权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Stochastic Resonance in an Optical Bistable System

光学双稳态系统中的随机共振

基本信息

批准号：
07640516
负责人：
KOHMOTO Toshiro
金额：
$ 1.47万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07640516/
关键词：
stochastic resonance optical bistability noise light spectrum analysis 非線形現象

项目摘要

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.The characteristics of the resonance signal depends on the correlation time and the intensity distribution of the input noise.In the present study, SR experiments in an optical bistable system were performed. The system is composed of a LiNbO_3 crystal and a polarizer, and its output is fed back to the crystal electrically. The system has features of stable operation and working in wide optical frequency range and with low optical power. In the experiment, exponentially correlated Gaussian noise and a sinusoidal signal are applied to the system. 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.Numerical simulations were also performed using simple model which has wide application field. The equation used in the simuilation is a Langevin equation for an overdamped system which has a bistable potential, a sinusoidal input, and the exponentially correlated Gaussian noise. The simulation results have the same characteristics with those of the experiments. The application field of the used equation is not limited to the present system, so that the results of the present study can also be applied to SR phenomena in other types of bistable systems.

随机共振（SR）是一种通过在输入相干信号中加入随机噪声来提高输出信噪比的协同现象。尽管它的外观很奇怪，但它发生在各种系统中。共振信号的特性取决于输入噪声的相关时间和强度分布。本文利用光学相干系统进行了共振信号的实验研究，并对共振信号的相关时间和强度分布进行了分析。该系统由LiNbO_3晶体和起偏器组成，其输出电反馈到晶体。该系统具有工作稳定、光频范围宽、光功率低等特点。在实验中，指数相关的高斯噪声和正弦信号施加到系统。实验结果表明，噪声相关时间越短，信噪比峰值越大，共振宽度越窄，产生峰值信噪比的噪声强度越小，并采用适用范围较广的简单模型进行了数值模拟。仿真中所用的方程是一个过阻尼系统的朗之万方程，该系统具有一个正弦输入和一个指数相关的高斯噪声。仿真结果与实验结果具有相同的特点。所用方程的应用范围不限于本系统，因此本研究的结果也可应用于其他类型的非线性系统中的SR现象。