Need help choosing a 405nm laser & optics

Hello, I'm new here and really don't know that much about lasers... however, I have a need for a 405nm "blacklight" laser and thought I might get some help in this forum. Thanks in advance.

I'm an artist who works with fluorescent and phosphorescent pigments. For a very long time I've looked into a good, strong blacklight source other than the standard 4' fluorescent tubes. Beside expensive and hot theatrical lighting, the 4' tubes are the best, but they don't pack much punch in daylight and they're big and ugly.

As new UV LEDs have come out I've tried to use them for a alternative and compact UV source, but they generally don't work as well as fluorescent tubes for what I do. The other day a friend came over with a cheap violet laser and it really lit up my paintings. I shot the laser through an old pair of binoculars to diffuse the beam and it worked better than any blacklight I've ever seen in daylight.

This gave me the idea of getting my own 405nm laser and some sort of diffusing optical attachment specifically to illuminate paintings - as I began looking around online I began to get confused with all the specs and details. I hoped there might be something I could buy with focal attachments - like a 405nm version of a green laser illuminator flashlight - but haven't easily found what I'm needing.

I sent a request for info from a couple of lab laser/ optics places and got quotes of several thousand dollars - not what I'm looking for.

I'm back to the handheld laser till I can figure it out. If it works well I might try something more professional for an always on duty-cycle.

Anyone know of a 405nm laser (I assume I'll need a powerful one) that has the fittings to attach diffusion optics, or has enough focus control to illuminate a 3x3 foot area (or more)? Or know where to find the laser/optics to EASILY make something for $200-$300 (less is better). If I can screw around and pop balloons, thats a bonus but not my aim. Any help is needed and welcome... maybe theres a really simple solution.

A few other questions:
I see a lot of laser companies are in China - I've seen the recommended sites in this forum - are there any problems with customs, etc. to the USA? Duty Fees? Is it generally legal to buy/own these lasers from China?

I've looked at these lasers - any recommendations tips or help?
Thanks.

500mw kit:
Survival Laser V 405nm Parts Bundle - Laser Components Only

300mw adjustable:
300mW 405nm Waterproof Adjustable Violet Blue Laser Pointer Pen

500mw waterproof
LZMG - MAGNUM 405nm 500mW Violet Laser Pointer Water Proof

100mW should be fine for your purposes.
There are many sources for focusable 405nm lasers and they are pretty cheap these days, too.

I've never heard of the second company and the third product is sold out.

Try these:

405nm 100mW blu-ray pen /adjustable [OLBVL100] - $69.99 : Zen Cart!, The Art of E-commerce

Power Rock 400mW blu-ray 405nm laser torch/adjustable/waterproof [OL-405T-400] - $102.99 : Zen Cart!, The Art of E-commerce

Try the Buy, Sell, Trade fprum, too. You may be able to find a good deal on just what you need.

I use my 650nm for a similar purpose (general illumination) and it does indeed work better than something similar but with LEDs. Any focusable laser will let you diffuse it enough to be safe and to do what you want.

As far as duty cycle goes you just need it to be in a good heatsink. Most handhelds are limited in their on times as heat builds up in a tiny host. You can contact some of the machinists and/or custom builders here on the board about a custom build using a low powered 12X BR diode. That would pretty much guarantee unlimited runtime.

I'd think as above 100mW would do fine, but a really bright room would require maybe 250mW tops depending on how well your phosphors react to 405nm. Just make sure it is really diffused out wide, for safety.

As far as where to buy from; I haven't heard anything good about Laserman, I'd avoid it. Survival Lasers are exceptionally good quality and perfectly legal here in the US; technically they don't sell pointers and no laser is sold assembled. A bit pricy but you get better quality than ordering from china, by far. Lazerer is a good place to get chinese stuff from on the cheap. I've ordered stuff from them and Laserlands before with no problems at all, it is cheap and you get what you pay for though, it won't compare to Survival Laser or Laserglow (CNI). A custom build by an expert builder here will absolutely be the highest quality and lowest price for that quality you can buy. People like DTR, RHD, Ehgemus, Eudaimonium, Lazeerer, etc are masters of their craft.

If you can get someone to build a: "Aixiz module heatsink adapter" that fits in one of StyroPyro's Lab Heatsinks (or similar); just get the adapter and lab heatsink with one of DTR's 405nm "ready to go" modules and you can put it together in a few minutes, and it should last a lifetime. That is what I would do in your shoes. (In fact I am doing a handheld version of that; DTR Module + Eudaimonium Host.)

Thank you. Thats super helpful.
I'm leaning towards SurvivalLasers... I might also order something cheap from China and see how it goes.

I asked about the legality of the Chinese laser imports only because I know of someone who bought a 24 pack of cheap Tritium keychain holders from some Chinese website - instead of the keychains showing up at the door it was the FBI, the NRC, and a 6 month legal issue.

I don't want to be that guy...

Cheers and Thanks.

if you want it to be always on i would NOT go with a handheld style laser.......

Tritium is a controlled substance that is illegal to own in quantities larger than the exempt amount. NRC is no joke, don't mess with radioactive materials without a license.

In the US it is legal to own any power of laser at any wavelength and in any shape/form. It is only illegal to SELL non CRDH certified lasers over 5mW that are assembled and marketed as "pointers" or "handhelds". So, you as a buyer cannot get in trouble for buying a laser. It can get ceased at customs and confiscated though, but you won't get in trouble. Buying/selling in parts or OEM modules is perfectly safe.

Both Lazerer and Laserlands have had no problems getting things through customs from what I can tell though. All of my orders and all of the orders I have read about have made it through no problem into the US.

Thanks again! I'll see how it goes, if this works like I want it to I'll post some pics. If I need to get more serious and make a safe, constant-on device (like something I could use in a gallery setting) , I definitely might see if I can get someone here to build me something custom - I like that idea a lot more than sending $ to China.

ShawPoster said:

Hello, I'm new here and really don't know that much about lasers... however, I have a need for a 405nm "blacklight" laser and thought I might get some help in this forum. Thanks in advance.

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UV led flashlights would be an option worth looking into.

Some dyes don't react the same to <390nm as they do 405/410nm, so the effect may not be apropriate. However, I would agree about trying LEDs. Just gotta be sure your LEDs are on wavelength. Too many sellers sell NUV LEDs with wrong wavelengths.

With the proper optics a sufficient beam spread that will yield a safe power density for 200mW can be attained though, if you do wish to use lasers instead.

Thanks to everyone who's offered advice with my "blacklight" laser project. I thought I'd share my current results.

I purchased a 500mw, 405nm kit from SurvivalLasers. Great service from them, they shipped immediately last Fri, I got my laser Monday morning. Plus I used the 10%off coupon code I found here on LPF. The kit was a snap to assemble, no problems or issues whatsoever. SurvivalLasers gets an A+ rating from me, from the clarity of the documentation to the product, to the shipping, all was easy and smooth. I didn't feel funky about ordering something from China.

The laser works great & is solidly built. I wanted to use it as a powerful blacklight "spot" to illuminate some fluorescent paintings - to do this I have the lens almost completely unfocused which creates a dot approx. 3 feet in diameter from across my studio. The laser doesn't light the whole room, which means it doesn't really affect other art in the same room (unlike most blacklights). Thats important to me, and would be crucial if I ever modified this lighting "system" for use in a gallery setting where it might share space with non-blacklight art.

The light is FAR brighter than my bank of 6, 4' blacklight tubes and really makes standard fluorescent pigments glow nicely. Europium and other glow-in-the-dark pigments absolutely go crazy. The laser also works much better than any UV LEDs or LED flashlights I've tried. The only thing similar I've used was a long-throw UV spot projector for showbiz - the laser is very similar, but the spot is obviously smaller, not stage-size.

- The fully diffused laser illuminates the fluorescent art almost TOO BRIGHTLY in total darkness.
- In a mixed light environment, at night, the glowing was pretty impressive.
- The laser did a SUPERB job with achieving a glow with indirect daylight - better than anything I've used previously, even expensive UV stage lights.
- In direct sunlight, and bright daylight the laser didn't do much to the fluorescent pigments from a distance (I didn't expect it to).

The one thing that is not perfect is that the diffused beam is not completely even - that is, there seems to be some fuzzy dots in an area of the beam. The dots don't turn when I adjust the focus, so I assume they must be from the diode. Maybe its a spec of dust (I didn't see one and blew some air) - maybe its just something unfocused lasers do - I dunno.

While everything works great, I do have some concerns:

- I'm concerned how safe the diffused & reflected laser light is for a viewer (who would not be wearing laser glasses). The beam is diffused to 3' dia. though at 500mw the laser I have is a Class4 - technically, even its diffused reflected light could be harmful. I'll get a lower powered laser and see if it still works - though I suspect it may not be bright enough for use in ambient light. I'm also wondering if this diode outputs Infrared. Till I know more its goggles only or I'm not looking at it, which takes away a bit of fun.

- I've worked with blacklights for 20 years - I know they are generally considered safe, but I don't know much about the specifics of the 405nm laser and its light. Especially since its so much brighter than a standard blacklight even when completely unfocused. I do know about the hazards of blue laser light, and wonder if 405nm is close enough in wavelength to have any similar hazards.

- As expected, the laser I bought has a short duty-cycle. If this system was to be used to constantly illuminate an artwork, a laser with a constant duty-cycle would be required (as well as a safe viewing power). Thats probably a chunk of cash - and perhaps not worth the bang for the buck. That said, again, as a blacklight "spot" it works better than anything I've ever seen, so the test was a success. I may or may not pursue the lighting concept. I'll try a low-power laser or two before doing anything more.

I'll be happy to post some photos of the laser illuminating blacklight stuff if anyone cares.

Thanks again for the advice and help.

*** As a side report, I did focus the laser completely, it will burn all sorts of stuff easily, even white colored stuff. It can be focused to a very small point and burn sharp micro-lines... pretty cool. When even partially focused this laser is extremely bright and goggles are a MUST! I was concerned about the unfocused beam generating heat on the artwork - not a problem from a distance - though when totally unfocused I could still feel the beam's heat on my hand from a foot or two away. When focused, I'd expect this laser to generate heat - even a a good distance, its surely not a toy. If you are looking for a cool laser to show your friends, this is NOT it - its way too bright for showing off or pointing at stuff, anyone around will need goggles, really! Of course with the goggles, you won't see that cool violet color, if you want to play with a violet laser and see it, get something MUCH less powerful. My 2-cents.

UV led flashlights would be an option worth looking into.

Some dyes don't react the same to <390nm as they do 405/410nm, so the effect may not be apropriate. However, I would agree about trying LEDs. Just gotta be sure your LEDs are on wavelength. Too many sellers sell NUV LEDs with wrong wavelengths.

The 405nm laser works great with most standard fluorescent pigments, like you might find in artist's paints etc. You can get a stronger glow in some colors with some shorter wavelengthight - but 405 seems to look great to me in general.

I've tried a bunch of UV flashlights - my favorite being the Novi UV. I've also tried some larger models with 40 UV LEDs, etc... they all definitely work, especially in total darkness, but after a short distance they lose their effect in ambient light. I was hoping to find a solution that would illuminate fluorescent art -brightly- in basic, incandescent room-light.

I've tried some larger single LED UV models too, with the same basic results.

If anyone cares about blacklight... the LED "blacklight" DJ lights (like from RadioShak etc.) really don't do much for fluorescents, same goes with the compact fluorescent "blacklight" bulbs (they're just dipped in purple lacquer and don't give off strong UV). Bang for the buck is still the tried and true "blacklight" fluorescent tube. They'll light up a whole room easily - but they cant be used for a strong spotlight - my aim. -THX

Great report! I would love to see some photos. :wave:

The limit for direct laser light is 1mW/cm^2 (1mW per square centimeter). Reflected diffused light would be less of a danger as well. I'd do the math for you but I suck doing things like converting units of area. if 500mW/3ft^2 is < than 1mW/cm^2 you're good to go. The only real danger is someone turning around and facing the laser - if it was mounted above on a celing rack in a gallery, you could avoid that hazard.

awesome, I'll do that math! Thx.

Also, there is no IR in a 405nm laser diode. It specifically has just one wavelength--405nm. You only need to worry about IR when using DPSS lasers, like 532nm green.

You might try putting a piece of frosted glass in front of the laser. It should widen the spread and make it more of an even glow. Should also make it just a little bit safer since there won't be any directs beam.

FYI: if I did the math right... all is OK. Makes me feel better but I'll surely use caution and care with this laser, focused or not. If ever used in "public" it would need to be 100% safe, so no kid ever looks at it, etc.

1'd. circle = 729.29cm2 the 500mw laser would be 0.685mw per sq cm.
2' circle = 2917.15cm2 - 0.171 mw per sq cm
3' circle = 6563.59cm2 - 0.076 mw per sq cm
4' circle = 11,668.62cm2 - 0.0428 mw per sq.cm

The reflected light from a painting would be less of course. If this further, I'd probably mount a laser out of anyone's direct view and direct it to light artwork obliquely from above via a mirror, etc.