Experimental study of additive-pulse mode locking in an Nd:glass laser

摘要

Self-starting additive-pulse mode locking (APM) has been investigated experimentally in a continuous-wave Nd:glass laser. Stress has been put on the study of the self-starting process and relaxation oscillation instabilities. An intensity threshold for self-starting APM is observed and related to the linewidth of the first beat note of the power spectrum of the free-running laser output. Under steady-state conditions, two distinct operating regimes are obtained: mode locking with repetitive self-Q switching and pure mode locking. Increasing the intracavity power gives rise to a strong chirp developing on the mode-locked pulses and to a simultaneous disappearance of self-Q switching.