Characterisation and modelling of a silicon-on-insulator non-linear 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 optical nonlinearities of the electronic origin result of the photocreation of a plasma with electron-hole pairs with a density of δ N (t). This is explained by a variation of the index of electronic origin [2] δn e = K e δ N (t) .…”

“…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].…”

“…In section 3, on page 3, after equation (3) and the sentence 'K e and K th are electronic and thermal nonlinear constants, these values have opposite signs and are adjusted according to the experiment with the wavelength λ = 1.064 µm [2] knowing that', the values of K e and K th should have been written: K e = −5.2 × 10 −21 cm +3 , k th = 5.8 × 10 −4 K −1 .…”