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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mode-locking a laser on prime-powers' frequencies

Being rather a theoretician than an experimental physicist, I have a question to the community: Is it experimentally possible to mode-lock a laser (fixed phase relationships between the modes of the ...
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104 views

Photon pumping in Laser

Let's consider a ring laser where the laser must pass through the gain material before it is sent toward a partially reflective surface $\ R=1-T $. The other mirrors are perfect reflectors with $\ ...
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28 views

Natural linewidth of hyperfine levels?

The D2 line of $^{87}Rb$ is the transition between the $5^2$$P_{3/2}$ and the $5^2$$S_{1/2}$ states. Its linewidth $\Gamma$ is always quoted to be $\sim 6 MHz$. But both states have hyperfine ...
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28 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 ...
3
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63 views

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 ...
3
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143 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 ...
2
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24 views

Inertial frames and Sagnac interferometers

Let's posit: I am in orbit around a large body, like a planet, and I am close enough to be tidally locked to the large body. Am I in an inertial frame? Even without looking at the stars, couldn't ...
2
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77 views

Stimulated emission in LASER

I have been reading about how lasers function : A photon is used for stimulated emission of electrons from the metastable state to a lower energy state. What I don't understand is : How can "giving" ...
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35 views

Limits on the information obtained through optical measurements

Consider a Gedankenexperiment shown in the figure below. There are two lasers $S1$ and $S2$ with exactly the same specifications on paper. In practice, they are of course somewhat different but ...
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99 views

Carbon fibre laser beam dump material?

A few years ago I came across a material used as a high power laser beam dump. It was made from carbon fibre which looked like a mat made of high density bristles ie all the fibres on the top of the ...
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82 views

What could cause the gradual loss (or change) of power in a CO2 laser over a long period (e.g. a year)?

For example, if it were a 10W CW CO2 laser that were used for ~45 minutes per day over a period of a year. Would you expect a slight reduction in power with age? Does the dissociation of CO2 occur ...
2
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80 views

List of laser-cooled atoms and ions

I'm familiar with the requirements for an atom or ion to be cool-able with laser cooling -- a closed transition -- or close enough that the leaks can be plugged with repumpers. But is there a list of ...
2
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117 views

Resonance condition in confocal cavity

In a confocal cavity, a beam traverses the length of the resonator 4 times between two transmissions along the same ray. . For example, in the above figure, path difference between two beams that ...
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63 views

Determine laser cavity modal content from beating / interference?

I'm trying to better understand the modal content and dynamics of laser cavities. I'm specifically interested in mode-locking, although this question is pretty general and applies to CW lasers too. I ...
2
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0answers
171 views

Laser divergence/convergence over large distance

I have hit a roadblock in my simulation, where there are 2 authors with contradicting equations on the model. So I have simulated both, and drew it out for a few diameters. My dish size is 40m. I am ...
2
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167 views

Why is Erbium Doped Fiber Amplifier (EDFA) preferred over Erbium Doped Waveguide Amplifier (EDWA)?

Why is Erbium Doped Fiber Amplifier (EDFA) preferred over Erbium Doped Waveguide Amplifier (EDWA)? The question has been asked from an engineering point of view, but obviously I would also be ...
2
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94 views

Macroscopic chromodynamics

Lately I've been reading about gamma ray lasing phenomena, and I've been wondering about the applications of this. More concretely, the above fantastic question led me to wonder if we could somehow ...
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347 views

Levitation rotation speed involving laser acceleration, pyrolytic graphite and a vacuum

The experment would involve a small NIB magnet levitating between or on the diamagnetic material pyrolytic graphite, unlike other forms of levitation this doesn't require power to run such as ...
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235 views

How is the “negative dispersion” derived?

I'm looking at Kopfermann H., Ladenburg R., Nature, 122, 338-339 (1928) and it appears Ladenburg in Ladenburg R., Z.Physik, 4, 451-468 (1921) was the first to discover the phenomenon of "negative ...
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409 views

Maxwell's Demon - laser cooling

There’s an interesting article on Scientific American that tells how to cool individual atoms to within a very tiny fraction of Absolute Zero. It uses two laser beams acting on a very cold rarified ...
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20 views

Coupling into FC/APC fiber

I am currently attempting to couple a 405nm laser diode into FC/APC fibre. The fibre is mounted on a flexure stage approximately 15.3mm from an f=15.29mm lens. I have managed to couple into the core ...
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21 views

In a superradiant laser, how does the collective dipole store the coherence of the photons?

In a standard laser, the stimulated emission is largely incoherent. How does a superradiant laser get around this? To my understanding, a magnetic field is usually applied to align the dipole moments ...
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25 views

How do we calculate the adjustment factor for hyperbolic secant pulse for calculation of peak power in ultrashort laser pulses?

In the formula for peak power it is equal to total energy divided by FWHM pulse width multiplied by an adjustment factor 'a' the value of which depends on the shape of the pulse. For hyperbolic secant ...
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47 views

Acquiring an Active Q-Switched Laser

I'm working on a senior undergraduate project in engineering physics, and I am building an instrument that will use a Q-switched laser as a short-pulse, low-pulse-repetition-rate light source. We need ...
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45 views

Difference between steady state intensity and saturation intesity in laser

Can some one explain the diffrence between steady state intensity and saturation intensity in lasers. And diffrence between gain at threshold and gain at steady state,why are these two gain equal? ...
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14 views

Relaxation Times in Quantum Optics

I am studying laser physics and in in the lecture we defined the transversal and longitudinal relaxation times as the relaxation times of the coherent/ population states of the density matrix. The ...
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51 views

coherent length measurement of a monochromatic laser source

i need to learn about how to measure coherent length of a monochromatic laser source.I know that I can use michelson interferometer or spectrometry.For laser which has long coherent length michelson ...
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96 views

Relation between minimum spectral linewidth and pulse duration

Is there a difference between minimum bandwidth and minimum spectral line-width of laser? What is the relation between them and the duration of a pulse?
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41 views

How much energy does a PV cell need to work?

How much energy does a $1m^2$ photovolatic/solar cell need to work? Can it work using a bunch of Laser lights? Edit: Ok so this PV cell is $1m^2$ is dimesions. The N-type has silicon doped with ...
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51 views

What is the “Obscuration Factor (OBF)”?

In a paper I am reading for my master thesis I came across this "obscuration factor (OBF)". The authors indicate that it is a measurement of the average intensity of reflection. They do not give a ...
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53 views

Any suggestion of laser pointer for everyday life study of fluorescence?

I want to buy a laser pointer to study fluorescence in my kitchen. Any suggestion? What kind of laser pointer? What stuff for demonstration?
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53 views

Laser travelling through a radially graded index of refraction

A laser beam propagates through a region whose refractive index varies as $\mu=\mu_0(\frac{r}{r_0})$. At a distance of R the beam makes an angle of 30° with the normal. Find the minimum seperation ...
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67 views

Maximum laser power that mirror can handle?

Can I use standard mirrors used for lasers used for laser shows to build some laser that has higher power and is able to burn materials? What are power and power density limitations that cannot be ...
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224 views

Minimum spread of frequency and wavelength in neodymium laser

What is the equation linking the minimum spread in wavelength and frequency of a pulsed laser, in relation to the lasers pulse time and operational wavelength. For example: If a Neodymium laser ...
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25 views

Stop CO2 laser firing through holes in glass

How would you prevent a CO2 laser with interlocks used to mark glass from firing if there were holes in the glass. Usually the interlocks prevent the laser from firing unless it is pressed against ...
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47 views

Can multiple lasers be concentrated in a circular area using some optical arrangements?

Can multiple lasers be concentrated in a circular area using some optical arrangements such as using a paraboloid surface? If yes, why do in high laser power systems do they use only 2D arrays of ...
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378 views

Definition of spatial and temporal coherence in QM?

It is often said that lasers are spatially and temporally coherent. Is there a simple definition of spatial and temporal coherence in the language of quantum mechanics? More specifically, can these be ...
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91 views

Diode lasers tapered amplifiers

I'm trying to understand how a tapered amplifier works, but I can't find any good resources. Can anyone point me to any resources where the way they work is explained? Or could anyone here explain it ...
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22 views

Ellipsometry measurments

Why it is good to measure on a wavelength range in ellipsometry instead of using a single wavelength. I understand this that the measured data (ψ and ∆ ) plotted against wavelength and if we have ...
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79 views

Energy conversion efficiency of Q-switched laser?

This is kind of an elementary question, but since i cannot find a reliable source on this i wanted to ask what is the formula for energy conversion efficiency? I know efficiency is calculated as ...
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139 views

What narrow-linewidth laser system runs at 2100nm with 1W of power?

For an experiment at our university we need a laser that runs at about 2.1 μm (about 20nm higher or lower would be fine too. We have found a multitude of lasers that achieve this (typically Thulium- ...
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13 views

How does back reflection damage optical cavity?

I have a basic question.How does back reflection damage optical cavity?please help me.
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19 views

DIY optical band pass filter or another alternative

I need to detect laser using a solar cell which would need me to either detect the laser wavelength or use pulse modulation and detect the frequency so I'm kinda here to ask if it's possible to simply ...
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28 views

optoelectronics-smallest wavelength of light

Sorry this maybe a stupid question , but i need to know: A few minutes ago i have read an article about optoelectronics: worlds first optical single atom switch The writer of the article ...
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13 views

Injection current modulation with a modulated RF signal to drive laser

I am using an RF modulated injection current to drive my laser in such a way that the modulation index = 0.8. At this point, I see the carrier and first sideband on the spectrum analyzer. If I now ...
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17 views

Phase matching type 2 in a uniaxial material

A uniaxial nonlinear material has the following refractive indices for a laser of wavelength 1000 nm and its second harmonic: $$\begin{array}{c|c|c|} & \text{1000nm} & \text{500nm} \\ ...
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31 views

How can I change the angle of a laser without mechanical aid

I'm trying to figure out a way I can bend change the angle of the beam coming from a cheap laser diode or laser pointer on the fly. One thought I had was a small prism or mirror that is attached to a ...
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10 views

Derivation of resonance condition for free electron lasers

In the book Principles of Free-electron Lasers by H. P. Freund and T. M. Antonsen, it is written that to get the resonance condition for a free electron laser, we start from ...
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9 views

References on particle cooling

I am looking for references on the topic of particle and mechanical oscillators cooling, in particular: Doppler cooling Resolved sideband cooling and Lamb-Dicke regime Stokes and anti-stokes modes ...
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11 views

How to find the focal spot size of a TEM 33 mode laser

I have a laser that has a TEM 33 mode beam profile. I would like to calculate the beam spot size when foucsed with a lens of a given N.A. I also know the M^2 for the beam. can I use the equation for ...