If you don't *need* to reach out 189000 km in a second, and to closer target nearly instantly (for example, because you are shooting down supersonic missiles) why use a laser? For sci fi scenarios that should be mostly based on fact a rail gun is a very efficient and effective option.

if you look at the equations kinetic weapons are the most efficient

a mil grade laser rifle is not going to be silent in an atmosphere that has any amount of water vapour in it.  it's also likely to leave a visible line from shooter to target of water vapour.

Lasers might sound very much like guns when fired in Earth's atmosphere. Small lasers make popping sounds. Crank them up to the power needed to ionize flesh in a fire fight, and they could very well sound just like guns.

 

Treadgar

Assuming supplies energy dense enough and laser tubes efficient enough to make it feasible:

Plus:

No ballistic curve to compensate for, so easy aiming.

No recoil.

Few to no moving parts.

No need for separate ammunition for different 'calibres' since that is a function of the tube.

Ammunition can be used to power other functions (sights, lights, designators) or other items, like vehicles, further reducing logistics requirements.

Minus:

Sensitive to dirt on the focus/output lens.

Relatively high tech base needed to produce and supply.

No internal moving parts for soldiers to clean and maintain.

Obvious visual trace in the dark or 'dirty' atmospheres.

it dont quite work like that.

only a fraction of the energy is reflected from a mirror.

the rest just blows your mirror up.

< it is really hard to type drunk>

^while?

 

 

What I would have said, but it wouldn't have been so funny!

The power of the laser dosn't need to be that high.  The advantage in my mind is that you can start with a FLIR foward looking infared radar.  That funtions as your sighting system.  Then it pulses the power when target is chosen. 

FLIR is an entirely passive system, so if you pulsed it, nothing would happen downrange.

Actually, "laser" stands for Light Amplification by Stimulated Emission of Radiation.  Basically, it is coherent light (exactly one wavelength) as opposed to most things which emit a range of wavelengths.

 

There are several different "colors" of laser which basically just means they are emitting different wavelengths of light.  So, if you can create coherent light on different wavelengths, you should be able to create coherent electromagnetic emissions on just about any wavelength.

 

Why not an x-ray laser?  Or an infrared laser?  Or any laser which used light beyond the visible spectrum.  Then there wouldn't be a visual trail for the human eye to track back to the user.  Also, if you picked a wavelength that doesn't get absorbed by the atmosphere you wouldn't have any vapor trail and the ray gun would be more efficient.

it's all about energy density for lasers and that means the shorter the wavelength the better.  the major problem right now with laser rifles is trying to figure out how to feed them the power they need.  battery tech just isn't up to that level yet and doesn't look likely to get there any time soon.  someone pops out that room temp superconductor though and laser rifles are just around the corner.

Hence Maser for microwave frequencies.

But Laser is probably good for the layperson.