If you say ordinary laser flashlight, you can only change it to LD (Laser Diode) if you want to increase the power, because at present, domestic laser flashlight generally works at full load or even exceeds the rated power 10%. If the power is increased, it will easily lead to the aging of the resonator and the sharp decline of the optical output power. However, some DPSSL can improve the crystal efficiency by improving the heat dissipation of the pump crystal, but the power increase is also small. If you want high power, why not make a hand-held gas laser like me? Someone mentioned the safety of laser. What I want to say is that things more dangerous than lasers are everywhere. I don't know why there are so many Notre Dame in Zhihu. If laser is dangerous, it is better to say that 220v AC is dangerous. What if Xiong Haizi touches his hand? And the destructive power of tens of watts of laser is far lower than that of various hand-held fireworks, right? It is also difficult to make and obtain materials, all kinds of fireworks, right? In this case, shouldn't Notre Dame mobilize people around you to ban fireworks first?