Showing papers in "Applied Optics in 1985"
TL;DR: In this paper, the authors present an approach to calculate the energy levels of Diatomic molecules in terms of the number of excited states in the molecules and the lifetime of these states.
Abstract: 1. Introduction.- 2. Units of Physical Quantities.- 2.1 Systems of Units in Physics.- 2.2 Fundamental Physical Constants.- 2.3 Systems of Units Based on "Natural Standards".- 2.4 Tables of Conversion Factors.- I Atoms and Atomic Ions.- 3. Isotopic Composition, Atomic Mass Table and Atomic Weights of the Elements.- 3.1 Parameters of Stable and Long-Lived Isotopes.- 3.2 Atomic Weights of the Elements and Atomic Mass Table.- 4. Structure of Atomic Electron Shells.- 4.1 Electron Configurations and Ground-State Terms.- 4.2 The Periodic Table.- 4.3 Parameters of Wavefunctions for Valence Electrons in Atoms, Positive and Negative Ions.- 5. Energetics of Neutral Atoms.- 5.1 Ionization Potentials of Atoms.- 5.2 Quantum Defects of Atomic Rydberg States.- 5.3 Fine-Structure Splitting of Atomic Energy Levels.- 5.4 Hyperfine Structure of Atomic Energy Levels.- 5.5 Isotope Shifts of Low-Lying Atomic Levels.- 5.6 Atoms in Static Electric and Magnetic Fields. Atomic Polarizabilities and Magnetic Susceptibilities.- 6. Energetics of Atomic Ions.- 6.1 Ionization Potentials of Atomic Ions.- 6.2 Electron Affinities of Atoms.- 6.3 Energy Levels of Multiply Charged Atomic Ions.- 7. Spectroscopic Characteristics of Neutral Atoms.- 7.1 Low-Lying Atomic Terms.- 7.2 Diagrams of Atomic Energy Levels and Grotrian Diagrams.- 7.3 Atomic Oscillator Strengths in Absorption.- 7.4 Lifetimes of Resonant Excited States in Atoms.- 7.5 Energy Levels and Lifetimes for Metastable States in Atoms.- 7.6 Lifetimes of Atomic Rydberg States.- 8. Spectroscopic Characteristics of Atomic Positive Ions.- 8.1 Low-Lying Terms of Singly Ionized Atoms.- 8.2 Lifetimes of Resonant Excited States in Atomic Ions.- 8.3 Energy Levels and Lifetimes for Metastable States in Singly Ionized Atoms.- 8.4 Optical Parameters of Multiply Charged Atomic Ions.- II Molecules and Molecular Ions.- 9. Interaction Potentials Between Atomic and Molecular Species.- 9.1 Van der Waals Coefficients for Interatomic Multipole Interactions.- 9.2 Long-Range Exchange Interactions of Atoms.- 9.3 Short-Range Repulsive Interactions Between Atomic and Molecular Species.- 10. Diatomic Molecules.- 10.1 Electron Configurations of Diatomic Molecules.- 10.2 Asymptotic Parameters of Wavefunctions for Valence Electrons in Diatomic Molecules.- 10.3 Spectroscopic Constants of Diatomic Molecules.- 10.4 Potential Energy Curves.- 10.5 Ionization Potentials of Diatomic Molecules.- 10.6 Dissociation Energies of Diatomic Molecules.- 10.7 Lifetimes of Excited Electron States in Diatomic Molecules.- 10.8 Parameters of Excimer Molecules.- 10.9 Einstein Coefficients for Spontaneous Emission from Vibrationally Excited Diatomic Molecules.- 11. Diatomic Molecular Ions.- 11.1 Electron Configurations and Asymptotic Parameters of Wavefunctions for Valence Electrons in Diatomic Molecular Ions.- 11.2 Spectroscopic Constants of Diatomic Molecular Ions.- 11.3 Dissociation Energies of Diatomic Molecular Ions.- 11.4 Electron Affinities of Diatomic Molecules.- 11.5 Proton Affinities of Atoms.- 11.6 Lifetimes of Excited Electron States in Diatomic Molecular Ions.- 12. Van der Waals Molecules.- 12.1 Potential Well Parameters of Van der Waals Molecules.- 12.2 Potential Well Parameters of Van der Waals Molecular Ions.- 12.3 Ionization Potentials of Van der Waals Molecules.- 13. Polyatomic Molecules.- 13.1 Constants of Triatomic Molecules.- 13.2 Ionization Potentials of Polyatomic Molecules.- 13.3 Bond Dissociation Energies of Polyatomic Molecules.- 13.4 Lifetimes of Vibrationally Excited Polyatomic Molecules.- 14. Polyatomic Molecular Ions.- 14.1 Bond Dissociation Energies of Complex Positive Ions.- 14.2 Bond Dissociation Energies of Complex Negative Ions.- 14.3 Electron Affinities of Polyatomic Molecules.- 14.4 Proton Affinities of Molecules.- 15. Electrical Properties of Molecules.- 15.1 Dipole Moments of Molecules.- 15.2 Molecular Polarizabilities.- 15.3 Quadrupole Moments of Molecules.- Mathematical Appendices.- A. Coefficients of Fractional Parentage.- B. Clebsch-Gordan Coefficients.
1,688 citations
TL;DR: Refinements in the fitting technique have resulted in only slight changes in the Drude model parameters for Al, Au, Ag, and W, and the optical resistivity has been calculated from the Druded model parameters ωτ and ωp and compared to handbook values for the dc resistivity.
Abstract: Infrared optical constants collected from the literature are tabulated for Mo and V. New data are presented for Cu, Fe, and Ni. Drude model parameters ωτ and ωp are given for the fourteen metals Al, Co, Cu, Au, Fe, Pb, Mo, Ni, Pd, Pt, Ag, Ti, V, and W. The Drude model parameters for Cu are revised from our earlier tabulation due to the availability of additional data. Refinements in our fitting technique have resulted in only slight changes in the Drude model parameters for Al, Au, Ag, and W. The Drude model parameters for Pb correct a numerical error in our earlier tabulation. For all fourteen metals, the optical resistivity has been calculated from the Drude model parameters ωτ and ωp and compared to handbook values for the dc resistivity.
1,126 citations
TL;DR: An alternative formulation is given herein which assumes the proportionality factor in the power law relationship is itself a function of range or extinction, and the resulting lidar equation is solvable.
Abstract: The conventional approach to solving the single-scattering lidar equation makes use of the assumption of a power law relation between backscatter and extinction with a fixed exponent and constant of proportionality. An alternative formulation is given herein which assumes the proportionality factor in the power law relationship is itself a function of range or extinction. The resulting lidar equation is solvable as before, and examples are given to show how even an approximate description of deviations from the power law form can yield an improved inversion solution for the extinction. A further generalization is given which includes the effects of a background of Rayleigh scatterers.
832 citations
TL;DR: One application of phase-shifting techniques to speckle interferometry is finding the phase of deformations, where up to ten waves of wavefront deformation can easily be measured.
Abstract: Speckle patterns have high frequency phase data, which make it difficult to find the absolute phase of a single speckle pattern; however, the phase of the difference between two correlated speckle patterns can be determined. This is done by applying phase-shifting techniques to speckle interferometry, which will quantitatively determine the phase of double-exposure speckle measurements. The technique uses computer control to take data and calculate phase without an intermediate recording step. The randomness of the speckle causes noisy data points which are removed by data processing routines. One application of this technique is finding the phase of deformations, where up to ten waves of wavefront deformation can easily be measured. Results of deformations caused by tilt of a metal plate and a disbond in a honeycomb structure brazed to an aluminum plate are shown.
740 citations
TL;DR: Numerical and experimental results presented show that the approach is capable of introducing accuracy and robustness to optical processing while maintaining the traditional advantages of optics, namely, parallelism and massive interconnection capability.
Abstract: Optical implementation of content addressable associative memory based on the Hopfield model for neural networks and on the addition of nonlinear iterative feedback to a vector–matrix multiplier is described. Numerical and experimental results presented show that the approach is capable of introducing accuracy and robustness to optical processing while maintaining the traditional advantages of optics, namely, parallelism and massive interconnection capability. Moreover a potentially useful link between neural processing and optics that can be of interest in pattern recognition and machine vision is established.
584 citations
TL;DR: It is shown that, for example, a train of unchirped pulses randomly distributed in frequency can have the same interferometric autocorrelation than a single chirped pulse, proof that pulse-to-pulse fluctuations are negligible.
Abstract: The performances of a tunable femtosecond dye laser are analyzed using accurate correlation techniques. The source is a passively mode-locked dye laser, of which both the frequency and frequency modulation are controlled by one or two intracavity prisms. Interferometric second-order autocorrelations, with a peak-to-background ratio of 8 to 1, are used simultaneously with the conventional intensity autocorrelation and the pulse spectrum to determine the pulse shape. The main advantages of the interferometric autocorrelations are that they provide phase information otherwise not available, and they are more sensitive to the pulse shape than the intensity autocorrelation. The phase sensitivity is demonstrated in an analysis of the Gaussian pulses with a linear frequency modulation. Analytical expressions for the envelopes of the interferometric autocorrelations of typical pulse shapes are provided for quick pulse shape identification. A numerical method is used to analyze the more complex pulse shapes and chirps that can be produced by the laser. A series of examples demonstrates the control of this laser over various pulse shapes and frequency modulations. Pulse broadening or compression by propagation through glass is calculated for the pulse shapes determined from the fittings. Comparisons of autocorrelations and cross correlations calculated for the dispersed pulses, with the actual measurements, demonstrate the accuracy of the fitting procedure. The method of pulse shape determination demonstrated here requires a train of identical pulses. Indeed, it is shown that, for example, a train of unchirped pulses randomly distributed in frequency can have the same interferometric autocorrelation than a single chirped pulse. In the case of the present source, a comparison of the pulse spectrum, with that of the second harmonic, gives an additional proof that pulse-to-pulse fluctuations are negligible.
480 citations
TL;DR: A simple equation has been developed for describing the bidirectional reflectance of some vegetative canopies and bare soil surfaces that has many useful applications such as providing a lower level boundary condition in complex plant canopy models and providing an additional tool for studying bid Directional effects on pointable sensors.
Abstract: A simple equation has been developed for describing the bidirectional reflectance of some vegetative canopies and bare soil surfaces. The equation describes directional reflectance as a function of zenith and azimuth view angles and solar azimuth angle. The equation works for simulated and field measured red and IR reflectance under clear sky conditions. Hemispherical reflectance can be calculated as a function of the simple equation coefficients by integrating the equation over the hemisphere of view angles. A single equation for estimating soil bidirectional reflectance was obtained using the relationships between solar zenith angles and the simple equation coefficients for medium and rough soil distributions. The equation has many useful applications such as providing a lower level boundary condition in complex plant canopy models and providing an additional tool for studying bidirectional effects on pointable sensors.
435 citations
319 citations
TL;DR: In a number of applications described in the paper, the eyetracker is coupled with other highly specialized optical devices, including accurately stabilizing an image on a subject's retina; accurately simulating a visually dead retinal region of arbitrary shape, size, and position.
Abstract: Major advances characterize the Generation-V dual-Purkinje-image eyetracker compared with the Generation-III version previously described. These advances include a large reduction in size, major improvements in frequency response and noise level, automatic alignment to a subject, and automatic adjustment for different separation between the visual and optic axes, which can vary considerably from subject to subject. In a number of applications described in the paper, the eyetracker is coupled with other highly specialized optical devices. These applications include accurately stabilizing an image on a subject's retina; accurately simulating a visually dead retinal region (i.e., a scotoma) of arbitrary shape, size, and position; and, for clinical purposes, stabilizing the position of a laser coagulator beam on a patient's retina so that the point of contact is unaffected by the patient's own eye movements.
312 citations
TL;DR: By introducing the phase data of a third wavelength, one can measure the phase of a very steep wave front and the repeatability of the measurement is better than 25-A rms (λ = 6328 A).
Abstract: This paper describes a method to enhance the capability of two-wavelength phase-shifting interferometry. By introducing the phase data of a third wavelength, one can measure the phase of a very steep wave front. Experiments have been performed using a linear detector array to measure surface height of an off-axis parabola. For the wave front being measured the optical path difference between adjacent detector pixels was as large as 3.3 waves. After temporal averaging of five sets of data, the repeatability of the measurement is better than 25-A rms (λ = 6328 A).
309 citations
TL;DR: From computations the smallest particles that can be photographed in various fluid measurement situations, including air and water, have been determined in terms of system parameters such as laser power, light sheet geometry, f/No.
Abstract: Mie scattering computations have been performed for light scattered by small particles from a pulsed sheet of laser illumination and collected and imaged by a camera lens. From these computations the smallest particles that can be photographed in various fluid measurement situations, including air and water, have been determined in terms of system parameters such as laser power, light sheet geometry, f/No., and photographic film properties. The particle scattering requirements of the individual particle image mode and the speckle mode are compared.
TL;DR: This paper describes some practical methods to calibrate the phase shifter in phase-shifting interferometry (PSI) using a piezoelectric transducer that has a nonlinearity of <1%.
Abstract: This paper describes some practical methods to calibrate the phase shifter in phase-shifting interferometry (PSI). The phase shifter used in the experiment is a piezoelectric transducer (PZT) that has a nonlinearity of <1%. Using the quantitative method described in this paper, the repeatability in the measurement of the phase-shifting angle is ~0.046° rms, and the 3σ value is 0.139°. A calibration-insensitive phase calculation algorithm is discussed and compared with other synchronous detection equations (e.g., the three-bucket or the four-bucket method). Experimental results verify the calibration-insensitive mechanism of the self-calibrating algorithm.
TL;DR: In this paper, a computer accessible catalog of submillimeter, millimeter, and microwave spectral lines in the frequency range between 0 and 10,000 GHz (i.e., wavelengths longer than 30 μm) is presented.
Abstract: This paper describes a computer accessible catalog of submillimeter, millimeter, and microwave spectral lines in the frequency range between 0 and 10,000 GHz (i.e., wavelengths longer than 30 μm). The catalog can be used as a planning guide or as an aid in identification and analysis of observed spectral lines. The information listed for each spectral line includes the frequency and its estimated error, the intensity, lower state energy, and quantum number assignment. The catalog has been constructed by using theoretical least-squares fits of published spectra lines to accepted molecular models. The associated predictions and their estimated errors are based on the resultant fitted parameters and their covariances.
TL;DR: Experimental data presented in the paper show that optimization of surface roughness is necessary to obtain optimum magnetic amplitude, friction, and wear properties.
Abstract: Stylus-profiling techniques cannot be used for surface characterization of polymeric surfaces, such as magnetic tapes, because of their relatively low hardness. An interferometric-optical-profiling microscope system was used to obtain high-accuracy surface profiles of magnetic media, rapidly and without physical contact with the sample. The profilometer consists of a conventional, reflection-type optical microscope with a Mirau two-beam interferometer attachment. The interference patterns of the surface can be observed through the eyepieces and can be detected with a solid-state linear array of 1024 detector elements. By translating the reference surface of the interferometer with a piezoelectric transducer while taking consecutive measurements, accurate surface-height measurements can be obtained from each detector element. The microscope system is controlled by a microcomputer, which communicates with a desk-top computer for further analysis of the surface-profile data. A computer-controlled specimen stage is added to increase the sample size. The reasons for selecting the Mirau two-beam interferometry are also discussed. Sample data of magnetic tapes are presented. Experimental data presented in the paper show that optimization of surface roughness is necessary to obtain optimum magnetic amplitude, friction, and wear properties.
TL;DR: Tests were performed on synthetic aperture radar images which show that the algorithm reduces speckle noise in images favorably with a 3 × 3 median filter.
Abstract: An algorithm is described which reduces speckle noise in images. It is a nonlinear algorithm based on geometric concepts. Tests were performed on synthetic aperture radar images which show that it compares favorably with a 3 × 3 median filter.
TL;DR: A light scattering technique for simultaneously determining the volume (V) and hemoglobin concentration (HC) of individual sphered red blood cells (RBCs) is described and results are compared with those obtained from hematological reference measurements.
Abstract: A light scattering technique for simultaneously determining the volume (V) and hemoglobin concentration (HC) of individual sphered red blood cells (RBCs) is described. Light scattered into two angular intervals yields measurements S1 and S2, respectively. Since a sphered RBC is essentially a homogeneous dielectric sphere having a complex refractive index that is linear in HC, with a proper choice of detector acceptance angles, tables relating V and HC to S1 and S2 can be computed via Mie theory. Absolute calibration is possible using droplets of water-immisible oils of accurately known refractive index. Results of experimental tests of the method are compared with those obtained from hematological reference measurements.
TL;DR: It is shown that the object height can be computed by measuring this phase accurately using phase modulation methods and by determining points on the reference plane and the object having identical phases.
Abstract: When a sinusoidal grating is projected on either a reference plane or a diffuse object to be measured, every point along a line normal to the grating lines, on the reference plane as well as the object, can be characterized by a unique phase value. By measuring this phase accurately using phase modulation methods and by determining points on the reference plane and the object having identical phases, it is shown that the object height can be computed. A working system requires a projector, a translatable sinusoidal grating, and a detector array interfaced to a microcomputer. Results of measurements on diffuse test objects are described and errors are analyzed.
TL;DR: The high reflectivities of these molybdenum-silicon structures will make possible application of traditional optics approaches in the EUV and support new developments including free electron lasers.
Abstract: Multilayer structures of molybdenum and silicon have been synthesized by sputter deposition onto flat silicon single-crystal silicon substrates and spherically ground (0.5and 22.0-m radii) fused silica substrates; and the reflectivities for 170.4-A (72.8-eV), 160.1-A (77.4-eV), and 228-A (54.4-eV) light measured at near normal incidence. Observed peak values ranged from 26.2 to 78 percent, the highest reflectivities occurring closest to normal incidence. Energy resolutions were about 10 in all cases. Model calculations were performed using optical constants and experimentally determined multilayer structural parameters. In all cases the measured reflectivities were equal to or larger (by up to a factor of 2) than the calculated values, a result attributed to uncertainty in the optical constants used in the calculations. Experimental and calculated angular-peak positions and energy resolutions were in good agreement. The high reflectivities of these molybdenum-silicon structures will make possible application of traditional optics approaches in the EUV and support new developments including free-electron lasers.
TL;DR: Any arbitrary generalized gradient-index interference coating (including homogeneous and inhomogeneous layers) possesses a digital configuration (sequence of thin high- or low-index layers), which is spectrally equivalent at all wavelengths.
Abstract: Any arbitrary generalized gradient-index interference coating (including homogeneous and inhomogeneous layers) possesses a digital configuration (sequence of thin high- or low-index layers), which is spectrally equivalent at all wavelengths. Such digital configurations are found directly from arbitrary-index profiles by using a prescribed two-layer high-low equivalent to a thin layer of arbitrary index. Digital configurations may be designed directly from given spectral requirements by using a flip-flop optimization scheme.
TL;DR: Digital speckle-pattern interferometry systems for automatic measurement of deformations of a diffuse object are presented, which are based on a fringe scanning method with phase-shifted Speckle interferograms.
Abstract: Digital speckle-pattern interferometry systems for automatic measurement of deformations of a diffuse object are presented, which are based on a fringe scanning method with phase-shifted speckle interferograms. A digital speckle pattern before deformation of an object is recorded in the mass storage device of a computer facility. After deformation, four digital speckle patterns are recorded as changing the phase of reference light such as 0, π/2, π, and 3π/2, respectively. Four speckle interferograms, whose phases are shifted by 0, π/2, π, and 3π/2, are generated by calculating the square of the differences between speckle patterns before and after deformation. These interferograms are low-pass filtered to reduce speckle noise. The calculation of the arctangent with four phase-shifted speckle interferograms gives the optical path difference which is proportional to the deformation. A correction of the discontinuity of the calculated phase gives the numerical data of the deformation in the whole object area. Some experimental results for the measurement of out-of-plane, in-plane, and 3-D deformations are presented.
TL;DR: This study predicts optimum fundamental mode oscillation in fibers with a V number of 5-25 with submilliwatt thresholds and nearly quantum-limited conversion efficiencies.
Abstract: Using the formalism of mode overlap, a theoretical analysis of optically pumped fiber laser amplifiers and oscillators is developed. The concept of normalized overlap coefficients is introduced to account for the effects of the transverse structure of the interacting signal and pump modes on the device characteristics. Simple and accurate closed-form expressions are derived for the gain of fiber amplifiers and the threshold and energy conversion efficiency of fiber laser oscillators in terms of the fiber and laser material parameters and the pump and signal modes. When applied to step-index Nd:YAG fiber lasers, this study predicts optimum fundamental mode oscillation in fibers with a V number of 5-25 with submilliwatt thresholds and nearly quantum-limited conversion efficiencies.
TL;DR: A general theoretical analysis of the errors that result from differences between the assumed and actual extinction/backscattering ratio profiles is presented.
Abstract: The Bernoulli solution of the lidar equation with the assumption of a constant extinction/backscattering ratio can lead to errors in the derived aerosol extinction and backscattering profiles. This paper presents a general theoretical analysis of the errors that result from differences between the assumed and actual extinction/backscattering ratio profiles. Examples of the influence of the constant extinction/backscattering ratio assumption on the lidar derived aerosol extinction profile are presented for various laser wavelengths.
TL;DR: The intensities of the resonances in the Raman spectrum particularly through the volume averaged internal field intensity are described and it is shown that the internal angle-averaged electric field intensity is localized near, but not confined to, the sphere surface.
Abstract: Structural resonances have been found in the Raman spectra of optically levitated liquid droplets of mixtures of water and glycerol. The observed resonances could be assigned by using the well-known Lorenz-Mie formalism. It was found that for the particular droplet under investigation quite high-order numbers (l = 8,9) of the natural modes of oscillation of a sphere play a dominant role. We describe the intensities of the resonances in the Raman spectrum particularly through the volume averaged internal field intensity. We show further that the internal angle-averaged electric field intensity is localized near, but not confined to, the sphere surface.
TL;DR: This impedance-computed tomography reconstruction process employs the solution of the Poisson equation and makes no assumptions of raylike behavior of the current flow paths.
Abstract: An electrical impedance-based method and apparatus for imaging the interior of a structure, such as a mineral or human body, having regions of differing impedance, are described. The technique involves impressing a number of excitation patterns on the body and measuring the resulting voltages at a number of sites. Because voltages need not be measured at current-injection sites, contact resistance problems are ameliorated. This impedance-computed tomography reconstruction process employs the solution of the Poisson equation and makes no assumptions of raylike behavior of the current flow paths. Results, based on computer-simulated data and real measurements, are presented.
TL;DR: Ion-beam sputter deposition of tantalum oxide films was investigated for possible optical coating applications and optical properties of such films were found to be a sensitive function of oxygen-to-argon ratio in the ion beam.
Abstract: Ion-beam sputter deposition of tantalum oxide films was investigated for possible optical coating applications. Optical properties of such films were found to be a sensitive function of oxygen-to-argon ratio in the ion beam. Refractive index and absorption coefficient were determined in the 250–2000-nm wavelength range by spectrophotometric transmissivity. The different bonding states of the tantalum atoms were revealed by x-ray photoelectron spectroscopy. The visible wavelength refractive index was found to be 2.18 and optical band gap 4.3 eV, so long as the films did not contain inclusions of metallic tantalum. Films with an admixture of oxygen deficient suboxide components had a low-energy tail of increasing magnitude in the absorption spectrum.
TL;DR: This paper points out a number of errors that have appeared in the literature concerning transmission-line models for metal grid reflectors (strip gratings and meshes) especially in regard to the design of laser mirrors and filter elements for use at submillimeter wavelengths.
Abstract: This paper points out a number of errors that have appeared in the literature concerning transmission-line models for metal grid reflectors (strip gratings and meshes) especially in regard to the design of laser mirrors and filter elements for use at submillimeter wavelengths. General formulas are given for the transmittance of lossy grids and for the equivalent circuit impedances to be used in these formulas for strip gratings and meshes at a plane boundary between two lossless dielectrics. The results apply for normal incidence and for wavelengths in both dielectrics greater than the grid period. Limitations of the transmission-line models for meshes at dielectric boundaries are discussed.
TL;DR: An imaging system is proposed as an alternative to metallized connections between integrated circuits, using multiple exposure holograms as a means of optical fan out allowing one source to simultaneously address several receiver locations.
Abstract: An imaging system is proposed as an alternative to metallized connections between integrated circuits. Power requirements for metallized interconnects and electrooptic links are compared. A holographic optical element is considered as the imaging device. Several experimental systems have been constructed which have visible LEDs as the transmitters and PIN photodiodes as the receivers. Signals are evaluated at different source–detector separations. Multiple exposure holograms are used as a means of optical fan out allowing one source to simultaneously address several receiver locations. Limitations of this technique are also discussed.
TL;DR: A process is described whereby 2-D arrays of small diameter spherical lenses are produced in a homogeneous photosensitive glass by a photothermal technique on the basis of the density change of the photonucleated microcrystalline phase developed relative to the unexposed glass.
Abstract: A process is described whereby 2-D arrays of small diameter spherical lenses are produced in a homogeneous photosensitive glass by a photothermal technique. The mechanism of the lens formation is explained on the basis of the density change of the photonucleated microcrystalline phase developed relative to the unexposed glass. The lens formation is related to such variables as optical exposure, thermal schedule, glass thickness, and lens diameter. Optical characterization of the lenses produced by this technique was carried out by interferometric and MTF measurements. One-to-one conjugate erect imaging lens arrays were fabricated and tested.
TL;DR: The technique of reference beam phase stepping is proposed to allow determination of object beam amplitude and phase for every pixel element and the use of binary levels for both picture display and camera readout is discussed.
Abstract: This paper discusses the possibilities of recording electrooptic holograms using a TV camera and digital frame storage for applications to hologram interferometry. The technique of reference beam phase stepping is proposed to allow determination of object beam amplitude and phase for every pixel element. The use of binary levels for both picture display and camera readout is discussed along with estimates of computation times.