Start-bit detection and a single gate pulse generation scheme scalable to high-speed operation for asynchronous packet processing have been achieved. It is based on phase-modulated two-bit preamble for a coder and one-bit-delayed detection combined with a balanced photodetector as exclusive OR (XOR) function for a decoder. By using pi/2 phase-shifted first-bit and a pi/2 phase-shifted one-bit delay line, single gate pulse can be generated with high-speed regardless of packet period. We have successfully achieved the single gate pulse generation with bit rate of 10.72Gbps and various packet periods from 12.8ns to 120ns. Amplitude of the gate pulse was almost constant with fluctuation of ±5%. Suppression ratio of a gate pulse could be improved up to 9.5dB via nonlinear absorption characteristics of an EA modulator. Autonomous gating operation for an optical digital-to-analog converter was also verified for two bit operation.
各種検索
サポート
ヘルプ