Diode-pumped femtosecond passively mode-locked Yb: LPS laser

A diode-pumped passively mode-locked Yb:Lu2Si2O7 (Yb:LPS) laser is demonstrated for the first time, to our knowledge. Using a commercial semiconductor saturable absorber mirror (SESAM) as the mode locker and a pair of GiresTournois interferometer (GTI) mirrors for group-velocity dispersion (GVD) compensating, we have obtained stable femtosecond mode locked pulses. Two output couplers of transmission of 1.6% and 5% were used to exploit the mode locked laser performance. For the output coupler with T = 1.6%, 195 fs pulses centered at 1042 nm were generated, and for the output coupler with T = 5.0%, 450 fs pulses centered at 1058 nm were generated. The corresponding output power is 130 and 610 mW, respectively. Higher output could be obtained but the laser operated at multi pulse regime. In addition, a preliminary continuous wave (CW) laser performance test demonstrated a slope efficiency of up to 70% with respect to incident pump power, which is much higher than the previous value of 35% with respect to absorbed pump power.