Recent progress in optical functional devices based on polarization bistable VCSELs

In this paper, we overview the current status of polarization bistable VCSELs and their applications to all-optical signal processing. We measured the BER of flip-flop operations and obtained a good BER value of 1.56 × 10^-10. We also measured the BER of flip-flop operations with AND gate functionality. From the BER variation for the set pulse power, we found that fluctuations of the switching threshold and the phase difference at the combination of the data and the set pulses affected BER. We demonstrated all-optical 2-bit recognition and packet switching using two 1.55-μm polarization bistable VCSELs. Optical packets including 40-Gb/s NRZ PRBS payloads were successfully switched to the one of four designated ports, depending on the state of the two bits in the headers with 4-bit 500-Mb/s RZ format.