WAVELENGTH VARIABLE FILTER DEVICE

摘要

PURPOSE:To allow a wide-band wavelength tuning over a wide wavelength band by organically coupling a monochrometer and filters of plural semiconductor elements. CONSTITUTION:The light signal at a point A is inputted by an optical coupler 51 to the monochrometer 52. The monochrometer 52 selects the light signal of a prescribed wavelength and outputs the same. The light signals of these wavelengths are amplified in the intensity thereof by an optical amplifier 53 and an isolator 54. The light signals of the amplified wavelengths are respective ly partly made incident by a start coupler 55 via optical fibers to n-pieces of the wavelength variable filter elements 60 and are partly made incident again to the coupler 51. The filter elements the wavelength bands of which conform to the wavelength bands of the incident light output the light signals of the prescribed wavelengths corresponding to a requirement in the wavelength variable filter elements 60. The selection of the wavelengths over the wide wavelength region is possible in this way.