| 摘要 |
PURPOSE:To enable optical and electrical effective feedback control by simple constitution by feeding back only primary diffracted beams to a laser element by a diffraction grating having a reflection function while other order beams are received and feedback-controlling a laser driving power supply. CONSTITUTION:Laser luminous flux 12 projected from the end surface of a semiconductor laser element 10 is reflected and diffracted by a diffraction grating 15 having a reflection function. Positive primary diffracted beams 16 are fed back to the element 10 again and optical feedback is conducted, reflected zero-order beams 17 are received by a photodetector 18, detected as monitor beams and converted into electric signals, and a driving power supply for the element 10 is feedback-controlled electrically through an optical output stabilizing control circuit 20. Accordingly, optical and electrical effective feedback control is conducted by simple constitution, reflected noises from the laser element are inhibited, and single mode oscillation is conducted while an optical output is stabilized. |
