Laser Definition and 1000 Threads

Hello, i just wanted to ask if you can explain to me what thermal lens effect is? I am supposed to answer why laser beam passing through ink or soy sauce creates this effect and i can't find any information on what actually this thermal lens is. I know of course that it is a lens, but why does...

Homework Statement Force F acting on a NdYAG laser of 1 kW continuous wave output by the impulse transfer of the photons Homework Equations F= dp/dt The Attempt at a Solution Photon Energy E=[/λ]=hν momentum P= [h][/λ] power of laser 1 kw at time (t) the laser emit photons t=[P][/E] = [λ...

Hi, I am new to the forum so apologies if I placed this in the wrong subforum though I think the subject is classical enough to be here. I was hoping to get a concise answer to what is meant by spectral and spatial shaping of a laser. My intuition says that we are modifying the amplitude of the...

chemical vapor deposition, Molecular beam epitaxy or magnetron sputtering What is the best way to bond GaAs to the intrinsic layer of a laser diode? I am planning on building a refactory oven on a concrete pad this summer once I clear of one side of my yard. There is just no way around it...

Is it feasible to recharge satellite's batteries utilizing a ground-based laser?

Dear all, I'm within my Ph.D. studies in laser engineering and most of the details are rather new to me. Working on short pulse systems, my advisor told me some times about the relation of the output coupler transmissivity and the outcoupled pulse length, but more as a rule of thumb. According...

Why laser output power decreases with increasing temperature? By increasing temperature, I mean increasing temperature of the active medium. I think that thermal lensing alone should not have effect on output power? Just different focusing (focal length). What happens with energy levels in...

Homework Statement A laser tweezer is a laboratory instrument, which uses highly focused laser beams to ‘trap’, hold or move small sized objects. The principle of the operation is that in the focal spot, the light intensity is inhomogeneous, and acts on the particle with a force that points...

Okay, so I have to write a 5-10 page report about temperature's influence on main laser parameters but, first of all, I want to ask: What are the main laser parameters? At which parameters should I be looking at?

Homework Statement Laser probes are being used to examine the states of atoms and molecules at high temporal resolution. A laser operating at a wavelength of 400 nm produces a 1 femtosecond pulse. Compute the mean frequency and frequency spread, ∆ν, of this laser pulse. Homework Equations c =...

hi Just a little question. How does one calculate the power of a QCL by theory? Is there any free software that allows one to calculate the power of a inputted laser medium for a qcl? Thanks. Adrian

I understand quasars as black holes with an accretion disk and occassional jets of mass being shot out of the black hole from it's top and bottom. (Correct me if I'm wrong) If so, what is the actual possibility for that type of quasar to be rotated so heavily that it rotates on a horizontal...

1. The problem statement, all variables and given/known date Homework Equations $$\delta v=\frac{c}{2nL} \:[1]$$ $$N=\frac{\Delta v}{\delta v}=\frac{2nL\Delta v}{c} \:[2]$$ The Attempt at a Solution I am having trouble with question 5, but have come to realize I think my cavity length is...

Hi Everyone! There is a type of CO2 laser cutter power meter on the market (Product link removed) The meter uses a block of black anodized aluminum bonded to the end of basically a mechanical meat thermometer, and has a zero adjustment on the back of the face to set the base temperature to...

The photons generated by a conventional quantum laser are all in the same quantum state. Doesn't that mean that they all have the same exact energy? Yet, because of energy-time uncertainty, the exact energy of any particle can never be measured. Also, the Copenhagen Interpretation says that...

Hello all, I want to use a laser beam as a straightness standard for use in measuring flatness of a machine guide way which is about 2 meters long. I'm envisioning a low power laser pointed at the sensor of a digital camera which moves laterally along the imperfect guide way. The waviness...

Homework Statement The duration of a laser pulse is 10^(-8) s. The uncertainty in its energy will be? Homework Equations ## \delta x \delta p=\frac{h}{2\pi}## The Attempt at a Solution speed of laser beam=c, duration is given so distance can be calculated exactly-shouldn't that mean delta...

How does the emission cross section of an emitting atom (such as Yb atoms in glass) affect the laser performance, namely the slope efficiency (signal power vs absorbed pump power) and laser threshold? Thanks a lot

I have two lasers with different intensity distributions (shown below) — one is Gaussian and the other one is rectangular (having the shape of a Fresnel diffraction pattern at the target). I am trying to compare the efficacy of the two lasers for burning a certain material (I am really...

China develops new laser gun similar to Star Wars. It can burn through skin to produce immense agony. Here...

Hi guys, can I get different frequencies from He-Ne Laser? if Not? why is it used in Infrared spectroscopy?

Question, does general or special relativity have any effect on the acceleration of laser sail from an external observer? Let's say a laser-sail is first accelerated to 0.2c. Ignoring diffraction, Due to redshift, the incoming laser beam would get stretched by 20%, reducing the power by 20%...

I need help to understand the energy transfer mechanism in Helium Neon Gas laser. When helium atom is excited and staying in its metastable state, it is said to have collision with neon atom and thus transfers its 20.61eV energy plus some of its kinetic energy 0.05eV to enable neon atom to reach...

So from what I understand, it's possible to have a very powerful laser pointer where you point at an arbitrarily large and far away surface and make the spotlight appear to move at faster than light. E.g. you can be holding the laser in your hand and you simply flick your wrist. My question is...

Hello, i hope i posted this in the correct forum! When measuring coherence of a HeNe laser using a Michelson interferometer, there are key points along the moving interferometer arm where coherence is highest. The distance between each of these peaks corresponds with the length of the laser...

Can an on board laser be used to propel a solar sail spacecraft if the laser is pointed at the sails ? Would Newtons third law affect the laser and maybe prevent the ship from moving ? Thank you for answering my very ignorant questions. NineNinjas911

754/5000 I am using the fluroescence spectroscopy technique to obtain the fluorescence spectrum of exposed neuroblasts to uv radiation (355 nm) from a Nd:YAG source and I need to characterize the radiation pulses of the laser. Specifically, I use a spectrometer (Avantes brand) with integration...

Hello, I have a question or perhaps a few questions regarding light and mirrors. When we point light at a mirror, it gets reflected back. But we can see the point light (assuming that it is a laser for the sake of simplicity) at a surface opposite to the reflective surface of the mirror. What...

If we run two identical lasers and put one at sea level and one on top of a high mountain, will they operate at different frequencies?

Homework Statement If a green laser is (wavelength = 532nm) sent through two slits with a separation of 127 um, how wide (in total) would the 11 green dots formed be if they were projected onto a screen 1.25m away from the slits? Refer to this diagram sorry for bad quality...

1. What is the advantage of using class 2 laser light? I would really appreciate if reference source is also given!Homework Equations Not needed.[/B]The Attempt at a Solution Well, I thought that using monochromatic light would made it easier to measure the distance between fringes. And also...

Above the threshold, the stimulation emission becomes dominant for lasing. If increasing the pumping, what will be the change of spontaneous emission and its contribution to the output power and FWHM of the signal, based on the threshold carrier density clamping and the threshold gain clamping...

Homework Statement Hello everyone ! I hope this is the correct place to ask. Here is my probem: I have to measure the refractive index and the thickness of the glass part of a mirror. The idea that I have, and that has been approved by my teachers, is the following: In order to measure the...

Hello, it is possibile to make speckles on a surface with a LED or something else? With a Michelson Interferometer you can get interferences with an LED -> are this already speckles? regards, Hans

Homework Statement a) If you were using a hands –on activity to verify your predictions and use measurements to determine the wavelength of the laser being used, describe any safety precautions you would have to take and sources of error that you might encounter. Be sure to explain how you...

Hi everyone, I would like to understand the answer to the question in the title. I got that when we use optical pumping of a laser, the probability, given an incoming photon of adequate energy, for an atom to absorb it and for an other to produce some stimulated emission out of it are equal...

3D Subsurface Laser Engraving works for clear glasses like Schott BK7 and B9 Borosilicate Glass. How does one do the same for relatively translucent minerals? I have read research papers on using lasers for tattoo removal and cancer radiation therapy. However, I want to know how the laser's...

We want to examine the thermal effects of irradiating a given material with a laser. The material under consideration can either be homogeneous and isotropic or a diffusive turbid material (e.g. biological tissues). Suppose we decrease the power by a certain factor. Will we still get the same...

Would the beam of a powerful laser have any gravitational tug?

The energy and momentum of a closed system is always conserved. If a laser can emit perfectly parallel and perfectly superimposed light waves (occupy the exact same space) that are perfectly 180° out of phase and of the same frequency, what can be said about the energy and momentum of the...

Hello all. I am buying a laser engraver for my business. The company I'm getting it from and the "industry" in general doesn't think I need safety glasses when operating it (most say cause the light isn't visible to the eye) . I don't personally feel safe with that assumption for my eyes or my...

Hi. When we see a laser ray, it seems that part of the ray are brighter than the other parts and they seem like they’re vibrating and moving. It also seems there are fractures in its path. I want to know why do we see like this? For example see this picture (it is from wikipedia). I circled...

Hello, Community college teacher here. I was instructed to employ a laser safety program in my intro physics lab. We mainly use Class II lasers that came with the PASCO Optics table and Laser Ray boxes. One of my adjunct faculty uses Purple and green laser pointers which is classified as Class...

Hi All, I'm new here and forgive me if I've posted in the wrong section, I'm more of a computer engineering/architect guy asking a physics question. Is it possible to have a projected laser beam repeated across multiple points? between the range of 600nm-900nm ? Example, a pad that takes in...

Most of the commercial Raman spectrometer uses 785nm or IR laser as excitation source. Though we could use visible lasers like 532 nm in this place, which can reduce the overall cost of the device by 1. Using less power laser( since intensity of raman signal is inversly propotional to the 4th...

<< Mentor Note -- thread moved from the technical forums, so no Homework Help Template is shown >> Let's say you have a laser cavity with two mirrors at either end, one is considered 100% reflective, the other 99.9%, so that a wave beam is emitted through this lower reflectivity mirror. I know...

The largest and most powerful lasers in the world can be used to make some of the most extreme conditions possible on earth. Scientists around the globe are using these lasers to try to miniaturise particle accelerators, make astrophysical conditions in the lab, and create fusion energy.

I have two measurement cases in my setup. An divergating laser beam (not an gaussian) is measured at two locations from lens , at nearby i.e. 400 mm, and far away, > 2000 mm away. My lens is an plano-convex lens. Which side should face the laser in these two cases? I know that the...

Homework Statement Imagine that you are conducting an activity with a laser to create an interference pattern. Use the appropriate equations to predict two ways (other than the way described in the following example) to change the interference pattern in order to have closer fringes. Explain...