| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an inexpensive and extremely compact wavelength stabilization unit, in which the oscillation wavelength of a semiconductor laser can be stabilized with a higher accuracy while decreasing the number of components by suppressing stray light entering a photoelectric conversion element, thereby stabilizing the intensity monitor PD current. SOLUTION: The wavelength stabilization unit comprises a wavelength filter 31 and a photodetector 4 mounted on a substrate 71, which is contained in a case 91. The photodetector 4 comprises a first photoelectric conversion element 5 for receiving a light 56, emitted from the end part (emission point 58) of an optical fiber 14 introduced into the case 91 directly and converting it into an electric signal A, and a second photoelectric conversion element 6 for receiving a light, passing through the wavelength filter 31 and converting it into an electrical signal B, wherein the electrical signals A and B are delivered to an operating circuit 8. The wavelength filter 31 has a side end face machined not to intersect a line connecting the emission point 58 and the edge part of the incident plane 311.</p> |
