Patent ID: 6590666
Filing Date: 2003-07-08
Classification: G01J

Abstract:
A system for optical spectrum analysis comprising:a local oscillator source for generating a swept local oscillator signal that sweeps across a range of frequencies; an optical coupler having a first input and a second input, said first input being optically connected to receive an input signal, said second input being optically connected to said local oscillator source to receive said swept local oscillator signal, said optical coupler having an output for outputting a combined optical signal that includes said input signal and said swept local oscillator signal; a heterodyne receiver having an input for receiving said combined optical signal from said optical coupler and an output for outputting a heterodyne beat signal that is representative of said combined optical signal; a relative frequency measurement system optically connected to said local oscillator source for generating measured local oscillator frequency sweep rate information in response to said swept local oscillator signal; and a signal processor for utilizing said heterodyne beat signal from said optical receiver and said measured local oscillator frequency sweep rate information from said relative frequency measurement system to generate an output signal that is indicative of an optical parameter of said input signal.