Patent ID: 9106334
Filing Date: 2015-08-11
Classification: H04B

Abstract:
1. A method for characterizing a parameter of an Integrated Coherent Receiver (ICR) being designed for normal use to receive a phase-modulated optical communication signal transmitted at a specified symbol rate f BAUD , and comprising: two optical input ports, an optical hybrid arrangement for heterodyne mixing of signals to be received at the two optical input ports, at a pair of complementary optical outputs, and a pair of balanced photodetectors to detect light exiting corresponding said pair of complementary optical outputs, to provide a differential electrical signal at an electrical output, the method comprising the steps of: providing a first polarized highly-coherent optical test signal at optical frequency ν injecting the first test signal into one of the two optical input ports of the ICR and the second test signal into the other of the two optical input ports, and sampling the electrical output of the ICR at a known primary sampling rate f injecting co-propagating said first and second test signals into a given one of the two optical input ports, and sampling the electrical output of the ICR at said primary sampling rate fs to provide a numerator value corresponding to said given one of the two optical input ports, the electrical output being responsive to heterodyne mixing of said first and second optical test signals; and calculating a value of said parameter from said numerator and denominator values.