1999 Fiscal Year Final Research Report Summary
Stochastic resonance in optical bistable systems
| Project/Area Number |
09440154
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物理学一般
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| Research Institution | Kobe University |
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Principal Investigator |
KOHMOTO Toshiro Kobe Univ., Faculty of Science, Assist. Professor, 理学部, 助教授 (70192573)
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| Co-Investigator(Kenkyū-buntansha) |
KUNITOMO Masakazu Kobe Univ., Faculty of Science, Assist. Professor, 理学部, 教授 (40031348)
FUKUDA Yukio Kobe Univ., Faculty of Science, Professor, 理学部, 教授 (40025482)
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| Project Period (FY) |
1997 – 1999
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| Keywords | stochastic resonance / optical bistability / noise light |
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| Research Abstract |
Stochastic resonance(SR) is a cooperative phenomenon that the output signal-to-noise ratio(SNR) is enhanced by adding random noise to the input coherent signal. In spite of its strange appearance, it occurs in various systems. In view of the ability of controlling SNR by adding noise, it is expected to be applied to signal processing, especially to optical signal processing.
(1)SR experiments in hybrid optical bistable systems were performed for a sinusoidal input signal. The experimental results show that, with smaller noise correlation time, the peak value of the SNR is larger, the width of the resonance is narrower, and the noise intensity which gives the peak SNR is smaller.
(2)Numerical simulations were performed using a simple model (a Langevin equations for an overdamped system with a bistable potential). The simulation results reproduced well the experimental results.
(3)SR for a binary input signal was studied by numerical simulations. It was found that the output signal has a gain of information, and that the noise with a small correlation time is favorable for SR and for the gain.
(4)The behavior of SR for image data was simulated. The simulation results show that this system can improve the visibility of images and can be a powerful tool for signal processing.
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