Visible Laser Fluorescence

[dsholz]

I've got a optics experiment where I need to use some uncollimated laser light from either a casio laser projector, (unmodified), or a microvision picoprojector, (unmodified) to cause some reasonable amount of fluorescence on an otherwise optically transparent surface (so that's using any of the following wavelengths: 640nm, 532nm, or 445nm).

Does anyone know of something easily available (outside of industrial biological dyes) that might allow me to do this?

 

[chipdouglas]

if you want the best fluoresence then go with a black light. if too big then go with a 405nm.

not many materials react with 640 or 532. and the same materials don't react to the wavelengths. and 445nm is too powerful of a diode to get good results.

michael.

 

[Cyparagon]

We need more info. Any self-respecting scientist would write more than two sentences in order to adequately explain an experiment.

 

[dsholz]

Hey Cyparagon, no need to get personal. This is just some side work for a private company that wanted to generate some fairly complicated fluorescence based patterns at high speeds. The patterns are a bit too complex and the speeds are a bit too high for a low cost scanning mirror setup, so I figured a DLP based (or raster scanned Microvision) projector might be a decent way to go (and I happened to have these laying around from some previous work). Alternatively, I could grab a Casio with its diodes removed and throw in a high power 405nm module (where the 445nm ones were), but the fluorescent image would be a fair bit more dim by comparison (since I certainly don't want to try to come up with 20+ watts of 405nm light).

 

[chipdouglas]

does the device have to constantly be scanning the image or is it just one pass then take of photo of the scanned fluoresent image?

remember the more laser power is not better. it will drowned out the fluoresence.

michael.

 

[dsholz]

Unfortunately, it needs to be constantly scanned.

More laser power (in the case of the 405nm solution), would probably matter, because the laser light would be evenly spread out over a potentially large surface. I'm a bit afraid that only around a single watt of 405nm (from a single diode/module drop-in replacement) wouldn't work particularly well because of this (the power density would end up being in the low microwatt range, I think)

 

[Benm]

445 could be pretty good to pump some glow in the dark paints and powders, but you'd need to experiment on that.

If you want to illuminate a large area i would recommend going for UV leds though, there are 1 (and even 3) watt star models available that chuck out quite a bit of uv for a lower cost than bluray laser diodes with the same optical power.

 

[dsholz]

Benm: Thanks for suggesting the UV LEDs, I hadn't realized they had progressed to 3 Watt power levels yet. That's certainly a valid option now, if I want to swamp them into a DLP projector.

I'm still hoping though someone might have some ideas for something that works with one of the other wavelengths though (it would be a lot easier to be able to use something I already have ready to go).

 

[Things]

445 still does a decent job with stuff like glow powder/paint, maybe get a sample and do some testing

 

[dsholz]

Things: You mean the kind that keeps on glowing by itself after being illuminated? Unfortunately, I need stuff that goes dark immediately after the illumination cuts off (so that I can do fast redraws).

BenM: On another note... I always knew that there were super high power Red LEDs, but apparently there are actually some 10-40 watt UV LEDs on the market, these things look terrifying:

10 Watts

40 Watts

 

[jimdt7]

I think you should buy some 500mw 405nm lasers ! I think that 405nm does better job with
fluorescence. Also buy a pair of good pair of laser glasses because you have only two eyes !

 

[dsholz]

Actually, as those LEDs are actually 365nm, I think they would lead to better fluorescence than a 405nm LED (although I still would prefer to use another wavelength, if possible).

 

[Trevor]

Hey Cyparagon, no need to get personal. This is just some side work for a private company that wanted to generate some fairly complicated fluorescence based patterns at high speeds. The patterns are a bit too complex and the speeds are a bit too high for a low cost scanning mirror setup, so I figured a DLP based (or raster scanned Microvision) projector might be a decent way to go (and I happened to have these laying around from some previous work). Alternatively, I could grab a Casio with its diodes removed and throw in a high power 405nm module (where the 445nm ones were), but the fluorescent image would be a fair bit more dim by comparison (since I certainly don't want to try to come up with 20+ watts of 405nm light).

A self-respecting "private company" doesn't need to hire a random hobbyist.

A self-respecting laser professional (???) doesn't need to go on a forum to ask some hobbyists how to do a job he or she is to be paid for.

I'm not sure what's going on here, but it sure is fishy. :can:

-Trevor

 

[chipdouglas]

Things: You mean the kind that keeps on glowing by itself after being illuminated? Unfortunately, I need stuff that goes dark immediately after the illumination cuts off (so that I can do fast redraws).

BenM: On another note... I always knew that there were super high power Red LEDs, but apparently there are actually some 10-40 watt UV LEDs on the market, these things look terrifying:

10 Watts

40 Watts

maybe you are not explaing the project correctly... it has to fluorese, but only for the time the scanning laser/led hits it.

i don't see the logic there. especially since you want a high powered light source too. you will not be able to see the fluoresence.

michael.