Questions tagged [lasers]

Questions related to lasers, laser-based systems or devices, and their applications.

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Can a very bright light attract an incoming laser guided weapon?

I would like to know if a very bright light will attract an incoming laser guided weapon such as a laser guided missile. Say for example that a tank has a six-foot pole on the top of it and attached ...
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0 answers
16 views

How can I visualize the phenomenon of Bound State in Continuum?

I am doing my Masters Thesis on Bound States in Continuum (BIC) and I am finding it difficult to visualize the concept. Is it possible to observe the phenomenon through an FDTD simulation? It is also ...
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2 votes
0 answers
41 views

Comparison of beam divergence between laser diode and DPSS laser

I'm currently comparing a pulsed laser diode and a pulsed DPSS laser. For the DPSS laser, the beam divergence is listed as "beam divergence (80% of total energy): $<4 \text{mr}$". The ...
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2 votes
1 answer
435 views

How much power does it take to supply a laser which delivers 100 watts? [closed]

To enable the functioning of a laser which delivers--on average--100 watts of energy in its beam, how much power does it take? (Does the 2nd law of thermodynamics dictate that the average power ...
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4 votes
1 answer
470 views

Alternatives to laser line?

I'm trying to project a very thin line at a low angle over some surface defects (peaks and troughs). The scale is ~20mm square, but the defects can be sub-mm (0.2 - 1.0mm). I am currently using a line ...
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  • 165
2 votes
2 answers
90 views

Using phone screen as a barcode

I have this extremely minor problem where my gym is 4 blocks away, and I'd like to go over with nothing but my phone. Unfortunately, I have to bring a card with me for them to scan with a barcode ...
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1 vote
0 answers
27 views

what does it mean to unfold a resonator

A way to find the modes propagating in a resonator of length $L$ is to write the field as $E(x,y,z)e^{i \omega t}$ and calculate $E(x,y,z)$ inside an equivalent periodic lens structure. Then imposing ...
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1 vote
1 answer
39 views

How would I use a laser to cut a moving solid object?

Using a laser to cut sections out of a small moving solid has been suggested for a manufacturing problem. However, usually lasers come as a point, which means that we'd have to make the laser head ...
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2 votes
1 answer
68 views

Why laser cutting speed suddenly decrease when cutting sheets from 1 to 3mm thickness then stabilize?

Please to understand what I mean, see the picture below : I don't understand why it is not a linear curve (or almost), because at first sight it should be no ? If you need 10 sec to cut a length of ...
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2 votes
1 answer
53 views

What is the highest repetition rate achieved for pulsed Terawatt and Petawatt-order lasers?

What is the highest repetition rate achieved for pulsed Terawatt and Petawatt-order lasers?
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0 votes
1 answer
45 views

What Rubber is Best for Laser Cut McKibbens PAMs?

I'm a layman engineer who's decided to take another step forward in my research and work with McKibbens Pneumatic Artificial Muscles. I’m new to creating custom rubber components and laser cutting, so ...
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  • 103
1 vote
1 answer
67 views

Best method of bouncing laser off series of mirrors

I'm preparing to add a DIY laser system with the beam bouncing from the module at the top of the stairs and then bouncing off a series of mirrors down the stairs to an LDR. My question is essentially ...
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0 votes
0 answers
19 views

How do I detect laser point?

I know military uses laser designators and they can be visible by their bombs or missiles from really long range. My question is how could I do such laser point tracking device? Lets say I point laser ...
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  • 31
1 vote
0 answers
17 views

Emerging beam from PPLN waveguide not behaving well through optics

We have a pump laser beam that is coming out of a single mode fiber and butt coupled into a PPLN waveguide crystal. We are capturing the beam at the output of the crystal with the focusing lens in an ...
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  • 11
0 votes
2 answers
49 views

What power lasers can be used to heat fabrics to 70 degree Celsius?

For a project that I was building I wanted to heat fabrics to 70 degree Celsius using lasers. Since fabric is a very wide term for now I was looking to draw heat patterns on 100% cotton T-shirt and ...
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  • 1
2 votes
1 answer
81 views

How solid state lasers work?

In solid state lasers a light source pumps the medium, which is a crystal. A crystal is excited and emits infrared light, until then everything is clear. What I want to know: after excitement, what ...
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3 votes
1 answer
72 views

What are some examples of laser-based additive manufacturing techniques?

I'm trying to research additive (or 'bottom-up') fabrication techniques that rely on lasers or other advanced photonic systems. So far, the most prevalent technique I've come across is two-photon ...
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1 vote
1 answer
64 views

Laser efficiency, what is this term?

I'm studying the laser input-output power relation. In particular I'm studying the laser slope efficiency $\eta_s$ ($\eta_s=\frac {dp_{out}} {dp_{in}})$. However, my textbook tells that $\eta_s$ can ...
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1 vote
1 answer
1k views

Laser saturation and laser saturation intensity

Can someone explain what is laser saturation and laser saturation intensity? I don't find a proper definition and it seems to me similar to steady state intensity.
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  • 187
1 vote
0 answers
21 views

Is it possible to use a laser push a 100 micron diameter droplet of water through a fine mesh?

Context I've had the thought of a printing device that uses a thin grid that has holes small enough to allow suspension of a water based ink above a sheet of paper using surface tension. I've ...
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1 vote
1 answer
163 views

Laser Power vs Efficiency

Is there some kind of graph or relation between laser power and efficiency. What I'm trying to find out is whether the efficiency of a laser decreases with increase in power or is it that there is no ...
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  • 402
2 votes
2 answers
42 views

Smallest possible elliptical hole

I am trying to fabricate a very small elliptical nozzle; if possible, 10um x 20um. I am almost certain that this cannot be achieved with regular machining. Ideally, the material would be corrosion ...
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  • 23
-1 votes
1 answer
85 views

How is digital image-data converted to a laser projection in laser printers?

By laser projection I mean the laser beam that is projected onto the photosensitive drum in the laser printer. The printer receives digital image data from a computer processes it and projects it onto ...
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  • 169
0 votes
2 answers
81 views

Can you focus a 300W LED to a small area?

I want to focus a 300W LED into a small area, about 5mm in diameter, much like focusing the sun's rays with a fresnel lens. I have to be like 2 meters away from the LED to focus the LED light with a ...
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0 votes
1 answer
34 views

Laser engravers and focal points

If I understand it correctly in a CO2 laser engraver/cutter the laser itself is fixed in position and mirrors are used to redirect the laser to the material. Is there some mechanism used to keep the ...
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0 votes
2 answers
725 views

How do I measure the time taken for a laser to cut a metal?

I am a placement student and was given a project asking to measure the time taken for the laser to cut a metal and send it to Excel into a spreadsheet automatically. I am a computer science student ...
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  • 1
0 votes
0 answers
25 views

How would measuring the number of photons on a finite number of pulses break coherence of a weak coherent laser source in COW QKD protocol

I' m trying to understand attacks on Quantum key distribution protocols. In the COW QKD protocol, pulses from Alice are passed through an asymmetric coupler and a fraction 'T' of the photons are sent ...
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1 vote
2 answers
118 views

What's the difference between pulsed lasers and frequency combs?

Can you please explain the difference between high-energy pulsed lasers and frequency combs?
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1 vote
1 answer
639 views

Scalable alternatives to CNC router and laser cutter

I am doing calculations on costs for alternatives for manufacturing this children's toy I invented, a puzzle where letters in plastic fit into wood. I have been using a CNC router to carve subtract ...
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0 votes
2 answers
202 views

Calculating energy loss from laser when shining through a material

When attempting to trap a particle in a laser beam i was able to achieve the effect. Pretty cool but now when i put of piece of plexiglass that is 1/8” thick i can no longer achieve the effect. The ...
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1 vote
1 answer
161 views

Trapping a particle in a laser beam (optical tweezers)

So upon watching videos and reading articles i understand few things. For one when the laser beam is focused to a tight enough point when placing a material in there (people use crayola markers) it ...
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3 votes
1 answer
60 views

How 2 lasers interacting causes a dot of light

Take a loom at this diagram You have probably heard of this before but im just curious what laser they are using to do this. They do t appear to be ionizing air. It seems the one laser is just for ...
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-1 votes
1 answer
100 views

Why is making a white laser so difficult? [closed]

There are red, green, and blue lasers out there but i can't find a white laser? how hard is to make one? Is it possible?
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1 vote
4 answers
78 views

Why are fine metal filters made of meshes?

Given that we have mechanisms of performing photolithography at 10nm, why are metal filters often meshes? Wouldn't it make a lot more sense to buy a single chunk of metal, and use the UV lasers to ...
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1 vote
1 answer
2k views

What is best sensor & method to measure human height?

My application needed to measure human height on a standing kiosk. I need to attach the sensor on kiosk ceiling type top. I used different kind of ultrasonic sensor for this purpose but nothing ...
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0 votes
1 answer
26 views

Suitable laser for Engraving

I have made a CNC machine from CD drive and want it to use for engraving purpose. which laser would be best for this job?
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3 votes
1 answer
63 views

Tea nitrogen laser debugging

I am making a tea nitrogen laser based off the rimstarorg youtube channel. I have a perfect setup as seen below I use 11, 1kv diodes to convert my 7,500 volt lug on my neon sign transformer to DC. My ...
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0 votes
1 answer
78 views

Can I use an optical fiber to direct a laser cutter? [closed]

Specifically, a 100W CO2 laser. Are there any considerations other than the maximum power for a fiber?
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1 vote
1 answer
66 views

Are DVD laser diodes single transverse mode?

I am looking for a cheap source of low power single transverse mode laser diode in order to focus them to a very small point. I thought I would get that from a DVD drive but the pattern I see at the ...
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1 vote
3 answers
1k views

How can I build a micrometer diameter laser beam from a common laser diode?

In order to build a lighting system for a microscope (with a digital camera) I want to make a very small diameter laser beam (parallel, rather than convergent). If possible around 1 um diameter. How ...
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1 vote
0 answers
24 views

Where could I find, or what is a material that could be used with 30 GHz pulsed DC current to produce 30 GHz pulses of light?

I need to produce pulses of light that turn on and off for equal intervals at 30 GHz. I know there are lasers that are capable of this frequency, so I need to know what materials they use to produce ...
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0 votes
1 answer
57 views

FM transmission over laser

Modulate a laser's wavelength? What are the inner workings of a laser, and is it possible to change the wavelength mechanically? Are there any lasers that can change wavelength?
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1 vote
1 answer
61 views

Device that emits a safe beam of light - doesn't have to be visible (Like laser, but safer)

I am looking for a light emitting device, which can produce a narrow and accurate beam, with a small "dot" size, for a significant distance (around the 100-150 meters) similar to that of a laser, but ...
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1 vote
1 answer
65 views

On construction of a triangular interferometer like LISA [closed]

I am planning to do a project in which I plan to mimic the LISA interferometer. For this I use the fabric material, Lycra to mimic space time and use spherical balls, forming a couple and connected to ...
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1 vote
1 answer
355 views

How the electronic circuit control laser diode? [closed]

I find this scheme here 1 - is data stream come from computer. This 'data' is an electric signal moudulated by the n°2 2 - this is the electronic circuit inside printer that a) activates the corona ...
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5 votes
1 answer
776 views

How does a laser printer write with light on the photosensitive drum?

I want to understand how a laser printers laser writes on a photosensitive drum. I am trying to understand this process. the photosensitive cylinder is illuminated by a laser beam that projects ...
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-1 votes
1 answer
172 views

Is it possible to adapt the design and principle of operation for a tunable microwave photonic notch filter to a visible light photonic notch filter?

I just read the 2015 excellent paper , "Tunable microwave photonic notch filter based on sliced broadband optical source". Is it possible to downconvert a microwave photonic notch filter to a visible ...
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  • 179
0 votes
1 answer
70 views

How is an digital coherent receiver able to achieve 100 Mhz line-scan rate for detecting coherent light in the presence of incoherent light?

Recently, I read an October 2006 IEEE JOURNAL OF LIGHTWAVE TECHNOLOGY, article titled, High-Sensitivity Detection of Narrowband Light in a More Intense Broadband Background Using Coherence ...
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  • 179
0 votes
2 answers
321 views

How do I sense reflective tape such as on a spinning wheel?

I know that the frequency and rotational speed of a spinning shaft or wheel is measured using a device that senses a piece of reflective tape on one of the rotating components. I am thinking a laser ...
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2 votes
2 answers
408 views

How does the Michelson interferometer measure the self-coherence function of coherent light in an incoherent background?

How does the Michelson interferometer measure the self-coherence function of coherent light in an incoherent background? Detection of coherent light in an incoherent background (Coutinho et al., 1999) ...
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