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Solar Pumped Laser

makay

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Hi everyone,
I'm just in the process of starting an open source project on creating a sun-pumped laser using a YAG rod. I'm not a physician but a product designer and want to make a open source sun-powered laser cutter (or to start with engraver) which is (once working) to be used in off-grid environments in the ever growing off-grid cities of the world but also in rural setting where there is no electricity. I am really interested in the hacking culture of devices to produce a guide using readymade materials like the rod and the mirror set up in combination with a large fresnel lens focussing the light into fiber optics and from what i understand there needs to be a proper cooling system to not brake the crystal. Anyone who has got some advise on this subject or tried to build one already please share the knowledge its for a good cause but also a really current subject.
Best wishes,
m
 



goninanbl00d

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In theory, it is possible. However, in practice, there's many issues that need to be taken into account.

Firstly, you'd need a large Fresnel rod and a relatively small YAG rod in order to acheive the necessary power densities.

Yes, the rod will also need to be cooled. Although there will be many hundreds of watts of sunlight focused onto the rod, only a few of those will be the 808nm required by the YAG. Using a bandpass filter may reduce the cooling requirements of the YAG rod.

I'm too sleepy to think of everything, but here's a start.
 

makay

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Thank you for making a start!
I'm in the process of creating a website trying to accumulate as much knowledge about the solar-pumped lasers as possible so as many people as possible can have a go at experimenting.
I was thinking of at least one square meter fresnel lens to focus the light. Here is a link to a big experiment in japan where they have 4 sq m fresnel lenses creating a fair amount of power.

Experimental study of solar pumped laser for magnesium-hydrogen energy cycle

if this could be done on a smaller and more affordable way e.g. hacking existing lasers it could work.
what do you think .....?
 

heruursciences

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The hard way: It would be something like fresnel lens or parabolic mirror to gather the sun's light, filter to reject the heat but pass everything shotrer than about 1,000nm. Condenser lens to concentrate the light, with other beam shaping optics. The light would be focused into a dye mixture surrounding the rod that converts the light to near 808nm. Alternately the sunlight can pump a flowing dye laser for better efficiency.

The easier way: Sun, solar battery charger, electrically driven yag laser
 

RA_pierce

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Don't forget that the Earth rotates in its orbit.
You'd have to adjust it every couple of minutes if you want the sunlight to remain focused at the same point.
 

makay

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Yes the fresnel lens definitely needs to be mounted on a solar tracking device. I understand that it seems to be the hard way but i think its worth trying for the quality of direct sunlight power and as little electricity as possible. I think also that fresnel lenses are fairly cheap in comparison with large photovoltaic cells and drivers and batteries. I think conceptually to use the sun directly without any batteries, even if it only works at day, makes sense. A machine that sleeps at night cannot keep anyone awake doing night shifts. A small computer, run on open source software and a small motors to move the laser head and the tracking device- thats where electricity is still needed but a fairly small panel should do it.
Any detailed descriptions of a possible solar laser set up?
 

Bluefan

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Nd:YAG probably has more absorbtion in it's spectra than 808nm, but 808nm is (no surprise) the best. I think a large solar cell powering a 808nm diode bar will be far more practical and efficient, and much cheaper than large optics and filters.

Solar cells have a relatively low efficiency and diode bars add losses too, but the eventual 808nm output will be far better than hard to focus spectrally rubbish sunlight which will be VERY lossy.
 
D

Deleted member 59864

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would it be easier to build a sunlight pumped laser if we first used a prism to separate out the bands for individual treatment? in my specific use case the goal is to convert everything into UV for industrial use.
 

Encap

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would it be easier to build a sunlight pumped laser if we first used a prism to separate out the bands for individual treatment? in my specific use case the goal is to convert everything into UV for industrial use.

What about on overcast or cloudy days? lol

No -is a good guess.

Use a prism to separate the wavelengths in sunlight--why for what reason or reasons? Bands for individual treatment?? What do you mean by "bands", what do you mean by "treatment"?
Convert " everything" meaning what --define "everything"? Into UV? --how do you imagine that might be accomplished?
Explain please.

My guess is what you are imagining can only exist in imagination for several reasons--- is just a daydream/imagining of yours.
Anything is possible in imagination, not so in the real world.

If a solar pumped lasers could be done in any practical, cost effective, reliable, viable versatile way so as to be useful in any way for anything, my guess is it would have been done and in use 100,000X, already.
PS Solar-pumped lasers are not used commercially because the low cost of electricity in most locations means that other more efficient types of lasers that run on electrical power can be more economically used .
 
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D

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1) the UV light is needed for an industrial process
2) by breaking the sunlight out into segmented bands of spectrum it can be used to feed conversion crystals (like how a green laser works)
3) this would be part of a renewable energy system, so grid sourced or PV electric power is NOT an option.
4) having worked with engineers in the past I know their first reaction is to shit on any new idea until they see it working, so I can comprehend your confusion.

now going in the other direction of inferred heat would be of interest to Bill Gates and his current Heliostat project, by converting all available sunlight into IR light it would better be able to heat the target, with temps high enough water can be thermally cracked into H2 and O2. IMHO the initial ideal application for such Hydrogen is supplying the Haber process used to produce ammonia for the commercial manufacture of chemical fertilizer.


What about on overcast or cloudy days? lol

No -is a good guess.

Use a prism to separate the wavelengths in sunlight--why for what reason or reasons? Bands for individual treatment?? What do you mean by that--what bands, what treatment?
Convert " everything" meaning what --define "everything"? Convert what into UV? --how do you imagine that might be accomplished?
Explain please.

My guess is what you are imagining can only exist in imagination for several reasons--- is just a daydream/imagining of yours.
Anything is possible in imagination, not so in the real world.

If a solar pumped lasers could be done in any practical, cost effective, reliable, viable way to be useful in any way for anything, my guess is i would have been done and in use 100,000X, already.

PS Solar-pumped lasers are not used commercially because the low cost of electricity in most locations means that other more efficient types of lasers that run on electrical power can be more economically used .
 

paul1598419

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I assume you are talking about a Nd doped YAG. These only absorb at very specific wavelengths. All others are useless. Many are driven with 808nm pump diodes as Nd does absorb well there. Nd: YVO4 is much more efficient, however.
 

WizardG

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would it be easier to build a sunlight pumped laser if we first used a prism to separate out the bands for individual treatment? in my specific use case the goal is to convert everything into UV for industrial use.

Did you read through the whole thread (which has been dead for a decade)? No, it would not be easy, or practical. Not in any sense. As stated you would be far better off with bunch of solar cells and an inverter.

This isn't a matter of engineers poo-poo'ing an idea they don't know how to make work. This is a matter of physics. We do know how to make it work. There have been lab' demos of solar pumped lasers. But the physics says the overall system efficiency will be garbage. Solar cells==>inverter==>commercially available UV laser is a system that will work better, cheaper, smaller, etc.
 

Encap

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1) the UV light is needed for an industrial process
2) by breaking the sunlight out into segmented bands of spectrum it can be used to feed conversion crystals (like how a green laser works)
3) this would be part of a renewable energy system, so grid sourced or PV electric power is NOT an option.
4) having worked with engineers in the past I know their first reaction is to shit on any new idea until they see it working, so I can comprehend your confusion.

now going in the other direction of inferred heat would be of interest to Bill Gates and his current Heliostat project, by converting all available sunlight into IR light it would better be able to heat the target, with temps high enough water can be thermally cracked into H2 and O2. IMHO the initial ideal application for such Hydrogen is supplying the Haber process used to produce ammonia for the commercial manufacture of chemical fertilizer.
Necroposting in a thread dead since 2010 notwithstanding.

In another thread your post #44 says: "There is an application requiring lots of UV light for the catalytic formation of a product, the desired power input is sunlight but the process doesn't work as well with full spectrum natural light. this is why a method to convert full spectrum sunlight into all or mostly UV is desirable. My question is how to go about creating the crystals or other components necessary to achieve this conversion goal. " Post #44 here: https://laserpointerforums.com/threads/solar-laser.97487/

It seems that with regards to using sunlight you are living in a daydream of your own design.
I get what you are imagining in your imagination regarding converting the entire spectrum of visible light sunlight and maybe a little of the invisible as well sunlight into UV laser light but that is purely an imaginary thing--a daydream not related to how photons behave in the real world and how the sunlight spectrum photons can and do function and interact with matter.
"Something for nothing doesn't exist, never has, never will " applies to the generation of electromagnetic energy of whatever frequency---as well as money and most everything else as well.

Probably would be a good idea to get an education about solar power generation as a primer on what is involved in something far simpler and easy to accomplish--- transforming sunlight into another form of energy.
State of the art in solar energy---maybe $25,000 of massive space consuming and ugly solar panels can supply a home with $100 of electricity per month until they fail? A typical U.S. home is 2,300 sq ft in size and uses about 1,000 kWh of electric power per month. The average location in the U.S. has about 5 hours of solar resource. This means the average needs to generate 1,000 kW of power to offset their $100/month electric bill. Given that an average home has access to 150 hours of solar resource per month (5 x 30 days), in order to generate 1000 kWh per month, a typical house would have to install a (1,000kWh/150hrs) 6.67kW solar system. Using the above estimates, a typical U.S. household would require approximately 30 kWh of energy storage capacity per day as well. As a rule of thumb, relatively low cost old lead acid batteries run about $200/kWh and standard lithium-ion between $500-$1000/kWh so 30X that is needed for autonomy + cost of a charge controller or controllers and a battery inverter/charger. --- all of that for $100/month of electric power?
Have a look at : https://www.solarquotes.com.au/blog/uv-solar-panels/

Basic physics---Conservation of energy see: https://en.wikipedia.org/wiki/Conservation_of_energy#Mass–energy_equivalence

Pretty clearly, you have no idea of what you are talking about with regards to electromagnetic spectrum, sunlight, photon wavelengths and photon interactions with matter, and especially lasers and what they are and are not and how they work/ function.

There are no "bands" ---bands of any kind are an artificial human created concept to make it conceptually easier to talk about how different portions of the electromagnetic spectrum interact with materials---just a name/symbol for portion of the electromagnetic spectrum--a range of energy/frequency or a name for a range of a spectrum---the visible spectrum is one continuous spectral expanse/range/"band" within electromagnetic wavelength spectrum.
Creating an artificial/pretend conceptual " breaking the sunlight out into segmented bands of spectrum so same can be used to feed "conversion crystals (like how a green laser works)" is not at all how a green DPSS laser is created and functions in the real world--much less an indication of how you would transform the entire spectrum of sunlight into UV light only---no such crystals or technology exists anymore than "dilithium crystals" from Star Trek exist. See: http://www.mit.edu/~locutus/SFB/rules/node12.html and https://en.wikipedia.org/wiki/Dilithium_(Star_Trek)

Maybe the below explainations will help with practical real world physics and physical reality vs imaginary physics and imagined physical realities i.e. an imaginary world.

"The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies.
The electromagnetic spectrum covers electromagnetic waves with frequencies ranging from below one hertz to above 1025 hertz, corresponding to wavelengths from thousands of kilometers down to a fraction of the size of an atomic nucleus. This frequency range is divided into separate " frequency bands", and the electromagnetic waves within each frequency band are called by different names; beginning at the low frequency (long wavelength) end of the spectrum these are: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays at the high-frequency (short wavelength) end. The electromagnetic waves in each of these bands and the reason they are named "bands" is because they have different characteristics, such as how they are produced, how they interact with matter, and their practical applications."
See: https://en.wikipedia.org/wiki/Electromagnetic_spectrum

"The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. The Visible spectrum has no "bands" it is one continuous increasing or decreasing photon energy level spread across the entire range called visible spectrum.
A typical human eye will respond to wavelengths from about 380 to 740 nanometers." see: https://en.wikipedia.org/wiki/Visible_spectrum
 
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barthchris

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Ive heard Mars atmosphere has the conditions prime for a natural laser. This was MANY years ago though.
 

WizardG

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Ive heard Mars atmosphere has the conditions prime for a natural laser. This was MANY years ago though.
Mars atmosphere frequently IS a natural laser. Pumped by solar UV. We've detected the 10.6 um radiation from Mars with our satellites.
 
D

Deleted member 59864

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I was going to post the link to the press release I am referencing, but your SPAM bot Nannie forbids it, so search for it yourself or not.
Google search terms, "
Liquid hydrocarbon fuel created from CO2 and water in breakthrough one-step process
By Colin Jeffery
February 24, 2016"

the New ATLAS link is the correct one.
 




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