Patent ID: 6452674
Filing Date: 2002-09-17
Classification: G01J

Abstract:
A wavelength correction apparatus for correcting a deviation of a testing wavelength from a reference wavelength, comprising:a reference light source for emitting a reference light of a specific wavelength; a light input terminal for inputting a testing light whose wavelength is to be measured and compensated, if required; an optical switch for receiving said testing light and said reference light and outputting one of either said testing light or said reference light from an output terminal; a control section for controlling operations of said reference light source and said optical switch; a light spectrum measuring device that provides at least an element that transforms the light output from said optical switch to parallel waves; a diffraction grating that spatially separates said parallel waves; an element that converges the light spatially separated by said diffraction grating on an output slit; and a processing unit that sets in advance the wavelength of said reference light, and at the same time determines the wavelength of the light that passes through said output slit depending on the orientation angle of said diffraction grating with respect to said parallel waves and measures the spectrum of the light output from said optical switch; and wherein; said light spectrum measuring device apparatus inputs the reference light from said reference light source by controlling said optical switch, and adjusts the orientation angle of said diffraction grating with respect to said parallel waves based on the error between the result of measuring the spectrum of said reference light and the wavelength of said reference light that has been set by said processing unit and an optical spectrum measuring device for measuring optical spectra output from said optical switch, and for activating said control section automatically at scheduled times specified by an operator.