Abstract: In a semiconductor laser module (10) in which the upper surface of a base board (14) comprises two surfaces, one surface acting as the upper surface of a lens mount portion (14b) onto which a lens (16) is fixed by YAG laser welding, and the other surface acting as the upper surface of a laser mount portion (14a), the upper surface of the lens mount portion (14b) being set to be lower in height than the upper surface of the laser mount portion (14a) by the length corresponding to the radius of the lens (16), the lens mount portion (14b) comprises upper and lower layer portions (14u, 14d) formed of materials which are different in thermal conductivity, and the lower layer portion (14d) is formed of the same material as the laser mount portion (14a) of the base board (14). The material of the upper layer portion (14u) of the lens mount portion (14b) is lower in thermal conductivity than the material of the lower layer portion (14d).

Abstract: It is an object of the invention to provide a thinned semiconductor laser module.

Abstract: It is an object of the invention to provide a thinned semiconductor laser module.

Abstract: A semiconductor laser module comprising a module package, a temperature control device, the lower plate of which is fixed to the inner bottom of the module package, a base plate fixed to the upper plate of the temperature control device, a semiconductor laser attached on the base plate for emitting laser light, an optical fiber fixed through the side wall of the module package, and a lens fixed on the base plate for optically connecting the semiconductor laser and the optical fiber. An upper plate of the temperature control device is fitted and fixed in a recess which is formed in the bottom of the base plate such that all side surfaces of the upper plate are in contact with all side surfaces of the recess. A lower plate of the temperature control device is fitted and fixed in a recess formed in the inner bottom of the module package.

Abstract: A semiconductor laser module is described in which the vicinity of one end of optical fiber 22 is fixed to one side wall of the semiconductor laser module 20, an electronic cooling element 23 is secured to the interior bottom surface of a module package 21, and a substrate 24 composed of a metal plate having a two-level construction in which the upper-level portion 24U and the lower-level portion 24D have a level difference h, the upper surface of the electronic cooling element 23 being secured to the lower surface of upper-level portion 24U, a semiconductor laser 25 being secured to the end portion of the upper surface of upper-level portion 24U, and a lens 26 being mounted on the upper surface of lower-level portion 24D of the substrate; whereby the overall height occupied by all components is reduced by the level difference h as compared with a semiconductor laser module in which the lower surface of the substrate is a single plane.