| 摘要 |
PURPOSE:To facilitate stabilization of the power and wavelength of a laser beam with a high accuracy by a small size, light weight and low cost controller by a method wherein the electric power of a power supply for pumping lamp is controlled by feedback control based on the level of the detection signal of a photosensor detecting a secondary diffracted light from a diffraction lattice and the resonance conditions of the laser system are determined by feedback control based on a light detecting position detected based on the detection signal. CONSTITUTION:A current is caused flow in a cooling device 18 is controlled by a control circuit 17 so as to keep the temperatures of a diffraction lattice 8 and a sensor 11 contact. Therefore, thermal expansion is hardly induced in the diffraction lattice 8 and the sensor 11 regardless to materials. A distance (l) and the lattice interval (d) are thus always nearly constant. Therefore, an angle theta and a light detecting position (y) are varied depending approximately upon only a wavelength. Therefore, the wavelength of a laser beam 6 is controlled to be a constant value by feedback control of the quantity of the light of a light source 2 in order to the level of a detection signal constant, and by feedback control of a distance between millers 3 and 4 for controlling the light detecting position (y) at a predetermined position. With this constitution, even if various parts of a light source device 1 are not made of materials with small thermal expansion coefficients, the fluctuations in the power and wavelength of the laser beam 6 caused by temperature variation or the like can be avoided and the power and wavelength of the laser beam 6 can be stabilized. |
