Compact 1790-nm dissipative-soliton mode-locked thulium fiber laser

We report an all-fiberized, dissipative-soliton, mode-locked thulium fiber laser enabled by a single-wall carbon nanotube saturable absorber operating at 1790 nm for deep-penetration three-photon microscopy in bio-medical imaging applications. The laser provides output pulses with a maximum pulse energy of 1.3 nJ and a minimum pulse duration of 310 fs after compression. With a new pump recycling design, a low pump threshold of 110 mW is observed. Consequently, a compact mode-locked thulium fiber laser cavity using a single-mode pump laser diode is successfully realized.