An on–off-Keying Optical Receiver With Dual Thresholds and Erasure Zone

An ON-OFF-keying optical receiver with dual thresholds and an erasure zone is proposed. This configuration can be applied to track the optimized decision level adaptively and obtain additional coding gain from forward-error correction without increasing the code rate. Our analysis shows that in both unamplified and optically preamplified receivers, the required Q value for the bit-error rate of 10^-12 can be reduced by 1.8 dB, if errors arise in burst nature and the optimized erasure zone width is around 7%-11% of the signal swing.