Reconstruction of near-infrared images via stochastic resonance in the photorefractive semiconductor InP:Fe

In this paper, a stochastic resonance utilizing the photorefractive semiconductor InP:Fe, which can reconstruct near-infrared (NIR) images, is proposed. Based on the band transport theory, we investigate the motion model of charge carriers in InP:Fe. When the photoexcitation rate of holes is comparable with the thermal excitation rate of electrons, the internal photoinduced field based on the space charge field undergoes resonant enhancement. When the signal resonates with the noise base on spatial frequency, the enhanced light-induced field can effectively direct the noise energy transfer. Reconstruction of images concealed by noise and subject to scattering at 1.06 µm wavelengths is achieved through this stochastic resonance, and the maximum cross correlation gains of the reconstructed images are 3.08 and 2.14, respectively. These results show that the contrast and visibility of a near-infrared image can be effectively improved by allowing the signals to grow at the expense of noise.