bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Diffractive Lenses in Optical Design
Authors: Buralli Dale A.
Published: February 2023

Diffractive optical elements, which have a history dating back to the work of Lord Rayleigh and R. W. Wood, have been a subject of renewed interest over the past several years, primarily due to advances in manufacturing technology. The purpose of this paper is to provide a basic introduction to the features of diffractive optics that are most applicable to optical system design.
Use of Low-Power Aspherical Elements in the Design of High-Speed Wide-Angle Telecentric Lenses
Authors: Moskovich Jacob
Published: February 2023

Low power aspherical plastic elements are utilized in the design of large aperture wide-angle telecentric lenses, resulting in lenses suitable for economical high volume production.
Beryllium Telescope Fabrication Technology
Authors: Rajic S. , Seals Roland D.
Published: February 2023

The development of a cryogenic beryllium telescope will be discussed. Particular emphasis will be placed on the optical and mechanical designs, efficient beryllium utilization, mirror single-point-turning, and baffle fabrication.
Key to Cost Effective Optical Systems: Maximize the Number of Qualified Fabricators
Authors: Thompson Kevin P. , Hoyle Lonnie
Published: February 2023

Since the 1990 IODC conference, many people involved in optical design, engineering, fabrication and assembly have experienced a shift in priorities. Technical excellence and cost effectiveness have always been primary factors in the engineering of an optical system. The relative weighting of these two factors has shifted to emphasize cost effectiveness. Concurrent with this shift, advances in tools for computer-aided modeling of the fabrication and assembly process allow the optical designer/engineer to be an active contributor to establishing options for improved cost effectiveness.
Design Considerations for Large Scale Optical Interconnects Based on Planar Optics
Authors: Amitai Yaakov
Published: February 2023

A new design method, for fabricating large scale optical interconnects based on planar optics, has been developed. The method incorporates both binary grating and volume holograms to achieve the desired performance with a simple recording procedure.
Optical Design for Crossbar Systems
Authors: Barrett C. P. , Walker A. C. , Neilson D. T. , Robertson B. R.
Published: February 2023

The optics for a compact 64x64 free-space optical crossbar have been designed and fabricated, and the required imaging and polarisation performance demonstrated.
Printing Medical Images with High-Power Diode Lasers
Authors: Clark Peter P. , Londoño Carmiña
Published: February 2023

We describe the design of an optical head that prints digital half-tone images with multimode diode lasers. The system combines the near-field images of four lasers to form a unique pel pattern that provides very high quality images. Even with the 8:1 anamorphism required, telecentricity is maintained in both meridians.
Telecentric Lenses for CCD Sensors
Authors: Rieche Gerd , Blei Gertrud , Holota Wolfgang
Published: February 2023

The paper presents a series of telecentric lenses for CCD sensors. The lenses are intended for object sizes 300 to 35 mm and sensor sizes 8 to 35 mm. They are of modular design and consist of combinable front and rear parts. For the imaging of small objects, the modular kit may be completed by three lenses with image scales 1:2, 1:1 and 2:1 designed for a maximum sensor size of 16 mm. The paper informs about the specifications, typical MTF curves, distortion and telecentricity.
Optical Design of Flat-Field Schmidt Telescope
Authors: Xing Tingwen
Published: February 2023

The optical system must be flat-field when a large area CCD is used as the sensor. A flat-field Schmidt telescope is described in this paper. The field flattener is apart from the image and composed of five spherical lenses. The specifications of the telescope are: focal ratio F=2, field angle 2W=6 degrees. Finally, the design results are given.
Liquid-filled underwater camera lens system
Authors: Laudo John S , Wurm Ken , Dodson Cliff
Published: February 2023

Camera systems used for deep-sea video missions require mechanical housings, which can withstand the immense pressures of the ocean. These housings are generally pressurized-air canisters. The size, weight and cost of these housings increase rapidly with the ocean depth of the mission. The risk of catastrophic implosion and resulting bodily harm to divers also increases with depth. This paper presents a liquid-filled camera system which reduces these risks and limitations by eliminating the need for such air-filled housings in a novel lens design.
Optical Design of Space Solar Telescope
Authors: Yang Jianfeng
Published: February 2023

In traditional design, the optical system(Gregorian system) consists of a primary, a secondary and folding plane mirror, which is shown in figure 1. Although the system has the strong point with wide working wavelengths, but it has two main weak points. the first is that the system has large additional polarization that interfere the measurement of the transverse magnetic field by mean of cross talk. The second, the system requires very high precision of mechanical alignment to keep aberrations below 0.1". The optical system of Space Solar Telescope(SST) using a reflect-refractor system(RRS) shown in Figure 2, which is close to a diffraction-limited system over the full field of view, consists of a paraboloidal primary, a collimator lens, two folding mirrors and a imaging lens.
Ghost reflection analysis for the main laser of the National Ignition Facility
Authors: English R. Edward , Miller John L. , Schweyen John
Published: February 2023

Ghost reflections are a major consideration in the optical design of the National Ignition Facility (NIF). The first-order layout (e.g., spacing between components), the lens shape, and the dimensions of the building are strongly affected.
Modern wavefront-based optical anti-aliasing filter
Authors: Dowski Edward R. , Cathey W. Thomas
Published: February 2023

We have developed a completely new type of optical anti-aliasing filter that offers both high performance and low cost. In contrast to other wavefront-based anti-aliasing filters, this new filter can operate with multiple aperture stop positions. And in addition, this type of filter sufficiently attenuates all spatial frequencies beyond the CCD detector bandlimit. Many of the most popular anti-aliasing filters currently in use just null out very narrow bands of spatial frequencies.
Optical Design Considerations for an Electro-Optical System Used in Active Matrix Testing
Authors: Miao Cheng-Hsi , Barnes David
Published: February 2023

AMLCD has been widely designed into many aspects of our daily lives, such as laptop computers, video games, car navigation, compact phone displays, etc. Every year, many new AMLCD manufacturing factories are completed. The need of an effective and efficient test system for in-line testing and off-line process monitoring is growing.
Sensitivity of AsxSe100-x thin films for electron beam irradiation
Authors: Nordman Nina , Nordman Olli , Peyghambarian Nasser
Published: February 2023

Recently we have reported on the influence of the electron beam on As2S3 thin films [1-3]. However, the sensitivity of the AsxSe100-x thin films with different compositions has not been investigated [4]. Here we report on our measurement of the index change of AsxSe100-x thin films for the construction of the graded index optical components.
Polycapillary Optics in X-Ray Microanalysis, Patterning, and Imaging
Authors: Gibson Walter M.
Published: February 2023

Focusing and collimation of x-rays over a broad energy and angular range with polycapillary optics provides new opportunities for micro x-ray fluorescence (MXRF), micro x-ray diffraction (MXRD), high resolution energy dispersive microanalysis with SEM, TEM, x-ray and ion microprobes as well as x-ray lithography, medical imaging and x-ray astronomy. The current status of such studies is reviewed.
What on earth is a ray, and how can we use them best?
Authors: Forbes G.W.
Published: February 2023

Although rays form the basis of both our intuitive thinking and our numerical modelling of optical systems, we must remember that they are no more than mathematical constructs with a relatively tenuous connection to the physical world. What's more, certain aspects of their link to wave-based models of optical systems have always been problematic. For example, the limit to what rays can tell us about the associated wave field remains unclear. The current state of the art is reviewed and a framework is then outlined that offers a more direct appreciation of these issues and promises extended capabilities for ray-based methods. The new approach involves modelling wave propagation by using — as an intermediate tool — a windowed Fourier transform of the field.
Aberrations of Optical Domes
Authors: Crowther Blake G. , McKenney Dean B. , Mills James P.
Published: February 2023

Optical domes have traditionally been sections of concentric spheres or hemispheres. The concentric spherical shape facilitates the optical system design following the protective dome as well as the fabrication of the dome. Very little attention has been given to optimizing the aerodynamic performance of optical domes. We are entering an era where the design norms of the past must change to accommodate increasing aerodynamic performance goals. New domes are being designed using techniques and design forms that are being developed to take optical as well as aerodynamic performance into account.
Correcting variable third order astigmatism introduced by conformal aspheric surfaces
Authors: Whalen Michael R.
Published: February 2023

Conformal optics can be defined as optical systems that are designed with the operational environment as the primary consideration and the optical imaging properties as a secondary concern.1 In the context of missiles, conformal optics addresses the impact of the shape of the outer dome surface on the aerodynamic performance of the missile airframe. Whereas conventional missile systems utilize spherical domes and flat windows to facilitate aberration correction, hardware fabrication and interferometric acceptance testing, conformal missile domes are driven by aerodynamic performance issues such as decreased aerodynamic drag, increased missile velocity and extended operational range, resulting in highly aspheric dome geometries that are more elongated in shape.
Tilt tolerant high-numerical-aperture two-lens objective for optical recording
Authors: Hendriks B.H.W.
Published: February 2023

In optical recording there is a strong drive towards higher densities and higher data rates [1]. In these optical recording systems the read out spot is diffraction-limited. The spot diameter is approximately λ/NA with λ the wavelength in vacuum and NA (=n5 sin θ (see figure 1)) the numerical aperture of the objective lens. To increase the data density the spot size must be decreased. This can be achieved by using a laser with a smaller wavelength or by increasing the NA of the objective lens. In either case this reduction in spot size leads to tighter tolerances for the optical system. A way to relax the tolerances of the optical system is by using a two-element lens system in which both lenses are actuated independently [2]. It has been shown that such a system is able to compensate for the spherical aberration arising due to disk thickness variations [2]. A problem is however the small tolerance for disk tilt. Here we present a way to compensate for disk tilt in a two-element objective lens system.
Lateral Shift Variable Aberration Generators
Authors: Palusinski Iwona A. , Sasian Jose M.
Published: February 2023

The use of aspheric plates to correct aberrations is well-known. According to theory, an aspheric plate located at the stop can correct for uniform aberrations across the field of view of an optical system, and when the plate is located away from the stop, field dependent aberrations can also be corrected. The classical example is the Schmidt camera which uses an aspheric refracting plate at the system stop to correct spherical aberration. Another example is the use of aspheric plates near an image plane to control distortion. There are applications in a variety of fields such as microscopy, optical data storage, and zoom lenses where it is desirable to generate variable amounts of aberrations.
The design of ophthalmic lens by using nonconic aspherics optimized with high order aspheric surface coefficients
Authors: Chang Ming-Wen , Sun Wen-Shing , Tien Chuen-Lin
Published: February 2023

Coddington's can be used to eliminate the oblique astigmatic error in the design of ophthalmic lens of spherical or other conicoidal surfaces. But it is difficult to do the same way to the nonconic aspheric ophthalmic lens design. In this paper we will present an efficient approach based on optimization of aspheric coefficients which enable the design program to obtain the minimum aberrations. Many high order coefficients of aspheric surfaces can easily result in inflection point, which increases difficulty in manufacturing. We solved the problem in the optimization as a target. The design of nonconic aspheric ophthalmic lens could obtain spectacle lenses well thinner in thickness and well flatter in shape than spherical ophthalmic lens and other conicoidal ophthalmic lens. In this paper, we use damping least square meathod to design aspherical myopia ophthalmic lenses, aspheric hyperocular lenses and cataract lenses. Design examples are given and comparisons are made.
Method of Specifying High Quality Optical Systems
Authors: Eisenberg Shai
Published: February 2023

For optical systems which are near diffraction limited, the Strehl ratio (SR) is a unique number, which links between the residual wavefront aberrations to the diffraction image of a point source. The Strehl ratio is related to the variance of the wavefront. In the present model, the different geometrical aberrations are computed to define their contribution to the Strehl value, which is employed as a merit function in the system specification. This criteria enables system evaluation (either by MTF analysis, geometrical spot and Point Spread Functions) prior to system design.
Development of zoom lenses for camera and Technical topics.: Design examples ,Analysis ,Optical design method ,Aspherical lenses ,and Manufacturing.
Authors: Masumoto Hisayuki
Published: February 2023

The presentation focuses on the recent evolution of camera zoom lenses. The history covers standard and telephoto SLR zoom lenses and LS zooms. Actual design examples and the new design technologies that achieved the development will also be presented.
Optical design for high-brightness, wide-angle, single-output projection system
Authors: Chen C. Bill
Published: February 2023

Dome simulators have been routinely used to train pilots for a wide range of mission simulation. These simulations often require several very bright, high performance projectors to cover the entire dome. Each projector generally consists of a main projection lens with input from several target and background channels. Each target or background channel has a high resolution, high brightness image source and a telecentric projection lens. The target and background images are first collimated by the corresponding telecentric projection lenses and then they are coupled into the main projection lens through a beam combining module positioned at the projection lens entrance pupil. The main projection lens finally projects the target and background images onto the dome. To achieve the critical requirement of nondiscernability, all the projectors have to be mounted outside the dome with only a few small open holes in the dome for image projection. In the target and background channels, telecentric condition in the image source side is necessary to achieve high contrast and uniform illumination.
Optical Design of a Stereo Zoom Microscope
Authors: Meng Junhe , Liu Jian
Published: February 2023

Stereo microscopes have many applications in the surgical operations such as ophthamic operation. Stereo zoom microscopes have also been in widespread use because of its versatility. The zoom lense in them are critical for whole optics. This paper describs the method and process of designing a stereo zoom microscope, especially its zoom part, and also gives the sequence of CODE V™ commands for optimizing its cam.
The two-mirror optical system with a small fold mirror
Authors: Liu Xinping , Li Yingcai , Yang Jianfeng
Published: February 2023

A new configuration of two-mirror optical system with a small fold mirror is presented in this paper (Fig. 1). Consisting of a concave (positive power) primary mirror followed by a small flat mirror, a concave (positive power) secondary mirror and four lenses, it gives the excellent image quality. A f/10 1.5-m telescope of the upper configuration is designed over the 4° field angle and 0.50~0.70 µm wavelength range. The aberrations have been highly corrected and the distortion is less than 0.2% over the field. The aberration curves are shown in Fig. 2.
Diffractive Optics Objective In Night Vision Device
Authors: Hai-xian Zhou
Published: February 2023

The refractive or reflection-refractive objectives in the conventional optics for night vision device are more complicated, because the objective in night vision requires larger relative apeature for more incident light flux and must provide adequate correction for the imaging aberratipons for less number of optical elements, wide field of view (FOV) as well as spectral response. This significantly reduces their desirability in a number of situation.
“Illumination Systems Design: Techniques In Transition”
Authors: Heinisch Richard , Leadford Kevin
Published: February 2023

The lighting industry, like many others, has gone through a tremendous amount of change driven by advancements in technology. In particular, the increased availability of raw compute power to a wider range of users has had a significant effect on how this industry designs the optical components of their products.
Lateral Optical Confinement in GaAs - Ga0.7Al0.3 As Heterostructure Waveguides Fabricated by Liquid-Phase Epitaxy Over Preferentially Etched Channels
Authors: Tsang Won-Tien , Wang Shyh
Published: February 2023

Recently, we introduced a new technique of fabricating optical waveguides with lateral optical confinement by first preferentially etching the waveguide channels in silicon substrate, and then filling the grooves with organic films by solution-deposition technique after a layer of SiO2 film was thermally grown as the optical insulating layer.1 We have extended the same concept of waveguide-formation to GaAs - Ga1-xAlxAs system by liquid-phase epitaxial technique.2 In this case, the waveguide channels were preferentially etched into the GaAs substrates, and then a layer of Ga0.7Al0.3As was grown on top of it followed by a second layer of GaAs. The GaAs layer serves as the light-guiding film, while the Ga0.7Al0.3As layer serves as the optical insulating layer.
Directional Couplers for Integrated Optics
Authors: Auracher F. , Boroffka H. , Kersten R.Th.
Published: February 2023

In the field of integrated optics directional couplers will play an important role. These couplers are not only important for providing just a direction dependent means of coupling but they are also important components for the realisation of optical modulators or switches /1,2/. The usual design for such directional couplers is shown in Fig. 1. Two parallel dielectric waveguides are placed in such close proximity that the evanescent fields overlap. In this case energy will be exchanged periodically between the two waveguides. Because the penetration depths are typically of the order of some fraction of an optical wavelength and the coupling strength depends exponentially on the separation of the two guides, the separation of the two waveguides must be very small and the tolerance for it must be kept very tight. For typical values of relative refractive index differences Δn/n between the core and. the cladding of 1 % for n≈1.5 and a separation of 1 μm the required coupling length for complete energy transfer would be ≈ 4 mm and a tolerance of 10 % (i.e. 0.1 μm) in the separation of the coupled waveguides would already require a 20% change in the coupling length /3/. While the relative tolerances are typical also for microwave components the absolute values are extremely small due to the much smaller optical wavelength. In addition to these tolerance problems there is still the problem of phase matching. The above numerical results were calculated under the assumption of two identical i.e. phase matched waveguides.
Mode Liftoff Using a Branching Dielectric Waveguide
Authors: Hsu H. P. , Milton A. F.
Published: February 2023

The use of any form of evanescent coupler to couple between a high index waveguide system and a low index waveguide system requires the introduction of a buffer layer to shield the evanescent coupling region from the high index substrate. For example to use a tapered velocity coupler to couple between a high index indiffused electro-optical waveguide and a low index single mode glass fiber as shown in Fig. 1, requires that the power in the electrooptical waveguide be lifted off the substrate over a low index buffer layer before the evanescent coupling region is introduced. A buffer layer with an index lower than the effective index of the fiber mode is necessary to prevent phase matched evanescent coupling between the guided mode of the fiber and the substrate modes of the electrooptical crystal.
Performance Limitations Imposed on Integrated Optical Devices by Polarization
Authors: Steinberg R. , Giallorenzi T. G.
Published: February 2023

I.O. (integrated optical) circuits will probably find their greatest use in single mode data transfer systems which utilize monomode fibers as the transmission lines. Single mode fibers will be connected to IO circuits which in turn will act to process and/or generate optical data signals. In the construction of any system one encounters many problems which are associated with the fact that conventional optical fiber geometries are circular, whereas I.O. circuit geometries tend to be rectangular. Coupling from a circular to rectangular waveguide of small dimensions represents one of the outstanding problems in the technology today. A second problem and the subject of this paper is IO device performance degradation caused by propagating TE and TM modes simultaneously in the waveguide. By virtue of their rectangular construction, I.O. circuits possess a fixed axis with regard to which TE and TM modes are defined. There is no corresponding polarization axis in fibers of circular cross sections. As a result, the polarization of a light wave propagating through a fiber is usually not conserved. As has been previously shown,1 linearly polarized light transmitted down circular fibers emerges as elliptically polarized light which when coupled to an IO device would excite both the TE and TM components. If the IO device possesses TE and TM components with different efficiencies, device degradation will result.
Integration of Deflection and Detection of Guided Light on Silicon Substrates
Authors: Brandt G. B. , Gottlieb M. , Marx G. E.
Published: February 2023

In this paper we report the fabrication and operation of a truly integrated optical-electronic device based on a hybrid thin film technology using silicon substrates to perform the electronic functions. This device, which demonstrates acousto-optic deflection, optical waveguiding, and detection on the same chip, represents an initial step in the development of planar signal processing devices which will exploit the advantages of miniaturization of electro-optic devices. In addition, a hybrid thin film approach to fabrication allows the designer to choose the optimum material characteristics for each function.
Study of Titanium Diffusion into Linbo3 Low-Loss Waveguides by X-Ray Photoelectron Spectroscopy
Authors: Pearsall T. P. , Chiang S. , Schmidt R. V.
Published: February 2023

In-diffusion of Ti into LiNbO3 has been used to produce optical waveguides which are simple to fabricate and whose properties are easy to control.(1) We have studied the diffusion of Ti into LiNbO3 by core level X-ray photoelectron spectroscopy in an attempt to determine the valence states present in the in-diffused metal, and whether or not the sites for Ti ions are the same throughout the sample, or whether a distribution of sites throughout the unit cell of LiNbO3 is indicated. X-ray photo-electron spectroscopy is a useful experimental technique to answer these questions. The characteristic difference in the binding energy of core electrons in a transition-metal ion, for example, depends on the valence state of the ion. The chemical shifts between adjacentvalence states are typically several volts, while the resolution of this technique in determining the spectrum is 0.5V. Thus chemical shifts in the spectrum of the Ti ions indicating the presence of more than one valence can be measured easily. By a similar argument, the characteristic energy separation between titanium levels and oxygen levels can be compared to those in X-ray spectra of TiO2 and SrTiO3 where the Ti ions are known to be in the +4 valence state.
CdTe Waveguide Devices and HgCdTe Epitaxial Layers for Integrated Optics*
Authors: Spears D. L. , Strauss A. J. , Chinn S. R. , Melngailis I. , Vohl P.
Published: February 2023

CdTe together with the HgCdTe alloys constitute a versatile materials system for certain integrated optical circuits in the 0.9-12 μm wavelength range. Favorable properties include a high electrooptic coefficient, a low bulk absorption coefficient, n- and p-type conductivity, and a good lattice match of the narrow-gap HgCdTe alloys to CdTe. This paper reports detailed studies of low-loss CdTe waveguides for 10.6 μm formed by proton bombardment1 along with results on grating couplers, acoustic surface wave modulators and electrooptic modulators integrated into such waveguides. The development of an improved technique for vapor-phase growth of high-quality HgCdTe layers on CdTe substrates is also reported.
Optical Fiber Transmission Lines
Authors: Keck D. B. , Maurer R. D.
Published: February 2023

The technology of optical fibers is shifting toward solving identified problems of utilization and toward reducing cost. As a consequence, effort has expanded into many special areas. A limited review of the present status in fiber fabrication, transmission and packaging will serve to indicate the evolutionary trend of the technology.
An Attachable Plastic Grating Coupler for Integrated Optics
Authors: Wei J.S. , Tan C.C.
Published: February 2023

We describe the fabrication of thin plastic grating couplers which can be conveniently attached to a film waveguide and later removed after use. These gratings provide the most convenient and economic means of coupling light into a thin film waveguide. Prism couplers are bulky, often expensive, need frequent repolishing and require considerable expertise for good coupling. Forming a holographic grating coupler directly on the guide requires a large investment in both equipment and time and a separate grating must be made each time the coupling position has to be changed. Thus, both commonly used coupling methods are costly and tend to degrade the waveguide after repeated coupling attempts. In the present scheme, 100 gratings can be made simultaneously in one step and stored for future use. Only one master grating is needed for replication purpose. These couplers can be applied at any position on the guide and removed without damage to the guide.
Distributed Coupling Between a Singlemode Fibre and a Planar Waveguide
Authors: Bulmer C.H. , Wilson M.G.F.
Published: February 2023

Efficient coupling of light between fibres and integrated optic circuits is necessary if integrated optics is to be used in optical fibre communication systems. It would also be advantageous if the fibre could be coupled to any chosen part of the integrated optic circuit. Butt jointing to the film edge(1) is feasible only between two accurately aligned guide ends with matched field distributions. However distributed coupling can occur between any two sections of fibre and film and a chosen amount of energy can be transferred. This paper describes a theoretical and experimental study of the distributed coupling, shown in Fig. 1, between a single-mode fibre and a thin film. Both guides have a step index profile and the two modes are phase matched by a spatially periodic grating deposited on the film. This particular configuration provides in principle for complete coupling but also introduces possible unwanted interactions which must be avoided by careful design.
Effects of Imperfections on the Efficiency of Optical Couplers
Authors: Fradin D. W. , Cheo P. K. , Peng S. T. , Tamir T.
Published: February 2023

The efficient operation of thin-film devices requires that a substantial fraction of the input laser power be coupled through the waveguide and into a useful output beam. When high-quality waveguide structures are used, efficient coupling can be achieved with either a prism or a grating coupler. Work with free-standing (slab) waveguides used in an early model of a thin-film modulator for CO2 laser radiation (Ref. 1) has shown both that practical waveguide structures can have serious structural imperfections in the coupling regions and that device constraints may preclude the use of optimized waveguide and coupler designs.
The CCD/Transit Instrument (CTI) Data System: Real-time Area Format Reduction and Analysis
Authors: McGraw John T. , Skillman David R. , Harvey David
Published: February 2023

The CCD/Transit Instrument (CTI) is a dedicated survey telescope designed to do a deep photometric and polarimetric survey of about 50 square degrees of the sky. This telescope will be used to find variable objects in real-time. The principal scientific programs of the CTI will be the detection of supernovae prior to maximum light, the supernova production rate as a function of galaxy color and redshift, and the definition on the basis of variability and nonstellar color of a sample of QSOs complete to faint limiting magnitude.
Application of the Maximum Entropy Statistical Method to the Reconstruction of Infrared Images
Authors: Grasdalen G. L. , Hackwell J. A. , Gehrz R. D.
Published: February 2023

During the past three years we have been using the computer controlled 2.3 meter telescope at the Wyoming Infrared Observatory to generate infrared images. Brief descriptions of the technique have been given by Grasdalen et. al. (1980) and Herzog et. al. (1980). The technique has been successfully applied to imaging regions of star formation (Hackwell et. al. 1982, Gehrz et. al. 1982) planetary nebulae (Bentley, 1982) and planets (Grasdalen et. al. 1983).
Optical switching technologies for the European RACE program
Authors: Parsons N. J.
Published: February 2023

The worldwide trend toward broadband communication networks presents major challenges in the design of switching systems to route high-capacity services efficiently and reliably. Some scenarios predict that the total data throughput of a local switching center may increase by approximately 3 orders of magnitude. The success of optical technologies in transmission systems suggests that optics could also be used to advantage in switching. The difficulties lie in quantifying the performance advantages of these emergent technologies in comparison with competing electronic alternatives.
Recent developments in the application of polymers to electro-optic and second-harmonic devices
Authors: Stamatoff J. B.
Published: February 2023

Nonlinear polymers have Pockets’ constants exceeding that of LiNbO3, low dielectric constants of approximately 3.0, and loss tangents less than 0.02 from dc to 40 GHz. These polymers may be spin coated to form thin films and lithographically patterned to form optical waveguides. The films exhibit good metal adhesion for electrode definition. The polymers, developed over the past five years, are now being used as the active core materials for the construction of integrated electro-optical devices such as modulators or crossbars for which the above properties should lead to high-bandwidth and low-power requirements.
Tunable photoluminescence of uniformly doped short-period GaAs doping superlattices
Authors: Choquette Kent D. , McCaughan Leon , Potts J. E. , Misemer D. K. , Haugen G. , Vernstrom G. D.
Published: February 2023

Doping or n-i-p-i superlattices are promising materials for tunable light sources. Long-period GaAs doping superlattices have exhibited wide tunability in the photoluminescence (PL) peak energy versus excitation intensity,1 but photopumped lasing has been observed only at high excitation, where excess carriers completely screen the superlattice space-charge potential.2 By contrast, short-period superlattices possess a smaller degree of luminescence tunability yet exhibit larger oscillator strengths because of the greater overlap between electron and hole wave functions in the n- and p-type layers, respectively. A desirable goal is to achieve lasing at carrier densities below the value that completely screens the superlattice potential, thereby permitting tunability of the radiation. We have investigated the limits of tunability in uniformly doped short-period GaAs doping superlattices and present results of low-temperature photoluminescence.
Mutual influence of parametric and Raman effects in silica fibers
Authors: Golovchenko E. A. , Dianov E. M. , Mamyshev P. V. , Pilipetskii A. N. , Prokhorov A. M.
Published: February 2023

Usually the parametric and the stimulated Raman scattering (SRS) effects in fibers are discussed independent of each other. We show here theoretically and experimentally that parametric interaction can suppress SRS in single-mode fibers. We also show that the Raman nonlinearity considerably changes the values of increment and frequency of modulational instability (MI).
Transient-stimulated Raman scattering in birefringent fibers: theory and experiments
Authors: Cosentino A. , Romagnoli M. , Trillo S. , Vozzella R. , Wabnitz S. , Wright E. M.
Published: February 2023

The propagation of intense subpicosecond pulses in single-mode fibers is under the influence of group-velocity dispersion, self-phase modulation, and stimulated Raman scattering (SRS): it may be described in terms of a nonlinear Schrödinger equation with a delayed contribution to the third-order nonlinear polarization.1-3 Applications may involve pulse compression by an external grating in the normal dispersion regime of the fiber or through the fiber itself in the anomalous dispersion regime by means of Raman soliton generation and self-frequency shift.
New analysis of loss in optical waveguides from random wall imperfections
Authors: Payne F. P. , Lacey J. P. R.
Published: February 2023

One of the most difficult problems to treat theoretically in integrated optics is that of radiation loss through scattering from random imperfections of the waveguide walls. Previous approaches to this problem have been based on coupled-mode analysis,1 with the radiation loss described by coupling between guided and radiation modes of the optical waveguide. Unfortunately this approach suffers from a number of drawbacks. Among these is the complexity of the final result for the power loss coefficient and from which it is extremely difficult to discern the important parameters in controlling waveguide loss. Furthermore, the coupled-mode approach is difficult to apply to rib and rectangular guides, for which there is no exact expression for the radiation modes. With these difficulties in mind, we have developed a new and much simpler approach to the problem of radiation loss based on treating the waveguide imperfections as a set of randomly distributed antennas, or sources.
Integrated optoelectronics for coherent communication
Authors: Oe K. , Kurumada K.
Published: February 2023

Monolithic integration of semiconductor optoelectronic devices including waveguides on a single small chip is focused now.1,2 We initiated the work with a sketch of monolithic structures for heterodyne detection called optical coherent block,3 and it has been followed by refining single-mode semiconductor waveguide devices such as the Mach-Zehnder interferometer.4 Then a prototype of a monolithic integrated coherent receiver including a local oscillating (LO) laser, a 3-dB waveguide directional coupler, and pin photodetectors (PINs) has been successfully fabricated with preliminary heterodyning detection experiments.1 Figure 1 shows a schematic of the first reported device. The size is small: 0.25 mm x 4.15 mm. The device applicability seems to be fairly high on the basis of the several advantages. First, the LO laser coupled to the monolithically jointed waveguide has normally operated with reasonable linewidth of a few tens of megahertz without an isolator between them for the ordinary system experimental setup. Then the device compactness and mechanical stability could be potentially superior to the hybrid device combination up to a certain level of the coherence. However, at present, dual PINs on the chip are not operating with the balanced mixing mode because of the technological immaturity, i.e., the PINs are electrically common on the conductive n-substrate. Namely, the integration of those components on a semi-insulating substrate is a final goal for the device completion. On the other hand, high performances of the coherent transmission experiments are reported in the system when conventional discrete devices are combined. Also, a silica (or glass) waveguide coupler instead of the fiber-type coupler will emerge in near future. Consequently, three sets of the components combination are likely to be candidates for the future system implementation.
New velocity-matched III–V traveling-wave electro-optic modulator structure
Authors: Tan M. R. T. , Wang S. Y.
Published: February 2023

A new velocity-matched III–V traveling-wave structure for electro­optic modulator application has been developed. The structure is modeled using the spectral domain analysis (SDA) method.1,2 The microwave properties of the new structure are characterized to 26.5 GHz.
Carrier-injection-type optical S3 switch with traveling-wave amplifer
Authors: Inoue H. , Kirihara T. , Sasaki Y. , Ishida K.
Published: February 2023

Semiconductor optical switches operating through carrier-induced
refractive-index change are promising components for photonic
switching. The large and polarization-independent refractive-index
change facilitates realizing compact optical switch arrays and
reliable connection with conventional fibers.1,2 We
developed an InP-based nonblocking 4 x 4 optical switch array using
single-slip structure (S3) as an optical switch
unit.3 This device has advantages, such as small size,
single-mode operation, and polarization independence. However, there
are also drawbacks; large total insertion loss and insufficient ON/OFF
ratio, which prevent extending integration because of power penalty
and cross talk.
Comparison between the beam-propagation method and coupled-mode simulations for nonuniform guides with circular symmetry
Authors: Black R. J. , Gonthier F. , Hénault A. , Lacroix S.
Published: February 2023

The field in optical fibers, whether they are longitudinally uniform or not, may be expanded over a complete set of modes. Whereas for uniform fibers the field evolution simply depends on beating given by modal phase differences, in the nonuniform case it can be described by a coupled-mode formalism.1 The choice of the set over which the expansion is made and the number of modes to be considered in a numerical simulation are both important. Two cases are examined: an abruptly tapered fiber2 and a nonlinear index fiber.3 In the case of an abruptly tapered fiber the nonuniformity comes from the fiber radius variation, and the set of normal modes is naturally chosen to be the local modes.1 In the nonlinear case the field is expanded over the linear modes, i.e., the modes of the guide when the Kerr nonlinearity coefficient n2 is zero or the injected power is low. For typically tapered fibers,2 a reasonably uniform convergence of the results is usually observed when the number of the guided modes involved is increased to between 3 and 6, the required number depending on the magnitude of the nonuniformity. However, the validity of such a convergence in terms of only low-order modes may be questioned. To verify these results, we developed a modified beam-propagating method (BPM) program to simulate the field evolution in cylindrically symmetric guides.4 Figure 1 gives a sample simulation for a finite-cladding tapered fiber. Figure 2 shows in this case the comparison of the power in each mode given in (i) the coupled-mode simulation (with sufficient modes for convergence) by the expansion coefficients and (ii) the BPM simulation by the overlap of the total field with the modal fields. The good agreement suggests that radiation is negligible and that only a small number of guided modes is adequate for a coupled-mode formulation to describe the field well. The nonlinear case comparison is also examined to check the convergence criterion validity.
Photonic devices grown by atmospheric-pressure organometallic vapor-phase epitaxy using tertiarybutylarsine
Authors: Young M. G. , Miller B. I. , Oron M. , Koren U. , Kisker D. W.
Published: February 2023

Because of the increasing interest in long-wavelength devices operating in the 1.1–1.55-μm wavelength region, growth techniques such as organometallic vapor-phase epitaxy (OMVPE) and chemical-beam epitaxy (CBE) are required to use toxic hydrides such as AsH3 and PH3 as the source of group V precursors. Of the two hydrides, AsH3 is more toxic, having a daily 8-h exposure limit of only 50 parts per billion, which requires the installation of elaborate safety systems prior to any growth. As a result, there have been many attempts to replace arsine with metal-organic substitutes.
Direct fabrication of coupler waveguide with index and dimensional taper by flame hydrolysis deposition
Authors: Yanagawa H. , Nakamura S. , Ohyama I.
Published: February 2023

Although a dimensional taper is proposed to obtain low-loss coupling between components with different mode profiles, it can achieve only a small taper ratio practically because a limited range of V values is permitted to suppress mode conversion loss under a single-mode condition. To obtain a large mode-profile-converting capability, therefore, a channel waveguide with both index and dimensional taper is required.1-3 In this paper the fabrication of such a taper is reported.
Monolithically Integrated In0.53Ga0.47As Voltage-Tunable Transimpedance Amplifier
Authors: Lo D.C.W. , Chung Y.K. , Forrest S.R.
Published: February 2023

Transimpedance amplifiers provide a high dynamic range and wide bandwidth over that obtained using high impedance amplifiers.1 However, most InP-based integrated optical receivers demonstrated today use high impedance amplifiers. This is because the integrated high-impedance amplifiers are easy to characterize. Another reason is due to the relatively low transimpedance observed for the integrated transimpedance amplifiers, which is attributed to the low value of the integrated feedback resistor.2 The integrated resistor is commonly fabricated using the FET channel layer because of its simplicity for integration with other FETs in the circuit. However, such resistors with a high value of resistance consume a large area which can result in a large parasitic shunt capacitance and inductance. Here we describe an In0.53Ga0.47As JFET transimpedance amplifier, which consists of a common source inverter stage, a level-shift buffer stage, and a narrow-gate transistor3 (5µm wide and 30µm long) as an active feedback resistor. The output resistance of the narrow-gate transistor operated in its linear region can be dynamically tuned over a wide range. Moreover, the device can be made very small to reduce parasitic capacitance and inductance.
Progress in optoelectronic integration
Authors: Leheny R. F.
Published: February 2023

Optoelectronic integrated circuits (OEICs), are circuits that monolithically integrate optical and electronic components on the same chip to provide a means to conveniently interface between optical and electrical signal formats. It has long been recognized that such integration could offer advantages over hybrid circuits in compactness, reliability, as well as, potential performance improvements resulting from reduced parasitics, and significant cost reductions, particularly in the case of arrays of optical components. Given the broad bandwidth, low loss properties of optical transmission systems OEICs represent a device technology to provide efficient, low cost interfacing to meet a broad range of present and future telecommunications, optical signal processing and computer systems needs. However, despite these many anticipated advantages, present OEICs typically do not outperformed hybrid circuits performing similar function. This is generally considered to be due in large part to the difficult materials and materials fabrication challenges presented by integration of very different devices on a single chip. However, continuing advances in device design and fabrication, as well as in material growth and processing technologies, rooted in advances made over the past decade in the design and fabrication of discrete optical and electronic components using both GaAs and InP materials, are today providing the means for realizing sophisticated integrated devices. At the same time the expanding interest in incorporation of optical components into short haul communication and computer network systems could provide the significant market demand required to further stimulate research on these devices. In this talk we will review the present status of OEICs and discuss some of the factors influencing continued research in this emerging technology.
Integration of InGaAs/InP p-i-n photodetectors with glass waveguides
Authors: Chan W. K. , Yi-Yan A. , Gmitter T. J. , Jackel J. L. , Nguyen C. K. , Bhat R.
Published: February 2023

The use of epitaxial lift-off1 to incorporate active optoelectronic components on low loss and inexpensive nonsemiconductor optical waveguides offers an attractive technology for high-performance integrated optics. Using this technique, we have previously reported the integration and optical coupling of short-wavelength GaAs metal–semi-conductor–metal (MSM) photodetectors with glass waveguides.2 Here we report the integration and optical coupling of long-wavelength InGaAs p-i-n photodetectors, which are important to fiber-based systems operating in the 1.3-1.55-μm-wavelength region, with glass waveguides.
Femtosecond soliton propagation in optical fibers with slowly decreasing dispersion
Authors: Mamyshev P. V. , Chernikov S. V.
Published: February 2023

Currently, solitons with a minimum duration of approximately 50 fs are obtained in optical fibers. Adiabatic compression of solitons in fibers with slowly decreasing dispersion (FSDD) is promising for the generation of high-quality pulses with a shorter duration in the near IR.1 New effects arise at the femtosecond pulse propagation in fibers. For the theoretical description of such a propagation, the traditional nonlinear Schrödinger equation needs to be modified. In recent papers2-4 nonlinear equations were considered, and the real part as well as the imaginary part of the third-order nonlinear susceptibility χ(3) was taken into account. In Refs. 3 and 4 the real spectral dependence χ(3) (ω) is discussed. In this paper we discuss the model that, in addition to the effects mentioned above, takes into account the Stokes losses associated with the material excitation during the Raman self-scattering effect and the dependence of the third-order nonlinear effects on the radiation frequency.
Design guidelines for laser-diode structures with low reflectivity for both TE and TM modes
Authors: Nilsson Johan , Jaskorzynska Bozena , Thylén Lars
Published: February 2023

Minimizing the modal reflectivity of semiconductor-laser facets is crucial when designing waveguided external cavity lasers and traveling wave amplifiers. For 25-dB gain, a modal reflectivity of approximately 10-4 is required to keep gain ripple below 1 dB.