Patent ID: 7012697
Filing Date: 2006-03-14
Classification: G01J

Abstract:
1. A method for determining an optimal attenuation level for an input signal in an optical heterodyne detection system wherein said optical heterodyne detection system includes an optical coupler for combining said input signal with a local oscillator signal to form a combined optical signal, a receiver that is optically coupled to said optical coupler for generating an output signal in response to one of said input signal, said local oscillator signal, and said combined optical signal, and an attenuator tat is optically coupled to said optical coupler for attenuating said input signal, said method comprising steps of: obtaining a base measurement of said output signal in response to said local oscillator signal and in the absence of said input signal; obtaining sample measurements of said output signal in response to said input signal as a function of difibrent attenuation levels; and determining said optimal attenuation level as a function of said base measurement and said sample measurements, wherein determining said optimal attenuation level comprises: