PURPOSE: To stabilize the characteristics of the titled laser by a method wherein a multilayer semiconductor, containing an active layer, is formed on a semiconductor substrate, and in the semiconductor laser with varying effective index of refraction along the active layer, the optical reflectivity of two resonator end faces which is in vertical position to the active layer is made smaller than the optical reflectivity in the cleaved form.
CONSTITUTION: In the case of a stepped substrate bype laser, the thickness of an active layer 3 at the stepped part is formed a little heavier than that of the flat part located on both sides of said laser, and the lateral mode is stabilized by generating the refractive index guide mechanism of lateral mode for the formation of a rib waveguide passage. Also, the end face of the resonator is formed by cleaving the crystal face vertical to the moving direction of the laser light, and an SiO2 film 9 is deposited on the above in the film thickness of λ/4n and λ/8n by performing a sputtering or an electron beam evaporation. At this point, (n) indicates the refractive index in the wavelength λ of the SiO2. Through these procedures, the noise level of the semiconductor laser can be stabilized at a low value on a wide scope of area, and a wide fluctuation due to moisture can also be prevented.
ITOU KUNIO
SUGINO TAKASHI
WADA MASARU
TERAMOTO IWAO
FUJIMOTO KAZUO
| JPS5434689A | 1979-03-14 | |||
| JPS5760884A | 1982-04-13 |