Experimental studies of switching characteristics for all-optical demultiplexer module

By combining the technology of all-optical saturable absorbers and the diffractive optics: a scheme of all-optical time division demultiplexing module is investigated. Following authors' proposal, design, test fabrication of the optical platform in the precious paper: this paper focuses on the characterization of switching performance. Using a multiple quantum well saturable absorber of InGaAs/InAlAs composition, and gain snitched semiconductor laser pulses of 25 ps pulse width, the switching function was demonstrated experimentally at wavelength of 1.55 mum. The switching on-off ratio was compared among 4 lens configuration, 2 lens configuration (2L) and free space, collinear geometry, No degradation was observed in the case of 2 lens configuration in comparison to collinear illumination. Thus the feasibility of all-optical switch module with power efficiency and high speed is predicted, under the assumption of the progress in sub-micron lithography.