Is the "UV Handheld Laser Engraving Kit" legit?

[shrinking_ultraviolet]

As seen on eBay (and I apologize if I have the wrong forum for posting this in, I'm still fairly new to the board here). I still can't post links, but here is the eBay item number:
324433789477

The title is, "1-W+ UV Handheld Laser Engraving Kit - GH04W10A2GC Diode - Extreme Ultra-Violet" by seller "Barnett Unlimited" and the alleged specs are:

• Rigid Aluminum Host - Black Color (Available in Silver Upon Request)
• Carbon Fiber Hand Grip - Violet Color (Available in Silver or Black Upon Request)
• Large Finned Aluminum Pointer Head
• Sharp GH04W10A2GC Diode
• 5 Mode Driver (High, Med, Low, Strobe, SOS)
• Adjustable Focus w/ 3 Element AR Coated Glass Lens
• Reverse-Clicky Tail Switch
• 22 AWG Silicone Jacketed Wiring
• Contact Me With Any Questions

It looks good on paper, but I wanted to know the local opinion (or if the seller is on the board even, or known to you all).

 

[bostjan]

The GH04W10A2GC diode is 405 nm. Not really UV and definitely not "Extreme Ultra-Violet." Usually if anything in a listing is obviously misrepresentative of the product, I, personally, tend to stay away from it.

 

[shrinking_ultraviolet]

Thanks, figures, it seemed too good to be true.

 

[Sowee7]

as he said 405nm diodes arnt uv, but they are really close, only 5nm away, uv starts at 400nm

 

[shrinking_ultraviolet]

I know (see username...) but I was looking for something more like 375nm. Someone put something like a 375nm on the board not long ago, but I couldn't recall what kind of diode it was.

 

[paul1598419]

Diodes in the 375nm range are typically very expensive and not that powerful. If you don't need the power then one might be a good deal for you.

 

[cornweda]

What is the advantage of UV laser for engraving over 405nm which have very good beam specs usually. I also worry about the safety of lasers where you can’t see the beam.

 

[shrinking_ultraviolet]

Unfortunately, I probably do need the power. The application is laser-induced fluorescence photography on brick walls in the presence of streetlights (since the imaging has to be done late at night when people are out of the way). The laser will have a 30 degree Powell lens on it, which spreads the beam out into a line, and the line is then slowly swept across the wall while the camera captures an image. Spreading the light into a line reduces the intensity a lot, and capturing the fluorescence under streetlights makes the signal-to-noise ratio bad. That's why I need the power. So far I've tried a 100mW, a 200mW, and a 900mW from DTR. The 900mW almost was enough. I got a decent image, but I had to stand too close to the wall when shining the laser.

I originally went searching for a 1.5W 405nm on eBay, but got side-tracked when I saw there was a UV laser at 1W for sale (above). UV should induce more fluorescence, so if it had been a 375nm 1W, that would have been worth trying.

 

[shrinking_ultraviolet]

What is the advantage of UV laser for engraving over 405nm which have very good beam specs usually. I also worry about the safety of lasers where you can’t see the beam.

Please see my most recent post (we overlapped). I'm not using it for engraving.

 

[cornweda]

Thanks I just saw engraving kit and didn’t understand why you need fluorescence . Although 405nm does induce fluorescence also.

 

[shrinking_ultraviolet]

Hah, yeah "engraving" was a red herring. Fluorescence is the main point.

 

[Sowee7]

Hah, yeah "engraving" was a red herring. Fluorescence is the main point.

405 should be good for exiting things, you dont need 375nm

 

[bostjan]

Depending on the camera, it might react to 375 nm light just the same.

Do you need a laser for this though? Maybe you can use an LED with a UV output that is quite a bit cheaper (but still expensive to me, FWIW).

Or, you could use a 405 or even a 445 nm laser and wither filter out the wavelength of the direct laser output optically or digitally.

 

[cornweda]

Also which spectrum of light excites the fluorescence molecules is entirely dependent on the molecule you are exciting. I know for many organic material 375nm does not work as well as 405nm. Perhaps you can tell us what dyes/molecules you are trying to excite?

 

[Anthony P]

You may want to contact "Lifetime17". I recently purchased a very nice 405 complete pointer that approaches 2W from him.

 

[cornweda]

How are the beam specs for your 405nm 2W laser?