Continuously diode-pumped passively $Q$Q-switched eye-safe 1537 nm Er:Yb:Lu2Si2O7 pulse laser

It is still a technical challenge to obtain a 1.55 µm passively Q -switched E r 3 + / Y b 3 + pulse laser with high energy and high repetition frequency, especially when it is end-pumped by a continuous-wave 0.98 µm diode laser. Benefitting from its long fluorescence lifetime of the 4 I 13 / 2 upper laser level and high thermal conductivity, E r : Y b : L u 2 S i 2 O 7 crystal may be an excellent gain medium for realizing a high energy and high repetition frequency 1.55 µm pulse laser. At a continuous-wave absorbed pump power of 6.1 W, a 1537 nm pulse laser with energy of 45.5 µJ, repetition frequency of 1.32 kHz, and duration of 25 ns was first, to the best of our knowledge, realized in an E r : Y b : L u 2 S i 2 O 7 crystal.