Laser Definition and 1000 Threads

Homework Statement A 35mW laser produces 526nm green light. What is the number of photons it emits each second? 1.9×1017 1.9×1018 1.0×1017 9.3×1016 Homework Equations The Attempt at a Solution I've been playing with E=hf and lambda = h/p ----- no success! The...

Is there any information on the physics of the airborne laser testbed available? Also, why is it 'airborne'? Is it referring to the laser? But aren't all lasers airborne? Thanks x

Can you please provide some explanation for the following two questions? Or please provide some links. Thank you. 1.) How does a laser heat up a material? Does the material absorb a photon and the material's atom gets excited? - when the atom relaxes, it emit an energy equal to that of the...

Can anyone recommend a good laser diode that won't cause damage to the eye with prolonged exposure?

Hello- On places like eBay and Amazon, one sees a lot of ultra-cheap, under $15 laser pointers in various colors. For example, my favorite green astronomy laser cost me twenty dollars from amazon last year. Contrast these prices with laser pointers from more respected brands, which seem to range...

Hello, A few questions which i could not find complete answers online (for a physics noob). I'll try and break them down here: // Comment: as for a good noob, i know nothing of the real calculation. // How do i calculate the amount of energy i will need to release as a LASER beam in order...

Hi, I wonder how to compare the power of a laser and an X-ray. For example 1mW power of a laser hitting an object is comparable to the an X-ray generating 1mW of power? Thank you.

Greetings, Is there a way to combine multiple lasers beams to create a more powerful beam? If so, what optics are needed? How do they need to be arranged? Thanks

Hi： I'm going to buy a DFB laser for my project, when I looked for Datasheet of such kind of laser, They give dimensions and equivalent schematic, and pin connections. For example: A 14 pin butterfly[NEC LASER DIODE NX8563LA Series], from the datasheet, pin 1 and 2 functions...

Hi: I confused about the follow things, why people say a laser has bias current and modulation current. why a laser has modulation current?

Hi guys, I'm interested to know what would happen if you get a red laser and combine its light with green or a blue laser. What i would like to do is modulate the higher freq laser with a lower frequency light source and get a different colour output. Firstly is this possible? and...

Hi there, This may sound like a silly question, but I'm looking at shining a high power laser onto a target material for a fixed period of time. I have modeled Alumina in Ansys Icepak, and the temperature increase has come to 4700 degrees C. This maximum temperature is only reached for...

ok, so I've seen the movie where they aline a HEnE laser with a photodiode to hear the modulations in the photon stream. i been trying to re-do it, and i just can't get it to work. I am NOT using a HeNe laser, I am using a normal laser from a pen, as i was sure the concept of the laseres...

Is it possible to widen the spectral FWHM of a laser beam. Any ideas? I understand the lasing process leads to the monochromaticity, but such a intense light source can have other uses. Thanks

Just curious after watching some lasers cutting 5mm thick steel sheets very fast, what is exactly cutting the steel? Is it just a laser beam? Light only? The machines run on bottles of gas, so if not, what exactly is the beam made of? thanks

I bought a red <5mW laser from thinkgeek.com, and it takes 2 AAA batteries. I took it apart though, took off the momentary pushbutton switch and soldered in a wire because i need to solder on a constant on/off switch at some point but I have noticed the laser is not acting how it was before...

How to make a DIY laser cutter(small size) ? Can you help me?

So the US Navy has shot down a drone with a Laser... 30 second video is here: http://www.cbsnews.com/8301-501465_162-20011041-501465.html Can anyone identify the major obstacles in such an effort. Seems like tracking/radar type software would be very similar to conventional...

Hi guys, I am of a Mechanical Engineering background, however my dissertation has a largely optics based focus, and I am struggling with understanding the heating effect of a Laser. I will be using various wavelength ND:Yag lasers, and will be focussing them onto a target material, which...

I have found a 5000 volt 20 milliamp laser at a Ham fest now logic tells me the power of the laser would be simply 5000V*0.02A= 10watt input then loses would maybe make it one watt. however I really doubt that it has that much power. I haven't been able to find a power supply capable either of...

Hi, can anyone explain how to tune the pulse width of excimer laser? Thanks Baris

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...

I'm working on tracing the beam path of a HeNe laser through two prisms, and I'm stuck on trying to find the incident plane in which to use Snell's law. Basically I have the equation of the angled surface of the prism, and I have the point where the beam intersects that plane. Now I need the...

Homework Statement A 655nm gaussian laser beam has a waist of 15mm located at a lens with focal length of 12 cm. What is the minimum beam waist and where is it located? Homework Equations Beam radius w = w0*sqrt(1-(z/zr)^2) w0 = min beam waist; z = distance, zr = Rayleigh range The...

When viewing the light coming from distant galaxies, it is my understanding that there are 2 redshifts occurring, the doppler effect from the galaxies' peculiar motions, and the cosmological redshift from space itself expanding. For the cosmological redshift, I visualize a square of space...

Hi, What is the equation for a E field of a single pulse of a laser? If that laser is shined onto say a grating spectroscope (square law detector), how can I go about deriving an expression for Intensity as a function of frequency at the output of the spectroscope? I know that the square...

my question is why oxygen lines does not appear in metal oxides spectrum taken at 532nm wavelength of Nd:YAG laser at atmospheric pressure. and what is the criteria for selecting emission lines for analysis?

I believe that the path of the photons will bend towards the center of mass, but I wonder what happens to the wavelength and the pulse shape while the photons are in the gravity well. The photons don't undergo any real acceleration, since they are in free fall, so their wavelengths should...

LASER Problems! HELP NEEDED! Homework Statement 1. The carbon dioxide laser usually emits at 10.6 um in the IR. Typically such a device puts out a continuous emission of from a few watts to several kilowatts. Determine the energy difference in eV between the two laser levels for this...

Hi all I am hoping that somebody here will be able to tell me why that different types of lasers eg He-Ne or Nd:YAG have different coherence lengths and how the coherence of a laser can be improved. I am thinking it is to do with the different gain mediums and the emission process...

Hey Guys, first of all I apologise if this question is posted in the wrong forum section and a mod has to move it to its correct location. I am trying to find information on combining the paths of several laser beams. I have found much complex information pertaining to the combination of the...

1.Calculate the average E-Field and B-field produced by a laser with power 10W and radius 1mm 2.Not sure where to start with this one. Use equations of Flux perhaps? 3. So given the modest amount of infomation and the fact the question represents 1 mark, i assume the calculation is straight...

Hi all Im doing work on laser interferometry for my final project,just wondering if there are any experts or experienced people in this field here,thanks much!

Homework Statement A Ti-sapphire femtosecond laser (1fs= 10^-15s, λ≈0.8μm) has an intensity of 1022 W/cm2 when focused to a spot of 1μm radius. What is the energy of the laser pulse? What is the peak magnetic induction B in Tesla and the electric field in V/m? What is the wave pressure in...

Hi all, can someone kindly advice on how to model a femtosecond laser beam profile when it is focus on/into a transparent material. Regards Jim

Homework Statement How can you know "the difference between the two lasing energy levels?" Homework Equations n(lambda) = 2(pi)r E = hf mvr = n(h-bar) The Attempt at a Solution no clue

1. A monochromatic laser is exciting hydrogen atoms from the n = 2 state to the n = 5 state. What is the wavelength of the laser? 2. frequency = f = delta E / h lambda = c/f 3. First, is the following approach valid: I find delta E by computing E5 - E2, where En = n2h2/8mL2...

1. The maximum electric field strength in air is 3.0 MV/m. Stronger electric fields ionize the air and create a spark. What is the maximum power that can be delivered by a 1.3 cm diameter laser beam propagating through air? 2. I = P/A = c*epsilon0*E2/2 3. Using E = 3*106 for E, I...

hi, pls can someone help me with converting FWHM bandwidth of a laser from metres to hertz

I've never understood how diffraction is possible, which has led me to mistrust a good deal of quantum physics. I'm mystified as to how light starts spreading out in all directions after passing through an aperture. Supposedly it's because light spreads out like a wave, but then how is it...

I'm making a laser torch based audio transmitter n receiver using 2n5777 phototransistor as receiver what must be the min power of the torch

Why did they land on the other side of the Moon? And how did they place the Laser reflector (http://en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiment) on the front side of the Moon?

I feel like a moron for not knowing the answer to this. I'm looking for a laser that can deliver a single 3mJ, 10nS pulse. Most of the laser specs I've found report the laser power in watts rather than the energy in mJ. So I did the following calculation: 3mJ/10nS=3x105J/S=300kW But...

Hey everybody, this is not exactly a homework question, but I am writing a term paper on the topic of laser trapping and cooling, and would appreciate any good sources that anyone could provide. This is an undergraduate thermal physics class, and does not need to be extremely technical...

Homework Statement A laser beam enters a 10.0cm thick glass window at an angle of 30 degrees from the normal. The index of refraction of the glass is 1.46. At what angle from the normal does the beam travel through the glass? Homework Equations sin theta 1 / sin theta 2 = n1 / n2 = v1 /...

Is it be possible to produce from the Intensity return of reflective IR laser the true color of the object causing the reflection of the laser? My though is that surfaces of the same material, but of different colors would cause slight changes in wave length of the laser light. These changes...

Can anyone tell how the intensity of lasers beams is measured. What equipment is used. Any relevant equations?

Hi, I am a physics undergrad and this term I have to write a 3000 word essay on one of about 10 possible topics. One topic which caught my eye was laser fusion. Whichever topic I choose, I will need to find information from a variety of proper sources (not just trawling google). This is what I...

Wow. Here's a video of the laser system. They need to get these manufactured and shipped out. And they're going to make a killing when they go mainstream! https://www.youtube.com/watch?v=eYXPqrXZ1eU Here's an article page on it...

Does a laser have a recoil since photons have momentum. Would a moving laser be slowed down (even a fraction) if was locked in the on position and then thrown at the ground