WAVELENGTH SWEEPING DEVICE

摘要

PURPOSE:To minimize the dispersion of light and to improve the accuracy of wavelength sweeping by correcting the dispersion of the light at the time of incidence owing to the inclination of an incidence and projection window to the optical axis by respective prisms of a beam expander. CONSTITUTION:The incidence and projection window 2 is provided to a sealed container 1a whose internal pressure is adjusted and the prism beam expander 6 and wavelength selecting element 13 are arranged in the sealed container 1a in order from the side of the incidence and projection window 2. Then the vertical angles and incidence angles of the respective prisms 7-10 are so set as to correct the dispersion owing to the incidence and projection window 2 by the prism beam expander 13. Consequently, the narrow wavelength width of the laser light is maintained to widen the range where wavelength can be swept continuously.