Active-passive mode-locked oscillators at 1.054 μm

Abstract

We report on the characteristics of active‐passive mode‐locked phosphate‐glass oscillators. These highly reliable oscillators operate at 1.054 μm and are characterized by the absence of satellite pulses for pulse durations t_p≳80 psec. They have very high peak‐to‐background contrast of 10⁷ to 10⁸. Transform‐limited pulse widths between 80 and 600 psec are reliably generated using a pair of intracavity etalons. The reproducibility of the pulse durations is better than ±10%, that of the pulse‐train maximum about ±10 to 20%. Single‐pulse selection with ±5% amplitude fluctuation has been achieved with threshold‐pulse selectors. For pulses shorter than 50 psec, satellite pulses are occasionally observed. A theoretical explanation for this observation is given.