| 摘要 |
PURPOSE:To obtain a semiconductor device which has a distributed Bragg reflector with which a periodical unevenness can be obtained with good reproducibility by providing insulators or metals or laminates of insulators and metals which are buried in a semiconductor along the direction of light propagation in a lattice-shape and periodically as components of DBR. CONSTITUTION:An N-type InGaAsP layer 2 laminated on an InP substrate 1 functions as a waveguide. Insulators 6 made of silicon oxide, silicon nitride, aluminum oxide and the like are provided on the InGaAsP layer 2 in a lattice- shape and periodically and buried in an InP layer 4. As the refractive index of the insulator 6 is substantially smaller than the refractive indices of the semiconductors 1, 2 and 4, the refractive index for a light 100 changes periodically along the direction of the light propagation so that DBR can be formed and can function as an optical filter. Moreover, if an electric field is applied to the N-type InGaAsP layer 2 through electrodes 21 and 22, the refractive index is varied by an optoelectrical effect so that the reflective wavelength of the filter can be controlled.
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