bluuebunny/crossref_metadata_2025 huggingface dataset:
ANALYSIS OF FLOOD HAZARDS IN MAGETAN REGENCY USINGDISTANCE SENSING METHOD
Authors: Jamilah Zahrotin , Widodo Amien , Singgih Purwanto Moh
Published: February 2023

Flood is an annual disaster that hits all over Indonesia, and Magetan Regency is one of the affected area . The high regional topography in the western part and the relatively flat topography in the eastern part making it potential for flood to be higher in the eastern part. The DEM (Digital Elevation Model) topography, Landsat maps, and hazard index maps can be identified by remote sensing using regional administration map data, the level of slope slope and vegetation density can be mapped using NDVI method, and the classification of the flood risk level of an area can be done using ArcGIS software. The slope of the slope and the density of vegetation will affect the level of potential flood hazard. There is a low level of potential for flooding on steep slopes because the air will flow and accumulate on the lower plains. Higher vegetation density will provide a good air catchment area. The level of vegetation density is also higher in the western part. Based on the percentage of the affected area, the low flood hazard level reaches 73.3%, so it can be concluded that the flood hazard level in Magetan Regency is low. It is necessary to provide adequate land and channels capable of providing air flow.
THE FIXED BAFFLE EFFECT ANALYSIS TO FILLING TANKS VARIATION ON THE STABILITY OF 4999 DWT TANKERS
Authors: Yudo Hartono , Amiruddin Wilma , Guna Satriananta Mahendra , Putra Nur Hidayat Wahyu
Published: February 2023

The tanker is transportation to distribute the results of oil and gas exploration, where most of the exploration results come from the ocean. In this study, an analysis of the effect of adding fixed baffles with a certain number of baffles on the stability of the tanker will be carried out. The method in this study is to analyze the data of 4999 DWT tankers using Maxsurf Stability Software. The simulation was carried out in 4 percentage variations, namely 30%, 40%, 70%, and 90%, with full baffle installation in each tank. After calculating the stability analysis on the 4999 DWT tanker, it was found that the model I tank (without baffles) did not meet IMO standards. While the model II tank (1 fixed baffle), model III tank (2 fixed baffles), and model IV tank (3 fixed baffles) on various fillings have met IMO standards. Where the tank model IV (3 fixed baffles) has the best stability value with a GZ value of 1.881 m at 30% filling, 1.602 m at 50% filling, 1.051 m at 70% filling, and 0.706 m at 90% filling. It was concluded that the addition of a fixed baffle to the tank was effective in increasing the stability of the tanker.
POSITIONING EVALUATION WITH GNSS USING REALTIME PRECISE POINT POSITIONING METHOD FOR MINING MAPING SURVEY
Authors: Wisnu Wardhana Gunawan
Published: February 2023

Real Time Precise-Point Positioning (RT-PPP) is a relatively new method for satellite-based positioning or better known as the Global Navigation Satellite System (GNSS). RT-PPP has similarities with PPP in terms of data accuracy and precision because it was developed from the previous method called Precise Point Positioning (PPP). However, RT-PPP has an advantage in real time because it gets correction from the L-band in the Satellite Based Augmentation System (SBAS). This study aims to evaluate the RT-PPP method for mining surveys. The precision evaluation was carried out repeatedly for 7 days at specific points, while accuracy testing was compared with the static differential method at 11 points spread over the mining area. The results showed that the standard deviation of the RT-PPP method was 1.0 cm and 1.1 cm in the east and north, 3 cm in elevation. The accuracy test shows 17.5 cm for the RMSE horizontally and 6.2 cm vertically.
Meet The Green Team
Authors: Wood Pete
Published: February 2023

Pete Wood looks at how a movement made up of activist engineers is working to deliver more sustainable products and processes
Sensors: the Gateway to Energy Efficiency
Authors: Fitzpatrick John
Published: February 2023

Demand for sensors is soaring and is being, in part, driven by the need for greater energy efficiency
In A Flap
Authors: Beck Chris
Published: February 2023

In February, the #KFCCrisis made news across the globe. What went wrong, and what lessons can manufacturers learn from the catastrophic breakdown of the firm’s supply chain?
Plotting a Route to Success
Authors: Beck Chris
Published: February 2023

PP Control & Automation’s renowned continuous improvement scheme is down to a highly engaged workforce, delegates at MM’s recent Experience Day event heard
Diffusing Digital
Authors: Offord Adam
Published: February 2023

Juergen Maier, chief executive of Siemens UK, ran a seminar session at MACH 2018 to outline how the Made Smarter Commission plans to drive the Fourth Industrial Revolution in the UK, the challenges ahead and what industry can do to bring it to life
Do political quotas work? Gender quotas and women’s political participation in Nepal
Authors: Yadav Punam
Published: February 2023

This article presents an investigation into the lives and lived experiences of women who joined politics through quotas. In particular, it explores the transformative potential of a quota policy through the ‘subject position’ of women politicians in Nepal, especially those who had no prior background in politics before being elected to their first political positions. Using Bourdieu’s theory of capital, I reveal how political quotas have strengthened women’s overall capital, allowing them to improve their position in both their families and society. Quotas have created new roles for women. The power and prestige attached to these new roles have not only offered some immediate changes to these women’s lives, but also led to changing perceptions of women in politics, shifting the discourse from a view of women’s participation in politics as an exception to one of it as an entitlement. This article is based on a qualitative study carried out with women politicians in Nepal.
Validación de un instrumento para medir el respeto de la autonomía del paciente en situación terminal durante la toma de decisiones médicas sobre el final de la vida
Authors: González-Huerta José Isaac , Medina-Ceja Laura , Espinel-Bermudez Maria Claudia , Alvarez-Del Rio Asuncion , Medina-Arellano Maria de Jesus , Cordova-Jimenez Irene
Published: February 2023

Antecedentes: El respeto por la autonomía de la persona consiste en considerarlas preferencias y valores de la persona enferma durante la toma de decisions sobre el tipo de atención que recibe y es un elemento bioético-jurídico. Sin embargo, no existen instrumentos validados sobre este fenómeno que ayuden aclarificar la percepción del médico sobre este principio. Objetivo: Elaborar, validar mediante juicio de expertos y pilotear para obtener la consistencia interna de un instrumento que evalúa el nivel de acuerdo de los médicos sobre los diferentes elementos que constituyen el respeto por la  autonomía de la persona enferma en etapa terminal. Métodos: Estudio transversal. Método de validación por juicio de diez expertos de México. El instrumento se piloteó en médicos de un hospital público de alta especialidad para determinar la consistencia interna del mismo. Resultados: Se generó un instrumento de 15 ítems con un índice de validez de contenido de 0.82 para 10 expertos. Fue piloteado en una muestra de 96 médicos. Se obtuvo un alfa de Cronbach de 0.694. Conclusiones: Se desarrolló, validó y evaluó la consistencia interna de un cuestionario para medir el nivel de acuerdo de médicos que atienden a persones enfermas en etapa terminal con relación a los aspectos constitutivos sobre el respeto de su autonomía. Se recomienda su aplicación en médicos para corroborar su utilidad y favorecer un diagnóstico situacional sobre la situación estudiada.
La regulació jurídica brasilera de l'exercici de la telemedicina en el context de la pandèmia de COVID-19
Authors: Sena Figueirêdo Beatriz , De Paiva Medeiros de Oliveira Flávia
Published: February 2023

O presente artigo tem como tema central a regulação jurídica do exercício da telemedicina, especialmente a partir do contexto criado na pandemia do COVID-19. Neste sentido, o estudo aborda os mecanismos legais e as orientações dadas pelo Conselho Federal de Medicina (CFM) para adoção da prática. Surgem, em virtude disso, diversos questionamentos referentes à situação trabalhista dos profissionais de saúde que utilizam a telemedicina como mecanismo de trabalho. O artigo, portanto, explanará a importância da adoção da telemedicina, como também as problemáticas oriundas de sua utilização.
La dignidad de la mujer como argumento jurídico relevante en la Sentencia del Tribunal Supremo español 277 /2022, de 31 de marzo de 2022
Authors: Marín Castán María Luisa
Published: February 2023

Este comentario se centra en analizar uno de los aspectos relevantes de la reciente sentencia dictada por el Pleno de la Sala de lo Civil del Tribunal Supremo español, el 31 de marzo de 2022. La decisión jurisdiccional, aunque tiene por objeto la determinación de la filiación, se pronuncia sobre la polémica cuestión que se sitúa claramente en el ámbito de la Bioética y que está siendo, ya desde hace algún tiempo, objeto de un intenso debate social, político y jurídico, cual es la maternidad subrogada y su incidencia en la dignidad de la mujer, como cualidad intrínseca inherente a sus derechos más básicos y fundamentales. En este supuesto, el Tribunal Supremo, de manera rotunda, considera que se produce una vulneración flagrante de la dignidad de la mujer gestante y de sus derechos inviolables. Tras examinar el significado del principio esencial de la dignidad humana, se concluye que dicha cualidad es innegociable e inalienable y, por tanto, no es susceptible de resignificación que la menoscabe o menosprecie en ningún caso, en ninguna otra cultura ni en ningún otro contexto.
Design and Modeling of Optical Systems Involving Electro-Optical and Photorefractive Materials
Authors: Hesselink Lambertus
Published: February 2023

Summary not available at time of printing.
Back-of-the-envelope diffraction analysis for optimizing the depth of focus of scanning beams
Authors: Forbes G.W.
Published: February 2023

Simple models are most effective for feasibility studies and in the preliminary stages of design. A particularly simple, but accurate, model is presented for analyzing certain diffraction problems and it is applied to the optimization of scanning beam.
Optimization of Brightness and Magnification in Holographic Image Combiner Systems
Authors: Aritake Hirokazu , Kato Masayuki , Nakashima Masato
Published: February 2023

In image combiner systems for mobile applications such as automobiles and trains, magnification is needed as well as bright images for bright environments.
Tutorial on The Applicability of Conventional Design Notions to Integrated Optics
Authors: Hesselink Lambertus
Published: February 2023

The objective of this tutorial is to explore similarities and differences between the design of conventional and integrated optical elements.
Focal plane pixel energy redistribution and concentration using microlens arrays
Authors: Southwell William H.
Published: February 2023

Pixels in focal plane detector arrays are typically square for efficient utilization of light.
Optical Data Storage Technology for Consumer Electronics
Authors: Huijser A. , Carasso M.G.
Published: February 2023

Consumer products based on new technologies are often introduced after a succesfull application of that technology in professional equipment.

Optical recording is an exception to this rule. Consumer applications of this technique as in the Laser-Vision video-disc and the Compact Disc digital audio systems are already for sale which cannot be said for the professional digital optical recorder (DOR) systems. This situation is partial due to different fields of interest, i.e. read-only (ROM) applications for the present consumer market and direct-read-after-write (DRAW) systems for professional use: a difference in media rather than in optical principles.
A Proposal for the Integration of Digital Optical Storage into the Mass Storage System (MSS) at the National Center for Atmospheric Research (NCAR)
Authors: Choy Joseph H. , O'Lear Bernard T.
Published: February 2023

NCAR is currently operating an AMPEX Terabit Memory (TBM)* system. This system was purchased for 1.1 million dollars, installed in March of 1976, and placed into full operation by February 1977. During the subsequent years, over two million dollars has been spent in system upgrades. The final $300,000 upgrade is currently underway. The system is currently managing approximately 9 × 1012 bits. The application for optical disk data storage that NCAR would be interested in pursuing at this time would be phased over the following sequence of events:

• Installation of an initial optical disk product connected to a CRAY-1A computer and the subsequent procurement of additional hardware capability for the purpose of building a new MSS capability.

• Designate the TBM as a READ ONLY device within the NCAR local network and commence the offload procedure, whereby all good data existing on the TBM is copied onto the optical disk MSS (ODMSS). This activity would be in addition to the normal operation of the ODMSS.

• Continually provide for system upgrades through the late 1980s and early 1990s to develop an MSS node on the local network. This node will provide data management and data storage capabilities for planned future computing enhancements which are projected to be 10 to 50 times the capability of the current CRAY-1A.
Some Calculations On A Hole Forming Mechanism Compatible With An In-Contact Overcoat
Authors: LaBudde Edward. V. , Shevlin Craig , LaBudde Robert A. , Carlino Charles
Published: February 2023

The development of an optical disk media suitable for applications in the computer industry requires the development of very high performance optical media and disk drive systems. Of major importance is the development of a media with sufficient sensitivity to be used with commercially available low cost and reliable lasers along with long life and reliability of data recoveries after extended periods of storage times. The overall performance of an optical disk is principally determined by the basic overall design as well as the selection of materials and processes used to manufacture the disk. Of particular importance is the need to develop a disk that has a highly stable operating performance in a wide range of environments, in particular the necessity to protect the recording layer from dust and other contaminations is critical in the error rate performance. This paper describes an overall disk design which promises to meet the stringent performance requirements for a computer compatible optical disk system. In addition, a relatively simple overall thermal and optical model will be developed to describe the behavior of the physical principles involved in the optical recording processes. This paper additionally will provide collaborating test and experimental evidence to confirm the validity of the analytical models. The significance of this paper involves the reporting of a full-up disk design, analytical models, and experimental evidence to confirm that a new disk design has been successfully achieved which promises to meet a high performance application.
Reading and Writing of Photochemical Holes Using GaAIAs Diode Lasers
Authors: Pokrowsky P. , Moerner W. E. , Chu F. , Bjorklund G. C.
Published: February 2023

Many investigations have been done on the field of frequency domain optical memories based on photochemical hole burning (PHB). This effect offers an extra dimension for the organization of an optical memory. At cryogenic temperatures several solid state materials such as aggregate color centers in alkali halide crystals exhibit inhomogeneously broadened absorption lines. In such an absorption line permanent narrow holes can be burnt by photochemical processes induced by exposure to intense laser radiation with a wavelength within the inhomogeneously broadened line.
Codes for Optical Data Storage
Authors: Heegard Chris
Published: February 2023

This paper considers the efficient storage of temporary information on optical data disks. Information that is stored in a digital memory can broadly be regarded as temporary or permanent. Temporary data is to be retained by the memory for some finite length of time after which it will be updated or forgotten. From a coding point of view, an optical disk can be described as follows. Binary data can be stored on the disk by associating the letter 0 with a blank and the letter 1 with a mark. Initially, a virgin disc consists of n blanks (n can be quite large, on the order of 10"). Marks are permanently written on the disk by the use of a laser. Once data is written on the disk, the ability to write future data is hampered by the existence of previously written 1’s.
Dynamic Testing of Optical Disk Flatness
Authors: Lewkowicz Julian , Cohen D. K.
Published: February 2023

It is shown that focus error signal spectrum, measured while disk is spinning, represents Fourier transform of the disk profile modified by the loop gain.
A Two Axis Linear Servo Motor for Optical Recording
Authors: Berg Thomas E.
Published: February 2023

The high track bit density used in the OPL optical disk drive requires a high resolution tracking system as well as a similarly high resolution focus servo system. The total capacity of the drive dictates a range of linear travel for the readout objective lens in the tracking axis which makes high precision with a single stage tracking servo actuator very difficult. Therefore the high resolution servo motors have been combined into a single two axis linear servo motor assembly. A coarse tracking servo motor provides gross tracking motion. This paper describes the development, design, and performance of the two axis linear servo motor assembly, which will be referred to as the Fine Servo Motor or F.S.M.
A Fast Random Access Servo System Utilizing a Digital-Audio Optical Pickup
Authors: Hamilton Scott , Lavender Tony , Dillard Larry
Published: February 2023

Within the past several years, it has become possible to develop a low-cost optical computer data storage peripheral due to the emergence of the video disc and the digital-audio optical pickup. The pickup is small enough that it can be incorporated into a desktop-size device that allows access in less than 200 ms to any part of over one gigabyte of information.
Read-Write Channel for Optical Recording
Authors: Verboom Hans J. , Bracht Roger R. , Steenbergen Chris
Published: February 2023

Generally optical discs are divided into several sectors in which an amount of data is stored. Each sector starts with a header which contains an address and synchronization information. If, because of aging of the disc, this sync-info is destroyed, one needs a backup for having access to the data in that sector. A convenient way of attaining this is to have a prerecorded clock (a depth modulation of the pregroove) in the disc. Using this clock, a defect-insensitive phase lock loop and a counter, the sync-info of previous sectors can be used to reach the data in the damaged sector.
Fast Access Actuator For Optical Disk Memory
Authors: Yoshizumi Keiichi , Goto Syoji , Inoue Hideaki , Imanaka Ryoichi
Published: February 2023

To apply the optical disk to data memory systems, faster random access is an essential requirement. We have developed a fast access actuator, the structure of which is fundamentally different from that of the conventional actuator. The optical head consists of a fast access actuator and a stationary optics as separate units, and the movable component weighs only 12 grams.
A Generalized Mathematical Model of Sources of Noise Affecting Optical Recording Processes
Authors: LaBudde Edward V. , LaBudde Robert A.
Published: February 2023

The characterization of the noise processes in optical recording is very important because the ultimate recording density and system bit error rate of the medium are dependent on the signal-to-noise characteristics. The selection of the modulation and demodulation methods are driven by the medium recording and noise processes.
The effects of wall stiffness on reproducibility of thermo-magnetically written domains*
Authors: Shieh Han-Ping D. , Kryder Mark H.
Published: February 2023

The reproducibility of thermomagnetically written domains has been studied as a function of writing parameters and intrinsic magnetic parameters of magneto-optic films. Films with higher anisotropy constant, smaller aspect ratio, higher coercivity, and compensation temperature near or above room temperature result in a higher degree of domain reproducibility. It is shown that a wall stiffness model is consistent with the experimental results. Larger wall stiffness makes the domains less deformable from an equilibrium value and consequently results in domains which are more regular in size and shape.
Plasmon Media Technology
Authors: Gardner K , Helfet PR , Longman RJ , Pettigrew RM
Published: February 2023

The ME write once disc developed by Plasmon Data Systems is differentiated from other optical discs by the use of a unique microstructure called Moth Eye on the disc surface. This surface structure takes its name from the fact that similar surfaces are found on the cornea of certain nocturnal insects including the night moth. The microstructure, which has a pitch significantly below the wavelength of light, acts as an impedance matching layer to reduce the surface reflection. The reduction in reflectivity can also be achieved in the case of metal and dielectric coatings on the ME surface and in this case the absorption of the film is increased.
High Speed Accessing using Split Optical Head
Authors: Koumura K. , Takizawa F. , Iwanaga T. , Inada H. , Yamanaka Y. , Yoshida K.
Published: February 2023

A magneto-optical disk drive is foreseen to be used as removable large capacity computer external file. However, the magneto-optical disk drive performance is less from access time and data transfer rate points of view, compared with the magnetic disk drive performance. Therefore, high speed accessing is desired for the magneto-optical disk drive when used as a computer external file. To improve the access time, a split optical system, which is constructed with a light weight moving part and a fixed optical part, was reported for the magneto-optical disk drive.(1) There are a linear type actuator and a swing-arm type actuator for accessing. In the former case, the optical axis displacement between a fixed part and a moving part is one of the problem. In latter case, access stroke limitation, because of the circle arc trace, is one of the problem.
Carrier to Noise Ratio and Crosstalk in Thermo Magneto Optic (Tmo) Rewritable Optical Disks
Authors: Mendez Antonio J. , Krenik Robert M.
Published: February 2023

Test methods are being developed to measure and characterize carrier to noise ratio (CNR) and crosstalk in TMO optical digital data disks. The conditions which optimize the CNR may also be sufficient to induce crosstalk in adjacent (+ 1, + 2) tracks. Thus, the onset of crosstalk must be related to CNR optimization. Some compromise must be established between minimum crosstalk and sufficient CNR.
Bit Shift Measurement and Overwriting in a Sampled Servo Format Magneto-optical Recording
Authors: Kataoka K. , Ohta N. , Yonezawa S.
Published: February 2023

Bit shift characteristics of two types of direct overwrite magneto­optical recording schemes are studied. In the first method shown in Fig. 1(A) where dc laser power and ac magnetic field pulses are applied, large bit shift of around 100 ns is caused. In the second method shown in Fig. 1(B) and Fig.2, continuously oscillating laser pulses synchronizing with data channel clock are irradiated in data field and magnetic field pulses are also applied positive or negative directions depending upon that magnetic domains are formed or erased respectively. In the second method, computer simulations and experiments show that the amount of bit shift is around 5 ns and formed domains are not chevron pattern as shown in Fig.3. In addition, more precise compensation method of bit shift is also developed for future high end applications.
Visible Semiconductor Lasers
Authors: Bour D. P. , Shealy J. R.
Published: February 2023

The semiconductor diode lasers currently used in optical data storage applications have wavelengths limited to 780 < λ < 870nm, and the recent availability of shorter wavelength lasers can potentially lead to major improvements. The use of visible semiconductor lasers in such systems will allow greater packing densities and higher data transfer rates, since the diffraction-limited spot size is proportionally reduced with wavelength. Furthermore, the output power required for writing is reduced at shorter wavelengths.
That’s CD-R
Authors: Hamada Emiko , Shin Yuaki , Ishiguro Takashi
Published: February 2023

Many and many optical recordable memory discs have been proposed with various recording materials and configurations. However, the reflectivities of those discs were too low to satisfy the condition (70-90%) defined in the Compact Disc (CD) standards. We investigated quite a new recordable optical disc, "That’s CD-R". The CD-R has a high reflectivity of more than 70% and single plate configuration as same as existing CDs. So it satisfies the CD standards and allows to reproduce by every existing CD players and CD-ROM drives. Moreover not only That’s CD-R is recordable but also the recordable area and ROM area as same as existing CDs are compactible on a single That’s CD-R.
A Study of a Flexible Optical Disk Drive
Authors: Tamaru N. , Hosaka H. , Hara S. , Funakoshi N. , Kogure K.
Published: February 2023

A high-capacity 3.5-inch optical disk drive with a phase-change flexible disk has been studied. This study aimed to produce a smaller, thinner drive and a lower-cost disk than conventional hard optical disk drives and disks.
Progress of Erasable Phase Change Materials
Authors: Chen Martin
Published: February 2023

A review of the significant progress made in the past several years and a discussion of current research on erasable phase change materials will be presented.
Erasable Products Summary
Authors: Knight Gordon R.
Published: February 2023

Erasable optical disk drive products finally became reality in 1988. 5 1/4" erasable optical drives were introduced and limited production quantities were shipped by Maxtor Corp., Sony Corp., and Canon, Inc. The media suppliers for these drives include Philips and DuPont Optical Co., Daicel Chemical Industries, Ltd., Sony Corp., Canon, Inc., and 3M Corp. The user capacity of the erasable disks used on these drives range from a single sided 256 MByte capacity to a double sided, 1 GByte capacity.
Performance Comparison of Various Data Codes in Z-Cav Optical Recording
Authors: Lee T.C. , Chen D.
Published: February 2023

Cartridge removability is one of the most important features offered by the optical disk drive. To take advantage of this feature, it is desirable to have a common tracking and data format. It is the intent of this paper to provide a performance comparison, in terms of data capacity and transfer rate, of the various codes, including (2,7), (1,7) for continuous composite servo(CCS) and RZ, NRZ, four-out-of-fifteen(FOOF) and four-out-of-eleven(distributed block format, DBF) for sample servo(SS) . It is hoped that this comparison will be useful for the selection of a common data encoding scheme.
Magnetically induced super resolution in novel magneto-optical disk
Authors: Aratani Katsuhisa , Fukumoto Atsushi , Ohta Masumi , Kaneko Masahiko , Watanabe Kenjirou
Published: February 2023

The linear density of an optical disk is limited within the cut-off spatial frequency which is determined by the spot size of a focused beam. If the spot size is effectively reduced by using new technology, a remarkable improvement in the density could be achieved. Still more, combining with the technology of shorter wavelength laser could result in more than one order development.
High Power Addressable Laser Arrays
Authors: Craig R. , Mehuys D. , Nam D. , Zucker E. , Chan B. , Welch D.
Published: February 2023

Individually addressable laser arrays can offer the simultaneous writing and/or reading of information with optical data storage media. Within the limits of the optical head, the data rates can be multiplied by the number of emitters in the array. We have fabricated addressable arrays which have demonstrated high power, stable mode behavior, and excellent uniformity of optical properties.
New Applications of Optical Data Storage
Authors: Freese Robert
Published: February 2023

Corporate storage needs have undergone a dramatic transformation in recent years. As companies downsize from proprietary mainframe environments to local-area, multi-vendor networks, storage challenges have multiplied. Before, a company could embrace a single, highly-centralized storage solution for its mainframe; now, the company requires a multitude of storage systems for its individual networks, and each network storage solution must manage the needs of network clients as well as servers.
4X Speed CD-ROM Player
Authors: Yazaki Shirokazu
Published: February 2023

Summary not available.
2.5” Quadruple Density CD-ROM Using Visible Laser Diode
Authors: Terasaki Hitoshi , Tsuchiya Yoichi , Ichiura Shuichi , Higuchi Masahiro , Ota Osamu
Published: February 2023

Recent advances in image data compression technology made it possible to record motion pictures onto a CD-ROM This paper is to report our achievements in which motion pictures were recorded using MPEG to a CD-ROM having quadruple density to that of the conventional CD-ROM and then played back at a quadruple data transfer rate using an optical pick-up with a laser diode of wavelength 635 nm. That is, one-hour playback pictures were obtained with only a disk.
SERODS: A New Principle for High-Density Optical Data Storage
Authors: Vo-Dinh T. , Stokes D. L.
Published: February 2023

SERODS is a new technology for high-density optical disk storage based on the surface-enhanced Raman effect.(1) The SERODS technology is based on the principle that the enhanced light-emitting properties of certain molecules embedded in an optical medium can be altered at the molecular level to store information. When they are close to a rough metal surface, certain molecules emit a strongly enhanced light called surface-enhance Raman light which is characteristic of their vibrations. Normal Raman signals are generally very weak and cannot be easily detected. The enhanced emission is due to the Surface-Enhanced Raman Scattering (SERS) effect, which can enhance the Raman signal up to 108 times.
Readback Channel Model for an Optical Tape System
Authors: Gopalaswamy Srinivasan , Kumar B.V.K. Vijaya
Published: February 2023

Optical tape can provide high write-once data storage and is thus attractive for archival applications. This paper develops a readback channel model for an optical tape system that uses the differential reflectivity in the media to store information. Examples of this approach are the use of phase-change media and formation of pits on the media. In our work, we considered on-off modulation, in which a binary “1” is represented by a circular mark of higher reflectivity.
Examination of read/write characteristics of an MO signal with a wobbled groove clock
Authors: Watanabe Hiroshi , Asano Kenji , Mamiya Noboru , Suzuki Yoshihisa , Hori Yoshihiro , Uchihara Yoshiharu , Sumi Satoshi , Hioki Toshiaki , Murakami Yoshiteru , Kaneko Masahiko
Published: February 2023

In order to increase density of an optical disk, we examined high frequency groove wobbling which is advantageous for creating a clock as a means to improve data utilization rate and reported the result in "An investigation of a clock generated from a wobbled groove"[1]. In this report, we describe the result of read/write characteristics of an MO signal by using a wobbled groove clock.
Integrated Optical Device - MiniDisc Laser Coupler
Authors: Nishi Noriaki , Toyota Kiyoshi , Okamatsu Kazuhiko , Saitol Kimihiro , Horie Kazuyoshi , Tanaka Kiyoshi , Nemoto Kazuhiko
Published: February 2023

For an optical head in compact disc (CD) system, an optical device called "laser coupler" (LC) has been developed and used in commercially sold players. This device integrates a laser diode, photo detectors and a micro-prism into one small chip.[1] Using integrated devices of this kind, we can make small, light and stable optical heads with less material and production costs. MiniDisc (MD) systems have become popular as a novel audio system. In this system, a 64mm-diameter disc in a cartridge can record and play back 74 min. of compressed audio data or store 140 MB of user data, using magneto-optical (MO) technology. To improve the portability of this MD systems, smaller, lighter and more stable optical heads are necessary. For this reason, several kinds of integrated optical devices, such as laminated prism [2], holographic optical element (HOE) [3,4], have been reported. In this paper we present a new integrated optical device which we call MiniDisc laser coupler (MD-LC). The simple construction of this device allows an easy mass-production.
Optical Disk Substrate Technology
Authors: Sandstrom Chad R.
Published: February 2023

Optical disk substrate molding involves using centuries-old inventions to mass-produce commodity products of the highest technology. As such, the process is required to fulfill three critical expectations. The substrate must be exceptionally flat. It must be precisely micro-, even nano-replicated. Finally in order to serve as a lens within the system, the substrate must be optically isotropic. This talk will discuss challenges and the state of the art of optical disk substrate processing.
Data Registration in Holographic Optical Disc
Authors: Zhou Gan , Pu Allen , Mok Fai
Published: February 2023

A holographic optical disc stores digital information in the form of volume holograms. It utilizes the two dimensional surface of the disc as well as the Bragg selectivity of volume holograms to achieve three-dimensional data storage. Very high storage density, up to 100 bits/μm2, has been demonstrated in the past in a thin disc-like medium. Here we focus on the data registration issues in the holographic disc system.
Signal and Servo Issues in DVD/CD and CD-R/RW Compatible Optical Pick-Up
Authors: Kim Jin-Yong
Published: February 2023

Optical pick-ups offering DVD, CD and CD-R/RW compatibility begin to use non-conventional optical components. Possible influences to HP and servo signals caused by these components will be discussed.
Digital Phase Detection for DVD using an Adaptive Dual Arm Correlator
Authors: Supino Lou
Published: February 2023

Correlation techniques are used widely in communications, sonar, radar, medical and other signal processing systems. The most desirable property of correlation as a Digital Phase Detector (DPD), is the ability to measure the time delay between two similar signals. This paper proposes the use of correlation techniques to generate DPD signals which can be used in place of conventional phase detectors. The proposed correlator generates a quadrature PES and a PES signal with a +/- 1/2 track sawtooth signal.
Optical Manufacture of A 3.66 Meter Diameter Mirror
Authors: Dancey R.
Published: February 2023

This mirror is the primary for the Canada-France-Hawaii Telescope located at elevation 4200 meters on Mauna Kea, Hawaii. The optical finishing was done under a firm price contract from the Canada-France-Hawaii Telescope Corporation to the Dominion Astrophysical Observatory in Victoria, B.C. The Observatory is a section of the National Research Council of Canada. The work took a total of three years, of which twenty months were spent on the grinding and figuring of the front surface.
The Next Generation Telescope and Its Optical Fabrication Needs
Authors: Barr L. D.
Published: February 2023

The science of astronomy has long depended upon the talents and abilities of the optical profession. Astronomers would soon be out of business without lenses, mirrors, filters, special coatings, polarizers, optical fibers, diffraction gratings, and numerous other things provided in the past by the optical industry for astronomical needs. The present discussion is about yet another astronomical need and how its eventual fulfillment may depend upon even further advances in the art of optical fabrication.
The optical element fabrication process
Authors: Parks Robert E.
Published: February 2023

The seven steps in the fabrication of a lens are discussed and examples are included to indicate the complexity of some of the steps. The types of tooling required are described as well as the accuracy to which some of the steps can be performed. Emphasis is on the practical aspects of manufacture.
"Sun Rejection Test"
Authors: McCaffrey John E.
Published: February 2023

For the past ten years members of the Tucson Engineering staff of Hughes Aircraft Company, have been using a low cost, simple test method for the evaluation of optical systems. We call this test arrangement the "Sun Glare" or "Sun Rejection Test" since it was first developed to determine how well a given lens configuration rejected direct solar energy outside the instantaneous field of view of the lens.
Design, Fabrication, and Testing of an f/0.3 Achromatic Focusing System
Authors: Sigler R. D.
Published: February 2023

One of the crucial problems in laser fusion research is the efficient delivery of enormous amounts of power (typically several terawatts) to irradiate pellets of approximately 100 micrometer diameter. An illumination system consisting of a pair of ellipsoidal mirrors and aspheric single element lenses has been used with a two beam laser for several years at KMSF and has been very successful.

1. The lens surfaces are so steep that it is very difficult to apply anti-reflective coatings.

2. The lens must be very thick to accomodate short radii of curvature. The deleterious effects of high power beams propagating through refractive media are well known.

3. The lens also causes the system to be stigmatic for only one wavelength. The last item is especially important as recent experience has indicated that pellet energy absorption is increased by harmonically generated short wavelength and/or broadband laser light.
Replicated Polygons For Laser Scanning
Authors: Harris George A.
Published: February 2023

Most laser scanning systems for printing applications use motor-driven polygon scanners. Typically, the polygon is a polished metal part approximately 3 to 4 Inches in diameter and one-half inch thick. A common number of sides is eight to sixteen. The majority are manufactured by polishing in stacks.
Antares Optomechanical Interface Solution
Authors: Saxman A. , Silvernail C. , Sweatt W. , Bauke W.
Published: February 2023

Summary not available.
Precision reflectivity measurements on large infrared mirrors
Authors: Anthon Erik , Seddon Ian
Published: February 2023

A system is described for characterizing the reflectivity of large infrared mirrors by making accurate photometric measurements on small witnesses and accurate spectral measurements on the large optic.
Substrate Misfiguring to Correct the Coating Thickness Error
Authors: Scholl Marija S.
Published: February 2023

The mirrors used for the High Energy Lasers (HEL) are characterized by their unconventional shapes and diameters of up to lm, and larger. The types of geometries that are being used are conic surfaces, or general surfaces which are not describable by the the equation of the second order.
Testing of Ruled and Holographic Type Gratings
Authors: Loewen Erwin G.
Published: February 2023

Diffraction efficiency is often the most important attribute of a diffraction grating. Usually the aim is to maximise, but for special cases the opposite is true. It is defined and measured as the ratio of diffracted light to incident monochromatic light. In many instances, the behaviour depends strongly on the plane of polarization. In order to predict behaviour, or to design gratings for specific performance, requires an accurate theory, naturally based on Maxwell's equations. Fortunately, such solutions have finally been developed during the last decade, and now include even cases where the metal grating surface is buried under more than one layer of dielectric. They also lead to relatively simple categorization of most gratings into families of similar behaviour.
Infrared Materials - CVD Materials
Authors: Taylor R.L. , Donadio R.N. , Connolly J.F.
Published: February 2023

For many years the practical applications of infrared technology were hindered by the optical materials then available - generally small, fragile single crystals with poor mechanical and environmental response properties. In the 60 's Kodak manufactured a series of infrared optical materials (IRTRAN) by the hot pressing of powders. Although these materials were a substantial improvement over the single crystals, their mechanical and optical properties were not optimum and, in addition, sizes over 7" in diameter were difficult and expensive to fabricate by this technique. In the early 70's under government support, the chemical vapor deposition (CVD) process was successfully applied to the manufacture of the infrared materials zinc sulfide (ZnS) and zinc selenide (ZnSe). For the first time infrared materials were available with excellent optical, mechanical and environmental properties. These materials could be manufactured in large sizes and various shapes in a cost effective manner. The availability of CVD ZnS and ZnSe together with high purity, optical grade germanium have provided the bulk of the optical components which have now enabled infrared technology to be successfully applied in many commercial and military systems.
Characterization and In-Process Optimization of Infrared Ion Implanted GaP Optics
Authors: Mentzer M.A. , Hunsperger R.G. , Zavada J.M , Jenkinson H.A. , Gavanis T.J.
Published: February 2023

Free carrier compensation by ion implantation is an important processing technology for the formation of infrared optical waveguides for multiplexing applications. This process leads to a cutoff condition for waveguiding that is wavelength independent. Gallium phosphide is a very attractive semiconductor material for such multiplexing since it is transparent from the visible out to the far infrared. In addition, GaP, together with its related ternary and quarternary compounds, has many of the optical and electronic properties necessary for integration of optical devices into sensing and signal processing circuits. Experiments were performed to characterize the influence of various H+ implantation parameters on the carrier compensation process and to relate the resulting optical effects to electronic changes. The techniques developed for monitoring subsequent temperature processing can be utilized to fabricate optimized optical components.
Considerations for Selecting Diamond Tool Specifications
Authors: Bancroft Robert A.
Published: February 2023

Diamond products play an important role in the fabrication of optical components. Whether the operation is surface generation or pellet grinding, careful attention to application variables will help in selecting the proper diamond specification.
Nonoptical Characterization of Optical Coatings
Authors: Guenther Karl H.
Published: February 2023

In the various phases of the development, production, and use of an optical thin film coating, it is vital to choose proper thin film materials not only with respect to their optical properties but just as essential with respect to their environmental durability. If environmental tests reveal failures in optical interference coatings, this may be due to interactions between the layers and/or between the substrate and the first layer. Such interactions can be best established and analyzed by depth profiling using electron and/or ion beam methods. Emphasis is placed on the practicability with dielectric coatings where difficulties may sometimes arise because of decomposition, diffusion, and charging effects during analysis.
Techniques for Manufacturing Ultraprecision Optical Plane Elements
Authors: Yin Mu
Published: February 2023

This article introduced an ultraprecision optical polishing method for optical plane elements using a special polishing mould material G-90 we made. We also discussed in detail that the polishing condition, polishing techniques characters, and physicochemical charaters of the polishing mould material how to influence the stability of optical fringes and polishing efficiency.
Diverse Optical Fabrication Technologies Used In the Nova KDP Arrays
Authors: Williams J. D. , Johnson B. C. , Marchi T. F. , Murray R. G. , Summers M. A.
Published: February 2023

Crystal arrays are precision optical components consisting of a matrix arrangement of Individual Potassium Dihydrogen Phosphate (KDP) crystal segments mounted edge-to-edge and constrained between two windows In an Index fluid-filled housing. The arrays act as a single optical element. They are mounted at the output of the laser and must, as nearly as possible, simulate the performance of a non-matrixed assembly. To achieve this goal, we have employed state-of-the-art fabrication technologies such as single-point diamond machining of KDP, finite element modeling of optical distortions, flexure mounting of large (~ 1 meter diameter) fused silica windows, numerically-controlled diamond wire sawing, phase-scattering apodization, and gradient-index (sol-gel process) antireflectlve coating.
ULTRASONIC MACHINING (Impact Grinding)*
Authors: Rutan Hartford L.
Published: February 2023

Ultrasonic machining or impact grinding is the use of ultrasonically induced vibrations delivered to a designed tool combined with an abrasive slurry, to produce accurate cavities of regular and odd shapes in hard brittle materials such as: fused quartz, glass, crystal, ceramic, carbides and various metals. Ultrasonic machining is a non-thermal, non-chemical, non-electrical process, and creates no change in the metallurgical, chemical or physical properties of the substrate.
A method for replicating optical surfaces using UV curing cements
Authors: Fantone Stephen D.
Published: February 2023

Aspheric optical surfaces may be quickly replicated using UV curing cement. We describe a technique for replicating aspheric refractive surfaces.
Characterization of Surfaces by Vibrational Spectroscopy: The Electrode Surface In-Situ
Authors: Golden William G.
Published: February 2023

Recent advances in the application of infrared spectroscopy to the study of magnetic disk surfaces with regard to analysis of lubricant thickness, extent of coating oxidation, impurities present, etc. have been shown to be useful in that the analysis need not be performed in a vacuum apparatus nor need the sample be destroyed. The infrared approach in the above applications has in many cases been reduced to useful empirical methods, but the technique typically relies on the superior throughput and sensitivity of Fourier transform infrared spectrometers (FTIR). Due to the advent of readily obtainable FTIR spectrometers, it is now possible to take infrared spectra of monolayer amounts of molecules adsorbed on surfaces.
Measurement of Surface Microprofiles using Differential Interference Microscopy
Authors: Eastman Jay M. , Zavislan James M.
Published: February 2023

Numerous techniques exist for measuring the microtopography of precision surfaces. This paper describes an instrument that measures the microprofile of a surface using differential interference microscopy. The vertical resolution of the instrument is approximately 5 Angstroms and its lateral resolution is diffraction limited. The instrument can produce surface profiles of up to 100 millimeters in length in less than 2 minutes.