| 摘要 |
PURPOSE:To obtain a laser light having accurate, stable absolute value of wavelength and high spectral purity, by absorbing the output light of a semiconductor laser provided with an external resonator into an absorbing cell, detecting a transmitted laser light, and controlling the wavelength of the laser light for an absorption line of the absorbing cell. CONSTITUTION:An output laser light from a semiconductor laser LD1 makes an incidence to a half-mirror 5 through a lens 3, some portion of which acts as a laser output P0 passing through the mirror 5. The remaining portion is reflected, travels back along an incident optical path, passes through a lens 4, some portion of which is again reflected by a diffraction grating 7 and travels back in the direction of the LD1. Thus the half-mirror 5 and the diffraction grating 7 constitute an external resonator. As to a method to change the oscillation wavelength of the LD1, changing an applied current, changing the temperature of the LD1, etc. are adopted. The reflected light from the diffraction grating 7 to a mirror 9 passes through an absorbing cell 12, and is detected by a photo detector 13, whose output signal is introduced to a lock-in amplifier 15. Its output is delivered to a laser control part 17 which controls the wavelength of the output laser of the LD1. |
