激光注入锁定技术压缩线宽的研究

Line Narrowing by the Laserlnjection Locking Technique

本文采用多模激光振荡的半经典理论,分析了在注入锁定时腔内各纵模与注入信号间的作用关系.用连续的Nd:YAG激光器产生的单纵模激光信号,注入高增益调Q非稳腔激光器中,实现了注入锁定,获得了脉宽为20ns、峰值功率为10.5MW的傅立叶变换极限的单纵模激光输出.

By means of the semiclassical theory of multimode laser oscillation, the relation among the resonator axial modes and the injection signal during injection locking has been studied. If the bandwidth of the field injected is sufficiently narrow, the axial mode nearest to the injection field will be excited and will first extract the energy from the gain medium to obtain amplification. However, other axial mode fields will begin to oscillate from the spontaneous emission noise. Instead of being amplified, they will be damped. Consequently, single axial mode oscillation is accomplished. By the injection of a low power CW single axial mode laser into a high gain Q-switched unstable resonator Nd: YAG laser, a stable single axial mode laser output of a pulse width of 20 ns and of a peak power of 10.5 MW with Fourier-transform-limited spectral line-width has been achieved.