WAVELENGTH FILTER AND WAVELENGTH MONITOR DEVICE

摘要

A wavelength filter includes a solid material that transmits a light; a pair of flat planes formed on the sold material substantially in parallel with each other; and a supporting member that supports the solid material on a plane of the solid material other than the pair of flat planes with an adhesive agent, the supporting member having a rigidity stronger than that of the solid material. The light is resonated between the pair of flat planes, the wavelength filter selects a wavelength that is determined by an optical length between the pair of flat planes, and the solid material is a birefringent material of which an optical axis makes a predetermined angle with respect to a normal to the pair of flat planes. With this mechanism, even in a state in which the solid material is supported by the supporting member, a stable wavelength-discriminating characteristic can be obtained.