Patent attributes
An optical field receiver comprises an optical brancher that branches a received optical multilevel signal into first and second optical signals; an optical delayed detector that performs delayed detection on the first optical signal by a delayed detector with a delay time of T/2 (where T is equal to a symbol time) and a phase difference of 90 degrees; a balanced optical receiver that converts the optical signal outputted from the first delay detector to an electric signal; and an optical intensity receiver that converts the second optical signal to an electric signal; and an electric field calculating part that generates, from the output signals of the first and second optical receivers, first and second reproduced signals indicative of the phase angle and amplitude value of the received symbol represented by the complex signal in each symbol time T.
