| 摘要 |
PURPOSE:To obtain a semiconductor laser light-source, adjustment thereof is easy, at a low noise level by a longitudinal single mode oscillation by feeding back an electric field from reflected rays fed back to a semiconductor laser by an erect image so as to coincide with an electric field from projected rays. CONSTITUTION:Projected rays 22 from a semiconductor laser element 21 are changed into parallel rays 24 by a lens 23, turned into convergent rays 26 by a lens 25, and imaged on a reflecting body 27. Reflected rays 28 from the reflecting body 27 pass through the lens 25 and are changed into parallel rays 29, are turned into convergent rays 30 by the lens 23, and are fed back to the semiconductor laser element 21. Accordingly to the constitution, since reflected rays from the reflecting body of projected rays from a semiconductor laser are fed back positively as an erect image, the characteristics of the semiconductor laser can be adjusted so as to be stabilized easily even when an electric field from projected rays is asymmetric, and the state of low noises can be set easily by a longitudinal single mode. |
