Porous silicon based all-optical modulator using asymmetrical Mach–Zehnder interferometer configuration

In this paper, nonlinear porous silicon based all-optical modulator is proposed and investigated by utilizing an asymmetrical Mach–Zehnder Interferometer (MZI) configuration consisted of two couplers with equal splitting ratio, and two unbalance arms, in which a porous silicon (PS) waveguide as the nonlinear element is only placed in one arm of MZI, and another arm is short fiber delay line. Results show that both a pulsed pump and continuous probe wave are simultaneously launched into the input port with the result that an outcome signal with ~14.10 dB modulation depth at probe wavelength is obtained at the end of the device under the conditions of an initial pulsed pump with 47.07 dB m peak, 10.88 extinction ratio and 100 ps duration, continuous probe wave of 0 dB m power, and 3-mm long PS waveguide. Extinction ratio and eye opening ratio of eye diagram are observed for various operation speeds.