Theoretical study of a nonlinear fast silicon photoconductive switch

Study of a silicon waveguide on an insulator photodiode for optoelectronic switching

“…The distances between the doped areas and between the electrodes are respectively 14 and 24 µm. When illuminating the photoconductor structure [1], we apply a positive voltage between the electrodes, the result is a photocurrent which is expressed according to the lifetime of carriers [1,2]. On the contrary, the photodiode is reverse biased, the photocreated carriers are separated by the intense electric field in the space charge area.…”

“…The mechanism of heat generation results from the contribution of various processes, which are the photocreated carriers and the Auger effect recombination. The heat source that results is [1,2]…”

“…where γ represents the coefficient of the recombination Auger and E g is the width of the forbidden band. The thermalization of heated free carriers by photon absorption, which implies a heating source given by [1,2]…”

“…This optoelectronic switch as a basic component admits one optical waveguide operating in the nonlinear mode. Doped regions were implanted on each side of this guide, forming a photoconductor [1,2] or a photodiode as in the case of our study. As soon as the resulting component receives a sufficient light power density, it generates an electrical signal (photocurrent) faster than the incident light pulse, which causes a switching as the intensity rises sharply from a low state to a high state.…”

“…Various studies have been conducted on SIMOX waveguides for diverse applications such as making spatial light modulators [8], optical switches [9,10] and photodetectors of photoconductive threshold power [1,2]. The photoconductive were studied first, which have the disadvantage of a high obscurity current and a relatively slow response time that depends on the lifetime of carriers (1 µs) [1].…”