Actively Q-switched dual-wavelength pumped Er³⁺ :ZBLAN fiber laser at 347 µm

Abstract

We demonstrate the first actively Q-switched fiber laser operating in the 3.5 μm regime. The dual-wavelength pumped system makes use of an Er doped ZBLAN fiber and a germanium acousto-optic modulator. Robust Q-switching saw a pulse energy of 7.8 μJ achieved at a repetition rate of 15 kHz, corresponding to a peak power of 14.5 W.

Experimental Investigation of Actively Q-Switched Er3+:ZBLAN Fiber Laser Operating at around 2.8 µm

“…Recently, also, Q-switched and gain-switched Dy 3+ : ZBLAN fiber lasers operating were reported [ 17 , 18 ]. Furthermore, in reference [ 19 ], the first actively Q-switched fiber laser operating near a wavelength of 3.5 μm was reported. In reference [ 19 ], robust Q-switching and a pulse energy of 7.8 μJ at a repetition rate of 15 kHz, corresponding to a peak power of 14.5 W, was achieved.…”

“…Furthermore, in reference [ 19 ], the first actively Q-switched fiber laser operating near a wavelength of 3.5 μm was reported. In reference [ 19 ], robust Q-switching and a pulse energy of 7.8 μJ at a repetition rate of 15 kHz, corresponding to a peak power of 14.5 W, was achieved. The authors also pointed out in this contribution an interesting problem with damage of the fiber tip observed for higher pump powers.…”

Q-switched Dy:ZBLAN fiber lasers beyond 3 μm: comparison of pulse generation using acousto-optic modulation and inkjet-printed black phosphorus

“…to exploit the 3-5 µm atmospheric transparency window for LIDAR. To meet this need, a dual-wavelength-pumped Er transition is currently being explored for 3.4-3.8 µm emission, which has been Q-switched [10,11] and gain-switched [12], generating up to 7.8 µJ pulses. Despite these advances, there still exists a 3.0-3.4 µm 'gap' in current fiber laser coverage, highlighting a need to consider alternative rare-earth-doped fibers.…”

Gain-switched Dy3+:ZBLAN fiber laser operating around 3 μm

“…These lasers can currently generate Watt-level output powers [4][5][6]. Lately, longer emission wavelengths above 3.5 μm have been presented [7,8]. For example, a CW (continuous wave) 3.92 μm laser action at room temperature has been observed using Ho 3+ doped fluoroindate glass fibers [9].…”