无内热激光器运转对抽运光光强的需求条件研究

研究了无内热激光器和激光放大器运转时对抽运光的需求条件.运用激光器的速率方程理论,给出了抽运光所应满足条件的表达式.无内热激光运转时,不仅要求抽运光光强要大于阈值条件,而且要大于某个最小抽运光强(与增益材料性质、抽运光波长、激光波长等有关).以掺镱的KY(WO4)2晶体为无内热激光器的放大介质,计算了抽运光光强应满足的空间分布条件.要使激光器无内热运转,抽运光光强需随激光光强的增大而相应减小.对于无内热激光器,抽运光光强的空间分布与谐振腔前后镜的反射率和增益介质长度密切相关,在谐振腔输出耦合镜反射率不是太低的情况下,腔内抽运光强需近似为均匀分布.

Pump Fields Requirements for Athermal Lasers

The pump fields requirements for athermal laser amplifier and oscillator are described. The expressions of the pump fields are derived by use of rate equations. The pump distribution of an ytterbium-doped KY(WO4)2 crystal is analyzed as an athermal lasers. For athermal laser amplifier, the pump intensity along the axis must be varied according to the laser intensity. With the increase of laser intensity, the pump intensity should be adjusted lower. For athermal laser oscillators, the pump distribution in the cavity is almost determined by the reflectivities of the rear and output coupler mirrors and gain media length. The pump intensity becomes lower and more close to uniform as the output coupler reflectivity is increased.