The Mid-infrared lasers (MIR) with high peak power and high repetition rate operating in the range of 2.7~3 μm have important application in laser surgery and optical parametric oscillator (OPO).

A recent study conducted by SUN Dunlu's research group at Anhui Institute of Optics and Fine Mechanics (AIOFM), Hefei Institutes of Physical Science(HFIPS), Chinese Academy of Sciences (CAS), achieved high power, high efficiency and quasi-continuous mid-infrared laser in the free running and LGS Q-switched modes by using the Er³⁺ doped YAP crystals as laser gain medium.

Basing on their previous research work on laser, this group further improved the laser performance of Er:YAP laser crystal by laser-diode (LD) side-pumping method, a Er:YAP crystal rod with concave end-faces was used to compensate the thermal lensing effect. The maximum output powers of 26.75W were achieved at 250 Hz, and 13.18 W at 1000 Hz which is the highest working frequency in all the LD side- pumped Er-doped MIR laser so far.

In addition, they demonstrated a LD side-pumped and electro-optical Q-switched Er,Pr:YAP laser with emission at 2.7 μm. A giant pulse laser was obtained with pulse energy of 20.5 mJ, pulse width of 61.4 ns, and peak power of 0.33 MW at the highest working frequency of 150 Hz.

These results indicate that the Er³⁺ doped YAP crystals are promising candidate for the high power and high frequency mid-infrared laser device, which possess great potential for the application of dental ablation surgery and OPO pump source.

This work was supported by National Key Research and Development Program of China, the National Natural Science Foundation of China, the Natural Science Foundation of Anhui Province, and the Youth Fund of Advanced Laser Technology Laboratory of Anhui Province.

Link to the paper:

13-W and 1000-Hz of a 2.7-μm laser on the 968?nm LD side-pumped Er:YAP crystal with concave end-faces

Performance of a 968-nm laser-diode side-pumped, electro-optical Q-switched Er,Pr:YAP laser with emission at 2.7 μm

Fig. 1. Schematic of LD side-pumped Er(Pr):YAP laser (Credit by QUAN Cong)

Fig. 2. Average output power of LD side-pumped Er:YAP laser versus pump power at different working frequencies and pump pulse widths. (Credit by QUAN Cong)