2.9-micron intermediate infrared mode-locked laser

The invention relates to a 2.9-micron intermediate infrared mode-locked laser, and belongs to the field of the full-solid-state intermediate infrared laser. The 2.9-micron intermediate infrared mode-locked laser comprises a 150nm optical fiber Raman laser, a collimation focusing system, a laser input mirror, a laser crystal, a laser reflector module, a laser output mirror and a mode-locked element; the pump light output by the 1150nm optical fiber Raman laser is irradiated to the laser crystal after passing through the collimation focusing system and the laser input mirror in order; the laserinput mirror, the laser crystal, the laser reflector module, the laser output mirror and the mode-locked element form a laser resonant cavity, the produced mode-locked laser is output in a coupling bythe laser output mirror; the laser crystal is holmium-praseodymium double-doped, the mode-locked element is graphene or black phosphorous saturable absorber. By adopting the 1150-nm laser pumping holmium-praseodymium double-doped laser crystal, the novel two-dimensional material graphene or black phosphorous are used as the saturable absorber to successfully realize high-efficiency high-beam quality 2.9-micron band mode-locked intermediate infrared laser output.