| 摘要 |
PROBLEM TO BE SOLVED: To provide an array waveguide type diffraction grating wherein a light transmission central wavelength does not depend on an ambient temperature in use, and a loss and wavelength multiplexing/demultiplexing characteristics are stable. SOLUTION: A waveguide forming area 10 which connects in order a light input waveguide 2, a first slab waveguide 3, plural juxtaposed array waveguides 4 having respectively different lengths, a second slab waveguide 5, and plural juxtaposed light output waveguides 6 is formed on a single crystal substrate 1. A cleaved and separated surface 80 is formed by cleavage along the crystal orientation surface of the substrate 1 so as to cross the path of light passing through the first slab waveguide 3 to separate by cleaving the first slab waveguide 3. The separated slab waveguide 3b side is fixed to a base 9, and the separated slab waveguide 3a side is fixed to the base 9 so as to freely slide and move via a high thermal expansion coefficient member 7. The high thermal expansion coefficient member 7 is expanded and contracted more largely than the base 9 in accordance with the change of the ambient temperature in use, and the separated slab waveguide 3a side is slid and moved in the direction of arrows A, B along the cleaved and separated surface 80. |
