| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect light quantity of one side of each light source. <P>SOLUTION: A wavelength selection layer 15 reflects and outputs most of laser beams with a wavelength λ2 from a second light source 12 toward a collimation lens 18, transmits and makes incident several percents of the laser beam on an optical monitor 17. Meanwhile, the wavelength selection layer 15 transmits and outputs all or most of laser beams with a wavelength λ1 from a first light source 11 toward the collimation lens 18. A reflection mirror 21 reflects part of laser beams deviated from the wavelength selection layer 15 among the laser beams with the wavelength λ1 from the first light source 11, and guides them to the optical monitor 17. Since the reflection mirror 21 has almost constant reflectance irrespective of the wavelength, even when the wavelength λ1 of the laser beam of the first light source 11 is changed by temperature change, etc., the quantity of the laser beams received in the optical monitor 17 is not changed. <P>COPYRIGHT: (C)2003,JPO |
