bluuebunny/crossref_metadata_2025 huggingface dataset:
Progress in high average power alexandrite laser systems
Authors: Heller D. F. , CHIN T. , Krasinski J. , Pete J.
Published: February 2023

We review recent progress in the development of alexandrite laser technology placing particular emphasis on the relationship between alexandrite’s material properties, laser physics, and the performance of high average power solid-state lasers. Recently, significant improvements in laser performance have been achieved through a better understanding of alexandrite’s laser physics. This work has provided important insights into the design of strongly pumped, low cross-sectional lasers.
Direct measurement of nonlinear energy deposition from an intense 532-nm photon field into alkali halides
Authors: Jones Scott C. , Shen Xiao-An , Braunlich Peter , Kelly Paul
Published: February 2023

We describe a photoacoustic method for the direct measurement of the energy absorbed by wide-gap optical materials during non-linear interaction with intense laser beams and present results obtained with ultrapure NaCl crystals exposed to 80-ps pulses from a frequency-doubled Nd:YAG laser. The measured temperature rise of the interaction volume depends approximately on the fourth power of the laser peak flux F and exceeds 300 K at F = 1.45 × 1030 photons/cm2s without laser-induced breakdown. We find no evidence of free-electron avalanche formation up to these temperatures and show that the mechanism of energy deposition is four-photon electron-hole pair generation and subsequent single-photon absorption by free electrons and self-trapped holes with small contributions from self-trapped excitons. We report the first photoacoustically measured four-photon absorption cross section: σ(4) = 2 × 10-113cm8s3in NaCl for linearly polarized 532-nm photons. This value is corroborated by σ(4) = 0.94 × 10-113 cm8 s3 obtained in physically similar KBr at 40 K by measuring the recombination luminescence of four-photon-generated self-trapped excitons.
Wavelength dependence of aerosol-induced laser break­down thresholds
Authors: Pinnick R. , Pendleton D. , Chylek Petr , Jarzembski M.
Published: February 2023

Measurements of aerosol-induced laser breakdown thresholds have been made for liquid droplets at four wavelengths using a pulsed Nd:YAG laser (λ = 1.06,0.53,0.35,0.26 μm). For droplets with a diameter around 50 μm, the threshold breakdown intensity decreases with decreasing wavelength. Thresholds are nearly in­dependent of droplet refractive index at the near-IR wavelength (λ =1.06 μm), but show increasing sensitivity to refractive index at shorter visible and ultraviolet wavelengths.
Multiphoton ionization process of CH3OH and C2H5OH induced by a XeCl excimer laser
Authors: Guan Y. F. , Zhu R. , Han J. C. , Liu H. X. , Li S.T. , Wu C. K.
Published: February 2023

In the multiphoton ionization mass spectrum of CH3OH induced by the XeCl laser, three kinds of ion are found: CH+3, CH2OH+, and CH3OH+. The ionic signal dependences on the laser intensity and the sample pressure are measured. From these results, it is concluded that CH3OH+ is directly formed after CH3OH has absorbed four photons, and that the collisions between CH3OH+ and CH3OH produce

CH

3
+

and CH2OH+. At the same laser wavelength, the ions produced in the C2H5OH MPI process are

C
2

H
5
+

, CH2OH+, CH3OH+, C2H2OH+, C2H3OH+, C2H4OH+, and C2H5OH+. The relative ionic intensities are 74%(CH3OH+),

12
%

(

C
2

H
5
+

)

, 6.1%(CH2OH+), 4.1 %(C2H3OH+), and < 2% for others. On the basis of the consideration of the mass spectrum theory for organic molecules, brief explanations of the result are given. The breakdown of the C-O bond and the C-C bond results in the formation of

C
2

H
5
+

; and CH2OH+, respectively. The McLaffety rearrangement process leads to the production of C2H3OH+. The analysis shows that the birth of CH3OH+ cannot be described in terms of the breakdown process of some molecular bonds; CH3OH+ is the product of a very complicated recombination reaction.
Dynamics of multiphoton ionization of acetaldehyde by UV laser
Authors: Zhu Rong , Han Jingcheng , Guan Yifu , Liu Houxiang , Li Shutao , Wu Cunkai
Published: February 2023

In molecular beam conditions, we present experimental results of the multiphoton ionization mass spectra of the acetaldehyde molecule in the gas phase by a quadrupole mass spectrometer, using a XeCl excimer laser. From the linear relationships of the intensities of fragment ions to the pressure of sample gas, it can be deduced that the multiphoton ionization fragmentation of the acetaldehyde molecule is a unimolecular process. This result reveals the photochemistry of acetaldehyde in the first single excited state ′(n
π
*): the radicals are all primary products in the UV photolysis of acetaldehyde. We also measure the variation of the intensities of fragmental ions with laser power. Based on these results, we propose the parent molecule dissociation-neutral fragments ionization model of the MPI of acetaldehyde, with which we explain our experimental results.
Fe(CO)5 multiphoton ionization mass spectra
Authors: Han J. C. , Li S. T. , Liu Z. A. , Liu H. X. , Liu G. P. , Wu C. K. , Shi J. L. , Li F. L.
Published: February 2023

Using molecular beam apparatus and a modified quadrupole mass spectrometer, the multiphoton ionization mass spectra of Fe(CO)5 vapor was investigated by irradiation with a XeCl excimer laser. By changing the laser intensity and sample pressure, we measured the ion peaks of Fe+, CO+, FeC+,

Fe

(
CO
)

n
+

(
n
=
1
,
2
,
…
,
5
)

and

Fe

2

(
CO
)

m
+

(
m
=
4
−
9
)

. The ion intensity of Fe+ was the strongest among these ion peaks in all experimental conditions. In comparison with Fe+, the ion intensity of

Fe

2

(
CO
)

m
+

(
m
=
4
−
9
)

was extremely weak.
Laser spectroscopic detection of OH in catalytic reactions on platinum
Authors: Ljungstrom S. , Rosen Arne , Wahnstrom T. , Kasemo B.
Published: February 2023

We are presently investigating the emission of OH radicals by laser-induced fluorescence (LIF) in the H2 + 1/202 → H2O reaction on polycrystalline platinum. Results are obtained for emission yields of OH as functions of pressure (5-500 mTorr), temperature (950-1300 K), and O2/H2 ratios. The rotational temperature distribution of the desorbing OH molecules is determined, showing a significant dependence of the total pressure. The rotational temperature is only 50-75% of the surface temperature of the catalyst, i.e., the emitted OH radicals are not in thermal equilibrium when they are produced. Apparent desorption energies are also achieved. They vary from 30 to 60 kcal/mole for different O2/H2 ratios.
Simultaneous imaging of species distributions in two-phase reacting flowfields
Authors: Allen Mark G. , Hanson R. K.
Published: February 2023

Hydrodynamic interactions between an evaporating fuel spray and a turbulent reacting flowfield pose a considerable challenge for combustion modelers and experimentalists. Simultaneous imaging of critical species concentrations provides an opportunity for more detailed observation of these interactions than was previously possible. We report here on our work to obtain simultaneous images of reactive intermediates (OH or CH), based on planar laser-induced fluorescence, and fuel vapor, based on planar multiphoton dissociation. Earlier work1 with single species imaging suggested that CH and OH images served to mark the instantaneous reaction zone and postcombustion zones, respectively, in a turbulent heptane-air spray flame. Photodissociation of C2H2 (a dominant pyrolysis product of the evaporating droplets) and imaging of the resultant CH fragment fluorescence enables tracking of the distribution of precombustion zones in the flow field. Using a tunable dye laser (Quanta Ray DCR-1 Nd:YAG pumped PDL) and an ArF excimer laser (Lambda Physik EMG 203 MSC), simultaneous images of pairs of these species distributions have been obtained. The laser radiation is formed into a thin sheet and focused into the flame. The resulting fluorescence is imaged onto an intensified photodiode array. The signal on the array is digitized and stored on an LSI 11/23 computer for processing and display. Near shot-noise-limited performance is often obtained, and molecular species detection limits are typically of the order of 10 ppm. In addition, we hope to infer droplet size fields from images of the Mie scattered light from a spectrally broad illumination source.
Classical and holographic interferometry systems combined to document inertial fusion experiments
Authors: Ankney J. S. , Busch Garland E.
Published: February 2023

Inertial fusion (IF) employs laser beams to implode spherical shells containing deuterium and tritium. Freezing the DTfuel in a uniform layer within the container aids in achieving the densities required for fusion. A documentation system has been developed which is used to record both classical interferograms of solid IF fuel layers within the container and then holographic interferograms of plasma as the container implodes. This optical system has the advantages of visible and UV utility, 2–4-µm resolution, and a low space requirement. Both systems share a catadioptric objective lens and a refractive relay lens. The visible classical interferometric beam and the UV pulsed holographic probe follow different off-axis paths within the object cone of the lenses. While the solid layer is being formed, the beam is diverted to a shearing cube interferometer using a lens-mirror assembly on a sliding stage. This assembly then slides out of the way before the implosion to admit the UV probe to the holographic camera, which records four holographic interferograms of the imploding plasma separated in time by 40–400 ps. The two operational modes, shearing interferometer and holographic, are serial; switching from one to the other requires only seconds.
Investigation of a transverse-excited high-power CO2 laser
Authors: Stanco J. , Sliwinski G. , Konefał J. , Kukielło P. , Rabczuk G. , Rozkwitalski Z. , Zaremba R.
Published: February 2023

Investigations of a high-power transverse-flow transverse-discharge closed-cycle cw CO2 laser, designed as a laboratory facility primarily for materials processing research, are reported. A self-sustained dc electric discharge between a multipin cathode (tungsten) and a planar anode (polished copper) has been used forexcitation of the working medium, a mixture of CO2, N2, and He. The discharge volume is 5 dm3. A controllable-speed centrifugal compressor circulated the gas at a pressure of ~ 80 kPa, with the mass flow rate reaching 0.5 kg s-1. The specific power per unit mass flow amounts to 200 kW/kg s-1. The discharge characteristics have been measured in various flow conditions to evaluate the effect of flow conditioning devices on the discharge stability. Various multipass unstable optical resonator configurations have been adopted based on previous numerical analyses. Measurements of small-signal gain distribution along the discharge channel (with a maximum of 1 m–1) allowed optimization of the resonator position relative to the discharge. The dependence of the output power on the electric power dissipated in the discharge was measured. For a two-pass resonator (M = 1.8 kanigen mirrors) with one amplifying pass, the maximum output beam power was 4.4 kW at an electro-optical efficiency of 10%. The beam divergence was ~2 times larger than the diffraction-limited value. This allowed satisfactory tests of laser welding and cutting. (Poster paper)
Prospects for a gamma ray laser based on upconversion Plenary paper
Authors: Collins C. B.
Published: February 2023

At the nuclear level the storage of energy can approach terajoules (1012 J) per liter for thousands of years. However, any plan to use such a resource for a gamma ray laser poses problems of a broad interdisciplinary nature requiring the fusion of concepts taken from previously unrelated fields of physics. Our research group has described several means through which this energy might be coupled to the radiation fields with cross sections for stimulated emission that could reach 10−7 cm2. Such a stimulated release could lead to output powers as great as 3 × 1021 W/liter. Since 1978 we have pursued an approach for the upconversion of longer wavelength radiation incident on isomeric nuclear populations that can avoid many of the difficulties encountered with traditional concepts of single photon pumping. Recent experiments have confirmed the general feasibility and have indicated that a gamma ray laser is feasible if the right material exists. Of the 1886 distinguishable nuclear materials, the present state-of-the-art has been adequate to identify 29 first class candidates. A laser-grade data base of their nuclear properties does not yet exist, but the techniques for constructing one are currently being developed. Resolution of the question of the feasibility of a gamma ray laser now rests on the determination of (1) the identity of the best candidate, (2) the threshold level of laser output, and (3) the upconversion driver for that material.
Photothermal microscope
Authors: Dovichi Norman J. , Burgi Dean S.
Published: February 2023

The crossed-beam thermal lens technique is used to probe weak optical absorbance and small variations in thermal diffusivity within a probe volume of a few cubic micrometers. By recording the signal as the sample is translated through the probe volume, a high spatial resolution image may be generated based on either the absorbance or thermal diffusion of the sample. Furthermore, use of an appropriate mask in the probe beam profile allows identification and study of interfaces between media with different thermal-optical properties. The photothermal microscope has been used to study both geological and histological samples. Fluid inclusions within mineral samples and localized bacteriological infections within human tissue samples have been imaged.
Profile analysis using laser-assisted spectroscopy
Authors: Freedman A. , Stinespring C. D.
Published: February 2023

We describe a microprobe analysis technique which has the potential for extremely sensitive quantitative measurements of surface and bulk concentration as well as depth profiles. This technique is termed profile analysis using laser-assisted spectroscopy (PALAS) and uses one pulsed laser to desorb or vaporize a controlled volume of the sample and a second pulsed laser to induce fluorescence in the desorbed species. The intensity of the laser-induced fluorescence provides a quantitative measure of the desorbed atom species concentration, while the energy density of the vaporizing laser controls the sampling depth. The requisite lateral resolution is provided by focusing the vaporizing laser. Present work is intended to demonstrate the feasibility of PALAS by making measurements of impurity and dopant concentrations in GaAs and InP which are III–V materials of interest. These measurements will be performed in such a manner as to demonstrate the utility of the technique as an in situ diagnostic for conditions encountered in metallo-organic chemical vapor deposition. Extensions of the technique to high and ultrahigh vacuum conditions encountered in molecular beam epitaxy and complementary surface diagnostic techniques are also possible.
Transient thermoreflectance measurements of thermal impedance at metal-metal interfaces
Authors: Paddock Carolyn A. , Eesley Gary L. , Clemens Bruce M. , Stec James P.
Published: February 2023

The interface between two different metallic layers can alter the thermal transport in a direction perpendicular to the film plane. Previously we have reported on transient thermoreflectance (TTR) measurements of thermal diffusion in compositionally modulated Ni-Zr and Ni-Ti films which contain many interfaces.1 The thermal diffusivity of these films was much smaller than that measured for the single element films. We use TTR to study the thermal impedance of four different metal-metal interfaces with varying atomic size mismatch. The structural order of metal-metal inter faces is very sensitive to this mismatch between the constituent elements. For Ni-metal interfaces, the size mismatch increases in the order Cu, Mo, Ti, Zr.2 The results of the TTR measurements for the single element films and for the four bilayer films Ni-Cu, Ni-Mo, Ni-Ti, Ni-Zr indicate that the thermal impedance of the interface is directly related to the atomic size mismatch of the constituent elements. The interface decreases the thermal diffusion in the film compared to that measured for constituent single element films. A numerical model has been developed to determine the thermal impedance of the interface from the measured data.
Some spectroscopic consequences of light-induced dephasing
Authors: Albrecht Andreas C.
Published: February 2023

Recent work in optical spectroscopies has shown how the amplitude and phase properties of the driving fields can significantly control the spectral response of a sample. This is particularly true for nonlinear spectroscopies where higher-order time correlation functions become important. It is only necessary that the spectral density of the appropriate field correlator match or exceed the damping widths of the spectroscopic system under study. In principle, recently in practice, phase and amplitude control, including multiple pulsing, led to the optical analog of NMR experiments. Even naturally incoherent light sources, properly manipulated, can provide information about the spectroscopic system on the time scale of the coherence time of the source. Furthermore, incoherence in the incident light can generate the same complex line shapes and new resonances that are otherwise caused by quasi-elastic pure-dephasing system/material bath interactions. A brief outline of these developments will be given. By way of specific example, preresonant and resonant spontaneous secondary radiation is discussed. Here only two driving fields are present yet it is seen how the spectral density of their correlation function can confer a complex spectral behavior even in a simple three-level system.
Progress in the gamma-ray laser program at Texas. 1: Flash x-ray techniques for pumping nuclear materials
Authors: Davanloo F. , Bowen T. S. , Collins C. B.
Published: February 2023

The central problem to the realization of a gamma-ray laser is the identification of a proper material from a slate of 29 candidates. The ultimate success of our pump schemes involving flash x rays will require investigation of the nuclear properties of those materials that are analogous to the kinetics of a conventional laser medium. The methodology to be used is the nuclear analog of the optical double resonance studies which yielded much of the laser grade data base on which rest the newer visible and UV lasers. Essential for success is the accessibility of a source of pulses of x rays of nanosecond duration that can emit a total of 1 J per keV of linewidth in a reasonably brief working period. Either laser plasmas or large e-beam machines can do this in a single shot, each of which requires about an hour of laboratory time to prepare; but costs are very high. As a result, none of these traditional light sources for the subangstrom region could be used to complete an evaluation of the 29 materials before the turn of the century. This paper reports recent success in demonstrating a compact flash x-ray device producing 150 mW of average power isotropically from 10-ns pulses at energies near 15 keV. At this level we produce a photon flux that is only 1 order of magnitude lower than the design objective of the Advanced (Synchrotron) Light Source. These results imply that a flash x-ray device of reasonably larger scale will support the screening of the gamma-ray laser materials in a timely manner.
Laser-induced ionization spectroscopy of small biological precursors in supersonic beam-mass spectrometry
Authors: Lubman David M. , Tembreull Roger , Sin Chung Hang , Pang Homing
Published: February 2023

In our work resonant two-photon ionization (R2PI) in supersonic jets is used as a means of optically selecting ions for mass spectrometry. The use of supersonic beam injection provides internally ultracold molecules with sharp spectral features for chemical analysis for molecules whose spectra would otherwise exhibit broad, unresolvable spectral contours at room temperature. The use of high-powered tunable monochromatic laser sources can be used to probe this sharp structure by using laser R2PI spectroscopy. This method has been used for analysis of small biological species based on the combination of wavelength selectivity and the high efficiency for producing molecular ions by the R2PI technique. One method investigated for use in solubilizing nonvolatile and thermally labile molecules involves expansions of supercritical fluids of CO2 and N2O at up to 400-atm backpressure in to a mass spectrometer at 10-5 Torr. The expansion of this ultradense jet is shown to provide cold spectra for molecules which would normally require significant heating for volatilization into the gas phase. A second method used in our work for volitilization of nonvolatiles uses laser desorption to rapidly heat molecules off a surface before they can decompose. The resulting desorbed cloud is then swept into a supersonic jet and into a TOFMS for analysis by R2PI. The parameters required to volatilize various compounds and the spectroscopic and mass spectrometric results for several small biological systems including amino acids, drugs, catecholamines, and vitamins are discussed.
Pulsed free jet expansion system for high resolution fluorescence spectroscopy of capillary GC effluents: application to a complex environmental sample
Authors: Pepich Barry V. , Callis James B. , Gouterman Martin
Published: February 2023

A new hyphenated instrument for the detection of fluorescent polynuclear aromatic hydrocarbons in complex enviromental samples is described. The instrument combines a high resolution separation tool, capillary gas chromatography, with a high resolution spectroscopic instrument, laser fluorescence excitation spectroscopy. Optimal interfacing of these two devices is accomplished by means of a novel pulsed free jet expansion system which withstands temperatures to 300°C, has a very low dead volume, pro vides an excellent duty factor match between the steady-state gas chromatograph and the pulsed laser, and yields cooled, isolated gas phase molecules for high resolution spectroscopy. As a test of the system, a complex environmental sample was analyzed for the geometric isomers of monomethylanthracene.
Femtosecond photoionization spectroscopy of molecules on surfaces
Authors: Matveets Yu. A.
Published: February 2023

Studies of femtosecond photoionization spectroscopy of molecules on surfaces are described.
Effects of fluctuations on quantum and nonlinear optical processes
Authors: Eberly J. H.
Published: February 2023

Examples from recent work with K. Wodkiewicz, M. Jamanol and J. J. Yeh will be used to review the kinds of effects that may be expected when stochastic fluctuations are imposed on quantum and nonlinear optical processes.
Role of fluctuations in nonlinear optical aberration processes
Authors: Smith Stephen J.
Published: February 2023

The power spectrum of a well-stabilized single-mode laser is deliberately broadened by introducing Gaussian frequency fluctuations in order to synthesize laser power spectra statistically well characterized to all orders. The objective is to carryout fully quantitative investigations of certain nonlinear atomic absorption processes. The results of a calculation of the power spectrum of a carrier frequency modulated by Gaussian noise will be outlined, and the approach to Lorentzian and Gaussian power spectra demonstrated as limiting cases. Experimental methodology for controlling the power spectrum to ~1 GHz from line center is discussed briefly.
Nonlinear optical frequency mixing in dye vapors
Authors: Popov Alexander K. , Lukinykh V. F. , Myslivets S. A. , Slabko V. V.
Published: February 2023

We review our theoretical and experimental studies of the nonlinear optical properties of complex organic molecules with double conjugated bonds. The experiments with UV and VUV generation have shown a number of advantages offered by the new kind of nonlinear optical gaseous media.
Theoretical modeling of two-color CARS spectra measured with a frequency-doubled multimode pump laser
Authors: Agarwal Govind S. , Farrow Roger L.
Published: February 2023

Coherent anti-Stokes Raman spectroscopy (CARS) is finding increasing application as a tool for measuring temperature and species concentrations in gases. When modeling experimental spectra, the effects of the spectral and temporal properties of the laser sources must be included to obtain quantitative results. Previous theories assumed fluctuating laser fields with Gaussian statistics or treated nonresonant CARS intensities only.
Three-laser CARS measurements of two species
Authors: Lucht Robert P.
Published: February 2023

Three-laser coherent anti-Stokes Raman scattering (CARS) measurements of two species on the same laser shot have been performed. Mixtures of nitrogen and oxygen and propane and nitrogen have been studied.
Stimulated Raman scattering in highly dispersive media
Authors: Kurosawa K. , Sasaki W. , Uehara Y. , Takeuchi K. , Fujiwara E. , Kato Y. , Yamanaka M. , Yamanaka C.
Published: February 2023

Stimulated Raman scattering in the VUV spectral region is of much interest for nonlinear optics, because of the strong dispersion of the refractive indices, as well as for generation of coherent radiation. We have investigated stimulated Raman scattering in molecular hydrogen (and deuterium) gases with an argon excimer laser that produces pulsed high-power coherent light tunable around 126 nm. Since the Lyman-α transition lies in this spectral region, the resonance effect was expected and the intense first and second Stokes lines were actually observed for narrowband pulsed-laser pumping with a 0.3-nm bandwidth. However, no anti-Stokes lines appeared. The relative intensities of the respective Raman lines were found to depend largely on the bandwidth of the laser. By using the broadband laser oscillation of 1 nm, in addition to the intense first Stokes line the second Stokes and anti-Stokes lines were observed. These differences of the relative intensities come from the dispersive properties of the gas. For these experiments laser pulses with a 4-6-ns pulse width were used. The transient effect is discussed.
Magnetic trapping of neutral atoms
Authors: Bergeman Thomas , Metcalf Harold
Published: February 2023

Magnetic trapping of laser-cooled neutral atoms has been demonstrated at NBS and is progressing in other laboratories. Confinement of any object requires exchanging kinetic for potential energy, and for neutral atoms, this necessarily derives from shifts of internal energy levels. This is implemented through the force experienced by the atomic magnetic moment in a carefully designed, highly inhomogeneous field. Since magnetic fields of convenient strength can shift atomic energy levels by only a few gigahertz (temperature ≌ 0.1 K), neutral atom traps are very shallow and must be loaded with very cold atoms. We present some motivations for using magnetic traps and then discuss the constraints and optimal configurations of various arrangements. For example, no trap can be isotropic. Next we discuss both the classical and quantum mechanical motions of trapped atoms. These motions are important for at least two reasons: First, several schemes under study for further cooling depend on knowing the position and velocity of the atoms, as well as the vector field at each point along the orbit. Second, magnetic traps depend on the atomic moment remaining aligned with the field as the atom orbits in the trap, and this precludes rapid motion through a low-field region.
Progress toward an alexandrite laser trap for potassium atoms
Authors: Yang K.-H. , Zeng X.-Z. , Stwalley W. C.
Published: February 2023

A detailed description of a corner-cube laser trap concept inside the cavity of a cw alexandrite laser operating in the

TEM

01

*

mode and using 4He cooling (at temperature ≲ 1.5 K) for trapping neutral potassium atoms is given in a recent paper.1 We report recent progress made toward the implementation of this trap concept: in optimization of the design of the laser cavity, in the understanding of the thermal lensing effects in the alexandrite laser, and in the status of the cryogenic apparatus.
Non-Approximation (Exact) Theory of the Geometrical Aberrations in the Optical Systems
Authors: Hristov Boian A.
Published: February 2023

Previously developed were by the author exact functions for a series of aberrations in the centered optical systems at the assumption that the object space is aberration free.

In the present report discussed are optical systems in the presence of object aberrations. Discussed is in details the function for transforming the object meridional curvature into image one. Given are functions and numerical examples for exact analytical correction of one and two aberrations with the help of linear Example is given for stabilization of the meridional curvature on a main ray for all object distances Za within the interval 0 ≤ |Za|≤ ∞.

Mentioned are some possibilities and trends of development of the non-approximation theory of aberrations.
Modeling of Image Forming Optical Systems
Authors: Hayford Michael J.
Published: February 2023

Integration of an element-based model of optical systems and the needs of image forming optical system definition and analysis are described.
GOSA - A Software Package for the Analysis and Optimization of General Optical Systems
Authors: Wang Yongtian , Zhang Sijiong
Published: February 2023

The technical features of GOSA, an optical CAD software package developed by Beijing Institute of Technology, are summarized. The program is the first in China which is capable of handling general optical systems, i.e., systems without rotational symmetry and/or with unconventional optical elements. Novel theories of image formation, such as Hopkins’ canonical coordinates, are employed in the program to improve its calculation accuracy and effectiveness. Extra care is taken to reduce the program’s memory requirement so that it can be run on IBM-series personal computers and compatibles with the basic 640K memory.
Infrared Motion Detection Optics in Plastics: Design, Manufacture, and Application
Authors: Pasco Ian K.
Published: February 2023

Combined Optical Industries has produced plastics optics for 58 years. Evolution of technology has seen the mirror security systems originally used, replaced largely by polyethylene lenses transmitting from 7-14 microns. The field has broadened to include general & environmental motion detection, & has seen the Fresnel lens joined by the Multilens for specialised applications.
Using Spreadsheets to Recalculate Airspaces for Diffraction-Limited Assemblies
Authors: Stephenson Dave
Published: February 2023

The use of spreadsheet programs (Lotus [1], Excel [2], etc.) as an optical design and production fabrication tool is reviewed. The common problem of melt and thickness recalculation prior to assembly is demonstrated using two approaches: (1) the spreadsheet preprocesses and writes a file for batch processing by a commercial optical design program, and (2) the spreadsheet uses matrix algebra and a partial derivative matrix to compute the respacing without any additional ray tracing.
Illumination Assessment for Non-Aplanetic Thermal Images
Authors: Rollin J.
Published: February 2023

The influence of coma aberration on the focal plane illumination is debated : tutorial examples are provided.
Innovative Wide-Field Binocular Design
Authors: Freeman M. H.
Published: February 2023

By using a number of aspheric surfaces in a novel afocal arrangement a new binocular system has been designed which avoids the use of erecting prisms and provides a very wide horizontal field of view. The method uses spherical reflecting surfaces to re-fold the light path so that the field curvature is substantially corrected. This allows larger than normal eyepiece lenses giving a greater eye-relief in spite of the wide field of view.
Lens Design of Wide-Angle Lenses with an Aspherical Surface
Authors: Ishiyama Toshiro , Suenaga Yutaka , Shimizu Yoshiyuki , Suzuki Kenzaburo
Published: February 2023

The application of aspherical surfaces in camera lens started over twenty years ago. Many people suggested and executed many ideas regarding the application of aspherical surfaces. One of the ideas is that the application decreases the value of the F No. The example of the applications is a pick-up-lens that picks up information on a disk using the optical method. In this paper, we discuss the application of aspherical surfaces in wide angle lenses with a large back focus for reflex cameras. The application mainly corrects distortion in the lens designs.

An object of the present paper is to show an inverse telescopic wide angle lens capable of simplifying the lens configuration thereby reducing the dimension of lens, correcting various aberrations in satisfactory manner, and still extending the back focus.
Determining Initial Ray Configurations
Authors: Stone Bryan D.
Published: February 2023

When optical systems are modeled, it is common to use either a ray-based or a wave-based model. However, when the system performance is evaluated, rays are typically traced as part of the process—even when a wave-based measure of performance is required. The ray set that is traced generally includes rays that start at a given set of object points and pass through a given set of points on the aperture stop. The desired locations of these object and aperture points can depend on the application, but for the purposes of this talk, it is assumed that one needs to determine the initial configuration of a ray that starts at a given object point and passes through a given point on the aperture stop.
Optical Design of an Imaging Spectrometer utilizing an Acousto Optical Tunable Filter (AOTF) as a Disperser
Authors: Deslis Apostolos , Kurzweil Charlie G. , LaBaw Clayton C. , Lowman Andrew E. , Mahoney Colin J.
Published: February 2023

Designing an imaging spectrometer using an AOTF can be a difficult task since there is no software that can simulate the bulk diffraction that can take place in the AOTF material. In this paper we will describe the method used to simulate the effects of the AOTF using a refractive grating at the center of the AOTF material.
Tilted field mirror for image access in the CVROS optical scanner
Authors: Taylor William H.
Published: February 2023

A configuration of the Compact Video Rate Optical Scanner (CVROS) which is potentially advantageous for line scanning and printing is one which employs a field mirror. The field mirror yields a flat scan line with excellent aberration and f-theta properties (1).
Lightweight, remote-sensing CCD camera with binary optical element
Authors: Weng Zhicheng , Lu Zenwu
Published: February 2023

Combining diffractive with conventional optical elements, an athermalized space borne imaging system has been designed, fabricated, and tested. The comparison results with conventional optical system are given.
Projection Lens Design using Double Telecentric Format
Authors: Miao Cheng-Hsi
Published: February 2023

The Double Telecentric system has many advantages over non-telecentric optical system. The inspection system in the Semiconductor or Flat Panel production are always need high precision and Low Distortion lens system. The Double Telecentric system meets that critical requirements while provides some other benefits such as insensitive of Magnification along the image plane, Uniform illumination, and long working distance.
Design and analysis of ophthalmic progressive addition lenses
Authors: Hasenauer David M.
Published: February 2023

Progressive addition ophthalmic lenses (PALs) are gaining wider acceptance among consumers to remedy presbyopia, the gradual loss of visual accommodation with age. PALs were originally introduced in the 1950s as an alternative to bifocal and trifocal designs. PALs allow continuous accommodation for objects over a range of distances (instead of at discrete distances).
Misalignment modes in off-axis lithography projection cameras
Authors: Descour Michael R. , Ford Bridget
Published: February 2023

The performance specifications associated with EUV lithography tools are among the most demanding for any optical system. Metrology techniques and alignment strategies define an alignment protocol: what type of metrology data needs to be collected and how is it analyzed to achieve or recapture required optical image quality.
High performance, wide angle, macro focus, zoom lens for 35mm cinematography
Authors: Neil Iain A. , Betensky Ellis I.
Published: February 2023

Today, zoom lenses dominate many optically dependent consumer and industrial products including photocopiers, point and shoot still cameras and video camcorders, to name just a few. However, in high performance applications, such as motion picture feature films, their acceptance has been limited due to a specific blend of optical and physical requirements; for example, high contrast image quality, continuous focusing to macro magnifications, minimal optical ‘breathing’ and small size, volume and weight.
Decade wide waveband optics
Authors: Jamieson Thomas H.
Published: February 2023

Lens systems employing elements of optical glass form acceptable images only over relatively narrow range of radiation wavelengths, usually only the visible waveband, whereas optical systems for use in the infrared waveband typically employ optical materials, which do not transmit at all in the visible waveband. Lens designs corrected over wavebands up to a decade wide, are the subject of this paper. Systems are developed, which have their long wavelength cut-off ten times their cut-on wavelength, specifically 0.55 to 5.5 micrometers and 1.5 to 15 micrometers. The lens systems described in this paper utilize optical materials which transmit substantially from the visible waveband through the medium infrared to the “far” infrared. The values of the converging powers of the lens elements of each material are carefully chosen such that the position of focus of each optical system for each wavelength within each waveband is substantially fixed in space.
Designs of Apochromats and Superachromats
Authors: Mercado R. I. , Ryzhikov L.
Published: February 2023

Criteria for color correction derived from the dispersion formulas of Hartmann, Cauchy, Schmidt, Conrady, and Buchdahl have been reported in the literature.1 These criteria were used to develop a simple method of selecting combinations of optical materials that are suitable for designing lens systems that are color corrected for at least three wavelengths in the spectral passband of applications. Earlier applications of suitable glass combinations were confined to low aperture apochromats and superachromats. In this paper, the applications of suitable glass combinations to medium and high aperture optical systems will be described. Design examples of photographic objectives and microscope objectives will be presented and the optical performance of these designs are shown.
MACRO Language Use in Optical Design and Analysis
Authors: Zhang Shiyu , Foo Leslie D.
Published: February 2023

Commercial optical design software routinely contains a programming language which can be used to augment and/or extend the optimization control and/or the analytical capabilities of the basic software package. In particular, we extensively use CODE V1 and its macro language in the design and analysis of optical systems. One example describes a method to calculate, remove or reduce the aspheric departure of a surface during the optimization process. A second example enables the designer to evaluate the dispersion characteristics of several materials over a given spectral band.
High numerical aperture designs for EUV projection lithography
Authors: Hudyma Russell , Sweeney Don
Published: February 2023

Several different projection optics concepts currently exist for extreme ultraviolet (EUV) projection lithography. Typically, these ring field systems have a numerical aperture at the image/wafer of 0.1 and will resolve 0.1 µm features at 13.4 nm. These systems are unobscured three or four mirror anastigmats. Since the designs were conceived to satisfy a resolution requirement of 0.1 µm, the forms do not exploit the full resolution potential of the extreme ultraviolet wavelengths between 11.3 and 13.5 nm. Higher numerical aperture optical designs are needed to take advantage of these short wavelengths.
Illumination lenses designed by extrinsic differential geometry
Authors: Parkyn William A.
Published: February 2023

The majority of lens designs can be subsumed under the imaging category, the purpose of which is an accurate rendering of the appearance of an object. Lenses have seen little use in the illumination field, where reflectors have predominated because of their lower cost and superior efficiency when used with conventional light sources. There has thus been little emphasis on the design of lenses for illumination, where the purpose is the fulfillment of a prescribed pattern of light distribution, and imaging of the light source is undesirable. Many of these prescriptions are for rectangular and other non-circular light patterns. Some important lighting prescriptions in today’s marketplace are for vehicular lamps, by the Society of Automotive Engineers, for ships, by the United States Coast Guard, and for traffic signals, by the Institute of Transportation Engineers. These are far-field prescriptions for an angular distribution of light. Illumination prescriptions for some nearby surface, such as the walls or ceiling of a room, can be transformed into intensity prescriptions.
Analytical Computation of Integrating Cavity Effect
Authors: Herloski Robert P.
Published: February 2023

In document scanning, integrating cavity effect (ICE) is defined as the increase in perceived reflectance of the imaged portion of a document due to the reflectance of the surrounding portion of that document. ICE occurs when light reflected off various portions of the document is captured by the illumination subsystem and then is redirected back to the imaged document area. This additional light is perceived by the imaging subsystem as an increase in document reflectance. In typical document scanners the perceived reflectance can change by as much as 20%, depending upon the “average” reflectance of the surrounding area. The illuminator characteristic that determines the level of ICE present is known as the illuminator kernel function, or One Trip Spread Function (OTSF).
Structured tantalum backlight reflector design
Authors: Dressler Max
Published: February 2023

In a spacelab experiment the shadow profile of a metallic alloy sphere of 8 mm diam. shall be imaged by means of LED illumination (640 nm) and backlight reflectors, using telecentric optics. The direction of the incident light does not meet the condition for direct reflection at the plano reflector surface; thus the reflectors must either have diffuse reflexion (model: white paper), act as diffractive elements with the correct blaze angle or consist of micro surfaces that are oriented in space to meet the condition for direct reflection.
Exploring Segmented Reflector Design for Uniform Illumination
Authors: David Stuart R. , Walker Claude T.
Published: February 2023

Recent advances in software and computer speeds have allowed for the reduction of prototyping and time to market for many illumination systems. This paper will address how software can significantly help the optical design in the task of designing and analyzing segmented reflectors. Segmented reflectors come in many different shapes and sizes. Therefore, the scope of this paper has been reduced to the discussion of MR16 (Metal Reflector 16/8" diameter) type reflector. MR16 reflectors have different shapes but nearly the same size (~1 ¾″ deep by ~2″ in diameter). However, the ideas and principles presented should apply to other types of segmented reflector systems.
Buried-Heterostructure DFB Lasers
Authors: Tsukada Toshihisa
Published: February 2023

Distributed-feedback(DFB) injection lasers are attractive for their capability of single longitudinal mode operation and monolithic integration. Double-heterostructure(DH) lasers with corrugated active regions were fabricated to obtain the laser oscillation at low temperatures. In this structure, however, the corrugated hetero-boundary acted as a carrier sink, thus increasing the threshold current density of DFB lasers.
Room-Temperature Operation of GaInAsp/Inp Double-Heterostructure Diode Lasers Emitting at 1.1 µm*
Authors: Hsieh J. J.
Published: February 2023

This paper reports the room-temperature operation of Ga1-xInxAs1-yPy/InP double-heterostructure (DH) diode lasers. Broad-area devices emitting at 1.1 µm have been fabricated from three-layer films grown by liquid-phase epitaxy (LPE) on InP substrates. Pulsed thresholds as low as 2. 8 kA/cm2 have been obtained for an active region thickness of about 0.5 µm. With thresholds in this range it should be possible to produce stripe-geometry lasers capable of continuous operation at room temperature. Such cw lasers would be of particular interest for communication systems using fiber optics, which have their minimum transmission loss near 1.1 µm.
Mode Selectivity and Amplification in Twin-Guide Lasers
Authors: Suematsu Y. , Yamada M. , Kambayashi T. , Kishino K.
Published: February 2023

An integrated twin-guide (ITG for short) laser is considered to be one kind of integrated-optics laser or a new type of Laser [1]–[3]. It integrates monolithically an active waveguide for the laser oscillation and an external passive waveguide through which the laser beam is taken. Oscillation characteristics of AlGaAs ITG lasers by optical pumping [1] and current injection pumping [2] were already reported. The axial mode selectivity and the reduction of output beam angle together with the possibility of monolithic integration of other optical devices, along the extension of the external passive-guide, were point out [3][4].
Properties of an epitaxially grown YAG: Nd3+ waveguide laser
Authors: Möckel P.G.
Published: February 2023

In integrated optics there is considerable interest in miniaturized lasers which can be used as signal sources for optical communications systems. Strong effort has been made, therefore, to develop the technique of epitaxially growing neodymium thin film lasers [1,2,3]. In the following, the experimental investigation of the waveguiding properties and laser performance of an epitaxially grown YAG:Nd3+ waveguide laser is reported.
Low-Loss Junctions between Dielectric and Metal-Clad Dielectric Waveguides
Authors: Tien P. K. , Martin R. J. , Riva-Sanseverino S.
Published: February 2023

Metal-clad waveguides,1,2 metal-clad optical components3 and optical strip lines have many advantages for forming optical circuits. First, they can be formed on any substrate since the metal cladding isolates the optical fields completely from the substrate. Next, since the metal has a negative dielectric constant at optical wavelengths, a dielectric film of an arbitrarily low refractive index can be used for the waveguides. This is particularly attractive as most of the high-quality optical films, such as glass, organic silicon, and solution-deposited-polymer films, have relatively low refractive indices. Finally, metal-clad waveguides have losses on the order of 1 dB/cm in the TE m=0 mode, provided that the dielectric films used have thicknesses of 1 µm or larger. We had proposed earlier in our letter3 that metalclad waveguides, polarizers and corner-reflectors can be formed together with LiNbO3 optical scanners and switches on a common LiTaO3 substrate to form an integrated switching circuit.
Determination of Characteristics of Diffused Optical Waveguides
Authors: Zolotov E. M. , Kiselyov V. A. , Prokhorov A. M. , Shcherbakov E. A.
Published: February 2023

A method is suggested for the determination of the refractive index profile in single-mode and multimode diffused waveguides from measured values of the effective refractive index of modes. Characteristics of the diffused waveguide in glass have been determined experimentally.