## 2 Mid-Infrared Optical Parametric Oscillation Laser (OPO)
### LiNbO\({}_{3}\), PPLN, MgO-Doped PPLN Optical Parametric Oscillator
 & **Reference** \\ \hline \multirow{8}{*}{2015} & \multirow{4}{*}{2015} & Huazhong & & & Output wavelength 3.81 \(\mu\)m \\  & & Institute of & \multirow{2}{*}{40 \(\times\) 10 \(\times\) 1 mm\({}^{3}\)} & 1.064 \(\mu\)m & Repetition rate 10 kHz \\  & & Optoelectronics & Nd: GdVO\({}_{4}\) & Average power 5.4 W \\  & & Technology & & Optical efficiency 15.88\% \\  & & Barcelona & & & Output wavelength 3.340 \(\mu\)m \\  & & Institute of & \multirow{2}{*}{2019} & 42 mm length & 1.064 \(\mu\)m & Parameter \\  & & Science and & 1 thick & Yb\({}^{3+}\) fiber & Optical efficiency 9.5\% \\  & & Technology & & & Output wavelength 3.26 \(\mu\)m \\  & & & & & Output wavelength \\  & & 50 \(\times\) 8.2 \(\times\) 1 mm\({}^{3}\) & 1.047 \(\mu\)m & Repetition rate 10 kHz \\  & & of Technology & 5\% mol & Nd: YAG & Average power 0.46 W \\  & & & & Optical efficiency 15.3\% \\  & & & & Output wavelength 3.7 \(\mu\)m \\  & & & 5\% mol & Yb\({}^{3+}\) fiber & Average power 3.2 W \\  & & & & Optical efficiency 18\% \\  & & & & Output wavelength 3.164 \(\mu\)m \\  & & 5\(\times\) 1 \(\times\) 30 mm\({}^{3}\) & 1.064 \(\mu\)m & Repetition rate 76.8 kHz \\  & & & & Nd: YVO\({}_{4}\) & Average power 4.3 W \\  & & & & Optical efficiency 17.1\% \\  & & & & Output wavelength 3.82 \(\mu\)m \\  & & 50 \(\times\) 2 \(\times\) 2 mm\({}^{3}\) & 1.064 \(\mu\)m & Repetition rate 100 kHz \\  & & Southampton & No mention & Yb\({}^{3+}\) fiber & Average power 5.5 W \\  & & & & Optical efficiency 45\% \\  & & & & Output wavelength 3.85 \(\mu\)m \\  & & 50 \(\times\) 2 \(\times\) 2 mm\({}^{3}\) & 1.064 \(\mu\)m & Repetition rate 200 kHz \\  & & 5\% mol & Nd: GdVO\({}_{4}\) & Average power 1.82 W \\  & & & & Optical efficiency 21.3\% \\  & & & & Output wavelength 3.99 \(\mu\)m \\  & & 50 \(\times\) 1 \(\times\) 10 mm\({}^{3}\) & 1.064 \(\mu\)m & Average power 2.1 W \\  & & 5\% mol & Yb\({}^{3+}\) fiber & Optical efficiency 5.2\% \\  & & & & Output wavelength 3.07 \(\mu\)m \\  & & & & Output wavelength 3.07 \(\mu\)m \\  & & 1 length & 1.55 \(\mu\)m & Repetition rate 125 kHz \\  & & Paris-Saclay & 5\% mol & Yb\({}^{3+}\) fiber & Average power 1.25 W \\  & & & & Optical efficiency 17.9\% \\  & & & & Output wavelength 3.35 \(\mu\)m \\  & & & & Output wavelength 3.35 \(\mu\)m \\  & & & 1.065 \(\mu\)m & Repetition rate 1 MHz \\  & & 5\% mol & Yb\({}^{3+}\) fiber & Average power 6.2 W \\  & & & & Optical efficiency 24.3\% \\  & & & & Output wavelength 3.2 \(\mu\)m \\  & & & & Average power 1.72 W \\  & & & & Optical efficiency 7.17\% \\  & & & & Output wavelength 3.5 \(\mu\)m \\  & & & & Average power 1.39 W \\
2018 & \multirow{4}{*}{2018} & \multirow{4}{*}{ \begin{tabular}{c} Changchun \\ **Science and** \\ **Technology** \\ \end{tabular}  } & \multirow{4}{*}{1\(\times\) 8.6 \(\times\) 50 mm\({}^{3}\)} & \multirow{4}{*}{1.06 \(\mu\)m} & \multirow{4}{*}{Optical efficiency 5.4\%} \\  & & 5\% mol & Nd: YVO\({}_{4}\) & Output wavelength 3.8 \(\mu\)m \\  & & & & Average power 1.39 W \\  & & & & Optical efficiency 3.1\% \\  & & & & Output wavelength 4.1 \(\mu\)m \\  & & & & Average power 0.72 W \\  & & & & Optical efficiency 1.84\% \\  & & & & Output wavelength 3.4 \(\mu\)m \\  & & & & Output wavelength 3.4 \(\mu\)m \\  & & & & & Repetition rate 50 Hz \\  & & 5\% mol & Nd: YAG & Average power 1.075 W \\  & & & & Optical efficiency 10.2\% \\  & & & & Output wavelength 3.87 \(\mu\)m \\
2020 & \multirow{4}{*}{ \begin{tabular}{c} Shandong \\ University \\ \end{tabular}