Patent ID: 6462823
Filing Date: 2002-10-08
Classification: G01J

Abstract:
A wavelength meter for measuring the wavelength of an input light signal, said meter comprising:a beam splitter for splitting said input signal into a first input signal and a second input signal; a fixed mirror for reflecting said first input signal; a moveable mirror for reflecting said second input signal, said beam splitter recombining said reflected first and second input signals to form a combined input signal; a measurement detector for generating a measurement signal related to the amplitude of said combined input signal; a reference light source having a reference wavelength for generating a first reference light signal that is split by said beam splitter into first and second reference light signals, said first reference light signal being reflected by said fixed mirror and said second reference light signal being reflected by said moving mirror, said beam splitter recombining said first and second reference light signals to form a first combined reference light signal; a first reference detector for generating a reference signal related to the amplitude of said first combined reference light signal; a position circuit for generating a start signal indicating that said moveable mirror is at a first position relative to said fixed mirror and that said moveable mirror is moving in a first direction, said first position being determined to a precision that is less than one reference wavelength; and a controller for recording a sequence of measurement signal values in response to said start signal and said first combined reference signal.