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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18 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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1answer
48 views

Will I see the light?

There is a perfectly smooth wall. We have a slit parallel to it. Through that a laser beam passes. As the slit is parallel to wall the laser beam will hit it normally. So now if I see obliquely I ...
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2answers
125 views

Why does a laser beam stay collimated?

I am looking for a simple way of explaining the collimation of a laser beam. The typical discussion of the two slit experiment of quantum theory relies heavily on the Huygens principle. Its ...
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1answer
38 views

Drawing in the air with lasers Question

Are there two different lasers that can be invisible when not overlapping, but visible when overlapping? I desire to build a hologram-ish thing, but with lasers. The system would use many lasers that ...
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1answer
48 views

What would happen if light was stored in a circular path? [closed]

This is like an idea for experiment. Lets say one has an optical cable that makes a circle. There is a little Y junction/valve to the circle, through which one pumps some coherent light in. The ...
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1answer
45 views

Is it possible to get a lasing from every luminescent media?

Let's assume that there is a cavity with a couple of mirrors and gain media between which possesses luminescence under some external excitation/pumping. Let the absolute quantum yield of the gain ...
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0answers
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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1answer
33 views

Frequency combs: comb line spectra from periodic pulse train?

Stabilized frequency combs can be generated using femtosecond mode-locked lasers after $f_{CEO}$ and $f_{rep}$ stabilization. Numerous sources have also pointed out that the periodic pulse train ...
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2answers
28 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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46 views

If I aimed two identical lasers at a screen, what would the interference pattern look like? [duplicate]

If I aimed two identical lasers at a distant screen, what would the interference pattern look like? Could this be modelled as a wavefront passing through two slits, i.e. the double slit experiment? I ...
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0answers
19 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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1answer
25 views

Resources on solid state laser resonator design and modelling

I'm an experimentally oriented physics student and have been fascinated by lasers for a longer time. I'm currently building a diode-pumped, frequency-doubled Nd:YVO4 laser from scratch. Before I start ...
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4answers
2k views

Do free-electron lasers actually lase?

Free-electron lasers are devices which use the motion of highly energetic electron beams to produce bright, coherent radiation in the x-ray regime. More specifically, they start with a high-energy ...
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2answers
24 views

Can you pass 400mJ laser light through a fiber?

What is the energy limit for fibre optics? For a dual-pulsed nd:yag laser firing at 10Hz with energy roughly 2x 400mJ, and pulse width ~5-10ns. My gut says that this is far too high to pass through ...
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2answers
44 views

Is an x-ray maser possible?

I was wondering if lasers evolved from masers. They applied the same principles to a different wavelength. Would it be possible to create a maser at a higher wavelength, using x-rays, gamma rays, ...
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1answer
35 views

Minimum Power Required to Maintain a Population Inversion

According to many sources, the minimum power required to maintain a population N in the upper level of a two level laser system is $$P_{min}=fA_{21}Nh\nu$$ where $f$ accounts for the lack of 100% ...
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1answer
17 views

Is Light Amplification Synchronise Electron/Positron Radiation possible?

Light Amplification Stimulated by Emission of Radiation vs Light Amplification by Sychronised Electron/Positron Radiation By applying a "custom" undulator(a series of powerful magnets) to break up ...
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1answer
52 views

What will happen in this LASER setup?

If I have 3 rectangular mirrors, say of dimensions length of 1 meter and width of 0.5 meter and I arrange them in the form of an equilateral triangle, which is of side 0.5 meter.(The mirrors are ...
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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 ...
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2answers
49 views

Does laser light with less than the work function still ionise some atoms?

If a gas is illuminated with a laser of a frequency less than (but more than half of) the work function of the atoms in the gas, the atoms will be excited into Rydberg atoms. Is there a finite chance ...
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2answers
88 views

Laser cooling of atoms: more area or more power?

I want to optimise a Magneto-Optical trap. Laser beams come from the the x, y and z directions (positive and negative) and slow the atoms down. Would it be better to increase the beam spot-size ...
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0answers
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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4answers
208 views

How can beam divergence be corrected for in a CO2 laser cutter?

I have a 90W RECI CO2 laser tube that I recently measured the beam divergence on. This was done by pointing the laser at a fire brick and melting it for a few seconds at different distances. Multiple ...
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2answers
41 views

What is crater's influence on laser ablation?

In many laser ablation experiments (especially Pulsed Laser Deposition), target is moving to avoid crater formation. But I can't find any source that says why it is needed to avoid it. So why is ...
3
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1answer
46 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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1answer
58 views

Laser-induced electrical discharge

Attracting lightning with an ion beam has been done in a lab but how strong of a laser is needed to reach the clouds to redirect the lightning bolt?
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1answer
48 views

How to increase/decrease laser pattern size

I have a laser pointer with a diffraction grating lens that creates a cross-hair, like the one seen below. I'd like to be able to increase or decrease the size of the cross-hair so that it may ...
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2answers
58 views

Visible light excitation by heavy particles [closed]

Can I excite visible light from an atom by a proton or muon beam? How would that be possible?
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4answers
107 views

Why shouldn't we shine laser light back into the laser?

After every laser there is an optical isolator that ensures the laser light cannot re-enter the laser, if reflected and sent back. What would actually happen if this were to happen? Would the laser ...
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2answers
70 views

How to measure 8 μm surface bumps?

I want to measure surface bumps which are larger in size than $8\ \mathrm{\mu m}$ on a uncoated plastic mirror. So it can be any number of smaller bumps and that would not effect the application. I ...
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0answers
16 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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0answers
30 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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1answer
33 views

How to collimate the LASER light using an electric field? [closed]

The He-Ne laser beam is passed through electric field plates. What is the mechanism occururing there and the principle of LASER light interacting with electric field?
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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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1answer
29 views

Bandwidth of laser pulses

I am working on a practice test for my optics class. The professor does not provide the solutions for the test. I was just wondering if someone could tell me if I am doing this correctly because it ...
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0answers
30 views

Right lens for my laser [closed]

I want to know if there is a way to find out size of lens(radius, it has to be sphere), when i know focal distance(120cm) and refractive index(1.7), for 2cm(diameter) laser ligting on it?
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0answers
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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3answers
49 views

Interference of two identical laser source

Do two identical but separate laser sources cancel out each other when point on the same spot? By the way both light will be coming from same direction. And of course, they will have a phase ...
1
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1answer
38 views

Are there any CO2-Laser notch filters? [closed]

I'm searching for a notch (band-stop) filter (like [1]) for a 10.6 $\mu$m CO$_2$-Laser and I have yet to find one. Is there some physical reason such filters don't exist or is there just no demand? ...
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2answers
87 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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2answers
40 views

Would it be possible to have light that is a cross between a laser and a none laser light? [closed]

Normally light moves through all three dimensions which is why it's intensity at any particular point depends on the inverse of the distance squared. For practical purposes we can say that laser ...
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0answers
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 ...
2
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1answer
48 views

Dispersion in ultrafast lasers

In mode-locked Ti:sapphire lasers, positive dispersion is caused mainly by the crystal. A prism pair placed in the laser resonator can compensate for some of the dispersion by introducing negative ...
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12 views

Why is the coupling constant in laser theory assumed real?

I'm reading the laser dynamics book "Light Vol. 2 Laser light dynamics" by Haken. On Page 123 of the book, the coupling constant g is assumed to be real. However, from the definition of g (see ...
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0answers
44 views

Trapping force in optical tweezer

I am reading a paper on theory of optical tweezers in ray optics regime by A. Ashkin. For reference "click here". It is given that Gradient force $F_g$ is directed perpendicular to the light ray and ...
3
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3answers
153 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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1answer
33 views

How a rangefinder works? [closed]

The speed of light is too high so how does a laser rangefinder calculate such a short time taken by the light to come back?
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1answer
40 views

Find alighment — Sacher diode laser littrow configuration

For a Sacher Diode laser Littrow configuration, I knocked it out of alignment. Does anyone know how I can find back the alignment? I was able to tilt the cylinder a little bit to find the bright spot. ...