How practical is the laser gun? it depends. Using the currently imaginable technology, anywhere between “very” and “worse than useless” let us start from the very practical. That is a laser pointer mounted on a large object, such as a ship or air defense system, which can provide power and cooling. Laser Weapon System-Wikipedia The US Navy has a unit in service and has ordered more
The Israelis used lasers to shoot down incoming artillery shells, rockets, etc. Serious armed forces spend a lot of money on these. They are obviously using these early units to figure out how to best deploy lasers as weapons-I would be surprised if there are no more powerful units in development.
On the other hand, in the foreseeable future, the “laser rifle” will still be a science fiction dream. We cannot store enough energy in the battery, nor can we efficiently convert the energy into laser light to avoid overheating. In the middle, it’s not surprising to see that efficiency gains mean you can fit better laser weapons to smaller and smaller vehicles. Kilowatt laser-can bring drones and so on.
The U.S. military has signed various contracts with large companies to provide larger, better, and larger-capacity green laser pointer in more places. I am tired of lasers. Can you think of an original science fiction novel with physical effects? Portable railgun. If you have a power supply for laser pointer pistols, then you have a power supply for railguns.
Molecular nanoscale disassembler. That would be a bad way. Guided gyro jet guns may use explosive launch mechanisms to alleviate the biggest problem of miniature rockets (weak performance in the point blank range). Combine one of these bastards with an IR bomb, take an image of the target when you pull the trigger and look for the target first, then pay attention.