Recent progress on mid-infrared pulsed fiber lasers and the applications

In the past two decades, great progress has been made in the development of inexpensive, compact and efficient mid-infrared pulsed fiber laser Q-switched, mode-locked, and gain-switched technology. The drawing process of mid-infrared fiber is becoming mature. The picosecond and femtosecond mid-infrared laser have covered the 2.0-3.5 mu m spectral region, and the saturable absorber is more diverse. The Q-switching of 3 mu m Dy3+ and 3.5 mu m Er3+ fluoride fibers have developed rapidly. Gain-switching technology has also excelled in this area. The mode -locked pulse is close to 100 fs, and the average output power has exceeded kilowatts. These achievements have promoted the application of mid-infrared ultrafast lasers in mid-infrared frequency combs, molecular spectros-copy, material processing, laser surgery, molecular biology and chemistry. Finally, the prospects and challenges of the future development of ultrafast mid-infrared laser sources are discussed and analyzed. The application requirements of mid-infrared fiber pulsed lasers in spectroscopy, supercontinuum technology, frequency comb, laser processing, and biomedicine will give rise to new scientific research and industrial production technology.