| 摘要 |
PURPOSE:To prevent the generation of the mode jump of an oscillation wavelength in a comparatively wide range of temperature by miniaturizing an optical system and by reducing the distance from the end plane of laser light emission to an external mirror. CONSTITUTION:A substrate 1 is nearly flat, a mask layer 2 is patterned in a required shape and a recession 1a is formed in the substrate 1 by etching the substrate 1 using the mask layer 2. Further, a projection 22 is formed by projecting part of the mask layer 2 in the air or in the recession by etching the substrate 1. Accordingly, light emitted from one end plane 32 of a laser chip 3 is reflected by an oblique plane 12 against the surface of the substrate 1, the reflected light is reflected again by the projection 22, the reflected light is further reflected again by the oblique plane 12 and returns to the end plane 32 of the chip 3. Consequently, both the end planes 31 and 32 of the semiconductor laser chip 3 and the projection 22 of the mask layer 2 constitutes an external oscillator. In such a constitution, the distance from the end plane 32 of the semiconductor laser chip to the projection 22 is short. |
