Laser Definition and 1000 Threads

For my experiment I need to take a 0.8 mm HeNe beam to 20 mm beam. Since we just want illumination, it appears there is not need for beam expander or a setup of special lens (there are a few configurations online). It was suggest to use a Plano-convex cylindrical lens. I talked to...

In many paper or book on laser, it is quite oftern to mention the pump and probe field. I understand what the pump field is, but what about the probe field? What we need a probe field? How does it work (how to "probe")? And why a probe field is always a weak field?

Hi, I am writing a program in MATLAB for robot localization based on scan matching and have the following problem: I have recorded 1228 laser scans at different positions and extracted extreme points from these scans. So that gives me 1228 sets of extreme points (every set might have...

Homework Statement I have a few questions because of the fact I just don't understand any of this... 1.A helium-neon laser (l=656 nm) illuminates a single slit and is observed on a screen 1.9 m behind the slit. The distance between the first and second minima in the diffraction pattern is...

Recently, i obtained a 100mW green laser pointer, and the thing gets me confused. On one side, the beam is bright enough to see from some distance at 90* angle to it, and the point is visible on a hillside some miles away. On the other hand, it doesn't burn anything, like advertisements often...

I ran across this site from 2001: http://www.afineline.org/projects/paint.html Apparently it didn't work very well. Anybody care to guess what kind of equipment it would take to make a red splotch appear on the moon to the naked eye from earth?

I would appreciate assistance with a thought experiment I've been having trouble with. What I asked myself was, If I had two Lasers of equal Intensity/power, say 200 milliwatts, one appearing green and the other red, with wavelenghts of say 555 nanometres and the other 660 nm, which laser...

ok, second question today: if we shine a laser (ideal laser; no spreading out whatsoever of the ray) in Earth's atmosphere, at some distance the intensity of the laser will die out due to it hitting air particles. what if we shine it in a vacuum? e.g outer space My guess is that it will...

Hi all, can a laser light be magnified by means of a magnifying glass?

Hey everyone, I am not knowledgeable in the field of physics, so please excuse me if my question is obvious or poorly worded. I have found myself reading recently about various Nuclear Fusion research, and just now I came across an overview of fusion contained by lasers, specifically at the...

Homework Statement wavelength 1.08um pulse duration 20ns pulsed energy 700mJ pulse rate 15Hz => Total number of pulses ~1800 per run Came across in a paper published. Was thinking a way to calculate the numbers of pulses ? Homework Equations laser beam comes in pulses with pulse...

Homework Statement A 200 mW horizontally polarized laser beam passes through a polarizing filter whose axis is 25 degrees from vertical. What is the power of the laser beam as it emerges from the filter? P=mW Homework Equations E (transmitted) = E (incident)cos() The Attempt at a...

Homework Statement In our Lab we have a Nd:YAG pulsed laser of 420mj ,10 ns pulse width...focused to 1 mm spot Homework Equations what's the power density? how it calculate? The Attempt at a Solution

Hey guys, I'm not exactly sure on which forum I should be posting this topic but I decided to post it here. Any mod can move it if deemed necessary. Anyway, I have been wondering about the infrared wavelengths that a remote control emits when trying to control, say, a TV or VCR/DVD player...

If you shine a beam of light at a black hole, most of it will either fall into the black hole, or will just graze past it, hardly being bent at all. But any photon that just happens to have L/E (angular momentum per energy) = M√27 will orbit forever (or until it hits infalling matter), with...

Not really a problem but a concept I am having trouble understanding and I was hoping someone can explain to me better. We performed an experiment in lab last week on finding the Young's modulus of copper by projecting a laser on the wall to magnify the effect of the change in length of the...

I'm a science fiction writer, currently I write a novel related to laser fusion. As I know in chemistry, catalysis is the process in which the rate of a chemical reaction is either increased or decreased by means of a chemical substance known as a catalyst. Are there catalysts in the nuclear...

In Quantum mechanics lectures we are learning that several factors influence the wavelength produced from a laser. These factors include doppler broadening of moving atoms in the laser, the uncertainty of the transition energy levels themselves due to the uncertainty principle, etc. Previously...

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

If I stick a 10936B (16bit binary servo card) into a HP 5507 card rack box with HPIB, will I then be able to gather position data (wave count) by means of HPBASIC over the HPIB bus? I am trying to update an old system which has a box based on 10740A coupler (rack/backplane), with 10745-60002...

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?

Hi I have a power meter that measures a Nd:YAG laser intensity with 20 pulses per second as 200 mW. The pulsewidth is 5 ns and I have information relating to the diameter and wavelength of the beam as 3mm and 216 nm, respectively. I also have an expression the intensity or power of the beam...

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.

hello im currently trying to learn about ultrashort laser pulses. particularly in the areas of group velocity dispersion etc etc. now I am pretty happy with the basics. modelocking a laser to give a dirac comb of finite pulse trains etc. I am happy with the mathematical description of an...

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 space grid for simulating the thermal conduction. This is a 1D heat...

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...