Polarised solid-state laser - has phase-conjugate SBS mirrors with use of differential thresholds to sustain stable emission

摘要

In a solid-state laser element, e.g. Nd:YAG, (1), low level excitation is maintained by conventional mirrors (2,3) the beam passing through a polariser (5), two quarter-wave plates (6,8) and two SBS phase-conjugate mirrors (4,7). - When the laser energy reaches their thresholds the SBS mirrors sustain the lasing action with much greater efficiency and, due to their different threshold energies, hold it ti a nearly constant level. The SBS mirrors also compensate for adverse thermal lens effects in the lasing medium.