Bit error rates (BERs) of all-optical flip-flop operations with AND-gate functionality using a 1.55-µm polarization bistable vertical-cavity surface-emitting laser (VCSEL) were measured. Optical data pulses of a 500-Mb/s return-to-zero pseudo-random bit-sequence were used. The best BER we obtained was 5.00×10−9 and the eye diagram was clearly open. Input-pulse power was about 17 dB lower than VCSEL output power. From the BER variation for the set-pulse power under fixed data-pulse power, we found that fluctuations in the switching threshold and power of AND pulse (combination of data and set pulses) affect the BER. We also evaluated the BER of memory operations.
