Applications of a Wannier-Stark modulator in waveguide configuration for optical signal regeneration, memory operation and computing in the telecom wavelength range

Based on an InGaAs/InP superlattice, a Wannier-Stark type EA-modulator has been operated around 1550 nm. A large transmission contrast with low applied voltage changes has been observed. Operating the modulator in a resistor based self-electrooptic effect configuration, a large tunability of the optical transfer function has been achieved by varying the electrical bias voltage and the feedback resistor value. As an example just the functionality of optical thresholding for the noise suppression in a digital optical transmission system and signal frequency multiplication will be shown. Simulation results demonstrate the feasibility to use this type of device for the realization of logic gate operations, like NOR and NAND. Due to the functional completeness theorem this means that in principal every logic functionality can be achieved. The critical parameters during optical computing operations are the optical bias stability and high frequency limitations due to the low-pass filter in the electrical feedback circuit. The waveguiding configuration ensures, however, a good stability and operation at low optical powers.