Laser Definition and 1000 Threads

Homework Statement [/B] (a) Why does input intensity affect gain? (b) Derive the expression (c) Find saturation intensity in terms of input intensity Homework EquationsThe Attempt at a Solution Part(a) Consider a narrow band radiation as an input, where its bandwidth is much smaller than...

hey! Whats the difference between the intencity graph of diffracted blue laser light and diffracted red laser light? Thanks

Hello, I have encountered this term quite a few times, but I don't really understand what it means. Is it an electric field somehow created by a laser? Could somebody explain this to me?

A laser is amplified exponentially, with spectral intensity I (\omega,z) = I (\omega,0) e^{\alpha z} The small-signal gain coefficient is given by \alpha_{21}(\omega-\omega_0) = N^* \sigma_{21}(\omega-\omega_0) = N^* \frac{\hbar \omega_0}{c}B_{21} g_B(\omega-\omega_0) = N^* \frac{\hbar...

For an EM wave close to the transition frequency ##\omega_{21}##, we assume the dipole moment to be exponentially damped and oscillating: p(t) = p(0) e^{-\frac{\gamma}{2}t} cos(\omega_0 t) Why do we expect the electric field to be proportional to ##\dot p##? Taken from my lecturer notes on...

If we use 2 lasers with selectable light intensities as input, with each level of intensity corresponding to decimal number. Like level 0 intensity - decimal 0 (MIN) level 1 intensity - decimal 1 level 2 intensity - decimal 2 ... level 9 intensity - decimal 9 (MAX) and directly shine both of...

I’m looking to demonstrate destructive optical interference using a laser pointer. I’m splitting the beam with a prism and projecting the beams onto one point on the wall. Somehow I’m failing to get any effect, however. Setup: 1. I’m using a static laser pointer, a prism and a handheld mirror...

Hi every one. I want to solve the Yb:YAG laser rate equations. I have three differential equation: http://8pic.ir/images/61nyu3ya2dw5i0xc9iis_thumb.jpg and the boundary conditions are: http://8pic.ir/images/wa8ss3kjesg0vllnv7ju_thumb.jpg the schematically figure of Yb:YAG crystal is...

Well I was watching this documentary.there was reference to laser telescope.it use laser to get images of universe.I know the basic principle.it shoots out laser is space and get images from reflected light.but is that lasers really powerful enough to get images of objects which are far in the...

Hey all, I'm hoping this is in the right section. Basically I'm interested in creating a laser point cloud, but can't think of the best shape to do it. E.G. shining a laser straight down through a median and having the light scattered into a lot more points. I'd than have a receiver to read...

I took apart my green laser, and found a red laser diode inside! Even stranger, I found a little cylinder that fit over the laser that normally would have thought to be a filter, but when I put it on the red laser, green laser light came out! I was totally stumped as to how this worked, but then...

The laser ranging of the moon doesn't make sense. The moon has a special mirror on it that doesn't reflect incoming light along the same angle as the angle of incidence only on the opposite side of the perpendicular, but instead reflects light back exactly on the same path as the light's...

I need to reduce the beam diameter of a laser I am using. I plan to do this by first passing the beam through a positive spherical lens with focal length f1 and then a negative spherical lens with focal length f2 and f2 < f1. By placing the lenses so that the two focal points overlap I will have...

Hello everyone, I am working with my modern physics professor Dr. Parshar to make a pulse laser for my modern physics lab. I have to make an itemized expense report for the materials and all that. I need help figuring out what crystal or doped glass would be best to use, not super expensive...

Homework Statement A thin converging lens made of glass (##n_g=1.55##) happens to have an inclusion of water (##n_w=1.33##) at the center. The lens surfaces have radii of curvature ##R_{out} = r_1=r_2=10m##, and the water inclusion has the shape of a diverging lens with radii of curvature...

Assume I have an ideal laser pointing which light will always move parallel to where the laser pointer is pointing. This mean that no matter how far I stand away from the laser pointer, I will see the same spot of light with the same light and intensity. In that case is it possible to determine...

So I've been looking into the Law of Reflection with Specular and Diffuse Reflection. I understand that electrons have a certain vibrational frequency in objects, and if a light wave matches that, that color wouldn't be observed. My question is, what if I took a red laser pointer and shined it...

Homework Statement I am currently embarking on a project which requires me to design a system where I can transmit voice over a distance, by inputting an analog voice signal on one end and then recovering the voice which I input on the transmitting end at the receiving end. The general design...

Dear all, I have pretty simple problem in terms of understanding but I can't write an analytical solution. Consider you have a laser beam (without divergence, single wavelength). You can see the intensity distribution on the screen perpendicular to the beam. Then you insert a thin glass layer...

If I modulated a laser frequency with voice, would a photo cell be capable of receiving that information?

http://prntscr.com/60xcwx Thank you

Hey guys I know that a laser can ionize air so that you could run current through air. I was wondering if anyone could tell me just how powerful (watts) the laser would have to be If I wanted to connect 2 point that are about 100 feet apart? 2 points have very low current but do have high...

Q. A LASER is operating at a frequency f = 6.1*10^14 Hz. A)Calculate the momentum of the photon emitted by the laser. B)A helium atom flies towards the laser at a speed of v = 3.5 m/s.During one laser pulse the gold atom absorbs on average 5 photons.Find the speed the helium atom after one laser...

Neon is the lasing element in He-Ne laser. The lasing transition(632.8nm) is from 3s to 2p. In the energy level diagram there is one 1.15μm transition from 2s to 2p. But we studied that 2s orbital have lower energy than 2p then how it is possible, in the energy diagram, 2s level have higher...

Hi Friends, I want to know that why one can't achieve diameter of a laser less than the wavelength of the beam in order to get more power through a lens. please explain in simple Physics

Tunable wavelength operation will prove important for many VECSEL applications. The target here will be to extend the relative wavelength tuning ranges from the currently demonstrated 3–8%, 33nm tuning near 972nm , 80nm tuning near 1980nm, and 156nmtuning near 2000nm, to the 10–15% level In...

Hi all, Recently I am reading an introduction on using laser to create the so-called optical lattices and a periodic potential to trap the atoms or as a grating, some applications like to act on the cold atoms. I don't have much background on laser but there are few concepts I don't...

Homework Statement We will be considering an active medium that consists of atoms with four energy levels. These energy levels are the ground energy level E0 and three higher energy levels E1<E2<E3. Consider the case where the onl radiative decay in this system occurs between levels E1 and E0...

Hello, Which type of laser are easier to make ? Micro-wave (MASER), infrared, visible light, UV... ? Which type of light leads in an easier way to a population inversion ? Is it maser because the level energy involved are closed ? Thank you

Hello, Can we make a laser with any type of radiance (IR,UV,visible,microwave,..) ? If we consider a three level system for example. In such a system, how can we avoid absorption from level 1 to level 2 ? Is it by choosing atoms/molecules in which the level 2 is greater than the fundamental ...

Hi everybody, I want to solve this problem but I'm stucked with several equations all over the books, if anybody is expert in lasing please help me! We want to make a laser at ħω=Ec-Ev. Assume that the mirror reflectivity is [(n-1)^2] / [(n+1)^2] , where n=3.5 is the refractive index of...

Just wondering If it is possible to laser cool an object from afar or from a large distance away? Suppose you wanted to laser cool a planet with satellites in orbit around it, Would that be possible? Doesn't matter If they'd have to be ridiculously huge to have a noticeable effect or would take...

So I'm just asking a hypothetical question here, just looking for insight on something I'm thinking about really. Scientists are able to reach almost absolute zero by slowing the movement of particles with lasers. So I was thinking, is the inverse possible? If a laser was to strike incident...

http://www.iflscience.com/physics/physicists-develop-reversible-laser-tractor-beam-functional-over-long-distances In this article, they said they could control the particle's direction by changing the laser's polarization. Could someone explain this to me? I have to do a presentation on it...

A friend and I would like to try communicating (Morse code signaling) with off the shelf laser pointers from two hill tops (~350m above sea level) separated by about 16km. It would be nice to do this without binoculars but I’m not sure if that is possible with readily available off the shelf...

I was reading about this latest announcement - a research group has used a laser to create polaritonic vortices: http://www.laboratoryequipment.com/news/2014/11/laser-creates-quantum-whirlpoolWhat can this type of technology lead to? What could it allow us to do? The article mentions that such...

I recently received by Ph.D. in physics. Most of my physics experience is experimental work with optics, ultrafast laser science, laser plasma physics (relatively weakly ionized and atmospheric density plasmas), and RF and microwave experiments. However, I would really like to get involved...

I just found out what relativity is and got some questions: Actually, only one: So, according to einstein, 1. Light travels the same speed independent of the source speed. 2. Its not possible to tell which object is moving compared to an other object. I got that if one object A is moving...

Hi there, I am making a beam splitter for an FTIR, but I do not know the anatomy of a beamsplitter of this type, does anybody have information on the design of these? I plan to order KBr crystal windows and apply the Ge coating myself using physical vapor deposition and assuring quality with a...

Hi, Recently I did an experiment to try and discover what some objects look like microscopically, using a laser and looking at their diffraction patterns. We used the fact that the intensity profile you obtain is the Fourier transform of the object you're shining it through, so we can recover...

The current and the voltgate from solar cell are verry small, so can i add a amplicifer circuit? And How add?

Homework Statement The fact that a laser's resonant cavity so effectively sharpens the wavelength can lead to the output of several closely spaced laser wavelengths, called longitudinal modes. Here we see how. Suppose the spontaneous emission serving as the seed for stimulated emission is of...

Reposting from another section... Can anyone explain to me how an excimer is formed? Like structure wise? Considering Xenon. I've gathered that an excited state Xe*, ground state Xe, and a 3rd body M react resulting in an Xe* excimer + M(carrying away excess energy). I'm struggling to find...

Hi, I have a very simple test bench set up with a HeNe laser, followed by a spatial filter, then an Iris and then a couple of lenses. I can observe many fresnel rings on my image plane. Changing the size of the iris, and its distance changes the number of of rings. I would like to know why...

I'm serching around the web to find the best laser poiter (with real safety class). the below one is the only thing that I could find: https://www.amazon.com/dp/B00NQCF35G/?tag=pfamazon01-20 Do you know any other brands suitable for educational goals? we need to use laser pointer for some...

Homework Statement A riffle barrel and a laser point directly towards a target some distance away. General relativity says that the bullet and the light experience the same downward acceleration during horizontal travel, yet the bullet hits the target well below the laser beam. Explain...

I know this might sound basic to a lot of you but in school I've started taking lasers and laser mechanics in my physics course and so we reached the whole four-level system and three-level system lasers and I have a question.. Why do four-level systems require less energy than the third-level...

Why do we need the presence of an intense radiation in Inverse Raman Effect and Multi Photon Absorption?

Is it possible with modern optic technologies to achieve the following effect: A relatively thing laser beam passes 30-50 cm and after that completely defocuses? It should defocus under very broad angle. What I exactly mean is creation of a 2D screenless images just in a thin air with help of a...

I am an undergraduate Physics major in my third year, and I'd like to concentrate in Astronomy or Astrophysics when I obtain my Masters and PhD. What kinds of physics classes should I take in preparation for this? I've already taken all explicitly-astronomy courses at my school. I was thinking...