| 摘要 |
PURPOSE:To permit the densification by providing a semiconductor laser which generates a high-output short pulse train as the peak power and a secondary high-frequency generator which uses a beam of light emitted from this semiconductor laser as the primary light beam. CONSTITUTION:A laser beam 6 emitted from one end surface (resonance interface) 4 of a semiconductor laser 2 is photo-feed back to the semiconductor laser 2 by an external reflector 8. At this time, when a semiconductor laser (modulator) 10 is current- modulated in a frequency equivalent to the roundtrip frequency during the time the beam 6 emitted from the laser comes returning, a laser beam 12 generates a pulse train which has a very large peak power and is secularly short. When the laser beam 12 having this large peak power is incident on a nonlinear optical crystal 14, which is used as the secondary high-frequency generator, as a primary beam of light, a secondary beam 16 obtained is very large as peak power and the secondary beam 16 passes through an optical system 18 composed of a lens and so on and is led to an optical system 18 composed of a lens and so on and is led to an optical disc 20. That is, this device has a high-output short pulse train generating semiconductor laser 22, which generates a high-output short pulse train as the peak power, and a secondary high-frequency generator 24. |
