레이저 점화기용 수동형 Q-스위칭된 Yb:YAG/Cr:YAG 레이저 출력 특성에 대한 연구

Abstract

We successfully constructed a passive Q-switched Yb:YAG laser ignitor pumped using a diode laser with low power and long pulse width. To the best of our knowledge, this is the first study to achieve a quasi-MW output power from an optimized Q-switch Yb:YAG laser ignitor by using a pumping diode laser module emitting at under a power of 23 W. The output pulse energy of our optimized laser is 0.98 mJ enclosed in a 1.06 ns pulse width, corresponding to a peak power of 0.92 MW. To achieve this, we experimentally investigated the dependence of the laser output on cavity length, initial transmittance of Cr:YAG, pump beam size, and output coupler reflectance. On the basis of the experimental analysis, we determined the design parameter values for our laser ignitor. We found that these results approximately agree with the theoretical results. If we can coat the optical component using an ion-beam sputtering method, we can obtain an more increased output pulse energy from our Q-switched laser.