precision spectroscopy of morphology-dependent resonances in microdroplet emission
Authors: Eversole J. D. , Lin H.-B. , Huston A. L. , Campillo A. J. , Lai H. M. , Leung P. T. , Liu S. Y. , Young K.
Published: February 2023

The spectroscopy of morphology dependent resonances occurring in
rhodamine6G dye emission from 14-16 micrometer diameter ethanol
microdroplets have been studied with high resolution (±1.5
cm1).
Application of MDSRS in atmospheric-chemistry studies
Authors: Aker Pamela M.
Published: February 2023

Recent observations of stratospheric ozone depletion suggest that heterogeneous chemistry plays a more prominent role than previously thought in determining global atmospheric chemical balance.
Raman spectroscopy of levitated diamond microcrystals
Authors: Whitten William B. , Shaw Robert W. , Ramsey J. Michael
Published: February 2023

Raman spectra are frequently used to characterize the quality of chemical vapor deposited diamond films and crystals. The spectra of CVD films often show features not present in high quality natural or synthetic crystals that are attributed to sp2 bonds, diamondlike carbon, or grain boundary effects.
Influence of multiphoton absorption on stimulated scattering and phase conjugation
Authors: Karpov Vladimir B.
Published: February 2023

Correction of wave front aberrations by nonlinear optical phase conjugation (OPC) is a well known way to obtain as high as possible intensities for near infrared and visible spectral ranges.
Simultaneous amplification and compression of picosecond optical pulses during Raman amplification in optical fibers
Authors: Headley Clifford , Agrawal Govind P.
Published: February 2023

A novel technique that can lead to simultaneous amplification and compression of picosecond optical pulses is proposed.
Black bandpass interference filters
Authors: Dobrowolski J. A. , Kemp R. A. , Sullivan Brian T.
Published: February 2023

Bandpass filters can be based on the intrinsic absorption in colored glasses, organic solvents, gases and liquids.
Mode locking through nonlinear spectral reshaping
Authors: Piché Michel , Belahlou Allaoua
Published: February 2023

The propagation of short optical pulses in a Kerr material has the effect of imparting a phase modulation to the short pulses.
In situ ellipsometric study of the growth of dielectric thin films
Authors: Rivory J. , Fisson S. , van V. Nguyen , Roisin Ph. , Vuye G. , Wang Y. , Abelès F.
Published: February 2023

CaF2 and TiO2 films, evaporated by a K-cell and by an electron gun respectively, are grown on Si substrates at high temperature.
Optical thin film optimization by Fourier transform filtering techniques
Authors: Verly P. G.
Published: February 2023

Fourier transform techniques of the type developed and implemented at the NRCC are well suited to the design of dielectric graded index optical coatings.
Trading one dimension for binary simplicity
Authors: Lohmann Adolf W. , Castaneda Jorge Ojeda-
Published: February 2023

A 2D binary mask as input together with a simple binary spatial filter can produce arbitrary complex amplitudes as ID output of a 4f system.
High-space-bandwidth-product computer-generated volume holography
Authors: Rosen Joseph , Segev Mordechai , Yariv Amnon , Barhen Jacob
Published: February 2023

Computer-generated holograms (CGHs) are becoming essential components in optical signal processing schemes.
Coding of kinoform structures by using four phase levels
Authors: Langlois Pierre , Bacon Nathalie , April Gilbert
Published: February 2023

Practical realization of discrete type kinoforms using phase quantization has been extensively studied.
Distortions of the probe-light wave front in a thermal-lens pump-probe experiment
Authors: Marcano A. , Castillo J.
Published: February 2023

Distortions of the probe beam wave front due to the scattering on the thermal lens induced by a pump light field are calculated using a nonlinear geometrical model.
Wide-angle Michelson interferometer for multiple-emission measurements
Authors: Ward William E. , Gault William A. , Shepherd Gordon G.
Published: February 2023

Current applications of the wide-angle Michelson interferometer have concentrated on its use as a device for measuring the Doppler shifts and widths of isolated emission lines. By coupling this device in series to an étalon or narrow band interference filter this restriction to single emission lines can be lifted. With such an approach, emissions from selected lines in a molecular band can be simultaneously observed and the rotational temperature, linewidth and emission rate measured. This has been implemented in the measurement of emissions from the O2 atmospheric band on the Wind Imaging Interferometer (WINDII) on UARS.