Masanobu Kobayashi, Y. Maeno, K. Oishi, K. Kawamura
Amorphous rare earth-transition metal thin films (RE-TM films) have properties suited for erasable optical memory media. They have been widely studied and will be soon in a step of practical use. These films, however, have the drawback of poor reliability due to their poor corrosion resistance. We have reported that the corrosion of the films is classified as being the surface oxidation, the selective oxidation of RE metals, and electrochemical corrosion.1,2 To protect the RE-TM films from the corrosion, two methods can be considered. One method is to improve the corrosion resistance of the films themselves. The other is to coat the films with protective layers such as SiO, AIN.3 We have studied the electrochemical corrosion of RE–TM films immersed in a NaCl aqueous solution and succeeded in improving the corrosion resistance of the films themselves by adding several metals.
{"title":"Improvements in Corrosion Resistance of Tb-Fe Thin Films","authors":"Masanobu Kobayashi, Y. Maeno, K. Oishi, K. Kawamura","doi":"10.1063/1.99401","DOIUrl":"https://doi.org/10.1063/1.99401","url":null,"abstract":"Amorphous rare earth-transition metal thin films (RE-TM films) have properties suited for erasable optical memory media. They have been widely studied and will be soon in a step of practical use. These films, however, have the drawback of poor reliability due to their poor corrosion resistance. We have reported that the corrosion of the films is classified as being the surface oxidation, the selective oxidation of RE metals, and electrochemical corrosion.1,2 To protect the RE-TM films from the corrosion, two methods can be considered. One method is to improve the corrosion resistance of the films themselves. The other is to coat the films with protective layers such as SiO, AIN.3 We have studied the electrochemical corrosion of RE–TM films immersed in a NaCl aqueous solution and succeeded in improving the corrosion resistance of the films themselves by adding several metals.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130920213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A two-dimensional finite-difference method was developed to study the thermal behavior of thin films, irradiated by a pulsed Gaussian laser beam. In particular, the method was applied to rare earth-transition metal alloy films for magnetooptical recording. The effects of the film parameters (thermal conductivity, specific heat, absorption coefficient and film thickness) and the laser parameters (output power, pulse width and beam size) on the heating and cooling behavior were extensively investigated. It was found that the temperature profile of a film was sensitively dependent on those parameters. The results might be utilized to predict the recorded bit size and also to optimize the laser parameters. For a given energy density of a laser beam, a large output power with a short pulse width was desirable for effective heating of a film. It was also found that heating by radial thermal diffusion became important with increasing thermal conductivity of a film. Therefore, to achieve high storage density, a film is required to have low thermal conductivity.
{"title":"Thermal Analysis of Thin Films Under Pulsed Laser Irradiation","authors":"Sung-chul Shin","doi":"10.1364/ods.1985.thdd2","DOIUrl":"https://doi.org/10.1364/ods.1985.thdd2","url":null,"abstract":"A two-dimensional finite-difference method was developed to study the thermal behavior of thin films, irradiated by a pulsed Gaussian laser beam. In particular, the method was applied to rare earth-transition metal alloy films for magnetooptical recording. The effects of the film parameters (thermal conductivity, specific heat, absorption coefficient and film thickness) and the laser parameters (output power, pulse width and beam size) on the heating and cooling behavior were extensively investigated. It was found that the temperature profile of a film was sensitively dependent on those parameters. The results might be utilized to predict the recorded bit size and also to optimize the laser parameters. For a given energy density of a laser beam, a large output power with a short pulse width was desirable for effective heating of a film. It was also found that heating by radial thermal diffusion became important with increasing thermal conductivity of a film. Therefore, to achieve high storage density, a film is required to have low thermal conductivity.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1985-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127714702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Optimem Division of Shugart Corporation has developed the Optimem 1000 optical disk drive to address the low end market for cost effective write-once optical storage systems. The Optimem 1000 is a 1 GByte per surface drive which is meant to compliment magnetic disk storage. Typical office type applications for this drive are electronic file cabinet storage, and CAD/CAM and medical image storage. In the document storage applications, the optical drive can be used as the central file server along with magnetic disk drives for work in progress.
{"title":"The Optimem 1000 Optical Disk Drive","authors":"G. Knight","doi":"10.1364/cleo.1984.tuh2","DOIUrl":"https://doi.org/10.1364/cleo.1984.tuh2","url":null,"abstract":"The Optimem Division of Shugart Corporation has developed the Optimem 1000 optical disk drive to address the low end market for cost effective write-once optical storage systems. The Optimem 1000 is a 1 GByte per surface drive which is meant to compliment magnetic disk storage. Typical office type applications for this drive are electronic file cabinet storage, and CAD/CAM and medical image storage. In the document storage applications, the optical drive can be used as the central file server along with magnetic disk drives for work in progress.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121039927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Schellenberg, W. Moerner, M. Levenson, G. Bjorklund, D. J. Bernays
The phenomenon of persistent spectral hole burning allows the frequency of a tunable laser source to be utilized as an additional dimension for the organization of an optical data storage system.1 Potential gains of greater than a factor of 1000 in achievable storage densities over conventional optical storage are possible. In addition, extremely fast random access times can be achieved in the frequency dimension.
{"title":"Progress in Frequency Domain Optical Storage","authors":"F. Schellenberg, W. Moerner, M. Levenson, G. Bjorklund, D. J. Bernays","doi":"10.1364/CLEO.1984.THI41","DOIUrl":"https://doi.org/10.1364/CLEO.1984.THI41","url":null,"abstract":"The phenomenon of persistent spectral hole burning allows the frequency of a tunable laser source to be utilized as an additional dimension for the organization of an optical data storage system.1 Potential gains of greater than a factor of 1000 in achievable storage densities over conventional optical storage are possible. In addition, extremely fast random access times can be achieved in the frequency dimension.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122677770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the investigation of amorphous rare earth-transition metal (RE-TM) thin films for magneto-optic (M-O) storage applications, optimization of Kerr effect enhancement using dielectric overcoating in a bilayer structure has been the subject of numerous theoretical calculations [1]. It has been generally assumed that the optical constants such as the refractive index, absorption coefficient and dielectric tensor of the M-O film are independent of the film thickness. However, in light of a recent report which shows a strong thickness dependence of magnetic hysteretic properties and Curie temperature of the Tb-Fe films due to variation in the microstructure [2], it is necessary to investigate experimentally the optical enhancement of the Kerr effect in media having varying RE-TM film thickness and compare that to the theoretical results.
{"title":"Thickness Dependence of Magneto-Optic Effects in Tb-Fe Film","authors":"T. Chen, M. Mansuripur, R. Malmhall","doi":"10.1364/ods.1983.tha5","DOIUrl":"https://doi.org/10.1364/ods.1983.tha5","url":null,"abstract":"In the investigation of amorphous rare earth-transition metal (RE-TM) thin films for magneto-optic (M-O) storage applications, optimization of Kerr effect enhancement using dielectric overcoating in a bilayer structure has been the subject of numerous theoretical calculations [1]. It has been generally assumed that the optical constants such as the refractive index, absorption coefficient and dielectric tensor of the M-O film are independent of the film thickness. However, in light of a recent report which shows a strong thickness dependence of magnetic hysteretic properties and Curie temperature of the Tb-Fe films due to variation in the microstructure [2], it is necessary to investigate experimentally the optical enhancement of the Kerr effect in media having varying RE-TM film thickness and compare that to the theoretical results.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131457657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In optical disc system, the precise measurement and evaluation of focused micro-laser-spot (usually less than lum in diameter) is very important. To meet this requirement, a new method using the concept of CT scanner has been developed. A knife-edge scans the spot on the image plane. Differentiating the signal received by the detecter under the knife-edge, we get a one-dimension (1-D) projection of 2-D laser spot. Rotating the knife-edge slightly, we can get different projections at different angles. The projections measured are processed by taking the convolution and back-projecttion, just done as in the CT scanner. In this way, we get the 2-D profiles of the spot, i.e. the Point Spread Function (PSF) of the optical head. The shape and size of the spot can be got directly from the profile. The 2-D Fourier Transform of PSF results in the OTF of the optical head, which discribes the quality of the optical system quantitatively.
{"title":"Measuring Two Dimensional OTF Applying CT Principle","authors":"Yang Xiang-yang, Wu Min-shian, Chin Kuo-fan","doi":"10.1364/ods.1985.thdd3","DOIUrl":"https://doi.org/10.1364/ods.1985.thdd3","url":null,"abstract":"In optical disc system, the precise measurement and evaluation of focused micro-laser-spot (usually less than lum in diameter) is very important. To meet this requirement, a new method using the concept of CT scanner has been developed. A knife-edge scans the spot on the image plane. Differentiating the signal received by the detecter under the knife-edge, we get a one-dimension (1-D) projection of 2-D laser spot. Rotating the knife-edge slightly, we can get different projections at different angles. The projections measured are processed by taking the convolution and back-projecttion, just done as in the CT scanner. In this way, we get the 2-D profiles of the spot, i.e. the Point Spread Function (PSF) of the optical head. The shape and size of the spot can be got directly from the profile. The 2-D Fourier Transform of PSF results in the OTF of the optical head, which discribes the quality of the optical system quantitatively.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126618747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic based optical storage media, dye-only or dyed-polymer, offer a number of advantages over thin metal films used in write-once, phase change, or magneto-optic media1. Organic materials have much lower melting points and thermal conductivities than metals. This can result in higher sensitivity and resolution for laser marking. Organic materials can be cast by spin coating, which leads to lower fabrication costs for discs as compared to the vapor coating techniques required for thin metal films. They are less subject to degradation caused by air and moisture. Furthermore, the chemical and physical properties of organic materials can be controled by manipulating the molecular structure to achieve the required performance.
{"title":"Characterization of a Dyed-Polymer Optical Storage Medium","authors":"J. E. Kuder, D. Nikles","doi":"10.1364/ods.1985.wbb3","DOIUrl":"https://doi.org/10.1364/ods.1985.wbb3","url":null,"abstract":"Organic based optical storage media, dye-only or dyed-polymer, offer a number of advantages over thin metal films used in write-once, phase change, or magneto-optic media1. Organic materials have much lower melting points and thermal conductivities than metals. This can result in higher sensitivity and resolution for laser marking. Organic materials can be cast by spin coating, which leads to lower fabrication costs for discs as compared to the vapor coating techniques required for thin metal films. They are less subject to degradation caused by air and moisture. Furthermore, the chemical and physical properties of organic materials can be controled by manipulating the molecular structure to achieve the required performance.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116366185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
At present, pre-recorded optical videodiscs and disc players are manufactured to the standard of the Laservision Association to assure mutual compatibility. This disc-player system with its video capability, large storage capacity, short access time and standardized players could be used for film editing, video program assembly and document storage if discs could be recorded by the user and immediately played back on standard players.
{"title":"A Draw Disc Compatible with Laservision Standard Players","authors":"R. Wilkinson, J. Winslow","doi":"10.1364/ods.1984.wcb2","DOIUrl":"https://doi.org/10.1364/ods.1984.wcb2","url":null,"abstract":"At present, pre-recorded optical videodiscs and disc players are manufactured to the standard of the Laservision Association to assure mutual compatibility. This disc-player system with its video capability, large storage capacity, short access time and standardized players could be used for film editing, video program assembly and document storage if discs could be recorded by the user and immediately played back on standard players.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132211202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optical disk file memory using a laser diode is one of the most promising devices for large capacity computer data storage. Several companies have been developing optical disk file memories during the past few years. However, almost all of these memories were designed for document data storage which does not require low error rate and interactive operation with computer. Recently, we have developed a highly reliable optical disk file memory for computer application. The basic specifications, features, and system structure of the developed optical disk file memory and several approaches for reliability improvement are described.
{"title":"Optical Disk File Memory for Computer Use","authors":"Y. Tsunoda, Shin-ichi Abe, Michio Miyazaki","doi":"10.1364/ods.1984.wca2","DOIUrl":"https://doi.org/10.1364/ods.1984.wca2","url":null,"abstract":"Optical disk file memory using a laser diode is one of the most promising devices for large capacity computer data storage. Several companies have been developing optical disk file memories during the past few years. However, almost all of these memories were designed for document data storage which does not require low error rate and interactive operation with computer. Recently, we have developed a highly reliable optical disk file memory for computer application. The basic specifications, features, and system structure of the developed optical disk file memory and several approaches for reliability improvement are described.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134095019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years much research has been directed towards developing magneto-optic recording technology, and in assessing its competitiveness in the computer data storage market. High areal density, removable media, reliability, and projected manufacturing costs make magneto-optic drives a very interesting mass storage alternative. However many drive designs have focused on only the above attributes, ignoring performance, thereby developing "slow" magneto-optic drives. Magneto-optic drives will certainly be more competitive if they are designed with equal or greater performance than comparably priced, comparable capacity, Winchester drives. This paper will examine the tradeoffs necessary to develop high performance magneto-optic drives. Design procedures for the read/write optics, media, modulation codes, formats, servo optics, and servo/seek mechanism and control, will be examined.
{"title":"Drive Issues for High Performance Magneto-optic Recording","authors":"D. Campbell","doi":"10.1364/ods.1987.wa1","DOIUrl":"https://doi.org/10.1364/ods.1987.wa1","url":null,"abstract":"In recent years much research has been directed towards developing magneto-optic recording technology, and in assessing its competitiveness in the computer data storage market. High areal density, removable media, reliability, and projected manufacturing costs make magneto-optic drives a very interesting mass storage alternative. However many drive designs have focused on only the above attributes, ignoring performance, thereby developing \"slow\" magneto-optic drives. Magneto-optic drives will certainly be more competitive if they are designed with equal or greater performance than comparably priced, comparable capacity, Winchester drives. This paper will examine the tradeoffs necessary to develop high performance magneto-optic drives. Design procedures for the read/write optics, media, modulation codes, formats, servo optics, and servo/seek mechanism and control, will be examined.","PeriodicalId":268493,"journal":{"name":"Topical Meeting on Optical Data Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124184213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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