Energy scalable passively mode-locked mid-IR Tm-fiber laser

Recently a lot of interest is drawn towards development of high-energy Tm-fiber lasers, operating around 2 μm - an attractive wavelength for LIDAR, ranging and remote-sensing applications, where μJ to mJ pulse energies are required. Such energy frontiers are usually achieved by the chirped pulse amplification outside an oscillator [1]. However, our approach - direct J femtosecond pulse generation in the positive dispersion regime - does not require external amplification. This radically different from traditional soliton formation mechanism was first suggested by us in [2] and later further developed in [3]. Here we present the results of theoretical and experimental analysis of the mode-locked Tm-fiber laser, based on a highly Ge-doped fiber. The study paves the route towards pulse energy scaling in the positive dispersion regime from alternative LMA fibers.