摘要 |
An optical waveguide has first dielectric substance region which is formed on a surface of the crystalline silicon substrate, and has second dielectric substance region which is formed outside first dielectric substance region. First dielectric substance region is provided with a region in which a concentration of impurity elements for increasing and/or decreasing a refractive index in a direction of transmitting light is periodically increased and decreased, or provided with a corrugated structure, or wherein its width is periodically changed. Therefore, utilizing the property of thermal equilibrium, the optical waveguide has a grating which is thermally stable even at ordinary temperatures.
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