Digital Optical Processing System Using Holograms
| Project/Area Number |
02455025
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | WASEDA University |
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Principal Investigator |
OHZU Hitoshi WASEDA Univ., School of Science and Engineering, Professor, 理工学部, 教授 (10063520)
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| Co-Investigator(Kenkyū-buntansha) |
MURAOKA Youichi WASEDA Univ., School of Science and Engineering, Professor, 理工学部, 教授 (50182085)
TAKEDA Mitsuo The Univ. of Electro-Communications, Dept. of Communication Systems, Professor, 電子情報学科, 教授 (00114926)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 1991: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1990: ¥4,400,000 (Direct Cost: ¥4,400,000)
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| Keywords | optical computer / optical information processing / optical logic operations / optical circuits / holograms / optical bistable devices / parallel operations / コンピュ-タ / 光接続 |
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| Research Abstract |
A digital optical processing system using holograms is studied. Optical digital circuits consist of holographic logic operations are investigated and demonstrated. Devices for practical use are proposed and the experimental results are shown.
Holographic logic operations have parallelism, however, can perform only one kind of operations. Since different kinds of logic operations are required in order to construct digital circuits, local variable logic operations, which can perform different operations at different positions, are proposed. The local variable logic operations are combined in order to construct holographic logic modules. Optical digital circuits are constructed by interconnecting the modules regularly.
High diffraction efficiency holograms are important, since the power consumption of the optical computing systems depends on the efficiency. In this study, ROACHs are introduced, which have high diffraction efficiency and have high accuracy of amplitude and phase distribution. The diffraction efficiency of 10% is achieved by use of the holograms. The ROACH has two layers for amplitude modulation and phase modulation, each layer for each modulation. In this study, compensation in the amplitude modulation layer is found to be required, since the amplitude modulation occurs in the phase modulation layer.
High speed spatial light modulators are also important in order to construct the digital optical computers. In this study, optical bistable devices, which have high speed nonlinear effects, are employed as the spatial light modulators. Researches of two dimensional characteristic of the optical bistable devices have not been performed. The MTF of the devices are measured, and resolution of 80 lines/mm is obtained at the contrast of 50%. It means that one device consists of array of 13mum X 13mum nonlinear elements. The switching power of each element is 0.8mW and the switching time is 80mus.
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Report
(3 results)
Research Products
(13 results)
