| 摘要 |
PURPOSE:To change only an output optical frequency without changing the intensity of output light by using the 1st feedback loop stabilizing the intensity of output light of a semiconductor laser and further the 2nd feedback loop controlling the output optical frequency modulation. CONSTITUTION:A plane of incidence and a plane of irradiation of the 1st and 2nd optical resonators 13, 18 are formed with a transluscent film made of, e.g., a dielectric multilayered film, an electrode is provided in opposition to a plane vertical to the planes of incidence and irradiation of light, the refractive index in the crystal is changed according to the voltage applied to the electrode so as to change the resonance optical frequency to an incident light. In order to obtain a desired optical output in response to the resonance optical frequency of the 1st and 2nd optical resonators 13, 18, the frequency is decided by the length of optical path and the reflectance of end face effecting on the refractive index of the crystal constituting the 1st and 2nd optical resonators 13, 18. The resonance optical frequency f2 of the 1st optical resonator 13 is set by the control of the length of the optical resonator, that is, the control of the optical path length or the control of a bias voltage applied thereto and an output light whose optical frequency is changed linearly is obtained in response to the applied voltage of the 2nd optical resonator 18. |
