Light Amplification by Stimulated Emission of Radiation. A means of creating coherent light by either driving an atomic or molecular transition in an optical cavity or firing a beam of electrons through an undulator.

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How I can launch light into PM fiber

A polarization maintaining fiber preserves the linear polarization of the light at the output, the light at the input must be linear polarized to see signal at the photodetector... However I can't see ...
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Michelson interferometry - is a compensator plate necessary?

I am studying the Michelson interferometer shown in figure 2 (similar design shown below) of the AMRITA vlabs tutorial. There it is stated that Since the reflecting surface of the beam splitter ...
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391 views

Laser Cutter Power/Wavelength to Cut Paper

I've been reading up on laser cutting and it seems that 808nm at around 2 watts is typical to cut paper. How would one calculate the wavelength and power required to cut an arbitrary material?
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78 views

Short Laser pulse in near field bandwidth

Is there a way to create a short laser pulse that has, at least in the near field, a very narrow frequency range?
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313 views

Phase noise and linewidth of laser

I learned that the linewidth of a single frequency laser is closely related to the phase noise. But this sentence from a book completely confuses me: "A quantum-limited beam in a so-called coherent ...
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222 views

How to create a barrier for sound waves?

Is there a way to create a barrier so that sound waves cannot pass through? Does laser light have this ability to act as a barrier or bounce sound waves back? This came to my mind when I was ...
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162 views

Low-cost 532nm DPSS laser modulation

Could anyone suggest modern means of modulating 100mW CW 532nm DPSS laser? This should be low-cost(<50$) in high volume. Frequency bandwidth is 10Mhz, so modulation of pumping diode would ...
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275 views

Laser beam position using galvanometer

In 3D printing techniques like SLA and SLS use lasers for solidifying a cross section / layer of the model that is printed. These machines, as far as I know, use XY laser scanners to project the laser ...
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251 views

How would one generate Brownian light? What would it look like?

When light is an equal mix of all visible frequencies, we call it white light. By analogy, sound that is a mix of all audible frequencies is called white noise. For sound, there is an additional ...
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110 views

What methods exist for us to measure the position and momentum of atoms that make up molecules?

In this paper, Localization of an atom by homodyne measurement. A. M. Herkommer et al. Quantum Semiclass. Opt. 8 no. 1, p. 189 (1996) (paywalled). the authors are able to localize atoms using ...
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93 views

Why can't incoherent light be collimated as well as laser light (e.g. in a laser pointer)?

Why does a laser pointer contain a laser diode, and not just an LED? A laser pointer contains a laser diode, which essentially shines coherent light over a large angle, and a collimating lens, to ...
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25 views

Master equation approach only suitable for good cavity laser?

As I understand, master equation and quantum Langevin equation are equivalent formalisms. However, in a Review of Modern Physics article titled sub-Poissonian processes in quantum optics, the author ...
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33 views

Frequency modulation in laser locking - what frequency?

In laser locking, e.g. using the PDH technique, the light (say of frequency $f$) is modulated so as to add two symmetric sidebands of frequency $\Omega$. I know the maths, I understand how this leads ...
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194 views

Shining a laser onto a mirror

Theoretically, if I shined a laser at a mirror at an angle of 0 degrees so that the light was perfectly reflected back to the light source, then I should not be able to see the light because it is not ...
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214 views

Using a transfer matrix to calculate beam width of off-axis Gaussian beam?

I have been reading a lot about ABCD matrices that are used for ray tracing. I can calculate the output offset $r_{o}$ (with respect to the optical axis) and the angle $\theta$ of the ray by $$ ...
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220 views

Decoherence of a Coherent Beam

If retarding films (i.e. wave plates) can retard the electric components of light (based on the films thickness) without affecting it's direction, couldn't I use a retarding film of randomly varying ...
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398 views

What laser and BBO are needed to create entangled laser streams?

I have been reading about entangled particles, lasers, the two slit experiment, etc. I really know nothing from physics (i.e. equations, formulas, theory); so please respond accordingly. From my ...
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105 views

Does chirp (GDD, TOD ) affect the temporal coherence of a laser?

Lets say we have a laser beam with finite temporal coherence. A broadband spectrum with a transform limited pulse of 100fs. If we measure its temporal coherence when the pulse is transform limited ...
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150 views

How to propagate a (tilted) gaussian beam through a telecentric f-theta-lens

My questions has two parts: First of all let's assume I have a gaussian beam and I send it through a telecentric f-$\theta$-lens (e.g. http://specialoptics.com/products/scanning_confocal.html) with ...
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63 views

What is a vectorial vortex beam?

I know that a Laguerre-Gaussian (LG) beam with topological phase non zero has helical wavefront, but still linear polarization. So if LG beams are not vectorial vortices, what could they be?
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42 views

plasma pressure initial condition

The authors in the paper below did a simulation of plasma plume evolution from a laser heated metal target. They used compressible transport equations and ideal gas EOS for Ar. I am having difficulty ...
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210 views

What are the practical consequences of “approximate” quantum cloning with a stimulated emission cloning machine?

Say I build some stimulated emission-based cloning machine for photons (e.g. some active laser medium). Alternatively I could do cloning via interference, e.g. a linearly polarized photon could be ...
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49 views

Measuring spin direction by means of coherent light?

Let us assume that we have the ferromagnetic surface where all atoms have the same direction of spins. And we can interact with the single atom in such lattice. Is it possible to measure the ...
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Converting laser light into visible white light

I was wondering how this lens works. It converts blue laser light into white light and effectively turns a portable laser into a flashlight. The info mentions phosphor coating. I used my Google Fu and ...
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139 views

Polarization in Lasers and Liquid Crystal Displays

When we talk about Polarization in Lasers we mean placement of the crystal at Brewster angle to block the s-polarization and only the p-polarization will survive. How do we compare the term ...
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386 views

gamma ray lasers?

Is it really possible in the foreseeable future to create a gamma ray laser? I've read these two articles on Wikipedia: the Hafnium controversy Induced gamma emission It sounds pretty amazing, ...
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50 views

Optics to correct focal distance across a plane

I have a laser beam which is focused to a point at a certain distance. I'm then going to use a galvanometer to scan that beam across a plane. Obviously, as the beam scans across the plane, the ...
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33 views

Book on spectroscopy (line dependency on parameters)

I am trying to find a book (undergraduate level) on Spectroscopy. I am interested in how molecular absorption lines depend on parameters like temperature and pressure (for example with gases). Can ...
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51 views

100x magnifying optics system for short laser pulse

I am now designing an experiment that consists of a 400 nm short pulse (~300 fs). In the experiment, we need to magnify the transverse profile of the pulse by 100x. That's the problem. I was ...
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55 views

Is it possible to directly pump a laser using sunlight?

Typically in the old days one would use a flash tube to pump a ruby crystal. Is there any way, or any lasing material, that could use concentrated sunlight directly for either continuous or pulsed ...
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Is it possible to efficiently extract phonons from a lattice?

The population inversion generated in lasers occurs in multi-level atomic systems. As an example, the Nd:YAG energy diagram is shown below. The pump pushes the Nd ions up to the upper levels, and ...
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86 views

Would a giant satellite laser work as a weapon?

If someone built a satellite to float about in space, which used mirrors to focus and magnify energy from the sun directly into one direct spot (like in the James Bond film Die Another Day) would it ...
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164 views

Rotating a Gaussian Beam

I need to see how the phase fronts of two gaussian beams interact when they intersect with each other. The two beams are tilted towards each other so that they intersect each other at their respective ...
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125 views

Quantum Cascade Laser [closed]

I want to learn about quantum cascade laser in a six month time. Can anyone please suggest me any reading materials or video lectures. I have background in calculus and linear algebra. I am learning ...
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139 views

Is “microbunching” in a free electron laser limited by the Pauli exclusion principle?

As I understand it, a free electron laser can basically be pictured as a synchrotron light source with an undulator which by the particular setup causes the electrons to self-attune so that they ...
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How far can light go?

When a ray of light is projected, (say) from the surface of Earth to outside in space. The condition is that, there is no obstruction to it till infinity (it travels only in vaccum). My question is ...
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How would a laser gun actually work?

So, let's assume that the "laser gun / phaser / beam weapon" from all sorts of Sci Fi were an actual thing. You know - a weapon that uses a laser to kill somebody. I'm trying to imagine the physics ...
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686 views

Is the output of a laser pointer polarized or not?

How to verify it? Is a laser necessarily polarized? I have a laser pointer with wavelength 532nm in hand.
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2answers
188 views

Spot of my light on the moon

This is a funny question, but worth answering. The distance between the moon and the Earth is 384,400 km. The speed of light is 299792.458 km/s. It will take 1.3 seconds (Approx.) for my laser beam to ...
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254 views

Material resistency to lasers beam

Keeping the average power constant, why some materials are more eager to be damaged by pulsed laser with respect of C.W. lasers, or viceversa? When i talk about pulsed lasers i think for examples of ...
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2answers
66 views

Can a beam splitter distinguish between more than two polarizations?

The following is based on a very basic understanding of lasers, that may be approximate or altogether completely erroneous. Given a (single-mode) laser beam, a beam-splitting polarizer ...
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3answers
126 views

Laser beam photon counting

I'd like to know if devices exist that are able to detect the single photon missing out of a normal laser beam. I am aware of the fact that single photon counters do exist, but I'd like to ask some ...
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1answer
53 views

LASERS: How do we get all the emitted photons of equal wavelength & equal phase? [duplicate]

As far as the working of lasers is concerned, I was convinced till the part that the light flashes on a ruby stone and the electrons are excited and then again go back to their ground state and then ...
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2answers
99 views

White Laser Light

I have heard that recently researchers have developed white laser light by combining semiconductor laser sources of different colors. However, I have heard that before these lasers become a practical ...
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1answer
339 views

Can very high power laser beams self focus in vacuum?

I first recall reading about such an effect in a SF story entitled "Rails Across the Galaxy" which involved self focusing laser beams. And in a science paper here
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1k views

Can you use a laser to measure the speed of light with a rotating mirror?

I have learned that the classical measurement of the speed of light with a rotating mirror does not work with a laser (as opposed to, say, a mercury-vapor lamp). Can you tell me if and how coherency ...
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1answer
386 views

Generated wavelength of free electron laser

Could you please help me understand how one can measure output frequency of free electron laser (provided that we know size of magnetic domains and electron energy)? This should be a function of ...
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2answers
114 views

Could a civilisation contact us by laser from 50 light years away?

The Kepler Space Mission has discovered over 1,000 planets. These discoveries may increase the confidence of some people that other civilisations exist. That is an opinion issue, and not what I want ...
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526 views

How does one measure the frequency of a laser?

I am taking a short introduction course on lasers. I never knew that the frequency of a laser is so high for a given wavelength (e.g. 780nm). I am wondering how people can measure the frequency of the ...
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117 views

Does the gain medium in a laser need to be replenished?

Just what the title states. The gain medium in a gas/fluid laser works by shedding stimulant energy. My elementary knowledge of physics tells me a photon is mass-less. Ergo, photon emission would ...