Laser Definition and 1000 Threads

Hello all, I am trying to model a received laser signal, x(t), reflected off a moving target. I am currently trying to model for both frequency change due to Doppler shifting as well as a time-varying phase shift, θ(t), due to the continuous change in distance from the target. My current...

Hello, As stated in the title, I've just completed a first year in physics and am interested in working in the field of laser science. Bear with me, as my questions may sound naive. Ideally, I would like to hear from those currently in the field, but any advice is welcome. 1.) Did you begin...

Hello all, I am trying to model a received laser signal, x(t), reflected off a moving target. I am currently trying to model for both frequency change due to Doppler shifting as well as a time-varying phase shift, θ(t), due to the continuous change in distance from the target. My current...

What is the best way to calculate the coherence length of a laser?

Hello, I need to figure out how to mathematically model via simulations a solar pump in space, or another type of laser that receives input from solar irradiation from the Sun. Amplifies it to the specified frequency i.e. 1064μm, and then transmits it to Earth. The problem is I'm just...

Fresnel biprism sorry if this is the wrong place. Does anyone know a supplier for a Fresnel biprism with apex angle approx 168° should be reasonably small (approx 2cm x 2cm). Looked everywhere but no joy.

I have a question that I haven't found any information elsewhere on how to approach. Just because yahoo answers seemed particularly keen to sniff out homework and mock those asking questions by it, just to clarify this is for my own knowledge not for any project for school or anything. Anyway, I...

Is the laser perfect monochromatic light source?

Homework Statement A transparent cube with index of refraction n = 1.6 and side length a = 4.0 cm is free to rotate about an axis passing through its center. A laser beam is aimed at the cube. After passing through the cube the beam hits a screen on the other side forming a spot. The spot is...

Hi, I was wondering what the diffraction pattern would be like if the suns light is diffracted through a pin hole or double slit diffraction grating compared to that of a laser beam? thanks.

hi, this is more of a biomedical engineering question but since it involves heat transfer i thought i would run it by the mechanicals... theres a cancer treatment called laser ablation and the dosage requirements are based on an understanding of how laser-light induced heat at a point source...

Hi. I am interested in medical physics, but I also like to become a laser scientist. If I have a masters in medical physics can I go straight to laser physics Phd, if not what better option can I take after having master in medical physics.

Hi I'm a first year undergrad student studying Electronics. I am really interested in creating a working Laser Induced Breakdown Spectroscopy(LIBS) setup in my summer break which is June and July. I'm reading about it these days, although still scratching the surface. I'm confused whether I'll...

Homework Statement a narrow beam of laser light (i.e coherent monochromatic light) wavelength 630nm is incident on a grating having 300 lines per mm. a piece of paper is curved 180 degrees beyond the grating. calculate how many spots of red light should be seenHomework Equations...

Homework Statement A collimated laser beam of power P = 106 Watt illuminates a 100%-reflecting micromirror at an angle of incidence of θ=30 for duration of = 0.015 seconds. Prior to laser illumination, the mirror is at rest. What is the mass of the mirror m if it acquires velocity of 1...

Hi forums I really want to do some experiments with lasers and i was wondering if for the double slit experiment a 100mw green laser is so powerful and bright. also there is a 30mw laser, would that be better. another thing is that i wanted to make a laser "microscope" but i was worried that a...

Would you pay for this?

Lets say its the future your camera has an insanely fast shutter speed. You're standing on the ground watching a train travel past at just under the speed of light and the train driver is shining a laser pointer out the front window. With your insanely fast reflexes you take a take a picture of...

Homework Statement Extending the Taylor approximation to higher-order terms in high-loss materials. Consider a lossy medium having a finite conductivity a but, for purposes of this problem, no laser susceptibility Xt. First-order expressions for the propagation coefficient ft and the...

Hey everyone, hope this is the right place to ask this question so I'll just put it out here. I've been measuring the pulse duration of a mode locked Ti:Sa laser with an autocorrelator. For a central wavelength of λ_0 = 800 nm and the spectral bandwidth of the Ti:Sa Laser (FWHM) Δλ = 8 nm, the...

Hello there! I was brainstorming a lot when I took a walk today. Not that I posses any type of degree in communication, although I find it interesting of IT communication and they techniques we use for cellar communication. NOW to what I thought about. Let's have an example: If I were to...

Homework Statement I am doing a lab and need to understand how laser light from a HeNe laser goes into a Si photodiode connected to a lock in amplifier, which I believe is simply a device for measuring potential, works. Homework Equations The Attempt at a Solution This lab was...

A simple model of a laser (URGENT!) Homework Statement Need to turn this in 2 hrs from now. Yes, I'm a slacker. (a) Suppose that N evolves much more quickly than n so that we can make the quasi-static approximation N ≈ 0. Given this approximation, re-write our equations as a 1-D dynamical...

Even with the feature that automatically shuts the laser off as a player approaches the line, I'd still worry about blinding someone. http://msn.foxsports.com/nfl/story/first-down-line-laser-could-be-coming-to-stadiums-012213

Recently in the news NASA has transmitted an image of the Mona Lisa via a laser beam and i was wondering about some of the theory behind how they did it and maybe trying to recreate something similar on a (much) smaller scale. I've seen some articles online that show a method for transmitting...

I have pulse frequency as 2.5kHz. How to calculate laser pulse duration at FWHM (full width half maximum)

Hi Guys, I've felt the need to post a few times in 3 yrs, and this is one of them :) I tried to go back and thank contributors of another thread, but it was locked (likely because it was resolved, or 3 years old!). I'm writing for a camera equipped computer, tracking a red laser beam...

I use a green laser pointer at night to do astronomy related work. I got a cheap $5 green laser pointer off of ebay, and when it's a warm summer night, the device works fine. However, the second it touches the cold, it fizzles out and gives me almost zero output. My idea was to use a...

I understand that stimulated emissions produce coherent photons. What happens as a result of their coherence? My guess is that the laser beam does not spread out as much allowing it to travel further. Also, what is the property of a laser that allows the beam to travel great distances?

Hi all, I have been looking at quartz and trying to work out the physics at a atomic level, how it reacts with photons/laser is of particular interest. I will leave this open as any knowledge you have is welcome, there is the obvious it converts electrical to mechanical and vice versa but...

Scientists can produce laser pulses of order one wavelength in "length" see, http://www.bbc.co.uk/news/science-environment-19489384 Do Maxwell's equations admit solutions of such short pulses? Can one approximate such a solution by multiplying a plane electromagnetic wave by the...

hello, I'm interested in make an fibre laser to engrave in aluminum, however in all foruns where i ask this question everyone sugest me to buy an professional machine. but I'm interested in learn more about this tecnology so i would like to make my own fibre laser. of course some componets i...

Hello, I wish to switch ON and OFF a high-voltage (that generates a high electric field) using a ultra-fast laser as a trigger. Basically I have a flow of charged particles that I want to quickly deflect using an E-field. The timing must be correct and controlled by a LASER. Does anyone...

So the laser test with the slits is as followed as far as I understand. When observed, electrons act as particles. When not observed, electrons act as waves. How can electrons know if your eyes are open or closed? Unless your eyes give off some wort of radiation that it can pick up on...

hi , does input light signal for laser amplification has to be provided by the external source or it is created by lasing material itself?

1. LiNbO3 is a negative uniaxial crystal. Consider a LiNbO3 crystal used for frequency doubling a laser operating at 1064 nm. The non-linear coefficient is d=3.4x10-23. For the setup considered it is desirable to have a non-linear conversion efficiency of 0.04 %/W, Assume constant fundamental...

Hey all! I am gearing up for next year to do a senior project, I want to knock it out in my spare time for the next 10 months. Ideas are: 1) Laser guided missile- 2 phase motor, one to go up then again to go to 'lazed' target. 2) Wifi barrier- setup focused jammers to create a 'wall'...

Hello Everybody, I'm trying to plot the frequency spectrum of RIN using Matlab. I've the following code function p=rateblock tau_s = 3e-9; N0 = 1e24; A =1e-12; P0 = 1/(A*tau_s); TSPAN = 0:1e-2:10.23;; Y0 =[0 0]; [T,Y] = ODE45(@rate_equation,TSPAN,Y0); subplot(2,1,1)...

Hi, having a bit of trouble with this question "In an argon ion laser ( λ = 514nm) the minimum beam waist is 1.0mm and is close to the plane mirror. Calculate the radius of curvature of the beam at the output mirror. 1.15m away" Attempt at a solution: θ = 2λ/pi W02 R = Z + ZR2/Z ZR =...

I have a couple of questions regarding laser cooling. I should preface this by saying that I've taken a course in Modern Physics, so I don't have more than a very basic understanding of QM. In this case, I am familiar with absorption/emission lines, Zeeman effect, degeneracy and quantum numbers...

I have a couple of questions regarding laser cooling. I should preface this by saying that I've taken a course in Modern Physics, so I don't have more than a very basic understanding of QM. In this case, I am familiar with absorption/emission lines, Zeeman effect, degeneracy and quantum...

Homework Statement In the units of watts (J/s) calculate the overall power of the laser light generated by Nd/YAG laser operating with a 10 Hz repetition rate in the third harmonic (355nm) at 150mJ per pulse Homework Equations I can't figure out how to do this problem see attempt below...

There are materials which block laser beams (or light globally) or weaken its intensity via shading i.e. a beam must have crossed a specific energy barrier in order to pass this shading where beams with less energy will fade and won't pass. The question is, is there a material or a type of...

So, it seems this is the most appropiate forum section for this question... Can anyone give a simple explanation of the parts that make a laser designating system and how a typical unit works. Also, once a coordinate is established, how does this information get communicated to other...

Hello there. I am wondering if anyone can shed some light on this topic. I am searching all over the Internet to find reliable sources on the possibility of gamma ray lasers. I know that it requires an atom that can be "pumped" without spontaneously emitting its energy so it can be triggered by...

Homework Statement A laser produces an average power of 7.0 W in a light beam 1.0 mm in diameter. Find (a) the average intensity and (b) the peak electric field of the laser light Homework Equations Intensity = P/ A Unsure about part B The Attempt at a Solution For part...

Do photons used to produce the Sagnac effect (interference) have to have their phase in a coherent state or will a collection of random photons have the same property. Along the same lines, if you purchase a simple laser pointer are the photon produced here in a coherent state? Finally, is...

Homework Statement Calculate the Q value for a krypton laser with λ=0.569 microns, 0.568m cavity and mirror reflectance of 100% for the rear and 52% for the output window. Homework Equations For a laser cavity=> Q=(4πL)/(λ(1-R1*R2)) The Attempt at a Solution Q= (4*π*...

Homework Statement Two astronauts are at rest in outer space, one 15.3 m from the Space Shuttle and the other 30.6 m from the Shuttle. Using a 123.0-W laser, the astronaut located 30.6 m away from the Shuttle decides to propel the other astronaut toward the Space Shuttle. He focuses the laser...

I'm looking for a laser safety glasses. The biggest laser I'm going to use is a <20 mW green (532±10 nm) laser, with no infrared leakage (though I checked it with only a phone camera in night-vision mode), so I will need something good enough for this. I also have other green and red lasers, but...