Patent ID: 6646746
Filing Date: 2003-11-11
Classification: G01J,H04B

Abstract:
A system for optical heterodyne detection comprising:means for measuring a fraction of a first optical signal before said first optical signal is combined with a second optical signal and for generating a first electrical signal that is representative of said measured fraction of said first optical signal, one of said first and second optical signals being a local oscillator signal and the other signal being an input signal; an optical coupler having a first input and a second input, said first input being optically connected to receive said first optical signal, said second input being optically connected to receive said second optical signal, said optical coupler having an output for outputting a combined optical signal that includes said first optical signal and said second optical signal; a heterodyne receiver having an input for receiving said combined optical signal from said optical coupler and an output for outputting a third electrical signal that is representative of said combined optical signal, said third electrical signal including a heterodyne signal; and a processor for receiving said first electrical signal and said third electrical signal, and for generating an output signal that is indicative of an optical parameter of said input signal in response to said heterodyne signal and said first electrical signal.