Femtosecond Tm:Lu2O3 Lasers Operating in the Spectral Region Below 2 μm

In this paper, diode-pumped SESAM mode-locked Tm:Lu
₂
O
₃
lasers operating at 1942 nm and 1968 nm are reported. Two different emission wavelengths below 2 μm are realized by using two different kinds of SESAMs. Based on a GaSb-SESAM, the mode-locked Tm:Lu
₂
O
₃
laser delivers femtosecond pulses at 1942 nm with the shortest pulse duration of 774 fs and a maximum average output power of 104 mW at an absorbed pump power of 3.82 W. With a GaInAs-SESAM, a pulse duration of 916 fs under a corresponding maximum average output power of 148 mW is achieved at 1968 nm at the same absorbed pump power of 3.82 W. To the best of our knowledge, this is the first report on femtosecond mode-locking of Tm:Lu
₂
O
₃
lasers operating at wavelengths below 2 μm.