Misalignment analysis of an active resonator using eigenvector method

An eigenvector method is used to calculate the mode distribution, misalignment and beam quality factor of a resonator with a two-dimensional misalignment angle. In the calculation model, the gain medium is regarded as a sheet inside the mirror. It is found that resonator misalignment leads to the uneven distribution of modes and the change of mode orders. And when the misalignment is in a certain range, it may bring forth new mode competition. The beam quality factor will not always get bad when disorder level increases, however, beam quality generally degrades as mode orders increases, and some degenerate modes may not be degenerate any more.