Lasers Definition and 222 Threads

I'd like to know where I can find the most powerful laser systems in the world right now. Anyone who's into this?

A question to people coupling lasers to optical fibers. What is the power and exposure time of laser beam directed in the eye which is considered dangerous? The ones I´m currently working with are 15 mW. Are there any ways to couple laser beam to a fiber without having to look into another end...

I am trying to find out, what is the affects the velocity of the light wave projected by the laser? I am going to ITT tech and this is a very diffucult thing to try and find on the web. I have been searching for over an hour trying to find the answer. I would really appreciate the help.

Hi! I have to make a presentation about the usage of lasers in measurements, but I am not sure what I should include. I thought of something like using laser beams for measuring distances, but I don't know how exactly this can be done and what else can be measured with lasers. I'd be greatful if...

How do lasers make use of the quantum theory of the atom. I tried to look it up but I couldn't understand what they were saying. :confused:

Does anyone know where I can find sites that explain how lasers & X - rays are related to the quantum mechanical model.

How does the combat lasers work? Military around the world is working on them and Russia used them on Chinese troops in some major border skirmishes in 1960's. I want to know what kind of light is used to temporary/prmanently blind opposing troops? do they use infra red or visible light ...

Cold Lasers? Hi, I was overheard one of my profs talking and he was talking about cold lasers. I googled it but I could not find anything worth while. Does the laser "slow" down the electrons in the obitals? I don't really know how to approach this one... Does anyone know anything about this...

I've been doing a ton of research recently on how lasers work. Basically a laser is actually L.A.S.E.R which stands for "Light Amplified of Stimulated emitted radiation". A laser is cohernet, which means it is only its wavelengths are not fixed. Low power red lasers are often known as...

When we have stimulated emisson as in a laser, a photon from a spontaneous emission makes an exited electron unstable which then falls back to its ground state releasing as 2nd photon. But why does the electron not just absorb the 2nds photon, move to an even higher energy level and then fall...

I am not sure what the thing is actually called, but let me see if I can describe it. It is one of those products advertised on tv, that you put on a wall and it shoots a laser beam all along the surface parallel with the ground. The problem I can't figure out is, some of them claim it can go...

Besides manmade lasers, from what phenomenon might the coherent light of naturally occurring lasers originate?

Hi! I just wanted to know if you guys can help me with a project I have. The project is on the "Engineering Uses of Lasers." All I'm asking for is some decent, usable websites and information. Most of the sites & journals I've looked through either have purely theoretical work or simple...

Lasers are being used to do many things now: eye correction, speed scaning, cutting, and now even to create iron! Scientists now use lasers to heat up hydrogen so they fuse into helium and all the way up the table into iron, just like stars. I want to know if lasers have mass. I know that...

It may seem to be a stupid question but please take a serious look at it: 1) (hypothetical): Imagine a perfect hollow orb (ball, sphere...) of some heatproof material - inside metallized to reflect most wavelenghts of light (a one-way-mirror). Assumed a perfect vacuum inside: what happens...

what is BEAM WAIST in lasers and where it is located?

I have read that you can limit the divergence of a laser by sending it backwards through a telescope. I have not yet been able to do this with my telescope, but seem to have some success using less powerfull lenses. Would anyone be willing to help me conduct this expiriment. The problem I am...

I do not know how to do the second part of this question. I never learned this. A laser used to weld detached retinas puts out pulses of 640 nm light, 25 ms long, which average 0.50 W output during a pulse. i) how much energy can be deposited pre pulse? ii) If the energy of a light...

Hey guys, this is my first time posting here (so if there's already a thread about lasers, please direct me there) Does anyone know a good source for the theory of lasers (specifically semiconductor lasers) at a second year undergrad level? I've looked at a number of books including Laser...

Hi, I am a ME working on a toy design. I know next to nothing about lasers diodes. Is there a laser diode of low enough power that it could be safely incorporated into a kids toy? (visible "dot" required. Or is all laser light potentially harmful to the retina? Thanks!

What is the meaning of the term "pumping a transition" in relation to lasers?

http://www.newscientist.com/news/news.jsp?id=ns99994288