Reducing loss of energy for Lasers

[Josiah]

TL;DR

Reducing loss of energy

Hi
I was told by someone that if you place the laser in a vacuum, then if would not loose energy. Is this true?

 

[anuttarasammyak]

Not only laser but light in general do not lose energy in vacuum.
Laser beam go in one direction. A beam receiver get the energy without the loss. Light, for an example sun light, goes all the direction whose energy density drops by r^-2 law. Total r^2-surface surrounding the light source get generated energy without loss.

 

[berkeman]

@Josiah -- Please take care not to try to reopen a closed thread. Your previous thread on this question was closed because you veered off into non-physical territory with your laser power questions. I will let this thread here proceed, but only if you stick to known Physics.

Here is how your previous thread was tied off:

The OP question has been sufficiently addressed. Thread closed. Thanks to all who participated.

 

[PeterDonis]

I was told by someone

This is not a valid reference. Can you find a valid reference (textbook or peer-reviewed paper would be best) that says what you're asking about? If not, we can't discuss it here.