Laser Definition and 1000 Threads

My friend once said that we can make a laser which can produce fire by taking out a normal laser from a damaged DVD player and "cutting some wire on the laser" ...is that true..? Is it possible to make a real laser that can scorch the things like the ones shown in movies..?

I feel kinda silly asking this question. If you were traveling near the speed of light towards another ship and you shone one of those simple red lasers towards that ship would that ship blow up?

What does saturation mean in laser physics? I am reading some material on two-level system, in which it mentions something call "saturating pump field", what does this field mean?

I am NOT referring to laser cooling, the technique for supercooling atoms. The 1980 science fiction novel Sundiver by David Brin describes a kind of spaceship that could fly into the sun. One way described to keep the inside of the ship cool was to concentrate the heat inside the ship...

In this project, by means of two mirrors (which can be tilted about two perpendicular axis) we deflect the laser beam so as to scan a rectangular screen and modulate the laser source to obtain a colored image on the screen. We don’t make use of sophisticated devices such as MEMS micromirror and...

Homework Statement The active element of a certain laser is an ordinary glass rod 18.7 cm long and 1.33 cm in diameter. If the temperature of the rod increases by 78.5oC, calculate its increase in length. Calculate its increase in diameter. Calculate its increase in volume. Homework...

Homework Statement A laser 632.8nm is sent through a single slit of widith 0.30 mm. Wats the width of the central maximum on a screen 1.0m in the back of the slit? Homework Equations asin(theta) = m lamda The Attempt at a Solution lamda: 632.8nm 0.30 mm= 3.0 x 10^-4 m...

what do we mean by ... 1. non molecular recombination 2. bi-molecular recombination and 3. auger recombination of laser... please reply if u have the ans. thank u

1. What do we mean by the carrier number at transparency. I mean, what is carrier transparency of a laser? 2. in an IEEE paper ("Circuit Modeling of Quantum-Well Lasers for Optoelectronic Integrated Circuits (ICs) Including Physical Effect of Deep-Level Traps" IEEE J. Quantum electronics...

There's a lot of advertising out here for laser treatments for all types of skin problems (acne, discoloration, wrinkles, etc). Here's one of the places that does these treatments: http://www.laserhq.com/1/index.html Do you think laser treatments work? How do lasers fix so many different...

I want to use a pulse current instead of continuous current in the Laser rate equation as input. What would be the equation for the Gaussian expression when I'll swap the continuous current with pulsed current in my equation and implement it in Matlab? please let me know the ans if u have any

Hi all, I've just got hold of a used helium neon 1 mW laser (spectra physics model 155) and would like to some experiments at home, does anyone know any good examples Thx

A pulse 300ns long is made using a continuous wave laser and a very(very) fast shutter. What is (approx.) the minimum spectral width of the pulse? I have no idea where to start. For starters what is the spectral width? and how would i go about solving this problem. Not looking for a...

Homework Statement A laser beam passes through a converging lens with a focal length of 19cm. At what distance past the lens has the laser beam's intensity increased by a factor of 6? Homework Equations I=\frac{c\epsilon_0 E_0^2}{2} ?? The Attempt at a Solution To be honest, I'm...

I wish to know more about the latest laser cooling techniques. I have heard about the use of radio waves to cool the laser. Can anyone throw more light upon it? Is there any latest technique in use these days to cool Nd:YAG laser ?

Is it in any way possible to build a 10 watt (battery powered) handheld laser?

Hi all, I am trying to find out what is the world's most powerful continuous laser? I would also like to know: - what wavelength range does it operate at and is there a trade-off between bandwidth and max power? - is there a graph anywhere showing laser power as a function of date...

Hello everybody I have a question about light (a laser) and speed. Let's assume a object (space probe) traveling in a constant motion that haze a vacuum inside itself. Now there are 4 lasers groped in pairs of 2 in south a way that both lasers in a group are connected with both their ends...

When did being an evil doctor become illegal? I just got a reply from Dealextreme that told me my green 150mw laser order was canceled because they can't ship anything more powerful then 5 mw to the united states?

hello... Can anyone tell me how can I simulate the laser rate equation with matlab? i allready wrote a code whics is as follows, %have to write one editor function dy=rate_equation(t,y) dy = zeros(2,1); I =50e-3; %for t=1:10; q =1.602e-19; v =9e-11; eps =3.4e-17; N0 =1.8e-18...

A helium-neon laser beam has a wavelength in air of 633nm. It takes 1.38 ns for the light to travel through 30cm of an unknown liquid. What is the wavelength of the laser beam in the liquid?

How do lasers work? Are there comercially bought materials to make a laser? What is the minimum wattage for a steel cutting laser? And does anyone know some cool experiments to do with lasers? Thanks in advance.

Homework Statement A typical “laser pen” pointer has a power output of 3mW at 670nm. If the angular divergence of the beam is 2mrad, estimate the maximum distance at which it could be seen by a day-adapted human eye. You can assume that in bright light, a normal eye will give a signal from...

Dear all, I have some problems with a program called the simulation of laser interaction with materials. In this program, they asked for some parameters which I am unsure of but I believe it has something to do with mesh size for simulating the thermal conduction. This is a 1D heat conduction...

If two lasers are pointed emitting end to emitting end in a vacuum (for lowest divergence), and emit 2 beams of light 180 out of phase, could both beams destructively interfere completely (no light coming from either emitting end after the beams converge)? If the experiment was done under...

Nice to meet all of you :smile: We know that laser is amplified light. There's possible if amplify the radioactive ray (alpha, beta, or gamma) with the same procedure like the laser mechanism? :confused:

Question, If in a vacuum, I have a laser pointing into a mirrior which bounces between two mirriors on the same spot, do the photons / laser energy continuously build up? If not whare does it go?

I'm looking for a textbook on laser physics. I'm considering either Lasers by Siegman or same title by Eberly & Milonni. I want a textbook more directed to a physicist and not the more engineering style, which may lack rigour (from the physics point of view). I'm not very comfortable with books...

Hi all, I understand laser to be monochromatic (i.e. single frequency) and coherent (i.e. all the waves are in phase with each other.) My question is : is laser a form of polarized light too? In other words, can the electric field be in almost all possible plane directions, or is it just...

What equations would I need for calculating this, say if I wanted to know what the power/intensity of an x watt, x wavelength laser would be reduced to after x metres?

I'm about to do some study on bifurcations and oscillations in lasers with saturable absorbers. however, my knowledge on lasers is fairly basic, so I'm not sure where to begin or find more information. If anyone could give me some advice, it would be very helpful :). What type of lasers...

pulsed laser diodes... i need to study pulsed laser diodes so can anyone give me some references for pulsed laser diodes...

Greetings, I am an electronic engineer doing some research on high power laser diodes. The problem I try to solve needs ~2300W of optical peak power coming from a high power laser diode. The pulses must be with very long (30ms) at very low repetition rates (2Hz). So,the duty cycle is...

Detailed ideas on how different wavelengths and pulse durations can limit scans

A laser cavity consists of a couple mirrors, a bunch of metastable molecules and some radiation. What's the partition of energy between molecules and radiation at equilibrium?

Homework Statement A laser of power P with wavelength \lambda is directed through a lens (focal length f) off the optical axis by a distance d. What is the sideways force on the lens? Homework Equations Not sure. The average radiation pressure is I/c, where I is the intensity. But this...

hello forum. a question about light and uncertainty: If a laser beam has a 2 cm diameter when it passes through an aperture that is 6 cm wide, the beam is not affected by the aperture. Why? What happens to the uncertainty principle there? Isn't the probability wavefunction affected by...

I am struggling with the following question: My attempt so far is: (in the diagram h is supposed to be A) (i have also assumed the pulse time is negligible, so the mass starts at the resultant velocity) The set of homework questions this has come from is supposed to be related to...

Homework Statement Light in the near-infrared (close to visible red) can penetrate surprisingly far through human tissue, a fact that is being used to "illuminate" the interior of the brain in a noninvasve technique known as near-infrared spectroscopy (NIRS). In this procedure an optical...

Is it possible to detonate or to ignite a fuel and air mixture using lasers, or a laser pulse, any type of laser, CO2 or other wise ? or is there any possible way of using Lasers for the propulsion of an aircraft, i am already aware of several methods, but they do not include ignite fuel, any...

How does the laser cooling work? I have read that it is used to cool ions in vacuum, by absorbing their kinetic energy with a laser beam; but I don't understand why the laser cool the ions and not raise their energy by moment transfer

I'm a physics students and I'm in my Final Year now. The title of my final year project is phase-locked laser system. I have quite some fun playing around with the mirrors, lens and laser stuff. I'm interested in doing my phd in photonics related area. I'm not sure whether I should go for...

So here's a crazy question...I was trying to think it through and have come up with nothing. Is it possible to bend a laser beam's cross section? For instance, if you are using a diode bar (which has a beam cross section resembling a line) is there a simple way to bend it into a...

I came up with this idea purely because I had some free time over the weekend. Basically, I want to transmit audio signals (i.e. from a standard 1/8" audio jack) by laser (in essence, streaming it by laser to a speaker setup somewhere else). Most of my interest are not on the circuitry side of...

Hi, I've decided to make my own meter for measuring laser power to around 10% accuracy if possible. Optical power meters are way too expensive for me though. One building block I've decided to use is a phototransistor, because I've found one which has very good linear response - when measuring...

I have a rack mount quad lab laser it has 4 series wired SMA905 connectorized diodes.I am wanting to use two of the to pump a Spectra Physic Millenia 1st generation 1064nm laser cavity which has 2 FC female connectorized collimation lenses. They pump a 4x4x7mm water cooled YVO4 crystal from two...

Hiya, Question 1: (Main question) I bought a lux meter while understanding very little about how light is measured. I'm hoping to measure the output of a laser in mW. I assume it's possible to do this at least to an accuracy of about 10-20% which is all I need? If so, please could someone help...

Hi all, I would like to ask a question. Some people tell me that the red light emitted from the ball pen (I don't know the exact word in English, I mean the pen that lecturer uses to focus light on the slides when conducting presentation, in Power point eg) is the laser light. Is it true...

The Earth moon distance = 3.8 * 10^8 meters Time for light to reach moon = 1.266 sec. A laser at the origin on Earth pointed at moon rotates .001 radian with angular speed w = 10 radians/sec. The arc length distance described on moon ,s= (radians) (radius) =3.8*10^5 meters The velocity of...

I would like to understand , how a beam laser changes its trajectory near of a supermassive body? Is there any relation with Einstein's equivalence equation between mass and energy?