| 摘要 |
PURPOSE:To stably set a frequency interval by sweeping the frequency of a reference laser, and using as the reference of the interval a Fabry-Perot resonator. CONSTITUTION:A light irradiated from a distributed reflection type laser 1 is transmitted through an optical isolator 3, and then divided by an optical branch unit 4 to first and second output lights at the power ratio of 1:1. The first output light of them is transmitted through an etalon plate 5, and then incident to a first photodetector 6. A pulselike light is incident on the photodetector 6 when the frequency of the laser 1 coincides with the resonance frequency of the plate 5. Light beams radiated from distributed feedback lasers 8-10 are combined by a first optical mixing unit 14. The light irradiated from the unit 14 is combined with the second output light from the branch unit 4 by a second optical mixing unit 15. The output of the unit 15 outputs a pulselike electric signal when the difference between the frequency of the light radiated from the laser 1 and those of the light irradiated from the lasers 8-10 falls within a specific range. First, second and third control signals from a controller 7 are respectively input into laser drivers 17-19, and driving currents are injected into the lasers 8-10. |
