Bit error rates of flip-flop operations with AND gate functionality using a 1.55-µm polarization bistable VCSEL

Abstract

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. Inputpulse 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.

Flip-flops using polarization bistable VCSEL with AND-gate functionality by two wavelength inputs

“…Thus, the wavelengths of these signals were exactly the same, and fluctuations in the phase difference between these two beams had to be minimized using PID control for stable operation. We measured the bit error rates (BERs) of flip-flop operations with AND-gate functionality and obtained a good BER of 5:00 Â 10 À9 using 500-Mb/s return-to-zero (RZ) pseudo-random bitsequence (PRBS) under the best operation condition [5]. However, the BER was slightly worse than that of the all-optical flip-flop operation using two inputs of set and reset pulses (1:56 Â 10 À10 ) [6].…”