Laser Definition and 1000 Threads

I need to enlarge the light produced by a small laser beam that I have for a science project. I can't buy a larger laser because they're too expensive and not in the right color. Any suggestions? Thanks!

I have been preparing for a physics practical on diffraction. More specifically, we will use a CD as a transmission grating (by peeling off the reflective layer), and measure the distance between the fringes for a specific distance between the CD and the viewing wall. However, it is unclear...

P.t = nhf n/t = P/(hf) = 1.25 × 10^16 Something wrong with my working or I just pick (E) as answer? Thanks

I am working with a Nd:YAG pulsed laser system produced by Continuum back in the early 2000s called the Precision II 8000. We just received the laser from another department at the University and have been setting it up to work unseeded at 532nm. The previous lab team had adjusted the output...

Garry Starkweather who was developing the idea for the laser writer at Xerox. Due to management opposition, he had to move to PARC to bring it to fruition. As a kid he was quite the tinkerer. A nice summary of his life and journey to laser writer development is in this NY Times obit.

a) On the black part, all incoming light is absorbed. This means that the momentum of the left-light beam doesn't change (i.e. momentum before hitting the black screen is ##\vec p_0## and after hitting it is zero. Thus ##\Delta \vec p = \vec p_0##). If momentum doesn't change, we get no...

I have conducted an experiment involving projecting a laser beam onto a surface and observing speckles that move relative to us. Those speckles become less visible (maybe smaller?) when the surface is smooth and that is especially the case with milk. I have dyed milk and water to see whether in...

Professor Ron Mallett is claiming that time travel is possible using lasers. I've put this in general for a reason (I was considering putting this in the sci fi section) Article here https://www.cnn.com/travel/article/time-travel-ron-mallett-scn/index.html What I would like to ask is regarding...

I've been trying to generate entangled photons using KTP laser pointer that normally produces green light at 532 nm. I was hoping that after removing the IR filter, I could add a reflective coating (right now the coating I have is a glittery metallic green nail polish) to reflect the green light...

Hello, Light, laser or not, is fundamentally electromagnetic radiation with visible wavelengths. Laser light has both high spatial coherence and temporal coherence (highly monochromatic) while regular light has both very low spatial and temporal coherence. Spatial coherence is not about spectral...

Hello to all, In a short pulse laser emission setup, can a pulse be emmited with beam length shorter than one wavelenght? (can a pulse have a duration shorter than its period?) Lets say a laser emmiter shoots a quarter cycle pulse, what would happen to this short beam? (lets supose the...

I guess the resonator will be stable when both focal lengths of lens and curved mirror meet. The curved mirror is fixed and it's focal length: $$f_{curved} = \frac{R_{2}}{2} = 50 \, mm.$$ Then the d should be: $$d=f_{lens}+f_{curved} = 100 \, mm.$$ I think that's also the distance for which the...

Summary:: Wave function of a laser beam before it hits the diffraction grating So I'm reading "Foundations of Quantum Mechanics" by Travis Norsen. And I've just read Section 2.4 on diffraction and interference. And he derives a lovely formula for the wave function of a particle after it leaves...

Hello, i am going to buy a laser and a telescope powerful enough to see the laser spot on the moon. The lunar phase i choose for the experiment is New Moon, for obvious reasons. When i move the laser, i should see the light spot move on the moon surface after about 2.5 seconds, due to the light...

Recently, I started to experiment with a laser and a coin used as a lens, being inspired by an old Cody's Lab video. My initial assumption was that through diffraction, the laser will be focused onto a spot on when the coin is a certain distance away from the wall. In a way, I imagined it as an...

I’m trying to find something that can replace Ion engines in my Star Wars story. Ablative laser propulsion seems like a good bet because it works in both atmosphere and a vacuum and just seems better than Ion engines.

Hi guys, It's one of the questions I'm asking myself needlessly but I really wonder about this ;) Say I have a laser at a wavelength λ. I can calculate the frequency by ν=c/λ. Then the linewidth Δν=cΔλ/λ2 that can be found through differentiation of two sides of the equation. The question is...

Hey all, I am trying to hack a 5mW laser pointer to be pulsed according to a driver signal from an Arduino. The laser pointer itself has an internal forward bias resistance of 22k and is driven by 2x AAA batteries. An oscilloscope says that the output voltage from the Arduino is a +5V...

If this could actually be achieved, it would probably win him another Nobel prize, and solve the dilemma of nuclear waste for good. https://bigthink.com/technology-innovation/laser-nuclear-waste?fbclid=IwAR1mFH03XE1x744PHRXCKfWmBt2qeRquOYMAgIXUjqSVEK1kqK2hSkUktcg

My wine raman spectrometer has this laser module included in the box as extra (in case the original one get busted). I'd like to know what kind of laser is it. This is its front, note the bronze is the actual laser unit that is fixed with 3 screws in the silver casing: This is back of it...

Summary: Lasers cutter and fume extractor Hello, I am wondering if anyone has experience with laser cutting and fume extractors. I have a laser cutter now and need to buy a fume extractor since it will operate in a closed environment. Some fume extractors on amazon are inexpensive (~$500) but...

Hello, I study laser physics, using "Laser Physics" by Eberly and Milloni. I am confused regarding the notion of gain and the saturation effect. According to the book, the gain is defined as ## g(v) = \dfrac{g_o(v)}{1+I_v/I^{sat}_{v}} ## where ## I^{sat}_{v}## is the saturation intensity and...

One of the emission lines of iron is 404nm, would iron absorb the heat from a blue laser and not copper? Not a student, just an old curious guy. Thanks, Philip

Dear readers, What happens to the divergence values of a laser diode (along and perpendicular to the emitting surface) when the driving current is increased or the output power is increased? Does the divergence: Increase along one axis? Increase along both axes? Decrease along both axes...

I don't know even where to start. In my reasoning peak florescence wavelength should be equal to its peak lasing wavelength. Is it something to do with pulse modulator (amplifier) that is used in Ti:Sapphire lasers? Or cavity length ? (But we were not given any cavity lengths). Any help would...

Hello! I read a bit about how lasers work and I am confused about the initiation process. From what I read, the amplification process (i.e. oscillations in the cavity at the right frequency, once the population inversion is created) is started by spontaneous emission. A photon that happens to...

I've been reading about lasers. Here is what I understand so far: We need to have population inversion, we need to have more atoms in excited state than in the ground state to achieve stimulated emission of photons. In He-Ne laser, we achieve that with Helium, it has metastable state at 20.6eV...

Homework Statement: So if I were to take Jew strong very strong magnets and place them repelling one another in a vacuum would I be able to create plasma and could I create a laser that can shoot it out? Homework Equations: sorry new to this :biggrin:

I read about semiconductor laser and its beam shape is conical with 50' of dispersion angle. But for me, it is hard to accept that it is conical because every single drawing I see is rectangular and the plan that laser going out is also a plain, not a hole. And this is the picture I saw...

Summary: specific modulation of lasers will cause ionisation, how is this being used in plasma physics? Just a simple question

I’m writing a story about warfare several decades in the future. While I was doing research into possible directed-energy weapons, I came across something interesting. I don’t know if there is a name for the whole concept but it can be generally described as the use of brief laser pulses to...

Colors come about because the wavelength is reflected off the object while the rest is absorbed. So orange looks orange because the orange is reflected while rest absorbed. For laser goggles that is rated for say 532nm (green wavelength). It must absorb the 532nm and so the reflected color...

If particle beam or laser beam weapon would be used to cut the electrical wires in high voltage transmission lines of the enemy. Could the current conducts into the particle beam (or laser beam) itself and can short circuit in the weapon platform? I know ionized air can conduct electricity...

Let's say we have a laser beam coming from a source called X, we would like to change its direction so that it would hit directly on the object that we have. What would be the possible solutions?

So, I was working on autocorrelation for my pulse laser system and I started to wonder what is the difference between single wave with 400nm of wavelength and two 800nm waves overlapped. In the knowledge, I know of, is that wavelength is the length between two picks. And when it is pulse laser...

From Wikipedia and other sources that I am reading, a laser detuning can excite an atom. However, for an atom to become excited its energy must be equal to the energy difference of two states. So how can laser detuning still excite an atom? The frequency from the laser would of course be near...

Many papers about random lasers mention the Q-factor of random lasers. Since a random laser has multiple peaks close to each other like shown in the figure. Does each of these peaks correspond to a unique random lasing mode, or is it just a single mode? Similarly what is the right way to...

I may be known on the EE side of PF as someone who hates waste and doesn’t like to throw away perfectly good machines; I like to resurrect faulty gear. This Dell printer was thrown away for want of a touch or two of solder, and works just fine. Do I really need to buy a whole new printer? This...

How do I build diy laser power meter. I tried shining 5 milliwatt laser on photodiode. Photodiode is connected to led. Led never turned on.

I've read that there are laser rangefinders who measure the distance not only by ToF (time-of-flight) method but also by phase-shift. I think I can understand that. Depending how much the phase of the input pulse shifts from the output pulse we can translate it into how much distance the pulse...

Hello, I've known about average laser rangefinders that we can use for domestic needs. They're relatively cheap and can measure up to 50 meters but that's about it. However, I've read that military laser rangefinders are able to measure distances using light up to 20 kilometers. How is that...

Summary: Laser rangefinder (distance meter) working principle Hello, could anyone explain to me (or direct to) how a laser rangefinder/distance meter works? I want to learn about it in as much detail as possible. All I could find so far were very premature explanations telling me that a laser...

I am writing a hard space opera. I plan multiple types of space battles, orbital, asteroid mine capture, board a ship (yes it is very hard to match its course). But my biggest question is the situation of convoy attack. In this case, attack frigates can speed up to 100 km/s. How could lasers...

Why was it important that both arms were parallel and perpendicular to the rotation of the earth?

I'm a physics student, and working on a class project that requires coming up with a method to control the exit angle (diffraction angle) of a monochromatic light source. For example, taking a laser (monochromatic, coherent light source), spreading the beam, and directing the light at a piece...

Reactionless drives are impossible. That means that a laser carried on a satellite would produce no thrust. Why, then, would shining that laser on a light sail not produce a net force? Using a fan to blow air on a sail does not work because the fan and the sail produce opposing forces. But...

Our teacher taught us "Laser" today and it made me confused. So Electron s energy in n=1 is around 13 eV (-13eV) and in n=2 is around -3.4 eV. Our teacher told us if we radiate a photon which has 9.6 eV energy (the difference energy of the first and second layer, n1 and n2, which is 13-3.4=9.6...

Hi everyone, I have this topic ,and I searched all over the internet without any results what is the affect of Laser Beam on cancelling the Gravity or reducing it if anyone can refer to a reference that can help me I will appreciate it

Hi, Is coupling light from a laser into a single-mode fiber (transverse electric) more difficult than coupling to a multi-mode fiber? If so, is it due to the geometry? Does the laser light have multiple modes to begin with or it can be designed to have just one mode? Thanks

Homework Statement The laser cavity is formed by two mirrors separated by 15 cm. One of the mirrors has an ultra-high reflectivity and the output mirror has the much lower reflectivity of 99.5 %. How many photons are there in the cavity?[/B] The power of the laser is 1mW and the wavelength is...