Lasers Definition and 222 Threads

if lasers produce so much power why can't we use it as an energy source

how come there is an electrical gradient in lasers? i means lasers are just monochromatic photons so how come a particle feels an electrical force there

i mean to say how does this method extract energy, I've read the wiki but in my head it seems as though you can only extract as much energy you put in and why can't we use this to get to absolute zero?

I am in dire need of some information on pulsed lasers. I'm not quite sure if this is the correct forum for this kind of question but here goes. I would like to know if you can buy a commercial pulsed laser system that can deliver a repetition rate of 40Mhz and 20 fs pulse duration while being...

Hi, I read something interesting about some amateur astronomers lasing the ISS with a blue-light laser, and the astronauts were able to spot it. How powerful would a laser have to be to be seen by the human eye from Mars? It would be shone from the dark side of Earth of course. Are we...

What's the purpose of having an air gap in certain gas lasers? Just to be clear, I'm talking about the air filled space between the lasing gas (with glass separating the two), and the partially silvered mirror at the end that let's the light out. Why isn't the partially silvered mirror just at...

Lasers are known to emit a particular wavelength, and with a bandwith that is extremely narrow. I have been told that if a laser medium is white light, such as the light from HID lamps or flash lights, the laser will amplify just one wavelength. Is this correct, or is it possible for a laser to...

Hello all, I need to design an experimental apparatus that involves manipulating the path of a laser. Thus far I only know the bare basics about optics and I have never attempted optical apparatus design, does anyone know a book that is a really good reference for experimental applications of...

Hey..!Its been a long time since I last posted..Any how I returned.. My question is about mEta stable states in atoms in Lasing Action.Wt actually these states are?And are they justifiable by Bohrs atomic model or Schrodinger Probabilistic orbits?If not then from where these additional states came?

I have a question. In an electric arc, the electric current going through the air makes a visible plasma arc as so: http://upload.wikimedia.org/wikipedia/commons/7/7a/Electric_arc.jpg My question is this: Could a high power laser create a visible plasma channel through its path. I ask...

Homework Statement A gypsy's crystal ball can act as a thick lens whose centre thickness is twice the radius of curvature of the surface. For a 10 cm sphere of glass with n=1.5 what is the focal length? Like this? : http://postimage.org/image/niisv7bq9/ Homework Equations I am not...

Homework Statement If a round trip gain in a 56.8 cm long laser is 5.16%, what is the net gain coefficient (g-\alpha). g is the small signal gain coefficient \alpha is the absorption coefficient L-length of cavity Homework Equations The Round Trip Power Gain: Gr= R1*R2*...

I'm writing an essay on liquid crystal lasers and have written the intro to my paper. Can I just double check with you all that I haven't written anything that's wrong? Thanks. Please let me know if I should also post the source I used. It's the first time I've posted something qualitative so...

Please read this carefully before answering,in fiction lasers are quite common and they seem to have the property to produce explosions.I am not asking if they exist,I am asking if with the right technology can laser beams produce explosions.Is this just some myth or is there some truth to...

I'm doing this for a home project over the summer. So let's say I took a small laser and passed the beam through some focusing lenses (or evena single lense). Is it possible for the beam to expand? Also, if the laser is powerful enough to burn through paper, will the focusing lenses be...

will, Red, Green and blue lasers wen crossed create the spectrum we crossed ?? hia, if i get red, green and blue lasers, and cross them at one point, and change the intensity of each one accordingly, will at the point of where they cross, display different colours relevant to the mixture...

Hi everyone, I am a little bit undecided about which way to take for grad study. Maybe you can give me some advice. The professor that I am planning to study with in a M.S. program (supposed to last for 3 yrs) fiber laser applications, ultrafast optics and neurosurgery. In my interview one...

Greetings everyone, I am an undergraduate physics student an I would like to receive your suggestions about introduction to laser books. Which one do you recommend for a beginner? The possible candidates I have found are as follows: Laser Fundamentals William T. Silfvast Basics of Laser...

So from what I understand nothing is faster than the speed of light, but how come lasers are faster than the speed of light? A quick google search shows that a laser set record by going 300 times faster than the speed of light! Also, what happens if you shine a regular consumer laser in...

Homework Statement A laser beam of diameter = 3.1mm in air has an incident angle = 26 degrees at a flat air-glass surface.If the index of refraction of the glass is n=1.5, determine the diameter of the beam after it enters the glass. Homework Equations n1sinθ1=n2sinθ2 The Attempt...

Hi, Not sure if this is the correct section to post my question, so if not apologies in advance. I'm wondering if there are lasers (need not be for consumer or general manufacturing purposes) that have the capacity to cut up to ten feet depth into dense materials like rock and perhaps some...

If a laser was shined at a device to measure the amount of photons striking it and then another laser was shined perpendicular to first laser, would the reading on the meter change?

Homework Statement A helium-neon (He-Ne) laser has a gain bandwidth (denoted here as the frequency interval over which the laser gain equals or exceeds the minimum threshold gain) given by ΔG= 1.0 GHz, centred on the λ = 632.8 nm emission wavelength. Show that in order to tune the...

Homework Statement A laser with monochromatic light of frequency 6.33 × 10^14 Hz is fired through a diffraction grating. If the first minimum in this diffraction pattern coincides with the position of the second order that was seen in the previous diffraction pattern, what is the width of...

Homework Statement Suppose that total population inversion could be achieved in a ruby laser. If half of the electrons in E2 could then drop to E1 in 30 ns, what would be the avg power of the resulting laser pulse over this time interval? Assume that the ruby crystal is a cylinder 5.00cm long...

I am doing a research paper in my Laser physics course, and I want to relate lasers to astrophysics. Does anyone have any initial ideas to build off of? I did some research, but the only thing I can come up with are green laser pointers and lasers to help align telescopes. While I find that...

Hi, i have question about lasers. What happens when I target same spot with 2 laser beams ? Let's saw two 1W laser. Will be final effect equal to one 2W laser ? Thanks

Hello folks of physics. Can anyone tell me about some exotic photon lifetime definitions for photons in laser cavity? I mean, I looked in all sorts of books related to that topic, and the entire bunch of authors use the same definition: cavity exiting energy through dissipated power; or...

Hi people :) I want to build an interferometer. In the course of looking for a suitable light source for my instrument I have been advised to check the 'coherence distance' of the sources; it is clear to me that this distance places practical limits on the design of the machine. However...

hey i am a total newbie and a beginner in science well i want to know if the following can be done:-:-p i have a number of laser diodes form dvd drives... is there a possible or a certain arrangement of prisms , lenses and mirrors that can be made in order to combine numerous less intense...

Hey all. I'm currently working on a project where I use a laser to transmit music playing from my iPod. The laser is hooked up to the iPod through a circuit, and there is a solar cell that the laser is pointed at. There are two wires coming from the solar cell that are connected to a stereo...

We all know about particles colliding and producing various other particles plus energy i.e. EM radiation, but is the reverse possible? Is it be possible for laser beams to 'collide' and produce matter? Has this been done experimentally or is there a theoretical reason that it cannot happen?

I've seen quite a few videos in youtube (like http://www.youtube.com/watch?v=woiTedSKPrk&feature=relmfu ) and I wonder why we can easily see the laser in the air, as if there was some diffusion of it in the air.

Hi, Is there a such mirror which can reflects a UV laser (~190nm wavelength) with Reflectance greater than 95% and also invisible laser (not necessarily in a high Reflectance)? Thanks

I am trying to learn about high-powered lasers. i am wondering what effects the actual power of the laser (the part that makes it burn). is it wave-length or frequency. Is gamma rays more destructive then visable light, ect. Any help would be greatly appreciated

could this work? some of the comments say stuff about power & voltage, etc which I don't know anything about. Cool idea but I still think there are better ways to power a car: http://www.physorg.com/news/2011-04-laser-revolution-internal-combustion.html

Yes, I realize this may not seem like a very smart question but allow me to give some background. I rent a room from a man in his 60s, let's call him Mr L. Mr L studied Pure Mathematics at university and was busy with his postgrad work when he suffered a schizophrenic breakdown. Because of...

Homework Statement See figure attached for problem statement as well as my attempt Homework Equations The Attempt at a Solution I don't know where to go from here. Can someone help me get started?

As I understand it, the Pauli exclusion principle states that no two like fermions can be in identical quantum states. I also understand that the quantum states are thus: n, which is the electron shell, l, which is the subshell, m_{l}, which is orbital, and m_{s}, which is spin. However, it...

The intensity (W/m^2) of an electromagnetic wave from an ordinary antenna decreases with the square of the distance from the emitter (in the far field.) Is the same true for a laser beam?

How to change the curvature of space-time around a very powerful laser beam?

Hi, I have this pretty cool 5mW green laser and I'm wondering if it is legal as long as I don't try to blind drivers and pilots.

Ive been wonder how big a laser would have to be to make plasma. So, how big? if its not possible is there a variation that would produce plasma? Thanks, Kalrag

Okay so here's the phenomena that I've wondered about for the past week. I have a 400mv green laser. Very powerful...shines pretty damn far (you might have seen some like it on youtube or the like). But here's the story: I have a neon poster in my room. The other night I got bored and...

WHat happpens when two Lasers meet,is their behavior same as when two Light beams meet that are emitted from a general Electric torch,i want to know what happens Thanks in advance

Hi all, I would like to ask a question regarding lasers and resonators: If I have a solid-state laser, and I know the following information: The gain medium diameter, it's length, population difference between the energy levels, gamma-alpha (r-a), broadening, wavelength, spontaneous...

I must say that after reading about this concept over the last few days it is one of the most fascinating things. Specificaly the concept of self amplification of spontaneous emission.(SASE) I am wondering is it possible to use a coventional synchronotron as an EFL? Apart from the undulator...

Consider the following: Two point-sources of lased light, one 600nm and the other 602nm. Each is collimated to form a beam 100 microns in diameter; thus, each forms a well-collimated laser beam. Aim each beam at each slit in a double-slit setup (each slit is 10 microns wide and 100 microns...

http://www.wickedlasers.com/lasers/Spyder_III_Pro_Arctic_Series-96-0.html The laser in this thing is an Indium Gallium Nitride multimode laser diode which is very cutting edge stuff - they have only entered the market this year, and are being used in high-brightness modern DLP projectors...

Homework Statement A spaceship (SH) moves with speed v=0.6c relative to a space station (SS) (sic!). Two lasers, A and B, on the SS are 5.00m apart as measured by the SS observers. The gamma factor for a speed v=0.6c is 1.25. The lasers are fired simultaneously acc. to the SS observers...