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Why are Yellow lasers so extremely under powered??

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Just had a simple little question here. How come the yellow lasers available to the consumer market are so incredibly underpowered yet so insanely expensive? does it have something to do with the crystal or the manufacturing process? Any foreseeable future for the price of exotic yellow or orange LD's to go down?
 





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Re: Why are Yellow lasers so extremely under power

You are right about the reasons they cost so much. I'm not sure you'll see lower prices soon though. Some of them have actually gone up in price. :(
 
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Re: Why are Yellow lasers so extremely under power

They are low power because they are brutally inefficient, and incredibly unstable. You are running basically two lasers in the cavity pumped by one diode. Using the primary lasing line of YVO4 and a secondary lasing line they are summed and frequency doubled. The coatings on the YVO4 and the NLO crystal are very exacting as well as they cut of the crystals due in part to the slightly different index of refraction inherent in the two lasing lines.
 
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Re: Why are Yellow lasers so extremely under power

hmmm. thanks guys. guess i'll just stick it to blue red and green.
 
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Re: Why are Yellow lasers so extremely under power

I think I know what you mean when you say underpowered. Its a synergy between cost, and wavelength conversion inefficiencies.
 
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Re: Why are Yellow lasers so extremely under power

I can't find the thread, so can't remember the exact numbers but I remember reading about dpss lasers, that green lasers are about 30% efficient, blue is 1-3% and yellow is 1% because the various crystals can only absorb and emit so much.

That's why a 1watt irdiode makes <300mw green lasers and so you would need alot of IR then for high powered yellow.

I don't have an explanation on the price, expensive crystals? special item?
Correct me if I'm wrong
 

Brodi

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Re: Why are Yellow lasers so extremely under power

nvmextc said:
I can't find the thread, so can't remember the exact numbers but I remember reading about dpss lasers, that green lasers are about 30% efficient, blue is 1-3% and yellow is 1% because the various crystals can only absorb and emit so much.

That's why a 1watt irdiode makes <300mw green lasers and so you would need alot of IR then for high powered yellow.

I don't have an explanation on the price, expensive crystals? special item?
Correct me if I'm wrong
Where would red lasers stand then? I am fairly new when it comes to the technology behind lasers and am really trying to learn this stuff.
 
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Re: Why are Yellow lasers so extremely under power

The main reason yellow laser POINTERS are pretty sucky is that it's impractical to temp tune the crystals in it. OPO's of any sort save for gas charged cells are freakishly temperature sensitive. In truth they are thrown together in a "Let's hope it lases and if it does lets sell it" fashion. Also IR>KTP> GREEN needs heat, and IR>KTP>RED needs cooling. That means that if it falls out of a very narrow temp range it quits lasing...
 

Razako

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Re: Why are Yellow lasers so extremely under power

I have a 6-7ish mw yellow laser and it's incredibly unstable. When measuring the output it jumps all over the place. It starts out at a weak 2-3mw and slowly climes up to around 5mw where it stays for a minute or two before quickly jumping up to 6-7mw. After the peak it drops back down to ~4-5mw and eventually drops lower as the laser heats up or the batteries start dying.

If you want stability and consistent output 594nm isn't for you. You can never be sure what yellows are going to do when you turn them on because there is a huge amount of variables that can change the output.
 
C

carulli

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Re: Why are Yellow lasers so extremely under power

Brodi said:
[quote author=nvmextc link=1211260372/0#5 date=1211769456]I can't find the thread, so can't remember the exact numbers but I remember reading about dpss lasers, that green lasers are about 30% efficient, blue is 1-3% and yellow is 1% because the various crystals can only absorb and emit so much.

That's why a 1watt irdiode makes <300mw green lasers and so you would need alot of IR then for high powered yellow.

I don't have an explanation on the price, expensive crystals? special item?
Correct me if I'm wrong
Where would red lasers stand then? I am fairly new when it comes to the technology behind lasers and am really trying to learn this stuff.[/quote]


Red lasers generaly are are not DPSS, this means the do not use a ir diode that pumps a crystals.
 
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Re: Why are Yellow lasers so extremely under power

nvmextc said:
I can't find the thread, so can't remember the exact numbers but I remember reading about dpss lasers, that green lasers are about 30% efficient, blue is 1-3% and yellow is 1% because the various crystals can only absorb and emit so much.

That's why a 1watt irdiode makes <300mw green lasers and so you would need alot of IR then for high powered yellow.

I don't have an explanation on the price, expensive crystals? special item?
Correct me if I'm wrong
wow! so if you take the infrared diode out of a blue or yellow....how powerful is that??

is it really as simple as, i can buy a cheap DX laser, take out the crystals, and i have myself a strong burning infrared laser? will my phone's camera pick up infrared like the TV remote infrared or will i need a special filter to see this? (as you can see i lack a bit of knowledge on infrared lol)
 
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Re: Why are Yellow lasers so extremely under power

No, its not as simple as just removing the crystals - all you'll have then is a highly divergent IR diode (which you can get dirt cheap on eBay anyway). You're right that they'll be high power though. My Prometheus 300-400mW green lasers use the same 2.5W pump as my Oceanus 20-40mW blues. The crystals for blue are more expensive, the process is more finnicky, and much more inefficient. Basically means big bucks per mW and a laser less stable than a greenie.

Yellow is even worse than blue! Its amazing we even get them in portable form at all. As chimp and heruur explained, you don't have just one DPSS process IE 808->1064 (for green) or 808->946 (for blue) to worry about, you have two (808->1064 and 808->1342) that both have to have their ideal conditions to give you any output at all. Even the slightest temp change of any component can make or break your already scant efficiency :eek:
 
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Re: Why are Yellow lasers so extremely under power

green is 20 percent efficient but can get to 30.blue is 1-3 percent efficient.Yellow is 1 percent.i got that from wiki
 
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Re: Why are Yellow lasers so extremely under power

jamilm9 said:
green is 20 percent efficient but can get to 30.blue is 1-3 percent efficient.Yellow is 1 percent.i got that from wiki

DX thought I was possibly going to buy tons of 200mw gerrnies, so they sent me a very nice one. It stabilises aorund 165 after its been on quite some time. 20-30mW 808. very stable, super bright. I'd bet this one happens to be a 30%'er, based on the stability I see, and (lack) of heat produced. Also, comparing with other DX 200's characteristics, and other known info. its so nice having a workable 200 DX, as something about the pen is nicer than the flashlight.

what I would like, is a nicely enginered 500mw output (finest of materials), engineered so it can still fit in the pen style. i bet it could be done using the highest efficiency xtals, and possibly turning the head (instead of black rubber), into low profile heat sink. who knows.
 




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