OPTICAL WAVE LENGTH FILTER

摘要

PROBLEM TO BE SOLVED: To obtain an optical wavelength filter having arbitrary transmission or cut-off characteristics and a tuning capability. SOLUTION: The optical wavelength filter is provided with a waveguide substrate 100 in which a waveguide 101, a first slab waveguide, waveguide array and a second slab waveguide are connected in this order; provided with a reflection type spatial filter 105 arranged in proximity to an image forming focal plane against the waveguide array 103, near the end face on the side opposite from the end face in which the second slab waveguide is connected to the waveguide array 103; and provided with a fine adjustment mechanism for positional adjustment of the reflection type spatial filter 105. Further, the wavelength filter is designed to control a frequency profile through the positional adjustment of the reflection type spatial filter 105.