Generation of ultra-short pulses from high-gain narrow-linewidth lasers

Modified type mode-locking with many passive-mode excitation has been proposed to generate ultra-short light pulses from high-gain narrow-linewidth lasers, The mode-locking with single-active-mode (MLSAM) which is the useful and practical case of the modified type mode-locking has been analyzed taking into account the effect of large locking signal and the variation of the saturated gain along the light path. An experiment has been done by applying a 580 MHz large FM locking signal to a He-Ne 3.39 μm laser, a typical high-gain narrow-linewidth laser. As a result, 170 ps pulses have been obtained with several mW average power.