| 摘要 |
PURPOSE:To obtain the optical integrated circuit whose characteristic is scarcely fluctuated and whose light utilization efficiency is high by providing an aberration correcting grating on an optical waveguide on which a laser light is made incident, correcting its lattice interval and diffracting the laser light. CONSTITUTION:When wavelength of a semiconductor laser light 4 is varied from lambda0 to lambda1, only in the case an incident angle to a grating coupler 3 is alpha0, alpha1 corresponding to the wavelength, strong coupling to an optical waveguide 2 is generated. Therefore, by installing a correcting grating 6 and correcting a lattice interval D and an inclination angle delta, an angle of diffraction from the grating 6 can be set to specific angles gamma0, gamma1 against light beams of wavelength lambda0, lambda1. Subsequently, they are refracted by an interface to a substrate 1 and become the incident angles alpha0, alpha1 to the coupler 3. In such a way, deterioration of the incident coupling efficiency which follows a wavelength fluctuation of a laser light is prevented and an aberration of a chromatic aberration is prevented, and an optical integrated circuit whose characteristic is scarcely fluctuated and whose light utilization efficiency is high can be obtained. |
