A handheld laser likened to a Star Wars lightsabre
Ugh, not again...
A lightsaber is NOT a laser. It does EMIT light, but the properties are different:
* A laser doesn't just end in three feet like that, (the beam eventually will diverge to the point as to seemingly fade away, but we're talking at significantly greater distances) thus would not have a defined shape or "tip" like a lightsaber.
* It can't, without SOME sort of outside interference, just double back on itself to create that defined length.
* A laser doesn't cast a shadow! Watch the films and you can see that lightsaber blades do. This is NOT a mistake due to the nature of the film props (which had a "stick" blade for the actors to use as a reference), as these shadows were cleaned up and made more defined (rather than removed) in the Special Edition and DVD edits of the Original Trilogy, and also carried over into the Prequels.
* This would create a weapon with literally NO observable mass in its blade. Although not a big deal for cutting purposes since it doesn't rely on mass, it's a VERY big deal for handling and control. In the film, lightsabers clearly respond as if there's mass to their blades (although this could be provided by some sort of gyroscopic effect).
* Light doesn't block light. Besides the shadows I mentioned, if a lightsaber was a laser, the blades would pass right through each other (this is the same reason why a blaster can't be a true laser, either. A lightsaber would be unable to deflect a blaster shot).
If anything, a lightsaber is probably much more akin to a plasma torch on steroids. Any use of a laser is probably for ignition purposes and is not itself a component of the blade.
Pointless rant? Maybe, but so long as people insist on identifying lightsabers with lasers, actually creating a REAL one that works like in the movies will never be possible. And dammit, I want to see a real lightsaber in my lifetime.