角锥腔固体激光器相干特性的研究

Study on coherent characteristic of solid state laser with corner cube resonator

多光束相干合成是获得高功率、高亮度激光输出的有效途径。首次采用倏逝波理论结合互注入特性揭示了角锥腔固体激光器远场输出为相干合成分布的机理,角锥腔对称部分的激光由于互注入实现锁相,相邻部分由于倏逝波耦合实现锁相,重点研究了固体激光器倏逝波耦合相干的特性。研究表明:锁相效果跟激光阵列排布方式有关,在相同的激光阵列排布方式时,腔长越长,占空比越大,则模式间耦合越强,锁相效果越好,越趋向于同相模输出。理论和实验证明了角锥是一个天然的相干合成元件,角锥多光束相干合成技术具有重要的科学价值。

Coherent beam combination technology is a significant approach for achieving high power laser beam with good beam quality. Based on ＂mutual injection and evanescent wave＂ characteristics of comercube resonator, it reveals that far field output of comer-cube laser was the inner reason and mechanism of coherent combining distribution by theory of evanescent wave. Evanescent wave coupling phase-locked combining characteristic in solid state laser was studied emphatically. The results indicate that the phase locking output is influenced by the distribution of laser beams and some other factors. When the distribution of laser beams is same, the cavity length and duty ratio determine the phase locking result. The longer cavity length and larger duty ratio, the stronger evanescent wave coupling is, so the phase locking result is much better, running to an in-phase mode output. Theories and experiments indicate that comer cube is a natural coherent combination element, and coherent beam combination technology by comer cube has important scientific value.