Observation of stochastic resonance in a liquid-crystal light valve with optical feedback induced by colored noise in the driving voltage

Abstract

Stochastic resonance is a noise phenomenon that benefits applications such as pattern formation, neural systems, microelectromechanical systems, and image processing. This study experimentally clarifies that the orientation of the liquid crystal molecules was switched between two stable positions when stochastic resonance was induced by colored noises in a liquid crystal light valve with optical feedback. Ornstein-Uhlenbeck and dichotomous noises were used for colored noise, and the noise was applied to the drive voltage of the liquid crystal light valve. The signal-to-noise ratio was measured with respect to changes in the noise type, noise intensity, and autocorrelation time of the noise. It was found that typical stochastic resonance was observed with a noise autocorrelation time of approximately 20 ms or more for both noise types, and dichotomous noise further enhanced the stochastic resonance compared to the Ornstein-Uhlenbeck noise. This suggests that it is possible to maximize stochastic resonance in a liquid crystal light valve by optimizing the conditions of colored noise.

Fourth-stable stochastic resonance and its application to weak fault signal detection of rotating machinery

“…Figure 3 shows that the power done to the system by the periodic force W varies with noise intensity under different the adjusting parameter k, where other parameters are given as below: f 0.0001, = A 0.2, = t f 10 , 0 = n 500. = It can be seen from figure 3 that the power W starts to increase and then decreases as the noise intensity D raises, indicating that a SR can occur in the nonlinear system written in equation (1). Moreover, increasing the adjusting parameter k would reduce the peak values of power W , whereas the optimal noise intensity D opt corresponding to the peak values of power W continues to increase, suggesting that adjusting k is able to trigger the SR in a signal with different noise intensity D .…”

“…According to equation (31), we can investigate the nonlinear dynamics in the nonlinear system of equation (1). Figure 3 shows that the power done to the system by the periodic force W varies with noise intensity under different the adjusting parameter k, where other parameters are given as below: f 0.0001, = A 0.2, = t f 10 , 0 = n 500.…”

“…Stochastic resonance (SR) is a kind of typical phenomenon in nonlinear systems, where injecting moderate noise to a signal can improve its signal-to-noise ratio (SNR) [1][2][3]. Therefore, SR has been extensively studied theoretically including double stochastic resonance [4], chaotic resonance [5], vibrational resonance [6] and superthreshold stochastic resonance [7], and widely applied to various fields, such as image enhancement [8], signal enhancement [9][10][11], mechanical fault diagnosis [12][13][14] and even other fields [15][16][17].…”