| 摘要 |
PURPOSE:To decrease a variation amount due to temperature change of the interval between a collimating lens and a semiconductor laser, by specifying a thermal expansion coefficient of a fixing member to which the semiconductor laser and the collimating lens are fixed. CONSTITUTION:A laser fixing plate 3 is formed by an aluminum plate whose thermal expansion coefficient alphaL is 2.3X10<-5>deg<-1>, a laser supporting seat 4 is provided projectingly on its laser fitting surface, and its projection height (l) is set to 15mm. A semiconductor laser 1 is attached to the laser supporting seat 4. A lens supporting base 6 is formed by a steel material whose thermal expansion coefficient alphap is 1.2X10<-5>deg<-1>, a V-groove 7 is formed along a laser optical axis X on the upper face, and it is stuck to a collimating lens 2 on this V-groove 7, and fixed by a band member 8. A reference surface H for crossing the laser optical axis X vertically is assumed in a connecting surface of the laser fixing plate 3 and the lens supporting plate 6, and a distance (p) between this reference surface H and a laser fixing point P is set to 29mm. In this way, a variation amount against a temperature variation of an interval size of the collimating lens and the semiconductor laser can be decreased.
|
