WAVELENGTH VARIABLE FILTER DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a wavelength variable filter device which can stably set a wavelength even if the light intensity of the specified wavelength largely varies. SOLUTION: When an electric signal level corresponding to light intensity is converted into a digital value in an analog/digital (A/D) conversion part 3, a bit overflow part 7 detects the saturation of the output of the A/D conversion part 3 when it occurs. The lower limit wavelength and the upper limit wavelength of a saturation area are specified and are stored in a wavelength/ intensity storage part 4 by scanning the wavelength by a wavelength scanning part 6. A peak position specification part 5 specifies a peak wavelength in a peak position detection part based on stored data and the wavelength of the wavelength variable filter 1 is set through the wavelength scanning part 6.