All-polarization-maintaining mode-locked Holmium-doped fiber laser based upon nonlinear polarization evolution

An all-polarization-maintaining, all-fiberized holmium (Ho) doped fiber laser mode-locked by nonlinear polarization evolution (NPE) is experimentally demonstrated for the first time. The NPE mechanism is realized via the combination of a polarizer and the cross-fusion of three sections of polarization maintaining (PM) fibers. With the appropriate manipulation of the splicing angles between the birefringent axes of the PM fibers, a highly stable mode locked operation is realized. The laser delivers stable dissipative-soliton resonance (DSR) pulses with a repetition rate of 10.34 MHz and an average power of 223.95 mW, corresponding to a pulse energy of 21.64 nJ and a peak power of 11 W. Furthermore, the output power test over 2 h implies superior stability of this design. The oscillator, performing the characteristics of self-starting, high pulse energy, and good stability, is attractive and promising for various practical application.