| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive small-sized wavelength stabilized laser module. SOLUTION: The backwardly emitted light of a semiconductor laser 1 is converted into light rays which are slightly spread from parallel rays through a lens 2. An array-like photodetector having at least two light receiving sections 5 and 6 is set up on the rear side of the laser 1 so that the photodetector receives the light rays. A filter 3 having such a characteristic that its transmittance continuously increases or decreases with respect to the wavelength of the light rays is set up between the lens 2 and photodetector so that all of the light rays 3 passes through the filter 3. At one 5 of the light receiving section 5 and 6, wavelength-nondependent signals are obtained by detecting the outside portion of the light rays and used for stabilizing and controlling the light output of the laser 1. At the other light receiving section 6, wavelength- dependent signals are obtained by detecting the central portion of the light rays and used for stabilizing and controlling the wavelength of the light rays. Consequently, the oscillation wavelength of the semiconductor laser 1 can be stabilized with high accuracy.
|
