Classification of mold clamping
Active mode locking: Periodically modulate the loss or optical length of the resonant cavity n
Passive mode locking: using the nonlinear absorption characteristics of the saturable absorber, the absorption of the laser in the cavity changes with the intensity of the optical field
Self-mode locking: the non-linear effect of the active medium itself can maintain the equally spaced distribution of each longitudinal mode frequency and have a definite initial phase relationship
Synchronous pump mode locking: periodically modulate the gain of the resonant cavity