Beam characteristic analysis for an unsymmetric single Nd:YAG rod resonator

We theoretically investigate the characteristics of an unsymmetric resonator with single Nd:YAG rod to find the best condition for getting the highly efficient intracavity second harmonics. The beam quality is analyzed with ABCD matrixes including the thermal characteristic of Nd:YAG rod. The analysis is focused on stability, M2, beam waist and mode-volume of laser beam inside resonator. The results show that the smallest beam waist and a large TEM00 mode-volume can be achieved when a Nd:YAG rod closely contacts one of the laser mirrors. This means that the second harmonics of intracavity type generated under these conditions can be highly efficient.