| 摘要 |
PURPOSE:To apply a semiconductor laser device to an optical disk, etc., by providing an end face coating made of 4 layers having different wavelength film thicknesses to obtain a monitoring current of practical level. CONSTITUTION:A 4-layer film 1 made of an alumina film 2, a silicon film 3, an alumina film 2 and a silicon film 3 is formed sequentially from the vicinity of a crystal on one end face of a resonator. The thickness is by optical distance 0.25 wavelength between the alumina film 2 nearest to the crystal and next silicon film 3, from 0.05 to 0.10 wavelengths at the alumina film 2 thereon, and 0.30 to 0.45 wavelength at the farthest silicon film 3. Thus, the controllability of the reflectivity is improved, and a monitoring current becomes approx. twice. |
