bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatially variant apodization algorithm
Authors: Fienup J. R. , Stankwitz H. C. , Dallaire R. J.
Published: February 2023

Apodization (apertureplane weighting) suppresses impulse-response sidelobes in imagery.
Analysis of Lucosz-type superresolving imaging systems
Authors: Welch Gisele , Rhodes William T. , Morozov V. N.
Published: February 2023

Lukosz1 proposed and analyzed a class of systems capable of providing resolution beyond the classical diffraction limit.
Signal recovery using phase and amplitude coding techniques
Authors: Khoury Jehad , Fu Jack , Woods Charles L.
Published: February 2023

In applications such as aberration correction in lens design, distortion correction of transmitted images from turbulent medium and deconvolution of blurred images, one would like to use exact inverse filtering.
Image transfer in mutually pumped phase conjugators
Authors: Sharp Edward J. , Wood Gary L , Salamo Gregory J. , Anderson Richard J. , Neurgaonkar Ratnakar R.
Published: February 2023

Mutually pumped phase conjugators (MPPCs), operating in the steady-state, exhibit stable conjugate output signals after some characteristic build-up time which depends upon the particular crystal being used.
60-80-nm XUV projection lithography
Authors: Newnam Brian E.
Published: February 2023

Extreme-ultraviolet (XUV) projection lithography using 60-80 nm illumination is a potential method for mass producing 1-GBit integrated circuits with subsequent extendibility to 4- and 16-GBits via phase-shift masks.
Advanced semiconductor lithography
Authors: Garza César M.
Published: February 2023

Optical microlithography has been the enabling technology behind the spectacular growth of the integrated circuit industry over the last two decades.
Large-aperture single-transverse-mode-vertical cavity surface-emitting lasers
Authors: Wu Y. A. , Chang-Hasnain C. J. , Nabiev R.
Published: February 2023

We report a novel buried-heterostructure vertical cavity surface emitting laser (VCSEL) which emits the fundamental mode with aperture as large as 16μm in diameter and has a low threshold current of 1.2 mA.
Semiconductor waveguide switches and modulators
Authors: Zucker Jane
Published: February 2023

There has been a recent explosion in the complexity and sophistication of semiconductor guided wave devices for modulation and switching of optical signals.
Non-steady-state optical-parametric-oscillator model
Authors: Wong S. K. , Schepler K. L.
Published: February 2023

Optical parametric oscillation (OPO) is becoming a valuable and versatile method for generating tunable radiation from the visible to mid-infrared.
Arrayed-waveguide grating multiplexers
Authors: Okamoto K. , Takahashi H.
Published: February 2023

The arrayed-waveguide grating consists of input/output waveguides, two focusing concave slab waveguide regions and a phase-array of multiple channel waveguides with the path length difference ΔL between the adjacent waveguides. The light beam from the input waveguide radiates to the slab waveguide and then couples into the arrayed channel waveguides. After travelling through the arrayed waveguides, the light converges to a focal point in the second slab region where the output waveguides are located.
Fabrication of buried-channel waveguides in K+–Na+ ion-exchanged glass and the application of these waveguides to notch filters
Authors: Mauchline Iain S. , Stewart George
Published: February 2023

Recently we reported a channel dropping filter1 using the coupling from a surface K+–Na+ guide across a low index interlayer to a multimoded overlay film. An improvement on the design was sought by the introduction of a buried waveguide. Burying of K+–Na+ waveguides was first reported using an electric field assisted process2 where both planar and narrow channel guides (width < 10/1m) were fabricated. However, only planar3,4 and wide channel guides (30µm)5 have thus far been demonstrated by thermal backdiffusion. Here we report a new diffusion recipe allowing the fabrication of narrow, single mode channel guides for wavelength filters by a purely thermal process.
Search for superradiance of two trapped ions
Authors: DeVoe R. G.. , Brewer R. G..
Published: February 2023

Laser-cooled trapped ion crystals offer a unique opportunity to study the interactions between atoms. We have previously developed a microscopic planar Paul trap1 which is small and strong enough to bring the ion separation into the sub-micron region where quantum collective effects become important. A search is underway for the superradiant coupling of two atoms which manifests itself as a variation of the spontaneous emission rate with the ion-ion distance. We have produced an ion crystal with a separation of 1.1 microns in an 80 micron radius planar Paul trap. At this distance, equal to 2.2 wavelengths of the 493 nm Ba + transition, superradiant effects should alter the decay rate by about 10%. The two-ion crystal is imaged with sub-micron resolution by a new diffraction-limited vacuum-compatible microscope. The spontaneous emission rate is measured by a high repetition-rate transient spectrometer with an error of less than 1% for a single ion in a few minutes. Efficient extinction of the exciting laser light is provided by a new nonlinear electrooptic sideband switch.
Investigations of long-term frequency stability of free-running semiconductor lasers for HDWDM systems
Authors: Gladisch A. , Giehmann L. , Tetzlaff F. , Rocks M.
Published: February 2023

In future multichannel optical networks equipped with high density wavelength division multiplex (HDWDM) or coherent systems the fluctuations of the transmitter laser frequencies must be small compared with channel spacing in the range of a few Gigahertz. Several frequency control techniques have been demonstrated to get an absolute and relative frequency stability [1],[2],[3]. In switched multichannel broadband communication systems additional expensive equipment is necessary to control all locally dispersed independent subscriber lasers. As an alternative in future it might be possible that the center frequency of a free-running laser diode is stable enough and no additional frequency control or only a simple control mechanism must be employed.
Effect of waveguide modes on the spatial-frequency response of a photoreceptor
Authors: Stacey A. , Pask C.
Published: February 2023

The need1 to understand the acceptance properties of cones can be addressed by treating them as waveguides carrying modes. The number of modes carried and the extent to which each is excited determines the power presented to photo-pigments.2 However the extent to which different modes are excited changes with the exciting field.3 Sources with different spatial frequency or different coherence properties will have different exciting fields. We show that for a sinusoidal intensity source, produced by a pair of plane waves forming a Young’s interference pattern, the power transmitted to the photo-pigments in the outer segment is a function of the spatial frequency of the source, and the number of modes carried. When only the first mode is carried the contrast in the transmitted light is independent of the spatial frequency of the source. When two modes arc carried however the contrast in the transmitted light drops off with increasing spatial frequency up to a cut off, then increases again. These results show how the optical properties of the photoreceptors can contribute to the human visual acuity response curve.
Precise measurement of angle alpha
Authors: Cui Chengwu , Campbell Melanie C. W. , Bobier William R.
Published: February 2023

The deviation of the fovea from the optical axis of the human eye is traditionally represented by the angle between the optical axis and the visual axis, the angle alpha. This angle is not only important in many fundamental measurements of the ocular constants and ocular aberrations, but also of great importance in clinical optometry.1 We have developed a computer-controlled CCD video camera system of a high magnification and have measured the angles in a number of eyes both horizontally and vertically. Specially designed light sources, reference targets and precisely adjustable optical mounts enable the system to monitor and maintain the eye position within 0.03 mm. Due to possible transverse displacement and tilt of the crystalline lens, aligning all the Purkinje images was not possible for some subjects as reported by some earlier workers.2,3 An approximate optical axis was then defined by aligning Purkinje images I and IV. The precision of the measurement is within 0.15 = B0. Repeatability of the measurement is found to be restricted mainly by the fixation error of the subject and is generally within 0.2 = B0. The angles we have obtained for the eight eyes ranges from +3.0 = B0 to +5.6=B0 horizontally, which is in the same direction but generally smaller than the values from Tschering’s measurement.2 However, the vertical values ranges from 0.5 = B0 to 1.5 = B0 with the visual axis downward which is opposite in sign to the value traditionally quoted. The angles for the two eyes of the same subject are within 1.1 = B0 horizontally and 0.6 = B0 vertically. Support of NSERC Canada is gratefully acknowledged.
Dissociation energy of the HD molecule
Authors: Balakrishnan A. , Vallet M. , Stoicheff B. P.
Published: February 2023

Fluorescence-excitation spectra of HD have been obtained in the region of ~84 nm showing two dissociation continua corresponding to the photofragments H (1s) +D (2s) and H (2s) +D (1s). Pulsed and tunable coherent radiation was used for excitation with detection by fluorescence emission of Ly-α radiation. By application of a delayed electric field for quenching of the photofragments, only the 2s atoms were selected for detection. At the high resolution achieved, the profiles of the two dissociation limits were clearly observed, and values of the thresholds obtained. The two limits are separated by 21.61±0.10 cm-1, almost 1 cm1 less than the expected difference in excitation energies of the D(2s) and H(2s) atoms. The lower limit, with subtraction of the H(2s-1s) energy, gives a value of D0(HD) = 36 405.83±0.10 cm-1 for the dissociation energy of the ground electronic state of HD, which agrees with the recent ab initio calculation1 of 36 405.784+0.10 cm-1. The apparent discrepancy (almost 10 times the quoted error of measurement) of the value derived from the higher limit remains to be explained. When the present value of D0(HD) is combined with known values of the ionization potentials of HD and H, the value Do(HD+) = 21 516±0.10 cm-1 is obtained for the dissociation energy of the ion, again in good agreement with theory.
ESQW modulator and ESQW SEED using asymmetric Fabry-Perot structures
Authors: Choi Y. W. , Kwon O.K. , Lee S.H. , Shim S. , Won Y.H. , Lee E.H.
Published: February 2023

In recent years, there has been much interest in the extremely shallow quantum well (ESQW, x ≤ 0.04 in AlxGa1–x As barriers) structure1,2 for use in opto-electronic devices such as self electro-optic effect device (SEED).
Tunable optical multiple-quantum-well notch filter
Authors: Cheung S.K. , Jain F. , Sacks R. , Grudkowski T.
Published: February 2023

A tunable Fabry-Perot optical multiple quantum well notch filter, consisting of strained InGaAs/GaAs multiple quantum well (MQW) layers, is shown to yield a high contrast ratio (> 1200:1) as well as wide tuning range (>10 nm).
Measurement of GaAs quantum well index from distributed reflectance in resonant vertical structures
Authors: Hickernell R. K. , Christensen D. H. , Wang J. , Leburton J. P.
Published: February 2023

The accurate design and efficient operation of resonant, vertical-cavity devices such as surface-emitting lasers and Fabry-Perot modulators depend on accurate modeling of the complex refractive index of quantum wells.
Design issues in the development of an optical associative memory
Authors: Ralston Lynda M. , Beaudet William R. , Ward Reeder N.
Published: February 2023

The optical associative memory is a content addressable data storage system designed to search all data on an optical disk within one rotation of the disk.
High-processing-rate optical-computing system with a time-division-multiplexed data stream
Authors: Mihailidi Margarita , Siddique Masood , Alfano R.R.
Published: February 2023

Real time computer vision requires processing rates of 1000 Gops and input data rates close to 1 Gbyte/s.
Transient dynamics in a self starting fiber based soliton laser
Authors: Abraham D. , Nagar R. , Eisenstein G.
Published: February 2023

This paper describes the turn on / turn off dynamics as well as the steady state behavior of a self starting fiber soliton source.
Dependence of image resolution observed through multiply scattering media
Authors: Mahon R. , Moon J. A. , Duncan M. D. , Reintjes J.
Published: February 2023

The ability to image objects hidden by or embedded in dense scattering media has become important in the context of investigating the potential for an optical method of imaging through human tissue.1
Infrared and auto-fluorescence imaging of subretinal structures
Authors: Eisner Ann E. , Burns Stephen A. , Zenzie Henry H. , Moulton Peter F.
Published: February 2023

Using in vivo imaging techniques, we are studying atrophy or uncontrolled new blood vessel growth beneath the retina.
Effects of improved ocular optics on the resolution limit of a confocal scanning laser ophthalmoscope
Authors: Munger Rejean , Ogston Shawn , Stargard Mario
Published: February 2023

We have used a newly developed instrument capable of confocal scanning laser microscopy (CSLM) as well as confocal scanning laser ophthalmoscopy (CSLO) to investigate the effect of the optics of an eye on the resolution limit of a CSLO.
Photorefractive reflection gratings in [111]-cut Bi12TiO20 for adaptive interferometry
Authors: Kukhtarev N. , Chen Bo Su , Venkateswarlu P. , Salamo G. , Klein M.
Published: February 2023

Ability to perform real-time interferometry has been demonstrated by recording transmission holograms in [110] cut Bi12TiO20 (BTO) crystal[1].
Phase-shifting mask evaluation using a stepper-equivalent optical aerial image measurementsystem—AIMS
Authors: Budd Russell A. , Dove Derek B. , Staples John L.
Published: February 2023

Phase shifting photolithographic masks (PSM) promise to extend the resolution and depth of focus of today’s optical steppers, (1).
Precision optical testing of a soft-x-ray camera at λ = 14 nm
Authors: La Fontaine B. , Wood O. R. , MacDowell A. A. , White D. L. , Tan Z. , Bjorkholm J. E. , Himel M. D. , Tennant D. M.
Published: February 2023

One of the major challenges facing the soft x-ray projection lithography program is realizing high resolution, diffraction limited imaging. Even though near diffraction-limited images were obtained with two different x-ray cameras, at λ = 14 nm 1 and at λ = 42 nm 2, a quantitative characterization of the imaging capabilities of these systems is still lacking.
Vector-based techniques for color-image processing
Authors: Rodriguez Jeffrey J.
Published: February 2023

Color image processing is often done by applying monochrome image processing techniques to the individual spectral components. However, such an approach is often sub-optimal and neglects cross-spectral correlations. An alternative approach is to treat the image as a vector-valued function and use vector-based algorithms in a 3-D vector space. This can lead to improved enhancement, analysis, and visualization.
Polarization-based optical logic gates in photorefractive crystals
Authors: Wu Weishu , Campbell Scott , Zhou Shaomin , Yeh Pochi
Published: February 2023

Optical logic in photorefractive crystals has been extensively studied1. Some logic gates such as AND and XOR were achieved based on photo-induced volume gratings, where the logic values ‘1’ or ‘0’ are represented by the presence or absence of light beams. One disadvantage of this encoding method is that some logic gates can only be obtained by the cascading of other logic gates, making it cumbersome and inefficient. In this paper, we propose and demonstrate logic gates whose values are represented by the polarization state of light2, i.e., ordinary and extraordinary beams in photorefractive crystals. Some advantages are that 1) switching between two logic states, or, a NOT gate can be easily achieved using a standard half-wave plate, and 2) the two logic states are both represented by the presence of light beams. We demonstrate that all sixteen two-input binary logic gates can be easily achieved without cascading. Two inputs are represented by the two writing beams with respective polarization states. As well, the output value of the logic gate is represented by the polarization state of the diffracted beam. We also demonstrate a polarization based optical full adder.
High accuracy address decoding scheme for 2-D optical-memory devices
Authors: Hsu W.-F. , Sawchuk A. A.
Published: February 2023

Optical data storage has advantages over electronic memory in data capacity and access bandwidth. The high bandwidth of optical storage is mainly due to the large access unit (page), perhaps 128 × 128 to IK × IK bits at each read/write cycle [1]. Work is in progress on developing 2-D cell-oriented optoelectronic (OE) devices for short-term optical data storage or buffering, having a typical density of 1 Mbit/cm2 [2]. In this paper, an electrically controlled, optical addressing scheme for random access to a 2-D OE array is presented. The address decoding scheme employs micro laser sources, volume holograms, and a smart pixel array. Approximately 4 log
2
J binary patterns are recorded in a volume hologram acting as an optical addressing system. The reconstruction beams from the laser sources regenerate half of the recorded patterns, which overlap at the image plane. Using a thresholding operation implemented by smart pixel devices, a designated storage position can be identified. In this scheme, coding technology is used to achieve a high relative ratio of the first two high intensity levels. The relative intensity ratio is constant and independent of the OE storage size. Using this scheme, the optical buffer can thus tolerate larger noise and non-uniformities.
Recoded trinary arithmetic using optical symbolic substitution
Authors: Alam M. S.
Published: February 2023

The problems of achieving parallel arithmetic has been investigated by many authors using residue number system, modified-signed digit (MSD) number system and recoded MSD systems.1,2 Using residue arithmetic, one can perform parallel arithmetic in constant time using symbolic substitution (SS), but the size of the truth table required increases rapidly with the increase of the operand length. The MSD representation has been widely studied for implementing parallel optical arithmetic. Recently, we proposed a higher-order MSD technique2 for parallel arithmetic using SS. This technique2 performs carry-free addition and borrow-free subtraction by checking a pair of reference digit from the next lower order bit position. However, MSD representation requires negative representation of a literal. Most recently, a redundant binary number representation3 has been proposed for parallel arithmetic using only two literals, 0 and 1. For long bit strings, this scheme3 doubles the operand length. To overcome the aforementioned problems, we propose the recoded trinary arithmetic processing technique which performs multibit carry-free addition and borrow-free subtraction in constant time by employing a two-step SS scheme. In the first step, a set of SS rules are applied to the pair of numbers to be added into an intermediate pair. Subsequent application of the SS rules to the intermediate pair of numbers yields the result. This technique also leads to a compact design by incorporating more information in fewer digits using a higher radix number system.
Quantum Wire Microcavity Laser made from GaAs Fractional Layer Superlattices
Authors: Chavez-Pirson A. , Ando H. , Saito H. , Kanbe H.
Published: February 2023

We report the first demonstration of lasing action in a quantum wire microcavity semiconductor laser made from an array of (AlAs)1/4(GaAs)3/4 fractional-layer superlattice (FLS) quantum wires.
Multilevel phase-only filter for inspection of printed circuit boards
Authors: Heyward Waddie , Yang Hedong , Tam Eddy , Feldman Mike
Published: February 2023

A multi-level phase-only filter is designed for an optical correlator used in the application of punch-through-hole printed circuit board inspection.
Spontaneous emission and mode descriptions for very small semiconductor lasers
Authors: McCall S.L.
Published: February 2023

Several designs for very small semiconductor lasers have been demonstrated. Some structures, e.g. microdisk lasers, have dimensions approximately a wavelength and, consequently, the spacing between modes is about the spectral width of gain. The spectral shape of a mode may be modified from a Lorentzian shape.
Quantum motion of an atom in a standing-wave cavity: A de Broglie waveguide
Authors: Cai Tianwu , Huang Hu , Bigelow N. P.
Published: February 2023

There has been growing interest in the fact that the interaction of the cavity field with an atom involves not only the internal atomic degrees of freedom but also the atomic center-of-mass motion.
In-line quarter-wave retarders for the IR that use one and three total internal reflections
Authors: Kan’an A. M. , Azzam R. M. A.
Published: February 2023

Two IR reflection quarter-wave retarders (QWRs) are described that maintain the collinearity of the transmitted and incident beams.
Technique for controlling light amount in absolute spectroradiometry
Authors: Cui Dunjie , Yang Huayuan , Bu Cuiying , Ren Jianwei , Feng Jiazhang
Published: February 2023

At present the world level accuracy of spectroradiometry is about of 1x10-2.
Experimental characterization of two LCTV spatial light modulators
Authors: Bouzid Ahmed , Riasati Vahid , Almanasreh Ahmed , Abushagur Mustafa A.G.
Published: February 2023

The two SLMs under considerations are a 320×220 pixel, 1.25" diagonal clear aperture liquid crystal display (LCD) extracted from an Epson video projector system, and a 3.5" clear aperture diagonal LCD extracted from a Citizen LCD television system.
Detuning effects in transit-induced multistability
Authors: Kim Jeong-Mee , Rosenberger A. T.
Published: February 2023

When atoms in a beam pass through the cavity mode in a bistable system, multistability may be made possible due to coherent Rabi cycling of the atoms if the transit time is less than a spontaneous lifetime. Our previous study of this effect was limited to the absorptive case, and we showed that the multistability should be experimentally observable in spite of the degrading effects of spontaneous emission, transverse variation of the cavity mode, and velocity distribution of the atomic beam. Now we extend that work to consider the mixed absorptive-dispersive case by including nonzero detunings between the atoms and the laser and between the cavity and the laser. We find that, by adjusting the detunings, it is possible to modify the relative size of the secondary positive-slope regions compared to the size of the primary region of hysteresis in the state equation. The consequences of this change could be improved ease of experimental observation and richer instability behavior. We will also report on the effects of varying the ratio of the longitudinal and transverse relaxation times.
Construction of an instrument to align and cement doublets
Authors: Cornejo-Rodríguez Alejandro , Jaramillo-Núñez Alberto
Published: February 2023

An optical instrument can be made of simple lenses, doublets, triplets, and/or combinations of them. The production of high quality cemented doublets and triplets requires of a special fixture in order to fix the lenses (that will be part of an optical element), to cement them without loosing their alineation.
Computing optical-path length in inhomogeneous media—an alternative method
Authors: Puchalski Jacek
Published: February 2023

In this paper a new method for OPL computation for gradient-index media has been presented. This method is suitable for use with the fast and accurate ray-trace procedures which were developed earlier.
Polymer-clad waveguide chemical sensors for iodine detection
Authors: Khalid M. , Guerrero D. J. , Sluss J. J. , Glatzhofer D. T.
Published: February 2023

We have fabricated waveguide chemical sensors for iodine detection that utilize thin polymer cladding layers of poly((E,E)-[6.2] paracyclophane 1,5-diene) (PDE).
Theoretical development of an optical demultiplexer based on modal analysis of a five-layer waveguide
Authors: Delbridge James N. , Sluss James J. , Batchman Theodore E.
Published: February 2023

We have performed a design analysis which indicates that a five-layer semiconductor-clad waveguide structure can act as an optical de-multiplexer, provided that the semiconductor cladding thickness is properly chosen.
Low-loss, strained InGaAs/GaAs SQW for very-low-threshold DBR lasers
Authors: Fallahi M. , Chatenoud F. , Dion M. , Templeton I. M. , Delage A. , Barber R. , McGreer K. A.
Published: February 2023

Grating-coupled distributed Bragg reflector (DBR) lasers are very attractive for wavelength-division multiplexing and surface-emission laser arrays.
Novel four-channel wavelength division multiplexer formed by cascading three-waveguide couplers
Authors: Barbarossa G. , Armenise M. N.
Published: February 2023

The superiority of the three-wave-guide directional coupler (3WC) in filtering operations over the conventional 2WC is well known, the main advantage being a spectral response that is the square of that of the 2WC.
Dynamical Properties of Distributed Bragg Reflector Surface Emitting Laser Diodes Subject to Loss Modulation
Authors: Avrutin E. A. , Gorfinkel V. B. , Luryi S. , Shore K. A.
Published: February 2023

With a view to avoid relaxation oscillation limitations of directly modulated semiconductor lasers, several novel modulation techniques have been proposed recently.
Model of étalon effects in Z-scan measurements
Authors: Sutherland Richard L.
Published: February 2023

The Z-scan is an elegant single beam technique for measuring nonlinear refraction and absorption.1 A thin slab of material (thickness ≪ Rayleigh length) is scanned through the focus of a Gaussian beam, and the far-field transmittance through an aperture is measured.
Stimulated scatterings and optical limiting in liquid crystal fibers
Authors: Li Hong , Liang Yu , Khoo I. C.
Published: February 2023

Stimulated backward scattering of a pulsed laser at very low thresholds has been observed in isotropic liquid crystals. By comparing the temporal behaviors of transmitted and back scattered signals with that of the incident pulse, we notice that the pulse reshaping occurs at both transmitted and back scattered signals.
Intensity dimension that mediates shading
Authors: Sunaga Shoji , Shioiri Satoshi , Yaguchi Hirohisa , Kubo Souichi
Published: February 2023

We previously reported that luminance mechanism mediates shading perception with a spatially lowpass-filtered edge in a 2 deg disk (cutoff frequency varied from 7.2 to 1.4 cpd)1. In the present study, we examined whether shading perception is based on luminance for lower spatial frequency region.
Display of optical Fourier transforms for use in engineering education
Authors: van der Gracht Joseph
Published: February 2023

Optical Fourier transforming systems are useful tools for teaching Fourier analysis and synthesis to undergraduate electrical engineering students. The use of such systems is limited by the cost of the equipment and the difficulty of demonstrating the transforming properties to a large group of students.
High-conversion-efficiency doubly resonant optical parametric oscillator: theory and experiment
Authors: Shaw Kenneth D. , Liby Bruce W. , Post Stephen G.
Published: February 2023

The nonlinear coupled wave equations describing a doubly resonant degenerate optical parametric oscillator (DROPO) with a Fabry-Perot-type resonator have been solved exactly, we believe for the first time.
Femtosecond surface photochemistry
Authors: Ho W.
Published: February 2023

The use of femtosecond lasers to study the dynamics of chemical reactions on solid surfaces is relatively new. In addition to the possibility of following reactions in real time, the high photon flux of these short laser pulses gives rise to novel reaction channels which are absent in the gas phase and with cw or nanosecond lasers.
Laser-induced fluorescence study of OH desorption from Pt(111) during the oxidation of hydrogen and the decomposition of water
Authors: Fridell Erik , Elg Alf-Peter , Kasemo Bengt , Rosén Arne
Published: February 2023

The OH desorption rate has its maximum at 8-9% H2 for surface temperatures between 1100 K and 1400 K. With H2 replaced by D2, the OD desorption rate maximizes at somewhat higher hydrogen content. The “apparent” activation energy for OH desorption increases from about 1.4 eV at low partial hydrogen pressures to about 2.0eV for a hydrogen content of 25% and more.
Holographic mirrors and holographic Fabry–Perot filters
Authors: Wang Weijian
Published: February 2023

The reflection and transmission coefficients of holographic mirrors and holographic Fabry–Perot filters are studied. The diffraction efficiencies, the angular selectivities and the wavelength sensitivities of these devices, and also their effects on the spectrum and on the coherence properties of the incident light are investigated.
High-speed multiplexed holographic recording onto a moving medium
Authors: Yamamoto Manabu , Tatemichi Hidetoshi , Nonaka Koutarou
Published: February 2023

A high-speed multiplexed holographic storage system using a moving medium, such as optical disks, is described. To achieve multiplexed volume holographic recording onto a moving medium, we use different diffracted light beams generated from an acousto-optic deflector(AOD).
Patchy mosaic of L and M cones permits efficient tradeoff between spatial and color vision
Authors: Buchsbaum G. , Calkins D. , Sterling P.
Published: February 2023

Optimal sampling for the luminance channel requires a fine array of cones with identical wavelength sensitivity. Trichromacy creates a problem because at each transition between M and L cones their different wavelength sensitivities must either introduce a spurious edge or else distort the magnitude of an existing edge.
Observation of time-dependent interference in induced-coherence experiments
Authors: Grayson T. P. , Zou X. Y. , Branning D. , Torgerson J. R. , Mandel L.
Published: February 2023

In earlier experiments on induced coherence without induced emission1, interference was demonstrated to be closely related to the indistinguishability of the photon path.
Invariant pattern recognition using calculus descriptors
Authors: Chang Shoude , Arsenault Henri H.
Published: February 2023

A new integral image descriptor invariant under changes of position, orientation and of scale, called the Calculus descriptor is introduced.
Analysis of a multimode-fiber specklegram sensor by using the mode-coupling theory
Authors: Yu Francis T. S. , Zhang Jianzhong , Yin Shizhuo
Published: February 2023

In this paper, the performances of a multimode fiber specklegram sensor (e.g., the sensitivity and the dynamic range) are analyzed based on a waveguide mode-coupling theory.
High-energy contrast measurements of a chirped-pulse laser system
Authors: Paquette M. , Beaudoin Y. , Chaker M. , Kieffer J. C.
Published: February 2023

Capable of intensities of 1018–1019W/cm2, small, efficient table-top-terawatt lasers are now used for basic research in high-field physics, the generation of ultra-dense plasmas and sub-picosecond X-ray pulses.
Squeezing the noise of the axial oscillation in ion traps
Authors: Marzoli Irene , Tombesi Paolo
Published: February 2023

The motions of a charged particle in a Penning trap are coupled by means of a magnetic bottle.
Statistical phase excursions in image-plane interferometry
Authors: Prasad Sudhakar
Published: February 2023

Ground-based interferometry suffers principally from atmospheric phase corruption that is quite large in the pupil plane for large aperture sizes and separations.
Iterative design of real-time phase holograms in liquid-crystal television
Authors: Neto Luiz Gonçalves , Sheng Yunlong
Published: February 2023

The commercial liquid crystal television (LCTV) provides interesting phase modulation which is useful for real-time kinoform, phase-only filter (POF) and electro-optic zoom lens. But the LCTV exhibits also coupled amplitude modulation and phase mismatching (Φmax).<2π). We compare analytic solution, input-output iteration, simulated annealing and genetic algorithm for designing optimal phase holograms. The reconstructed image can be with random phase in the case of the kinoform or with a given amplitude and phase function in the case of the POF. The error in the reconstructed image is the central spot of zero order and other orders of diffraction caused by phase-amplitude cross coupling and phase mismatching as observed in optical experiments. Our analytical solution shows that the error can be reduced when the sampling points on the operating curve of the LCTV satisfy certain conditions. For the simulated annealing and genetic algorithm we defined the cost function that can be directly calculated without calculating the Fourier transform of the hologram so that the algorythms are fast and efficient. Experimental results will be shown.
Modes in n-dimensional first-order systems
Authors: Kauderer Mark
Published: February 2023

The evolution of the Hermite–Gaussian modes in one dimensional centered nonlossless sytems is a well known result.1 Using the generalized Hermite polynomials used by Arnaud2 we can easily prove by induction the corresponding result for any finite dimensional first order system, including misalignment and the corresponding normalization terms. Phase conjugators are easily incorporated into the analysis. Various properties of the generalized Hermite polynomials are proved. Biorthogonality of the modes is demonstrated. The higher order modes are not periodic, i.e. they have no self consistent solutions except the separable one dimensional solutions. Some applications involving the Hermite–Gaussians are also presented.
Demonstration of new methods for the design of asymmetric optical systems
Authors: Stone Bryan D. , Forbes G. W.
Published: February 2023

Methods for the layout of asymmetric systems have been recently developed.1,2 These methods provide a framework for constraining the configuration of an asymmetric system to ensure that the system possesses a prescribed set of low-order imaging properties. Such a procedure can significantly reduce the dimensionality of the configuration space, and there is a commensurate simplification in the process of determining good starting configurations. To illustrate the effectiveness of these methods, they have been applied to a relatively simple (yet far from trivial) problem in lens design. Specifically, the class of systems comprised of two conic mirrors have been studied in order to determine the best such system for soft X-ray projection lithography. The results of this investigation are reported.
Subwavelength structured surfaces for infrared optical elements
Authors: Raguin Daniel H. , Faklis Dean
Published: February 2023

Subwavelength structured (SWS) surfaces offer optical engineers new degrees of freedom in the design of optical systems. SWS surfaces may be designed as broadband antireflection surfaces for windows and domes, they may be used as polarization components such as linear polarizers and wave plates, and they may be used as narrowband filters for applications such as document security, spectral signature design, and laser end mirrors.
Limiting factors in peripheral spatial vision
Authors: Levi Dennis M.
Published: February 2023

Spatial vision is severely degraded in the retinal periphery. Visual resolution, detection thresholds and positional judgments are all impaired. Several factors might limit spatial vision in the periphery: these include: increased optical and neural blur; reduced contrast sensitivity; shifts in “spatial scale”; spatial undersampling and increased positional uncertainty. By studying detection and position discrimination under a wide range of conditions including: low contrast, Gaussian blur, bandlimited masking, segmentation and Gaussian jitter, it is possible to estimate how each of these factors interact to limit peripheral spatial vision. Our studies suggest that at least two key factors operate to limit spatial vision in the periphery: i) a shift in spatial scale, which accounts for alterations in detection thresholds with increasing eccentricity, and ii) increases in the uncertainty of the position labels of the underlying spatial filters, which result in increased positional uncertainty with increasing eccentricity. The relationship between these factors, and plausible underlying anatomical and physiological mechanisms will be discussed.
Light scattering around the glass transition region: Anomalous scattering and nanoscale inhomogeneities, and the boson peak
Authors: Schroeder John , Saha Susanta K. , Silvestri Markus R. , Whitmore Michael A. , Moynihan Cornelius T.
Published: February 2023

Rayleigh-Brillouin scattering and low frequency Raman scattering were studied in several fluoride and oxide glass samples with temperature as a variable. The temperature varied from room temperature to beyond the glass transition region. The Landau-Placzek ratio and the Brillouin shifts as a function of temperature in the glass transition region showed anomalous scattering phenomena in this region. For the Raman scattering the frequency regime studied is from close to the exciting line to ~200 cm−1 with the temperature range extending beyond the glass transition region. The intensity and the line width of the most dominant spectral line, the boson peak, was studied extensively and was interpreted in its relation to the extent of the density fluctuations in glass. The above results were interpreted as evidence of the physical origin of the non-exponential character of the structural relaxation kinetics and their relationship to thermally induced nanoscale inhomogeneities.
Soft-x-ray spectra of plasmas produced by high-intensity subpicosecond laser pulses
Authors: Jiang Z. , Kieffer J.C. , Chaker M. , Beaudoin Y.
Published: February 2023

We study the X-W emission (40 Å-200 Å) of plasmas produced by a high intensity subpicosecond laser. The experiments were performed using the INRS Table Top Terawatt 500 fs laser at both wavelengths of 1.05 μm and 0.5 μm and at intensities up to 5 × 1017 W/cm2. The spectra were recorded with two flat field UV spectrometers. We use both 101-07 Kodak and Shanghai 5 FW films. A comparison between the two films will be presented. The influence of various laser parameters on the ionization dynamics has been studied. In particular the laser pulse width was changed by controlling the compression gratings. Spectra obtained with pulse durations of 0. 5 ps, 1.3 ps, 5 ps and 1 ns will be presented and discussed.
Chromatic aberration of a nonlinear graded-index-rod lens
Authors: Chen Zhihao , Li Yucui
Published: February 2023

It is well known that the use of graded index (GRIN) rod lenses provides many advantages over the use of conventional lenses. A nonlinear (intensity-dependent) GRIN rod lens may be the logical evolution of the linear (intensity-independent) GRIN rod lens. With the development of laser technology, nonlinear fiber optics, and nonlinear optical material, researches on nonlinear GRIN rod lenses are clearly needed. A nonlinear GRIN rod lens, for example, an erbium doped GRIN fiber lens, may be fabricated by the current technology. From the reference1, it is expected that the nonlinear coefficient in such lenses may reach 7 × 10-15m2/W or above. This means that low beam power may produce large nonlinear effects in the lenses. Recently, we have studied some properties (imaging and ray path) of nonlinear GRIN rod lenses.2-4 However, to our knowledge, properties of chromatic aberration in such lenses have not been published before. Chromatic aberration is dominant in the imaging system. Our numerical results show that properties of chromatics aberration in a nonlinear GRIN lens are strongly dependent on the beam power and the incident beam waist, which has no counterpart in the linear case and under the geometrical optics approximation.
Scientific understanding and applications of laser cleaning
Authors: Zapka W. , Tam A. C.
Published: February 2023

Particulate contamination is a major yield loss factor in the manufacturing of microelectronic, data-storage, and other hi-tech devices. A single particle as small as 0.1 μm in size can cause complete micro-electronic circuit failure, or seriously degrade read/write performance of magnetic storage devices or even result in a crash of the magnetic head. Standard cleaning techniques, typically performed in liquid baths, have two major drawbacks: first, there is limited cleaning efficiency for submicron particles, and secondly, liquid baths tend to redeposit or even add new particles to the submersed surface. ‘Laser cleaning’, a technique currently being developed, appears capable of overcoming the above shortcomings. We observe that, particles of size 10 - 0.1 μm can be efficiently removed from various surfaces, and there is no need for a liquid bath. The technique we studied is based on the use of -pulsed infrared or ultraviolet lasers to explode a thin liquid film which is condensed onto the surface to be cleaned. Such explosion was studied in detail with nanosecond thermometry, photoacoustic detection, and fast photography. Momentum transfer from the expanding steam to the particles on the surface is believed to be the cause for the ejection of the particles. Ejection to ‘macroscopic’ distances (exceeding a few mm) from the surface facilitates particle collection procedures and thus prevents redeposition; this is of importance for practical application of ‘laser cleaning’.
Soliton transmission in cascaded distributed erbium-doped fiber amplifiers
Authors: Wen Senfar , Chi Sien
Published: February 2023

Soliton is considered to be the carrier for high bit–rate and long distance fiber communication system. Because of fiber loss, soliton is amplified periodically to maintain its power. Recently, lumped erbium-doped fiber amplifier (LEDFA) is successfully demonstrated to amplify the soliton.1 However, soliton experiences large power perturbation with LEDFA and it is stable only when the soliton period is much larger than the pump period.2 Thus the soliton pulsewidth can not be too short for long distance transmission. To reduce power perturbation, distributed erbium-doped fiber amplifier (DEDFA) is suggested.3 We numerically study soliton propagating in the cascaded DEDFAs of different doping densities. The results show that, for the soliton period less than the pump period, the soliton pulseshape can maintain well with the cascaded DEDFAs of proper doping density, but optical bandpass filter between DEDFAs is required to reduce neighboring interaction and maintain soliton separation. For example, with lpsec/km/nm dispersion, 30km pump period and 650GHz bandwidth filter, the pulseshape and separation of a 5psec soliton pair (9.9km soliton period) with 10 pulsewidth separation can maintain well over 10Mm. In this case, the maximum power variation is 3.2%; while, with LEDFA, it is 84%. Furthermore, the required pump power is greatly reduced to compare with the Raman amplifiers.
Dynamics of simple soliton arrays in architectured guide structures
Authors: Doty Sandra L. , Fork Richard L. , Haus Joseph W.
Published: February 2023

Recent experimental work on harmonic modelocking shows constraints on temporal spacing and frequency spectra can produce highly uniform trains of solitons. In addition, recent numerical simulation and analytical work predict: (1) solitons on the separate cores of dual core fiber can exhibit both repulsive and attractive interactions, and (2) individual solitons, satisfying certain threshold conditions, can propagate primarily on one core of dual core fiber despite significant coupling between guides. We use numerical simulation and analytical techniques to study the consequences of these findings for simple soliton arrays propagating in dual guide structures. In particular, we examine the case where strong constraints are imposed on the temporal spacing, amplitude, and frequency spectra of solitons in a given core, but weaker, or no constraints are imposed on solitons in the adjacent core. We find conditions, e.g., where a uniform train of solitons propagates primarily in the core where the strong constraints are imposed. We also find interesting dynamics for a “free” soliton in the second core that result from the interaction of the “free” soliton with the periodic potential produced by presence of the uniform soliton train on the first core. We examine routes to stability of this coupled system.
Spatial-soliton x-junctions and couplers
Authors: Akhmediev Nail , Ankiewicz Adrian
Published: February 2023

The intensity pattern created by the collision of two bright (dark) solitons can be considered as a nonlinear X-junction. In a self-focussing (self-defocussing) medium, this induces changes of refractive index, thus setting up a linear X-junction as well. It is possible to use this induced X-junction as a linear device. It can be much smaller than present X-junctions. The X-junction can be made in a photo-induced medium where the refractive index is changed permanently. This can be done because the exact solutions for the intensity distribution are known. We find a linear relation between the transmission ratio of the bright soliton coupler and the squire of the tangent of the angle between the two solitons. In the case of zero angle, this X-junction is a one-beat-length device in the sense that 100% of the energy goes to the left output if initially only the left input is excited. The coupler created by two dark solitons is a half-beat device. A linear coupler exploiting exact solutions has no loss, and is thus an ideal coupler in this respect at a given wavelength. The length of interaction for this coupler is the shortest possible and is thus optimal.
General type-I conversion efficiency for second harmonic generation in biaxial media
Authors: Wu Lin , Maldonado Theresa A.
Published: February 2023

For a general wavevector direction in biaxial media, there are two orthogonal extraordinary waves that propagate.1 General expressions for Type I conversion efficiency from an extraordinary fundamental wave to two orthogonal extraordinary second-harmonic (SH) waves are derived for arbitrary wavevector directions with respect to the principal coordinate system of biaxial media. The derived expressions for phase-matching include the fact that the walk-off angle between the Poynting vector and wavevector is different for each wave; i.e., there are three walk-off angles to consider. Two new parameters are introduced which modify the phase-matching conditions and which are functions of the permitivity tensor, wavevector, and walk-off angles. These expressions reduce to the condition for uniaxial media. The fundamental and SH extraordinary waves deviate as they propagate. Therefore, the effective overlap region is reduced due to this walkoff effect, lowering the conversion efficiency. The derived general expressions for Type I conversion efficiency include the directional dependence of the walk-off angles on the wavevector. The results are applicable in the limit of low conversion efficiency. Numerical calculations will be presented for specific materials. This work was supported by the NSF under grant no. ECS-9158022.
Evolution of optimal-optical interconnection by using spatial light modulators
Authors: Ololo Anthony , Caulfield Henry J.
Published: February 2023

Free space optical interconnection is a necessary ingredient to the eventual production of optical computers as well as electronic multiprocessors.
Storage density of 3-D disks
Authors: Li Hsin-Yu Sidney , Psaltis Demetri
Published: February 2023

The 3-D holographic disk (HD)1 consists of a thick disk-shaped photo-sensitive material where information is holographically stored in page format in the volume of the disk using angle or wavelength multiplexing.