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Colors, beam beam brightness & burning! The differences please!

waterface

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Hi, i think i've asked before but can't find my post!

So whats the difference in colours?

Blue, red, green, violet, orange etc! All i know is that green is the most visible to the naked eye & blues are the best burners!

How come there is a 1.7w in blue for wample but not in green or red!? A brief explanation or link appreciated as i'm wanting a new laser that has a really bright beam & yet burns like a blue, but i hear blues aren't that visible, maybe i'm wrong!

Cheers!
 

IsaacT

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Okay, I'll do my best to cover all the bases.

COLOR: Better to think of it as wavelength. The visible spectrum goes from about 400nm to 800nm(although 800 would be near impossible to see I think you might could see a glow at higher powers). The lower the wavelength of the laser, the higher frequency. Because of this, lower wavelength lasers will burn better. This is because the photons are more densely packed, whereas with higher wavelength lasers the photons are spread more.

So a 405nm would be like:
-------------------------
And a 650nm would be like:
- - - - - - - - - - - - - - -

So per mw, 405nm lasers will burn better than 445nm lasers.

BRIGHTNESS: The peak of human eye sensitivity is somewhere around 515nm(EDIT: 555nm!). So per mw, 515nm(EDIT: 555nm!) color would be much brighter than that of colors further away. 532nm is close enough to the peak that it seems to be the brightest wavelength of laser. 445nm would be close behind that, and 405nm and 650nm are much further down and harder to see because of how far from the peak they are.

405------445---473------532-555--589---635--650------------800
LOW----------------------|--PEAK------------ LOW--------IR/NEAR IR



POWER: This all has to do with the stability of the chemicals they use to make the diodes. The materials used to build 445nm diodes seem to be able to take a hell of a lot more current and heat than those of 405nm or 650nm.
Also, 532nm 589nm 473nm, etc. are all DPSS lasers, so you lose a lot of power in the conversion process and cheap crystal setups wont take enough heat so powerful ones are more difficult to find....and much more expensive.


I think that was everything, if anyone sees any errors let me know, and if you have any other questions feel free to PM me. What I don't know I would love to find out.

Cheers,
Isaac


PS- A high power blue will have a very visible and pleasing beam. I consider them to be the best of both worlds, so if you want both visibility and burning, that should be your best bet.
 
Last edited:

ZRaffleticket

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Compare beams/spots with this.

Wavelength - color - type - power - notes

405nm - violet - single mode diode - rarely reaches the 1W mark - blu-ray diodes
445nm/450nm - royal blue - single mode (SM) OR multimode (MM) diode - multimode can be pushed past 2W from multiple emitters, single mode can make it past 200mW
473nm - light blue - DPSS - rare and hard to produce, 100mW is about what you can get in a handheld - try lasever.com and go with a custom host, cheapest, most powerful option for handhelds
488nm - greenish blue or cyan - OPSL or gas - needs a lot of active cooling and a ton of power for gas, needs proper alignment and cooling for OPSL
510-525nm - green - diode - pretty hard to find, cutting edge technology that's starting to pop up, not much more power than 50mW due to this - can be bought from laserbtb.
532nm - green - DPSS - very common, starting to see modules get affordable in the range before 1000mW's - once again recommending custom lasever or laserbtb.
556nm - yellow-green - DPSS - not powerful whatsoever, inefficient and hard to align - CNI sells these, but I mentioned this because it's ~1nm above the peak sensitivity of the average human eye: regarding 555nm, the lower in nm the dimmer and the higher in nm the dimmer (per milliwatt)
561nm - yellow-green - DPSS - not powerful, though can easily be purchased for under $1k at around 5-15mW - CNI is a good source

589nm - yellow/orange - DPSS - can reach about 100mW's as the highest advertisement in a portable, almost as bright as a 532nm per mW. - CNI and laserglow sell these
593.5nm - yellow/orange - DPSS - not powerful, 30mW's is really pushing these in a handheld - mostly replaced by 589nm due to this one's inefficiency and mode hops, CNI/LG

607nm - orange - ??? - just wanted to throw this in there, considerably less than 3k for 200mW - not sure what the process is called but instead of an IR pump it's a 445nm pump, sold by kvant
635nm - cherry red - diode (SM or MM) - these can make it to 1W in the multimode lasers, as for the SM diodes they might reach 200mW's, not 100% sure - much more visible than 650nm and these can be found everywhere, DTR is a good source since he sells them and is a very good member
650/660nm - red - diode (SM or MM) - the 1W models have huge beams and are MM, and the SM ones ma out around 300mW's, usually having some wings. - the 250-300mW ones usually are the cheap $30 red lasers you find on the internet, don't trust all the ones that say 1W or more.
671nm - red - DPSS - 400mW is the most you'll see out of a handheld - sold by CNI or make a custom lasever.

Anything lower than 400nm is UV and higher than 700nm is IR (well, close enough to it. not sure what the exact starting points are but these are accurate enough for me)

Hopefully this coffee fueled... brick... is pretty helpful.


@Wannaburnstuff the only thing wrong there is the peak sensitivity set at 515nm, it's 555nm. Photopic vision is what "sees" colors, and is centered at 555nm. Scoptopic vision is set in your range and only deals with fractions of milliwatts IIRC.
 

brucemir

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Hey wannaburnstuff and Zraffleticket, two GREAT posts that explain a lot to some of us who are afraid to ask!
 

IsaacT

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Ahh yes! I always forget that bit! Thanks for the correction, I'll edit my post above accordingly.

Isaac
 

waterface

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Thanks wannaburnstuff for your informative posts, i'm looking at getting a high powered blue when i have funds!!

I guess as in best of both worlds a cyan blue would be better than a darker blue!?
 

IsaacT

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A cyan blue(I think you are referring to 473nm) will be very expensive and you will not be able to find high powered ones. 445nm will be your best bet....I equate it to like a sapphire blue.
 




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