bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Resolution 3-D Imaging of Biological Objects by Standing-Wave Fluorescence Microscopy
Authors: Bailey Brent , Lanni Frederick
Published: February 2023

Axial resolution in conventional fluorescence microscopy is considerably worse than transverse resolution because the axial location of a specimen feature is not encoded directly in the image, but rather, is indicated by its degree of defocus.
New nonlinear-optical technique for 2-D gated medical imaging with longlaser pulses
Authors: Bashkansky M. , Adler C.L. , Reintjes J.
Published: February 2023

It was known for some time now that gated imaging with short laser pulses is possible in a scattering medium.
High-speed measurements of gain-switched 1.5-μm compressively-strained MQW gain-coupled DFB lasers
Authors: Delfyett P. J. , Zah C. E. , Bhat R. , Caneau C. , Favire F. , Pathak B. , Lin P. S. D. , Gozdz A. S. , Andreadakis M. C. , Koza M. A. , Iqbal M. Z. , Izadpanah H. , Lee T. P.
Published: February 2023

Low chirp semiconductor lasers may play important roles in high speed light-wave communication systems.
Improved Z-scan techniques for ultrasensitive measurements of nonlinear refraction and absorption
Authors: Xia T. , Said A.A. , Sheik-Bahae M. , Senesi F. , Wamsley C. , Hagan D.J. , Van Stryland E.W.
Published: February 2023

Z-scan is a method for measuring both nonlinear refraction and absorption using a single beam. Changes in transmission of the beam through a far-field, on-axis aperture are measured as the sample is scanned through the focal plane[1].
Comparison of the effective nonlinearity of chemically enhanced bacteriorhodopsin thin films
Authors: Song Q. Wang , Zhang Chunping , Gross Richard , Birge Robert
Published: February 2023

Interest in using photochromic protein bacteriorhodopsin (bR) for optical processing and real-time holography has increased dramatically in recent years.
Error diffusion on a space filling curve
Authors: Knox Keith T.
Published: February 2023

Error diffusion is a digital halftoning algorithm that produces high quality binary images, with good detail rendition and little apparent texture noise.
Fourier-optics description of photorefractive phase conjugation of nonuniform beams
Authors: Meigs Andrew David , Saleh Bahaa E. A. , Tataronis John A.
Published: February 2023

We have measured the reflectance of a photorefractive phase-conjugate mirror as a function of the angle of misalignment between the pumps and the angle between the probe and the backward pump.
Novel phenomenon of beam fanning in organic solutions and thin films
Authors: Abdeldayem Hossin , Witherow William K. , Shields Angela W. , Penn Benjamin G. , Frazier Donald O.
Published: February 2023

The induced nonlinear phase on an input beam by an intensity-dependent refractive index medium, modulates the beam and projects interference fringes of nonuniform intensity.
Japanese superresolution lithography
Authors: Terasawa Tsuneo , Fukuda Hiroshi , Imai Akira , Okazaki Shinji
Published: February 2023

Lithography is one of the most important microfabrication technologies for ultralarge-scale integrated (ULSI) devices. To improve the resolution of optical lithography, the use of high numerical aperture lenses and shorter wavelength exposure light have been investigated.
Terahertz pulse generation and detection: carrier-transport effects
Authors: Norris T. B. , Son J. , Sha W. , Whitaker J. F.
Published: February 2023

THz pulses have been generated using ultrashort optical pulses incident on biased semiconductor structures via optical rectification and carrier transport.
Transient carrier dynamics in electric and magnetic fields
Authors: Jin Y. , Hewitt T. , Ware K. , Zhang X.-C. , Kingsley L. E. , Weiner M.
Published: February 2023

We report measurement of the influence of electric and magnetic fields on optically induced picosecond electromagnetic radiation from semiconductors.
Optoelectronic integration for high-performance computing and communication
Authors: Kang S. M. , Morikuni J. J.
Published: February 2023

For high-performance computing and communication, the availability of gigabit-per-second optical links would offer a tremendous improvement over the ten megabit-per-second optical links offered by present-day Ethernet systems.
Scaling of diffractive and refractive lenses for optical computing and interconnections
Authors: Ozaktas Haldun M. , Lohmann Adolf W. , Urey Hakan
Published: February 2023

Discussion of scaling of integrated circuit features and their effect on system parameters such as power dissipation, speed, chip area etc. have contributed useful insights to the understanding of the trends and limits in very large scale integration.
Vertical cavity surface emitting lasers with a large mode suppression ratio
Authors: Dziura T. G. , Yang Y. J. , Fernandez R. , Wang S. C.
Published: February 2023

Vertical cavity surface emitting lasers (VCSELs) are being developed for optical communication, computing, and display applications.
Phase correction of coupled arrays of vertical-cavity surface-emitting diode lasers for on-axis emission
Authors: Warren M. E. , Lear K. L. , Vawter G. A. , Chalmers S. A. , Hadley G. R. , Zolper J. C.
Published: February 2023

Two-dimensional arrays of coherently coupled vertical-cavity surface-emitting lasers (VCSELs) primarily emit in an out-of-phase mode that results in four major off-axis lobes in the far-field.
Contrast ratios of spatial light modulators and optical correlation
Authors: Gianino Peter D. , Horner Joseph L. , Woods Charles L.
Published: February 2023

The contrast ratio of a spatial light modulator (SLM) is defined as the ratio of the maximum to the minimum readout light intensities under uniform write illumination.
Multiwavelength substrate interconnects for demultiplexing applications
Authors: Wang Michael R.. , Jannson Tomasz. , Sonek G. J..
Published: February 2023

Single wavelength fanout and multi-wavelength WDM components are important in optical fiber communication links and wafer scale integrated (WSI) systems for optical interconnection and networking. The use of transparent substrates as beam propagation and interconnection media for such devices are attractive owing to the dimensional freedom and compact packaging the substrates offer. Substrate fanout1,2 and WDM3 optical interconnects based on 2-D holographic diffraction have been reported. However, in some planar-integrated transceiver and networking applications 3-D diffraction based devices may be required to achieve the planar fanout and WDM interconnects. Herein, we report on the realization of a substrate WDM device following our previous work on substrate fanout and simplified holographic 3-D diffraction theory.4
Optical-frequency control for dense wavelength-division-multiplexing (DWDM) networks by using sum-frequency generation in multilayer waveguides
Authors: Guy Martin , Villeneuve Bernard , Svilans Mikelis , Têtu Michel , Cyr Normand
Published: February 2023

The intrinsic wavelength stability of current free-running DFB lasers implies that wavelengths in a DWDM network could be periodically measured and corrected to keep them within tolerances. The main element of the wavelength controller is based on the measurement of the surface emission angle of a sum-frequency (SF) signal generated by the interaction of two counterpropagating near-infrared waves in a semiconductor multilayer waveguide.1 This angle is related to the optical frequency-difference between the two input signals. We have shown that a frequency-difference of less than 2 GHz around 1.3 µm can be resolved with a simple optoelectronic setup using a photodiode sensing array.2 In this paper we incorporate into the setup a reference wavelength as one of the two inputs. This reference is obtained by locking a DFB laser to an atomic transition of Krypton at 1.318102 µm using the optogalvanic effect. We describe a calibration procedure for measuring the frequency-difference between the reference and another laser. We then show absolute control, within a few GHz, of a slave laser at 1.304 µm by adjusting its current to obtain a prescribed SF emission angle, i.e. a prescribed wavelength. This technique could also be used to control laser frequency in the 1.55 µm communication band. The frequency resolution demonstrated in our work is already compatible with the projected requirements of next-generation high bit rate DWDM networks.
How to teach teachers the use of the OSA Optics Descovery Classroom Kits
Authors: O’Shea Donald
Published: February 2023

A demonstration of the use of the OSA Optics Discovery Kits. This project of the OSA Education Council has placed over 20,000 kits in the hands of school-age children, The kits contain simple lenses, a mirror, a hologram, a polarizer and other simple optical items, and are used to stimulate curiosity and interest in optical concepts.
Laser spectroscopy of HgRG and Hg2 molecules in supersonic beams
Authors: Koperski J. , Atkinson J.B. , Krause L.
Published: February 2023

Fluorescence of HgHe, HgNe, HgAr, and Hg2 van der Waals molecules was excited in a pulsed expansion beam by pulsed radiation from a frequency-doubled dye laser. The vibrational structures in the excitation spectra resulting from dye-laser scans were registered with a transient digitizer. The HgRG spectra each consist of two vibrational progressions, one on the long-wavelength side and one on the short-wavelength side of 253.7 nm atomic Hg line. Standard vibrational analyses yielded the frequencies, anharmonicities and dissociation energies for the ground- and excited states of the molecules, which are compared with data reported elsewhere. Although there is general agreement with previous spectroscopic results, there are some discrepancies for the HgAr spectrum [1], and also for the Hg2, spectrum [2].
Determination of the electron transition moment of the SiH (A2Δ-X2Π) band system determined by recording of shock-excited spectra with an optical multichannel analyzer
Authors: Shin Joseph B. , Shen Jin. Z. , Cann Mark W.P. , Nicholls Ralph W.
Published: February 2023

Band systems of the astrophysically important molecules SiH and SiN have been excited by shock excitation of silane/N2 mixtures. Spectra were digitally recorded by use of an optical multichannel analyzer. They were analyzed by comparison with spectra produced by realistic numerical synthesis methods. Data for the SiH (A2Δ–X2Π) system will be presented. They include band-strengths and the variation of the electronic transition moment with wavelength and internuclear separation. This work has been supported by research grants from Natural Sciences and Engineering Research Council of Canada.
Optical dating of Chinese ancient pottery
Authors: Li Zhengzhi , Shen Jiangfeng
Published: February 2023

We proposed a method for laser dating of ancient Chinese pottery, which determines the time since the pottery was last exposed to sunlight. An argon-ion and krypton laser are used to excite electrons from thermally-stable light-sensitive traps and the subsequent recombination luminescence is used as a measure of the past radiation dose.
Activation kinetics and amplification of the phototransduction G-protein cascade revealed in the a wave of the human electroretinogram
Authors: Pugh E. N. , Breton M. E.
Published: February 2023

A theoretical model1,2 of the phototransduction G-protein cascade predicts that the activation phase of normalized rod responses to brief flashes can be characterized by a parameter, A, the amplification constant. A has the units s-2 (per photoisomerization), and is expressible in terms of biophysical parameters of the cascade. Empirical investigation of amphibian rods has confirmed a number of quantitative predictions of this model1,2, and yielded the estimate A ≈ 0.1 s-2. We have applied the G-protein cascade model to the a-wave of the human ERG, established to be proportional to the receptor photocurrents. The model provides an excellent description of families of a-waves from normal observers, and yields the estimate A ≈ 10 s-2, about 100-fold higher than A of amphibian rods. Theory shows that 25-fold of the 100-fold increase in A is due to the 25-fold smaller volume of the human rod; the residual 4-fold likely due to temperature-dependent increases in the rates of two cascade steps. We show that estimation of A in eyes having photoreceptor disease shows can yield insight into the mechanism of the disease.
Electronic transition moment in the nitric oxide β band system
Authors: Luque Jorge , Crosley David R.
Published: February 2023

Fluorescence emission scans have been made of bands of the NO ß-system (B2Π-X2Π) following laser excitation of v′ = 0, 1, 2, 3, and 7. Time dependent decays furnished the radiative lifetimes for these levels. The band intensities were used together with calculated Franck-Condon factors and r-centroids to derive an empirical electronic transition moment which varies with internuclear distance. The functional form agrees well with that deduced from an analysis of chemiluminescent spectra of several bands,1 and with lifetime trends measured here and previously.2
Collisional avalanche in atomic cesium
Authors: Lenef A. , Kreysar D. , Rand S. C.
Published: February 2023

Light tuned to the 6p 2P½ → 8s 2S1/2 excited state transition wavelength 761.09 nm in a region of (ground state) spectral transparency of Cs causes abrupt appearance of population in the 6p state after delays of up to five seconds following the introduction of radiation into the vapor cell. These nonlinear dynamics occur at laser intensities well below that necessary for laser-induced plasma formation or saturation, and only at vapor densities exceeding 1016 cm-3. The temporal evolution of p state fluorescence is reproduced by calculations of a laser-induced critical reaction (avalanche) involving resonant energy exchange between excited 6d 2D3/2 and ground state atoms during collisions. Experimental threshold density and the variation of avalanche delay with incident intensity are shown to be in good agreement with theoretical expectations based on measured excited state collisional cross-sections. Implications of this effect, in which the rate of excited state collisions can be varied optically at constant vapor density, for unique studies of local fields in nonlinear optical interactions of dense systems and collisional contributions to excited state dephasing are suggested.
Infrared kinetic spectroscopy of free radicals by using a novel difference-frequency-generation spectrometer
Authors: Miller C.E. , Eckhoff W.C. , Curl R.F. , Simon U. , Tittel F.R.
Published: February 2023

We have developed a continuously tunable, high brightness, high resolution spectrometer for obtaining infrared spectra and kinetic information for free radicals. This source is based on difference frequency mixing of two single frequency visible lasers in AgGaS2 using type I non-critical phasematching. We have previously demonstrated that our spectrometer extends the advantages of difference frequency generation spectroscopy into the 4-9 µm (2500 -1100 cm-1) portion of the infrared fingerprint region.12 Improvements in the infrared power output, the multipass absorption cell, and the experimental geometry have now enabled us to record the first free radical spectra with this spectrometer. The ν2 C=O stretching fundamental of HOCO was observed in the 1862 cm-1 region3 and portions of the the ν2 CCN antisymmetric stretching vibration of HCCN have been found near the 1740 cm-1 value predicted from matrix isolation studies.4 The implications of the CCN antisymmetric stretching motion on the question of quasi-linearity in HCCN will be addressed.
Variable-reflectivity folded-cavity surface- emitting quantum-well laser
Authors: Cheung S. , Jain F.
Published: February 2023

A novel folded cavity surface emitting laser structure with variable reflectivity, consisting two oppositively 45°-flipped downward etched facets and a strained multiple quantum well (MQW) Fabry-Perot modulator, is proposed.
Enhanced Raman scattering from submicrometer Si grating structures
Authors: Zaidi Saleem H. , Chu An-Shyang , Brueck S. R. J.
Published: February 2023

Sub-micrometer Si grating structures are of interest for a variety of applications, i.e., light emission in porous Si, solar cells, etc.
Pulse-position-modulated resonance-domain diffractive elements
Authors: Turunen Jari , Tervonen Eero , Noponen Eero , Mäkelä Tapio , Pekola Jukka P. , Paalanen Mikko A.
Published: February 2023

When the transverse features of a diffractive optical element are comparable to the wavelength of light, the element is said to operate in the resonance domain.
Simple polarization-diversity receiver using semiconductor-clad Y-branch glass waveguides
Authors: Veasey David L. , Larson Donald R.
Published: February 2023

We have developed a simplified approach to the fabrication of a photonic polarization-discriminating receiver for optical polarimetrie sensor and optical communication applications.
Efficient electro-optic intensity modulation in AlGaAs/GaAs differentially etched directional couplers
Authors: Khan M. N. , Yang W. , Williamson F. O. , Gopinath A.
Published: February 2023

Characteristics of an AlGaAs/GaAs ridge directional coupler modulator with back-to-back Schottky contacts are investigated both theoretically and experimentally at 0.83 µm.
Finite-difference method and Green’s-function solutions for waveguide eigenvalue evaluation
Authors: Cox Hollace L. , Merse Timothy G.
Published: February 2023

With the wide spread use of graded index optical waveguides and fiber optic transmission lines, there is a greater need to explicitly include the position dependent permittivity in the two vector forms of the wave equation.
Mode-locked monolithic extended-cavity laser diodes
Authors: Hansen P. B. , Koren U. , Raybon G.
Published: February 2023

Optical pulses sources lend themselves to a multitude of applications.
Photorefractive characterization of polymers
Authors: Liphardt Martin , Jones Brian , Ducharme Stephen , Takacs J. M. , Zhang Lei , Athalye R. V.
Published: February 2023

The polymer Bisphenol A 4,4'-nitroaminostilbene mixed with 40 wt. % benzaldehyde-diphenyl hydrazone is typical of the epoxy-based photorefractive polymers recently shown to be photorefractive.1
Transport modeling of multiple quantum-well photorefractive devices
Authors: Smith Stephen L. , Hesselink Lambertus
Published: February 2023

The combination of large electro absorptive effects in semiconductor multiple quantum wells (MQW) and photorefractive-like transport offers the promise of producing fast, efficient thin film dynamic holographic materials for such applications as compact free space interconnects and high speed optical processors.1
A 10× Schwarzschild system for soft-x-ray projection lithography
Authors: Tichenor D.A. , Kubiak G. D. , Malinowski M. E. , Stulen R. H. , Haney S.J. , Berger K. W. , Nissen R. P. , Schmitt R. L. , Wilkerson G. A. , Jin P. S. , Sweatt W. C. , Chow W. W. , Bjorkholm J. E. , Freeman R. R. , Himel M. D. , MacDowell A. A. , Tennant D. M. , Wood O. R. , Waskiewicz W. K. , White D. L. , Windt D. L. , Jewell T. E.
Published: February 2023

A 10× reduction Schwarzschild system is being developed for projection imaging at 13 nm wavelength. The optical design is optimized over a 0.4 mm field of view in the image field using 0.1 µm design rules. An off-set aperture, located on the convex primary, defines an unobscured 0.08 numerical aperture. Multiple primary and secondary elements were fabricated, matched and clocked to minimized the effects of small figure errors on imaging performance. The system is illuminated using soft x-rays emitted from a laser plasma source and collected by an ellipsoidal condenser. A 45° turning mirror is required to direct the collected x-rays onto a near-normal reflecting mask. Precise matching of the Mo/Si multilayer coatings is required on all five reflective surfaces in the system. Incidence angles vary on the Schwarzschild primary as a function of radius from the optical axis, requiring a tapered multilayer coating to maintain peak reflection at the operating wavelength.
Multispectral data exploration
Authors: Subotic Nikola S. , Gorman John D.
Published: February 2023

In many applications it is necessary to perform quantitative scene classification and information extraction on imagery following compression/decompression. An example is the segmentation of multispectral imagery after downlinking. Traditionally, the compression and classification algorithms are designed independently using separate performance metrics, then grafted together. This approach has the advantage of modularity. However, no regard is given to the interaction between the two algorithms which may be significant. An alternative approach is to jointly design both the compression and classification algorithms to maximize their combined performance. This latter formulation has two advantages. The first is that the joint design uses the most pertinent metric of performance—that of the classifier (probability of correct classification). The second is that the interactions between the algorithms are accounted for in the design.
Image processing for acousto-optic tunable filter (AOTF) hyperspectral imaging instrument
Authors: Cheng Li-Jen
Published: February 2023

AOTF is a high resolution, fast programmable bandpass filter, operation through the principle of optical diffraction at a moving index grating generated an acoustic wave in an anisotropic medium. The diffraction generates two monochromatic beams with polarization directions orthogonal to each other. Therefore, this filter provides opportunities to develop instruments capable of taking images as functions of wavelength and polarization. This filter can be tune in sequential, random, and multiwavelength access modes, providing observational flexibility to broaden the area of applications. Recently, we have successfully developed AOTF polarimetric hyperspectral imaging breadboard/prototype systems operating in the visible and infrared wavelength ranges and performed field experiments on natural and artificial objects. Results illustrate enhancing/enabling capabilities of this technology in remote sensing, and also reveal a need of a “real-time” multidimensional imaging processing in order to take the full advantage provided by AOTF. This paper will discuss image processing issues relevant to the use of AOTF instruments for remote sensing applications.
Efficient modified signed-digit arithmetic using optical symbolic substitution
Authors: Ahmed Jamal U. , Awwal Abdul A. S. , Cherri Abdullah K.
Published: February 2023

An efficient scheme is derived for adding and subtracting MSD trinary and quaternary numbers. It results in much fewer rules to be implemented then a previously proposed system. The schemes were tested and implemented using electrically programmable logic devices. For optical implementation of a nonholographic content addressable memory may be used. The quaternary system is more advantageous since conversion to/from binary is easier.
Polarization-Independent Phase Conjugation of Lightwave Signals in Fiber and in a Semiconductor Optical Amplifier
Authors: Jopson R.M.
Published: February 2023

We propose a technique for polarization-independent phase conjugation of lightwave signals and use it to phase conjugate with a polarization dependence of ±0.5 dB.
Sub-μK cesium by adiabatic cooling in an optical lattice
Authors: Spreeuw R.J.C. , Jessen P.S. , Kastberg A. , Phillips W.D. , Rolston S.L.
Published: February 2023

Cesium atoms are confined to a lattice of optical potential wells, created by four intersecting laser beams. As the light intensity is slowly reduced, the atoms adiabatically cool to a 3D temperature well below 1 μK.
Experimental Investigation of High-Harmonic Generation in Ar, N2 and H2 by Picosecond Dye Laser Pulses
Authors: Liang Y. , Augst S. , Chin S. L.
Published: February 2023

High-harmonic generation is investigated in Ar, N2 and H2 with dye laser pulses. The diatomic molecules are proposed to act as atoms in harmonic generation processes.
Optically-induced Anderson Delocalization Transition in Disordered 1-D and 2-D Systems
Authors: Li S. , Khurgin J. B. , Lawandy N. M.
Published: February 2023

Numerical studies reveal a sharp optically-induced delocalization transition for disordered 1-D and 2-D systems exposed to a strong non-resonant optical field.
Optical measurement of aero-optics
Authors: Craig James
Published: February 2023

Optical measurements of aerodynamically induced optical degradation have evolved over the last few decades from commerical optical testing instruments to specialized aero-optic diagnostic systems. New diagnostic systems feature vastly increased temporal and spatial resolution and accuracy.
Large-capacity optical correlator using a Ce:Fe-doped LiNbO3 crystal with a tunable visible-light diode laser
Authors: Yu Francis T. S. , Yin Shizhuo , Yang Zhaohui
Published: February 2023

In this paper, a large-capacity optical correlator using a specially Ce:Fe: doped LiNbO3 crystal with a tunable visible-light diode laser is presented.
Smart liquid crystal spatial light modulator for use in real-time image-intensity contouring
Authors: Snook M.W.G. , McOwan P.W. , Hossack W.J. , Vass D.G.
Published: February 2023

Smart pixel back-planes have been designed to detect the edges (intensity gradients) within a selected intensity range to give an isotropic contour map or isophote. Isophote detection is important in determining shape from shading, slant and texture classification as in human vision.
Describing quantum dynamics in cavity QED by using stochastic wave functions
Authors: Carmichael H. J.
Published: February 2023

From the point of view of theory cavity QED presents interesting new challenges. The interaction of photons and atoms inside cavities has been studied for many years, since this interaction forms the basis of standard laser theory.
Nonlinear spectroscopy of the Jaynes–Cummings molecule
Authors: Thompson R.J. , Carnal O. , Turchette Q. , Kimble H.J.
Published: February 2023

Of particular interest in quantum optics is the study of atom-cavity interactions in the strong coupling regime in which an intracavity photon is likely to be absorbed and reemitted before escaping into the external environment. We have recently achieved conditions appropriate to this regime in an apparatus consisting of a beam of Cesium atoms coupled to an optical resonator of finesse 330,000 and length 0.35 mm.
Modeling of soliton-dragging logic gates with gain
Authors: Saxena S. , Wai P. K. A. , Chen C.-J. , Menyuk C. R.
Published: February 2023

Soliton dragging logic gates have been proposed to perform ultrafast switching in an optical network using time shift keying.
Spatially resolved electro-optic sampling and reflectivity changes in photoconductive switches
Authors: Keil U. D. , Dykaar D. R. , Kopf R. F. , Darack S. B.
Published: February 2023

Electro-optic sampling with femtosecond lasers allows electrical measurements to be made with response times as fast as 150 fs.
Measurements of the inner scale of turbulence and the refractive-structure parameter by means of scintillation
Authors: Hill Reginald J. , Otto William D.
Published: February 2023

The inner scale of turbulence, 1, and refractive structure parameter, Cn2, were obtained from measured atmospheric scintillation. Simultaneous propagation over two parallel paths was continuously monitored.
Accurate calibration of 3-D scanning stages by four-beam laser interferometry
Authors: Nakamura Osamu , Goto Mitsuo
Published: February 2023

Mechanisms for any kind of scanning probe microscop, are required to ensure accurate and precise scanning in three-dimensional (3D) microscopic space.
Fabrication of photorefractive 3-D waveguides for optical dynamic interconnections
Authors: Itoh Kazuyoshi , Matoba Osamu , Ichioka Yoshiki
Published: February 2023

Optical interconnection is believed to be a key technology to parallel distributed computing systems.
Multiplexed optical interconnects for multichip modules
Authors: Sharma Rohini , Kiamilev Fouad , Morris James , Childers John , Badoni Vipul , Feldman Michael
Published: February 2023

A thorough design and analysis of Optically Interconnected MultiChip Modules (OIMCMs) has been performed.
Polarization BRDF
Authors: McClain Stephen C. , Chipman Russell A.
Published: February 2023

By combining scatterometry with polarimetry, a polarization dependent BRDF is measured with the potential to separate roughness, contamination, and subsurface damage. Two instruments which measure the polarization BRDF will be presented and results discussed.
Moiré interferometric techniques for Si temperature measurements
Authors: Zaidi Saleem H. , Lang Michael K. , Brueck S. R. J.
Published: February 2023

Precise temperature measurements are critical for process control in a wide variety of materials. For semiconductor manufacturing, temperature control is required for processes such as oxidation, diffusion epitaxial growth, etc.
Linking research to needs in the market-place
Authors: Baur Thomas G.
Published: February 2023

I will discuss Meadowlark Optics’ strategy for product development and commercialization of technology from publicly funded research laboratories. Examples will be included.
Masking effect of sub-Nyquist gratings on the detection of sub- and supra-Nyquist gratings in peripheral vision
Authors: Wang Yi-Zhong , Thibos Larry N. , Bradley Arthur
Published: February 2023

Previous experiments in peripheral vision have demonstrated that sub-Nyquist gratings raise threshold for detection of orthogonally-oriented test-gratings regardless of whether the test spatial frequency is above or below the Nyquist limit.1 In the present study we examined this masking phenomenon when the test and mask have the same orientation, as occurs naturally for 1-dimensional patterns such as edges and square-wave gratings.
Delta-k lidar for measurements of sea-surface waves
Authors: Churnside James H.
Published: February 2023

In delta-k lidar, a laser beam containing two different k-vectors is projected onto the sea surface. These can be obtained by using two different frequencies, two different propagation directions, or some combination techniques.
Integrating cavity-absorption meter: absorption spectra of pure water and seawater from 400 to 700 nm
Authors: Pope Robin M. , Fry Edward S.
Published: February 2023

The integrating cavity absorption meter or (ICAM), previously reported in Applied Optics1, has been refined to enhance stability, sensitivity, and operational wavelength regions.
Two-electron multiphoton ionization of atoms with elliptically polarized light
Authors: Dietrich P. , Corkum P.B.
Published: February 2023

Electrons which are created in a multiphoton ionization process can collide with the ion from which they emerge.
Properties of photorefractives for optical pattern recognition
Authors: Salerno Deanna McMillen , Hudson Tracy D.
Published: February 2023

Applications of photorefractives as holographic storage media include neural networks, optical computing, and optical correlation or pattern recognition.
Optical fiber array temperature sensor for scattering-surfaces
Authors: Wang Zhihai , Adams Bruce , Schietinger Chuck , “Bear” Tinsley F. G.
Published: February 2023

Scattering surface temperature measurement has been a very difficult problem in science and industry.
Infrared fiber optic sensor for the determination of TCE in water
Authors: Ewing K. J. , Schneider I. , Jaganathan J. , Bilodeau T. , Nau G. , Aggarwal I.D.
Published: February 2023

There is currently a need for chemical sensors which can detect and measure various organic contaminants in soils and groundwater.
Squeezing effects in particle trapping by oscillating fields
Authors: Baseia B. , Vyas Reeta , Bagnato V. S.
Published: February 2023

An important purpose of trapping atoms is to minimize the center of mass motion. This requires an understanding of any fundamental limits on the residual particle motion.
Intracavity-ring-laser, femtosecond, phase-sensitive spectroscopy
Authors: Atherton Briggs W. , Diddams Scott A. , Diels Jean-Claude
Published: February 2023

The frequency difference between the two counter-propagating pulses (CPP’s) in a mode-locked dye ring laser can be varied from 0–1 MHz by modulating an intracavity Pockels cell synchronously with the cavity frequency.
Switchable, computer-generated holograms for image processing by using liquid crystals
Authors: Stalder M.
Published: February 2023

The key elements of the described devices are a computer generated phase hologram and a liquid crystal layer covering the structured hologram surface. The optical influence of the hologram can be controlled by applying an electrical field to these layers. The optimization algorithm for the required holograms, the fabrication of the devices and application examples are discussed.
Double-multiplexed computer-generated holograms
Authors: Mendlovic David
Published: February 2023

The most important element in an optical data processor is the complex spatial filter. Lohmann and Paris1 invented the detour phase method for binary encoding of a complex filter function. The reconstructed object is obtained along the first diffraction order. In many applications such as multiple correlation or complex incoherent correlation2, a filter that contains information of two objects is required. In this project we suggest a technique for encoding two objects using a single computer generated hologram, without using a plotter with higher spatial resolution. This was done by improving one of the detour phase encoding methods. The reconstructed objects are obtained along orthogonal diffraction directions. Laboratory experiments were done in order to demonstrate the suggested technique.
Overview of brain-imaging methods
Authors: Beck Robert N.
Published: February 2023

Advances in computer technology have spawned numerous systems that increasingly enable us to employ quantitative imaging methods to study brain structure and functions in health and disease. These systems include computed tomography (CT), digital radiography (DR), magnetic resonance imaging (MRI), positron emission tomography (PET), single photon emission tomography (SPECT), electroencephalography (EEG), magnetoencephalography (MEG), as well as autoradiography and various forms of microscopy for in vitro studies. As an object for study, the brain may be characterized by its physical, chemical, and isotopic composition at each point, which gives rise to properties that can be detected and localized, and thus mapped into image space. Each imaging modality responds to a limited number of object properties; thus, each produces images that are incomplete representations of brain structure and/or function. In addition, these mappings are always inaccurate, as imaging systems invariably introduce some blurring, distortion or deformation, interference, and artifacts. Moreover, these mappings are always imprecise, or irreproducible, as random statistical fluctuation, or noise, is always present. Nevertheless, each of these imaging systems has unique strengths. However, it is the synergy among them that compensates for the limitations of each, and together, they bring unprecedented power to the study of the brain.
Fiber-optic sensors for environmental applications
Authors: Lieberman R. A.
Published: February 2023

The use of optical fibers for chemical monitoring predates communications uses. In recent years, advances in fiber optic and semiconductor technology, as well as in analytical chemistry and biochemistry, have made fiber optic chemical sensors very attractive for a wide variety of environmental applications. Remote spectroscopic measurements via optical fibers (passive fiber optic chemical sensing), including fluorescence and Raman spectroscopy, and often multiplexing many fibers to provide simultaneous multipoint chemical information, have become well accepted in the process control and environmental monitoring industries. Active techniques, in which chemically sensitive devices, or “optrodes”, are attached to fibers, are being intensively studied, and a few sensor systems based on these are beginning to appear as commercial products. Intrinsic sensors, in which optical fibers are the actual chemical transduction devices, have begun to attract wide attention, because of their potential for continuous long-path monitoring. Chemical sensing requirements challenge fiber optic researchers: new optical fiber designs (D-fibers, hollow waveguides, multi-core, off-center core, tapered geometries, and others) are being investigated to enhance fiber chemical sensitivity. New fiber materials (fluorozirconate, chalcogenide, sapphire, silver halide, and others) are being developed to extend transmission into the infrared “chemical fingerprint” region of the electromagnetic spectrum.
Frequency-varying microbend sensor: design criteria for high sensitivity
Authors: Brosig Jill , Anderson Betty Lise
Published: February 2023

In traditional microbend sensors, the amplitude of a series of small periodic bends in an optical fiber changes with the measurand. In this new approach, the prebent fiber is embedded in a compliant material, and the sensor is designed such that the changing measurand causes changes in the spatial frequency of the bends. Because the microbending loss is a highly resonant effect, very high sensitivity can be obtained. Furthermore, the sharpness of the resonance curve is controlled by the Fourier transform of the physical deformation. In amplitude-type sensors, the shape is always small bends separated by short straight pieces, due to the nature of the deforming process. For a prebent fiber, the shape can be arbitrarily chosen, thus allowing design freedom in controlling sensitivity. This sensor is also expected to be more reliable and have longer life than amplitude-type sensors.
Local-field effects in lasing without inversion: An enhancement of gain and absorptionless index of refraction
Authors: Dowling Jonathan P. , Bowden Charles M.
Published: February 2023

It is well known that, for static fields, the local microscopic electric field EL, that couples to the atomic dipole moment p, is related to the macroscopic field E and volume polarization P, in a dense dielectric medium, by the Lorentz-Lorenz (LL) relation.1 For dense media, this relation implies a nonlinear relationship between the microscopic molecular polarizability α and the macroscopic susceptibility χ, for a material volume density N. The LL relation also holds for arbitrary time-dependent fields in a nonlinear medium.2 What this implies is that all of quantum optics that uses an external electric field rather than the local field is internally inconsistent and will yield only approximate results for an optically dense medium. We consider the effect of the local field interaction on a simple three-level A system predicted to exhibit lasing without inversion and a high index of refraction at zero absorption.3 A threshold transition allows us to choose a value of this parameter that enhances inversionless gain and absorptionless dispersion by at least two orders of magnitude over that foundin usual lasing without inversion.4
Femtosecond-pulse-front shaping with lenses
Authors: Rudolph W. , Kempe M.
Published: February 2023

Many applications of fs light pulses involve interactions with single lenses. Information on the pulse and phase front transformation are desirable in particular for imaging purposes and for on-axis focusing to achieve ultimately large intensities. The unavoidable interplay of chromatic and spherical aberration determines the space-time characteristics of the intensity distribution in the focal region of a single lens. Conditions are derived under which spherical aberration dominates. Here a temporally unbroadened, in-focus pulse occurs while the spatial distribution is that expected from an annular lens aperture and cw light. If chromatic aberration is the major aberration the in-focus pulses are considerably broadened. Both effects could clearly be measured in a modified Michelson setup using 100 fs pulses. In an intermediate parameter range both chromatic and spherical aberration contribute to the pulse broadening and to the spatial intensity pattern. From Fresnel diffraction we expect a small pulse to pass through a given on-axis point which can either precede or follow the in-focus pulse. Another weak intensity peak is produced by the pulse traveling on-axis. By measuring its separation from the main pulse, for example in the marginal focal plane one can estimate the aberration parameters.
Optical pulse compression by means of a single mode fiber and phase conjugation
Authors: He Q. Byron , Yi Xianmin , Yeh Pochi , Chi Sien
Published: February 2023

Optical phase conjugation has been widely studied for applications in distortion correction at spatial or temporal domains.1 For temporal domain applications, it has been shown that the broadened optical pulses due to group-velocity dispersion (GVD) and self-phase modulation (SPM) can be exactly restored to their original shapes with a perfect phase conjugate mirror.2,3 Here we propose and analyze a novel approach to compress various kinds of optical pulses with a single mode fiber and a low reflectivity phase conjugate mirror. When a short optical pulse with enough intensity propagates in a single mode fiber, new spectral components as well as a nearly linear chirping in frequency are generated due to the effects of SPM and GVD. By placing a low reflectivity phase conjugator at the end of the fiber, the broadened pulse is reflected back to the fiber with a reversed chirp and a lowered intensity. After propagating in a fiber of slightly longer length, the pulse can be compressed up to 10 times from its original width. The compression ratio, optimal length as well as various kinds of wave forms are investigated and the results will be presented.
Binoculars with wide-angle peripheral vision
Authors: Betensky Ellis
Published: February 2023

To scan a wide visual field the human eye rotates about a point located several millimeters behind its entrance pupil. Unless the eye is relocated with reference to the eyepiece to view a particular portion of the scanning field, this limits the scanning field of view to a function of the optical system exit pupil diameter and the pupil diameter of the eye. This limitation is implicit in the design of binoculars, and results in the unnecessary reduction of peripheral vision for the static eye because the field stop is used to restrict the scanning vision to a well corrected limit. If the instrument is held firmly to the head so that the user cannot scan the peripheral portion of the field, then the peripheral field can be increased significantly at low manufacturing cost because of the eye’s low resolution for extra-fovial images. New binoculars have been designed to significantly increase the peripheral vision using this concept. They have conventional objectives and prism systems, but employ negative power after the prisms to reduce prism size, and have simplified eyepieces. Additionally a positive field lens is moveable across the intermediate image to effect a rapid-change 2:1 dual power.
Six-element lens corrected for all third-and fifth-order aberrations
Authors: Shafer David R.
Published: February 2023

In a well-corrected complex lens system, with a fairly fast aperture and wide field of view, the image aberrations which limit performance are usually sagittal oblique spherical aberration and higher-order Petzval curvature. Because of aberration balancing in any well-optimized design, it may not be apparent that these two 5th-order aberrations are in fact the limiting aberrations. It is not generally recognized that it is possible to correct all the 3rd and 5th-order monochromatic aberrations to zero in relatively simple designs, without aspherics. Several years ago I found an 8-element solution and more recently several 7-element designs. Now I have found two different 6-element solutions. One has no thick lenses or strong meniscus shapes and can also be corrected for axial and lateral color with no additional elements. I suspect there may be a five-lens solution, without color correction, that would involve some thick lenses.
Imaging properties of concave ellipsoidal mirrors
Authors: O’Connor Leticia S. , Spangler Jon A. , Byrne Dale M.
Published: February 2023

Applications for concave mirrors that are off axis portions of surfaces of revolution are increasing due to continued improvements in fabrication techniques and an accompanying reduction in cost. For imaging applications, it is desirable to know the effect that object position has on the resulting image position and quality and how these image characteristics depend on the surface geometry. We have addressed these topics for the specific case of an ellipsoid of revolution. We analyze the imaging properties of the ellipsoid by considering that a point source is located at an arbitrary position in the vicinity of one focus. The point source is modeled as emitting a cone of rays symmetrically distributed about a specified direction. The intersection of this diverging cone with the ellipsoidal mirror defines the region of the ellipsoid that images the point source. Ray aberrations are evaluated by considering the transverse ray intercepts at a target plane that is oriented normal to the converging cone of rays. Wave aberrations are determined in the traditional manner by considering the optical path difference between the convergent wavefront and a spherical reference wave centered at the paraxial image location. We will show how aberrations vary as different portions of the ellipsoid are involved in the imaging process and also illustrate the effect on the geometrical image produced by a tilt of the target plane.
Exact spread function for a pulsed-collimated beam in a medium with small-angle scattering
Authors: van de Hulst H. C. , Kattawar George W.
Published: February 2023

The temporal and spatial spreading of a pulsed beam in a medium exhibiting small-angle scattering is of fundamental importance in many areas such as astrophysics, meteorology, and oceanic optics. Although many papers have been published on this subject, we feel that none have given a complete solution to this problem, i.e., both the spatial and temporal profiles for a collimated pulsed beam. It is the solution to this problem which will be presented.
Recent experimental measurements of topographic-map structure in primate V-1 and presentation of a miniature space-variant active vision system
Authors: Schwartz Eric L.
Published: February 2023

This paper will present the history and current status of understanding of the spatial architecture of primary visual cortex (V-l, striate cortex, area 17) in primates. Special emphasis will be placed on experimental techniques, mathematical and computational analyses, and the relevance of V-l architecture to current work in machine vision. The intention is to provide an overview of the difficulties, both conceptual and experimental, which have characterized this field for the past fifty years, and to provide some insight into the importance of spatial architecture in visual cortex to both biological and machine vision.