Laser Definition and 1000 Threads

Hi I am confused about the concept of Power Spectral Density (PSD) of a laser. Say I hook up my laser error signal to a PSD: Is it correct to say that the PSD basically gives me the Fourier transform of the signal? Niles.

Hi all, Does anyone know of any references on how much a laser would spread out in space? I'm not sure if this is the right place for this, but I know there are various experiments planned in the future for space that rely on lasers going back and forth between satellites. Just looking for...

So my brother had a birthday party the other day where this company that rents laser tag guns comes over and all his friends played a big game of laser tag outside. the guns worked surprisingly well, and there was even a "grenade" that would shoot lasers out in all directions once a pin was...

I was watching a show on the science channel called "Alien Encounters". Well in one of them they showed a ship that looked as if it was propelling itself by firing a laser at it's solar sail. Now I am pretty sure that from what I understand about physics, that would not be possible. Correct if...

I'm working with a setup involving a collimated laser (Thorlabs model CPS180), two polarizers, a beam splitter, and 2 photo-diodes. While measuring the intensity of the laser via LabView, without changing any of the components, I find the intensity varies by 0.2mV for the first hour of...

from online descriptions of laser mouse operating principle it's unclear to me that the mouse would need to be particularly big. Is the size of the mouse really based on ergonomics considerations and it could in practice be fit into much smaller case if we wanted to? Is the mouse actually mostly...

Hi to you all, I have a quick question about laser pulse energy. For Q-switching solid state laser source, can you change the energy of a laser pulse without changing the wavelength? If so, how? Thanks so much...

Hi, I'm doing a experiment/report on this topic, I'm trying to get a better understanding of the equation "nλ = dsinθ" ALL length measurements are in meters for simplicity's sake. n = bright spot number from the central bright spot (n0) d = distance between slits The angle "θ" and distance...

Would a nuetrino laser cause any damage if aimed at a target and the nuetrinos had sufficiently high, ultra-relavisitic energy? Obviously, photons, and relativistic collimated beams of protons, electrons, etc. would do damage, but all such "lasers" interact with electromagnetism. They destroy a...

Dear, I am reading a paper on Bose Einstein condensate and an atom laser. I have two questions which are bothering me for a time. - When you are going to make do all the atoms start with the same the Broglie wavelenghts or do they start with different wavelenghts due to different...

Homework Statement I've conducted two laser experiments. One with single slit, and one with a double slit. I've produced two graphs which look something like these...

Hi, I am creating a laser microphone in labs at the moment, and was wondering if anyone could help explain how/ why it works. We are shining a laser a a reflective surface and using a photo-diode and some basic op amp electronics to detect the reflected beam and produce a voltage output...

I've been mulling over whether or not to undergo laser surgery to correct my vision. Myopia set in when I was 12 and has gradually become worse (~ -3.75, 4 now). Being rather active, I find glasses to be a big pain because they get in the way often, sometimes even leading to injury. I was...

I have a keychain-type red laser pointer (5mW typical type) and I was using it for something when all of the sudden it is really dim. Even if I bump up the voltage it is still dim and I'm suspecting it is fried. I overvolted it for about 2 sec with a weak 5v source off an arduino but it worked...

Ultrafast laser spectroscopy, as I know, is used for the determination of femtosecond events in condensed phases. My question is, what applications do these discoveries have, or are they just for "research"?

Hello Forum, I understand the difference between LEDs and lasers: both operate at optical frequencies, but the LEd has a larger beam divergence and a higher spectral content, less temporal coherence... Assuming we are able create the same beam divergence for a laser as for a LED (using...

Does anybody have any tips for doing this well? Frankly, I'm pretty terrible at it. I mean, once I get a small amount going through, I can do a little bit of optimisation by adjusting the angle of the fibre in one direction, and then adjusting the angle of the incident beam along the same plane...

What would happen if I bought highly sensitive photographic film such as ASA 800 and shined a laser pointer on it? When I get it developed will the photons that the laser emitted show up on the film?

I know that lasers will always have divergence due to diffraction. With that said, they don't diverge until after the point of focus, correct? Is there a limit to how far a laser can be focused?

I am using a laser diode to count aerosol particles flowing through a gas stream. The refracted light is being funneled to a photo-multiplier via fiber optics. When there is no gas flowing (and therefore no particles) we are seeing some strange results from the output signal of the...

Hello, iam new to polariton lasing and have to hold a speech about it. So I've got some questions and it would be great if someone could answer them. In a polariton laser, lower polaritons form a quasi bose einstein condensat at k=0. [My most important question:] I don't get it when the...

hye ~ i want to ask some help from u guys about the rate equation MATLAB coding for linear or ring cavity laser..i have problem to find the coding by my self..do anyone of u know the full coding to be share here??

I'm looking for a good laser for optic experiments. All the professional papers I've read show the use of a 351nm Argon Ion laser. A new 30 mW one of these is about $6,000, but I see used ones pop up on Ebay from time to to time. My question is, is there a difference between this laser used...

What is the difference between a laser and a one-atom photon amplifier? Can we just say that a laser is many one-atom photon amplifiers put together? Is there any difference in the resulting photon statistics?

Background I am currently doing a project that requires me to construct a probe which dentists use to transmit laser light to a patient's teeth to determine if the teeth is vital or not. Wanna know if it is feasible for me to extract the laser from an optical mouse and use it to construct...

I have laser drilled hole thin ceramic specimens and I am required to measure the diameter of the holes. Suggest me some methods.

For a pin photodiode, risetime=bandwidth/0.35 i get ~3ns for s5973 will it be affecting the measurement of 10ns laser pulse? How can i reduce the rise time?

Hey guys, I've been wondering what would happen if you had two lasers pointed at the same spot emitting pulses of visible light such that the pulses would meet the spot at the same time(lets assume the spot is in midair, no screen). the lasers could either be directly opposite each other or they...

Does anyone know if it is possible to design an excimer laser that produces a continuous beam well into the UV frequency range (enough to througly ionize the air in the path of the beam). I have been reading up on excimer lasers and it sound like they operate in pulses, which may be ok for the...

Hi people, please excuse me if this is the wrong forum to ask, I am new. I want to build a cheap DIY trip wire that records how many times it is set off. If I could use some sort of laser to be more discrete that would be a bonus (and just cooler). Also if it is possible to record the time that...

I'm trying to compare some figures of power for continuous wave vs. pulsed lasers. I have a known application which uses pulsed nitrogen lasers (λ = 337.1nm, http://www.newport.com/images/webdocuments-en/images/12224.pdf) to produce fluences of ~20-200Jm^-2 and pulse widths on the order of...

Hello all First off, I'm afraid I do not have much in the way of electrical engineering knowledge or experience, hence why I am here. I hope you will be gentle with me :) I am trying to determine the process (i.e. components, equipment etc) that I would need to set up an laser activated...

I'm doing a very short presentation on a laser. I want to discuss the most important concepts of a laser (in less than ten minutes). What should I include? I was thinking about stimulated emission and amplification. (But I'm not sure I really grasp these concepts) For instance, does...

Hello Everyone, Here is my situation: I am using a laser to take distance (height) measurements on a variety of surface types (e.g. mirror, machined surface, plastic, etc.) and I would like to quantify the repeatability of the laser measurements on each surface type. Please note that I care...

i am buying Pulsed Laser Diode in Plastic Package 25 W Peak Power SPL PL90 and there is some parameters about semiconductors lasers... Forward current = 40 A why all this current ? then in the catalog Reverse voltage= 3 Volt then they say the Threshold current = 1A ? what is the...

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 need a equation that discrip the movement of laser ray in the tube in a way that it won't get out

Hi all, I was reading Lasers and i read something like this: for spontaneous emission, the rate of decay of electrons in high-energy state to low energy state is given by: \frac{dN_2}{dt} = P_{21}N_2 where P21 is equal to the probability of electron to drop from higher energy state...

Are photons in the laser output beam mutually independent and can the multi-photon output be described as the tensor product of individual photon states?

I am modeling a non-linear phenomenon. For that i need to calculate electric field distribution of a laser beam. I will be using pulsed laser beam with following parameters: " Laser pulse with 500-microJ pulses(Ep) at 1.064 micro-m with 12.5-KHz (f) repetition rate, pulse duration = 20 ns...

What does the following statement tells about the laser output, i can understand the literal meaning but what does it tell about the power levels, temporal profile etc.? "the pump laser delivers 500-μJ pulses at 1.064 μm with a 12.5-kHz repetition rate" Thank you for your time.

Homework Statement Revered Members, An electron in ground state makes its way to an excited state upon absorption of photon of energy, equivalent to energy difference between ground state and excited state, and after some time, it decays by emitting the photon and returns to the ground...

Hi, I need a book about laser plasma interactions for my thesis. I'm reading P. Gibbon book "Short Pulse Laser Interaction with Matter" and further reading the autor suggests to use Kruer book "The physics of laser plasma interaction". This book is not available in my university and before...

I am trying to use an Nd:YAG laser for pulsed laser melting My laser is an EKSPLA NL313, which has a 5 ns pulse. I need to produce a decent size spot (~1 cm2) with a fluence of about 1 J/cm2 for the laser melting, which is no problem with this laser. However, the spot needs to be very uniform in...

hi my question has to do with this energy level diagram http://upload.wikimedia.org/wikipedia/en/e/ed/Hene-2.png" i was wondering, what the meaning of this "fast radiative transition is"? as far as i understood this, the light that you mainly want to get is the transition from 3s to 2p. but...

In several papers, diagrams, etc. about atomic experiments I saw pairs of lasers beaming in opposite directions. Naive question: why two lasers are used instead of one and a mirror? Or even further: why six lasers are used (2 in each axis) instead of just one and bunch of mirrors?

Hello everyone, new to the forum. I've been planning to make a compound bow using a cad program(Pro E), and I need a good laser cutting company to fabricate my parts. The part that concerns me most is the bow riser(black, center piece with the grip) as I want it made out of one solid piece of...

Hi Here they explain the concept of gain clamping in steady state lasers...

I have some serious doubts regarding He-Ne laser: 1. In He, the ground state energy value is taken is 0 eV and the meta stable state is taken as 20.61 eV. similarly in Ne the meta stable levels are taken as 20.66 and 18.7 eV respectively. How these values are arrived at? In Bohr's expression...

As a quick heads up, I'm buried over my head in an imager project, and the portion that has given me the most headache is the UV source. Essentially, I need the source to make nice little 13 micron dots in the 405 nm range. I've been assured by a pair of vendors that this is an easy matter...