Spectral control device

The invention relates to a spectral control device which is applied to a master oscillator power-amplifier dual-cavity structure excimer laser. The spectral control device comprises two stages of linewidth narrowing modules; the first-stage linewidth narrowing module and an output coupling device are adopted as two end mirrors and are respectively arranged at two ends of a laser discharge cavity; the first-stage linewidth narrowing module, the output coupling device and the laser discharge cavity form a main oscillation resonant cavity of the excimer laser, so that first-stage linewidth narrowed laser output with a certain output energy can be formed; and the second-stage linewidth narrowing module is arranged in a transmission light path between the main oscillation resonant cavity of the excimer laser and an energy amplification cavity, and can perform linewidth modulation on the first-stage linewidth narrowed laser output with a certain output energy which is outputted by the main oscillation resonant cavity, so that second-stage linewidth narrowed laser output can be formed. With the spectral control device of the invention adopted, problems such as low degree of freedom of spectral control, high spectral tuning difficulty, poor spectral tuning flexibility and high possibility of optical component damage of an existing single-spectrum control device can be solved.