# Temporally Programmable Hybrid MOPA Laser with Arbitrary Pulse Shape and Frequency Doubling
## 5 Conclusions  
In summary, desired pulse shapes were demonstrated in a hybrid MOPA system mainly made up of three Nd:YVO\({}_{4}\) amplifiers. By investigating the amplifier dynamics, the pulse shape transfer function of an end-pumped Nd:YVO\({}_{4}\) amplifier was obtained. The numerical simulation for the first amplifier indicates excellent agreement with the experimental results. Interesting pulse shapes, such as that of a car, were obtained through the theoretical method, showing the effectiveness of the theoretical method in achieving arbitrary pulse shapes. Furthermore, several pulse shapes were obtained through the same method for the MOPA system made up of three amplifiers. A high peak power level of 41.6 kW and a narrow linewidth less than 0.06 nm were achieved, with good beam quality. A green laser was generated by this source, with a maximum conversion efficiency of 42.6%. Compared with  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & & \multicolumn{3}{c}{**100 kHz, 41.4 W**} & \multicolumn{3}{c}{**40 kHz, 38.3 W**} \\ \cline{2-9}
**Pulse Shape** & **Leading** & **Falling** & **Pulse** & **Power of** & **Leading** & **Falling** & **Pulse** & **Power of** \\  & **Edge** & **Edge** & **Duration** & **Green** & **Edge** & **Edge** & **Duration** & **Green** \\  & **(ns)** & **(ns)** & **(ns)** & **Laser** & **(Ws)** & **(ns)** & **(ns)** & **Laser** (W)** \\ \hline square & 9 (1.53) 1 & 15 (5.7) & 168 & & 3.63 & 6.6 (2.4) & 8.6 (3.6) & 39 (38) & 14.5 \\ Gaussian & 45 (32.6) & 51 (37.9) & 63 (47.2) & 5.3 & 16 (11.7) & 20 (13.7) & 23 (17.5) & 16.3 \\ parabolic & 49 (57.2) & 54 (64.4) & 123.4 (96) & 4.19 & 14 (14.4) & 18 (13.2) & 29 (24.7) & 16.0 \\ multiple-step & 8 (2.0) & 12 (7.5) & 111 (-) & 4.23 & - & - & - & - \\ \hline \hline \end{tabular}  
* The data in the bracket is for green laser.  
\end{table}
Table 2: Temporal parameters of 1064 nm and an output power of 532 nm.  
the input pulse of SHG, the pulse shape of the green laser was distorted due to the nonlinear effect, especially for the ones with a slow leading edge and a falling edge. The solid-state MOPA system with arbitrary waveforms, high peak power levels, and narrow spectral linewidths shows great potential in precision manufacturing, optical sensing, and Lidar applications.  
Supplementary materials are available online at Zenodo DOI: 10.5281/zenodo.854840 ([[https://zenodo.org/record/854840#.WaeZ4](https://zenodo.org/record/854840#.WaeZ4) SGMcY]([https://zenodo.org/record/854840#.WaeZ4](https://zenodo.org/record/854840#.WaeZ4) SGMcY)). Video S1: SBS pulse distortion_40 kHz_40 ns. Video S2: SBS pulse distortion_100 kHz_168 ns. Video S3: SBS_frequency shift_100 kHz_168 ns.  
**Acknowledgments:** National Key Research and Development Program of China (Grant No. 2017 YFB1104500); National Natural Science Foundation of China (61475083).  
**Author Contributions:** [PERSON] conceived and designed the experiments; [PERSON] provided guidance and funding; [PERSON] performed the experiments; [PERSON] and [PERSON] analyzed the data; [PERSON] conducted the simulation; [PERSON] wrote the manuscript and created the figures. All authors have reviewed the manuscript.  
**Conflicts of Interest:** The authors declare no conflict of interest.