Compact CNT Mode-Locked Ho3+-Doped Fluoride Fiber Laser at 1.2 μm

A diode laser pumped carbon nanotube mode-locked Ho
³⁺
-doped fluoride fiber laser at 1.2 μm was demonstrated for the first time. Stable mode-locked pulses with an average power of 1 mW at a repetition rate of 18.47 MHz were obtained at a pump power of 348 mW. The pulse energy and peak power of this mode-locked laser oscillator were about 54 pJ and 12.6 W, and were increased to 2.41 nJ and 0.54 kW, respectively, by using a 15-cm Ho
³⁺
-doped fluoride fiber amplifier. The pulse duration was measured to be 4.3 ps by an autocorrelator. Because the operation wavelength is close to the zero-dispersion wavelength of 1.3 μm, this mode-locked fiber laser exhibits unique features.