DQPSK optical receiver circuit
AssigneeFujitsu Limited
InventorsTadashi Ikeuchi, Naoki Kuwata
Life of this patent
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Abstract
A DQPSK optical signal is split by the splitter 1 into Data 1 and Data 2 systems. For each system, a phase-modulated optical signal is converted into an intensity modulated electric signal, and clock reproduction and data reproduction are independently carried out for each system. While a phase difference occurs between the data of each system, a clock signal having an intermediate phase of the reproduced clock of each system is generated to latch data of both systems by using the clock signal. This results in the data of both systems having the same phase.
Claims10
A DQPSK optical receiver circuit for receiving an optical signal which is DQPSK modulated, comprising:
- a splitting unit for splitting a received optical signal;
- a first photoelectric conversion unit for converting one phase modulated component of one of the optical signals which is split by the splitting unit into an intensity modulated electric signal;
- a second photoelectric conversion unit for converting a phase modulated component which is orthogonal to the one phase modulated component of the other optical signal split by the splitting unit into an intensity modulated electric signal;
- a first data reproduction unit for reproducing a data signal and a clock signal from an output of the first photoelectric conversion unit;
- a second data reproduction unit for reproducing a data signal from an output of the second photoelectric conversion unit;
- and
- a phase synchronization unit for synchronizing phases of an output data signal of the first data reproduction unit and an output data signal of the second data reproduction unit.
Dependencies are inferred from the claim text.