How to build a laser

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Nirelan

Joined Nov 5, 2018
39
No offense, but it does not matter. Instead of just telling someone else they don't know something and acting like you do, if you know how to do it say so, if not that's ok.
 

Thread Starter

Nirelan

Joined Nov 5, 2018
39
I've never built a laser or claimed to. I was just saying if he does not know how to there is no reason to shit talk. He can respond to a diff question, without insulting someone.
 

BR-549

Joined Sep 22, 2013
4,931
I have never found a "coherent" explanation for laser light.

The generation part is easy. And of course that is what all the explanations spend their time on.

One takes a media.......make it radioactive....fire a photon....get monochromic photon chain reaction.

Big deal. A carrier wave is monochromic.

NO ONE explains the linear beam in an understandable way. Does the media only emit in one or two directions due to self interference? Is a lens or other focus device required?

What process or device makes a linear focus? Can this be applied to RF? How about matter waves....sound and such? Does the focus have to be a multiple of the wavelength? Is there an interference pattern in the beam?

IS the beam an interference pattern itself? Could we steer it?

Can laser light be explained and described in a RF manner?
 

Tonyr1084

Joined Sep 24, 2015
9,744
I am beginning to smell troll.
Take a shower. :) Just kidding.

Look! I've asked several times now and so far I've gotten not even 1% of an answer. When you build this laser, WHAT DO YOU INTEND TO DO WITH IT? FOR WHAT PURPOSE IS IT BEING BUILT?

You wouldn't build a laser that can etch dog tags if you want to shoot down incoming ICBM's and you wouldn't build a laser to shoot down incoming ICBM's IF you only want to etch dog tags. So - - - - - - - - WHAT GOAL DO YOU WANT TO ACHIEVE WITH THIS LASER? Not calling you a troll, nor dumb, nor anything else. If you want to know how to milk a cow you first need to define what your purpose is. If it's for a pail of milk - OK, say so. If you want to run a dairy - OK, SAY SO. TELL US WHAT YOUR GOAL IS WITH THIS LASER YOU WANT TO BUILD?

Geez, if this doesn't get an answer then I may need to shower too.
 

nsaspook

Joined Aug 27, 2009
16,333
I have never found a "coherent" explanation for laser light.
...
Can laser light be explained and described in a RF manner?
Yes it can. The same principle is used in a Maser.
https://journals.aps.org/pr/pdf/10.1103/PhysRev.99.1264

Coherent RF makes precise Doppler shift measurements possible with very small pulse widths (as low as one cycle of the carrier frequency).

https://www.mwrf.com/blog/are-you-being-affected-phase-coherence
https://www.digikey.com/en/product-highlight/a/acconeer-ab/a111-evaluation-kit
 

Tonyr1084

Joined Sep 24, 2015
9,744
You cant go to the store and just get a kit, but people have done it.
Yes. People have done it. Some started out in a garage, others in the back yard. Orville and Wilber - bicycle mechanics - built a flying machine. Something everyone (most everyone) thought could never be done. Truth is - everything that has ever been done HAS BEEN DONE. Those things that have not yet been done - have not yet been done.

you don't know what I know.
My son said those exact words to me. His thinking was that he knew more than I gave him credit for. Then I told him "No, but I KNOW what you DON'T know." In other words, leaning on years of experience and wisdom I knew the things he had yet to learn. Things he had no idea of as of yet.

We're not calling you dumb. Generally as a rule (AAC guidelines) prohibit us from name calling. Yeah, it happens, and I suspect I may have inadvertently at times joined in the frickus. Every one of us has the opportunity to do something astoundingly great. It just takes that one moment of inspiration where someone crosses an orange with a snail and comes up with something nobody would have ever considered. Consider "Carrot Cake". CARROTS? CAKE? They sure don't sound like they belong in the same sentence, unless you're a cartoon rabbit character.

So if you create something totally unique and ingenious - wonderful. Wonderful for all mankind. However, Thomas Edison successfully found ten thousand ways NOT to create a light bulb. He knew what he knew but he had to discover the other parts - the parts he didn't know.

Someone created an IC in their garage. OK. I won't ask for proof of that. But for an absolute certainty nobody in any garage ever created an IC that operates at 5 gigabytes speed, or a chip with 5 terrabites of memory. The first memory chips were wire cores with toroids. Something you could create anywhere. And the old computers - the earliest, before vacuum tubes, were large banks of relays. Yes, you could build such in a garage. But in terms of modern electronics, building an integrated circuit requires a clean room with controlled lighting, temperature and humidity. Massive pieces of equipment designed to handle the lithographic's of micro-miniaturizing the traces along with advanced chemistry to deposit different types of dopants. Can you create an IC? Yes. I took a CMOS AND gate and built a device for my car. It didn't survive the environment though because back then I knew very little about noise and environmental concerns (from an electrical standpoint). Since the chip blew out in a few days, and after blowing out a few of these chips I rebuilt my device using relays and diodes. All this was done in a damp basement.

Yes, building a laser can be done. But the term LASER actually means Light Amplification by Stimulated Emission of Radiation. I don't think (and could be wrong) a LASER DIODE is a true laser. But in the interest of shining a beam of light or producing a spot on a wall simply consists of a light source and some lens or lenses to focus the beam and contain it within a near zero degree angle of dispersion. I've done such with a regular pair of reading glasses and an overhead light. By holding the glasses above the work surface at a specific point I could focus the overhead light onto my bench top and actually produce an image of the lamp itself. That's not a true "Laser", it's just focusing light and creating a projector. I've done similar with a sheet of cardboard and a small hole. Cast the shadow and the sun can be projected as an image. During eclipses you can see the progression of the moon shadow as it crosses the face of the sun. I've even cast images onto a wall using a very small mirror (12 mm diameter [or square]). Showing it off to my friends they just thought the spot on the wall was round because my mirror was round. But then, by coincidence, a seagull flew through the view and you could see a tiny shape shadow of the seagull. As clouds approached you could see the silver lining. My friends thought I was evil, possessed or in some way a wizard. Nope! Just the science of focusing light.

So, I have one question yet for you to answer: WHAT THE HECK DO YOU WANT TO DO WITH THIS LASER? Please answer that question. I've asked it several times now and as yet you've not been willing to disclose the purpose of this laser. Are you a terrorist? Do you intend to knock airliners out of the sky? Do you want to start a building on fire from a distance? Do you want to teach your children something about science? Do you want to discover a cure for something? WHAT DO YOU WANT TO DO WITH IT? Do tell.
 
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