Laser Definition and 1000 Threads

Let me explain the situation: I have an experimental setup consisting mainly of a Michelson interferometer, so I want to use it to measure the coherence length for two different situations, when the beam is focused on a mirror and when it is focused on a sample. Therefore, before analyzing the...

I am trying to stabilize the laser by locking it to a transition peak with the help of the PID controller. On the controller frequency response plot if I change any parameter of the P,I or D the amplitude or phase response changes. I do not know how to read the graph of the transfer function...

Hello I am a laser engineer interested in Physics.

Hello! In my summer lab, me and my labmates are trying to generate entangled photon pairs using a spontaneous parametric down-conversion (SPDC) entanglement source with BBO crystals. We're using a 405 nm diode laser from Matchbox with model number 405L-21A. Our setup is as follows: we shine the...

I have set up a simple interferometer as follows: a laser is aligned by two mirrors and then passed through a 50/50 beamsplitter. Both arms have mirrors which reflect the beam back through the beam splitter and to a camera, which measures the pattern (concentric circles, as expected). When both...

Hi! I'm working in a lab this summer doing quantum optics, and my team is working on a Mach-Zehnder interferometer setup. We got it well aligned and interference fringes appeared as expected. However, soon after building it, the fringes began to fade in and out of view without us changing...

Hello friends! I was looking for a forum in which I could ask and hopefully have answered, questions regarding my brand new cnc laser. When I searched, "Is it necessary to have a physical ethernet cable connection between my laser and my computer?", this forum had some answers to a related...

Hello everyone, I am using a lock-in amplifier SR860 with the aim of reading an optical pulse from a laser break-out board operating at 30 kHz as the reference. The reference signal is not being picked up by the lock-in amplifier. However, it is being read by the oscilloscope. I have used a...

What would be the ideal wavelength and power of a laser to kill an insect on human skin without burning the skin ?

In a lecture (at 10:24) on the birth of the laser printer, Gary Starkweather mentions that a HAM radio license was required to use early lasers (he finished undergrad in '60). Why was this? (All the following questions are just filling out the primary question.) What were the...

From "Boffin : a personal story of the early days of radar, radio astronomy, and quantum optics", by R Hanbury Brown... If it had been truly coherent (e.g. laser light), wouldn't the detection events have been uncorrelated? That is, two independent Poisson processes?

Accepted thinking is that time slows as speed increases, relative to a non-moving reference frame. But supposing that the object approaching C is a ship in rotation around the earth, and on that ship is a laser mounted on a gimbal such that the laser is always pivoting and trained on exactly...

From what distance does the diffuse radiation of a „hair removal laser“ cease to be a threat? I apologize for the peculiar question, but I'm curious about the following matter: I walked past the window of a hair removal studio about 50 meters away earlier, and I noticed repeated bright red...

For that we will need a laser pen and two square pieces of opaque, non reflecting material. In both these squares a slit will be cut, wide enough to let a beam of the laser pass through without any refraction effects. First, after the laser has been turned on, one of the squares is placed in...

Hello! I have an optical setup and a laser producing a gaussian beam and I would like to get the waist of the beam at the end of the setup (i actually want to know what focal length to use for some lenses, such that I get a certain beam waist in the end). Getting the ABCD matrix for my setup is...

New British LASER is one heck of an anti-aircraft gun! LIGHT-SAVER Britain blows up drones with £140m LASER dubbed ‘DragonFire’ in incredible first – with each shot costing just a tenner The futuristic laser can destroy a target from miles away with pin point accuracy... The highly focused...

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Hi everyone, let me propose an experiment to see if you agree with my points. There is a 1cm2 1-micron thick aluminum substrate with a matrix of 100x100 nano-holes each with 100x100nanometers cross section separated by 100nanometers. Then, we focus a 1W laser with visible wavelength: 1-...

Hi everyone I'm making a shoot 'em up like Fantasy Zone, i.e. the player can face either left or right (as opposed to only facing one direction while moving forwards and backwards). I've made separate scenes for the laser that fires left and the laser that fires right. The player should...

Hi everyone I'm making a game in which a player's laser can destroy enemies and cancel out enemy lasers. My code for the player laser executes queue_free() when it enters the collisionshape for the enemy laser and enemy. The player laser is only supposed to destroy one item per shot...

Homework Statement: hw Relevant Equations: hw I am looking for a light source, preferably a laser, for a specific optical experiment. The experiment involves a spherical object positioned 6 meters away from this light source. My goal is to shine the laser through the sphere, specifically...

The answer key is the light is directed through one polarising filter then filter is rotated and the light changes intensity. I don't understand how that proves that the light is plane polarised. I think if the light is unpolarised, the intensity will also change when it passes through...

Hello! I have this photodiode which I connect to an oscilloscope using a normal BNC cable to an oscilloscope, terminated with a 50 Ohm resistor. I measure the output from an optical cavity (which is basically laser light), which in my case looks like a flat signal close to zero, and regular...

The angular position of t)he first diffraction minimum is θ≈sinθ= λ/a, and dsinθ=mλ, so m = (dsinθ) /=[d(λ/a)]/λ =d/a = (2.4 x 10-4 m)/(8.0 x 10-5 m) =3. Since both bright and dark pots separated on both sides of central bright region, so the smaller bright spots observable within the central...

Hello! In a STIRAP process, for the right parameters (assuming a ##\Lambda##-type transition), the lifetime of the excited state doesn't come into play, so one can achieve very narrow linewidths of the measured transition of interest, regardless of the linewidth of the intermediate, excited...

Hi, I am worried about climate change. I want to cool the earth. Would it work to build solar panels to provide shade, and then to blast the captured light energy out into space via lasers? I think only certain frequencies will go through the ozone. Could solar powered lasers help cool the...

I know a laser is generally treated as a coherent state (i.e. a plane wave). However, if a laser turns on and back off quickly, can the resulting light be treated as a gaussian multiplied by the plane wave that would have been emitted if the laser were continually active?

Objectives: - best path for optics needed to focus and "draw"/project a high resolution image onto a workspace around 500mm square (for a Laser Direct Imaging machine) - where to cost effectively purchase or make the optics necessary to build a prototype The problem: I need to project a high...

All resources I’ve found for grating resolving power assume uniform distribution on the grating and produce airy disks. Resolvance is determined by the Rayleigh criterion where the peak of one wavelength is at the minima of the adjacent one. This definition doesn’t seem applicable for Gaussian...

Hi, I am a phd student in hardware security, I want to know what is the effect of the laser on power-off transistors and can it modify the threshold voltage of these transistors? And is there an equation that links the laser and the threshold voltage degradation? Sincerely

The context behind my question is quite silly, but I've encountered some people who believe lasers cannot produce explosions, even at insane levels of energy. Now, I'm not big on physics nor will I pretend I am, I think they could but I came here to get a more knowledgable opinion(using a silly...

I like this idea. Very creative, but in retrospect it sounds obvious. Just create a path of ionized atoms.

There is a video, where the author shows the interference of laser beam on a strand of human’s hair: I bought a laser pointer and reproduced this experiment. Indeed, when a single hair is placed on the way of the laser beam, I see the “scattering” picture (a series of points with intervals of...

I am using 2 lenses in a 4f configuration. The input is a large collimated beam (632nm). After passage through the 2 lenses the beams vertical dimension remains constant, however, the horizontal dimension get smaller, as if it is being focused only in the horizontal direction. Does anyone have...

Is the explanation at the end of the video correct?

How does this Lawson–Woodward theorem work. I read on the wiki that the particles cannot be accelerated by lasers. But I do see acceleration of electrons with free space. I wonder how this is done. https://rdcu.be/c0fRw http://dx.doi.org/10.1103/PhysRevAccelBeams.19.021303 In addition, I have...

I read something about accelerators using nanotubes. I am a little concerned about the design mentioned in the "High Density with Perpendicular Carbon Nanotubes" part of this paper(https://doi.org/10.3390/photonics8060216). Can wakefield acceleration be done in an electron field? Or maybe I...

I read a paper about coherent surface plasmon amplification by free electron pumping in an article a few days ago. It seems to work as some kind of free electron laser-like light source, and I wonder how high the energy of photons can go in this way. Also I read in another paper about...

https://quantum.phys.lsu.edu/old-website/seminars/abstracts/Kaushik10.pdf I have discovered an experiment in the link above where you get NOON entangled states by mixing classical laser light with quantum light from SPDC. But I cannot understand the mathematics behind it. Can you explain it to...

A screenshot from a book which describes it: So I am trying to picture this one: 1. A laser is "pumped" through a cylinder made from lithium niobate which is placed at 90 degrees, perpendicularly...so that the laser passes through the body of the cylinder (and not through the 2 round ends)...

Is there analytical proof that a photon Pe will be emitted by an excited atom Ae when another photon Pp of the same frequency is passing by Ae in LASER production? I tried using Feynman diagram to show a high probability of this event. I failed (most likely because I am not an expert in QFT)...

Compact electron accelerator reaches new speeds with nothing but light https://phys.org/news/2022-09-compact-electron.html Multi-GeV Electron Bunches from an All-Optical Laser Wakefield Accelerator Abstract We present the first demonstration of multi-GeV laser...

Is there a math that describes these shapes at least one frequency?

I have realized EIT with continuous laser. What are the requirements for the intensity, duration and repetition frequency if EIT is realized with pulsed laser? you can attach any reference:biggrin:thanks a lot!

I would like to build a microscope witch can be used with different monochromatic light sources (laser diodes), and this system should has small astigmatic and coma aberration, but keep the chromatic aberration property. Can I use two spherical or ashperical lenses (facing with convex side to...

I was wondering you if you could use a laser to put out a fuse or to stop combustion? Could you use some form of laser/laser cooling to put out an explosion mid-explosion?

The Telegraph is running this story with little detail. https://www.telegraph.co.uk/world-news/2022/05/18/russia-claims-laser-weapon-can-destroy-drones-1500km-earth But, is such a laser possible? Wouldn't it scatter, and how much energy would be absorbed by the atmosphere?

Hello! I have a laser with only one input for external signals. Currently I use that to send the error feedback signal when I measure the power transmission from my cavity (not using PDH). If I want to use PDH, I would need to modulate the laser frequency, which means that I need to send to the...

ρ_kdk = k^2/π^2 dk is the density of field modes (what we are trying to solve for here), and as ρ_kdk = ρ_λdλ, and k=2π/λ, we can rearrange this to get ρ_λdλ = 8π/λ^4dλ This is where my confusion lies. I am not sure what to do next. I know this equation physically means the number of modes per...