Abstract
Mid-infrared (MIR) pulsed
lasers near a 3 µm
waveband show great potential
for the high absorption of
water molecules and many
important gas molecules. A passively Q-switched mode-locked (QSML) Er3+-doped fluoride fiber laser with a low
laser threshold and high slope efficiency around a 2.8 µm
waveband is reported. The improvement is achieved by depositing
bismuth sulfide (Bi2S3) particles onto the cavity mirror
directly as a saturable absorber and using the cleaved end of the
fluoride fiber as output directly. -QSML pulses begin to appear
with the pump power of 280 mW. The repetition rate of the QSML
pulses reaches a maximum of 33.59 kHz with the pump power of
540 mW. When the pump power is further increased, the output of
the fiber laser switches from the QSML to the continuous-wave
mode-locked operation with the repetition rate of 28.64 MHz and
the slope efficiency of 12.2%. The results indicate that Bi2S3 is a promising modulator for the
pulsed lasers near a 3 µm waveband, which paves the way for
further development of various applications in MIR wavebands,
including material processing, MIR frequency combs, and modern
healthcare.
Funder
National Key Research and Development
Program of China
National Natural Science Foundation of
China
Key Technologies Research and Development
Program of Anhui Province
Natural Science Foundation of Anhui
Province
Fundamental Research Funds for the
Central Universities
Subject
Atomic and Molecular Physics, and Optics,Engineering (miscellaneous),Electrical and Electronic Engineering