dreaming of an ultraviolet handheld pointer

[dyeote]

I know that the diodes exist - check out the first item on this list - but that itself is not enough...
There has to be a massive commercial market* to drive down the prices, before hobbyists like us, who generally don't have 4000+EUR to drop on a single diode, can realize their 'DIY laser construction' desires...

*The markets which allow us to enjoy relatively cheap diodes, as I understand them, please feel free to help^ by adding relevant/interesting info:
780nm - CD drives
650nm - DVD drives
638nm - Digital Laser Projector's red
445nm - Digital Laser Projector's blue
405nm - BluRay drives

so... is there any hope?

Edit (additions):
808nm - among other things: 532nm DPSS modules, used for high visibility pointing in astronomy/presentations. I've also personally seen huge table-mounted modules in this wavelength used extensively in scientific research labs. Not sure (yet) why this particular wavelength is so popular in this function.
685/690nm - cheap diodes available, market TBD

^thanks: bloompyle

I have an extra question: has anyone here (on LPF) built a handheld with a built-in TEC (Peltier cooler)? If so, I would love some practical advice in this matter

 

[bloompyle]

685/690 is pretty cheap. 3x 35mW diodes off ebay for $10 shipped, give or take. Not sure what makes them so cheap.

808nm is pretty cheap because it's used a lot in various DPSS lasers. More importantly, the commonly constructed 532nm pen for astronomy hobbyists (used for star pointing) and presentations.

 

[Leodahsan]

Its worth noting that the 808nm diodes used as "pumps" on DPSS systems commonly have a lower deviation of wavelength (λ) / temperature. I saw cheap 808nm diodes that included a λ graph, with 801nm being its dominant wavelength at 25ºc, and 808nm at 60ºc.

 

[Sigurthr]

It is theoretically possible to make a tripled or quadrupled Nd:YAG in a handheld format, but the level of engineering needed pretty much exceeds hobbyist capabilities.

 

[scumbagatheist]

 

[dyeote]

It is theoretically possible to make a tripled or quadrupled Nd:YAG in a handheld format, but the level of engineering needed pretty much exceeds hobbyist capabilities.

Many things are theoretically possible :/ do you know of an NLO crystal with a strong THG coefficient for the 1064nm or 808nm lines, which is also commercially available? (I don't)

anyway: my main curiosity / thought process here is: why were 375nm diodes developed in the first place? and now that they exist, which market needs to blow up for their prices to be driven down?

 

[Sigurthr]

Iirc they were for next gen optical storage, but technology went the solid state digital streaming route instead.

 

[Cyparagon]

Many things are theoretically possible :/ do you know of an NLO crystal with a strong THG coefficient for the 1064nm or 808nm lines, which is also commercially available?

I'm not sure it works that way. The couple I've seen first double the 1064, then sum in some more 1064. So there's actually green at one point in the cavity.

 

[ARG]

I wonder if I could chill a 405nm diode down to 399nm. That would be UV

I see the advantage of having cheap UV diodes for technology (3D printers) but why for handhelds? It would probably be the same as 405nm in appearance.

 

[kilter]

^ Wait. WOuldn't UV be invisible? How would it still be like 405nm??? :thinking:

 

[scumbagatheist]

^ Wait. WOuldn't UV be invisible? How would it still be like 405nm??? :thinking:

That depends...Some people have the ability to see in wavelengths as low as 380nm.

I cannot imagine that if it was visible that it couldn't be that different, visually, to the observer.

 

[bloompyle]

Similar be anything from looks to capabilities. UV would act just like 405nm in that they both activate GITD surfaces, and fluoresce objects. Also, people can usually see their UV flashlights as a dull violet. The equivalent of 808nm being "invisible" since it's IR, but we all know the reality here

 

[ARG]

^ Wait. WOuldn't UV be invisible? How would it still be like 405nm??? :thinking:

You can still see UV, it just won't look as bright.

You can also see (808nm) IR, but 2W of IR looks about the same as 1mW of 660nm.

 

[Sigurthr]

That depends...Some people have the ability to see in wavelengths as low as 380nm.

I cannot imagine that if it was visible that it couldn't be that different, visually, to the observer.

My observed confirmed visual range is 337nm-848nm (I may be able to see beyond it but no sources have been available to test further). I'm not sure where you got the 380nm figure from. Lots of folks can see the 365nm mercury line as well.

If I wanted to make an absolute guestimation of the maximum visual spectrum range I would set it at 300-900nm.

 

[scumbagatheist]

Sig, I too have an extended visual spectral range.

I admit, I have no source for my reference to 380nm. I used that figure based on what I remembered from reading a thread weeks ago, about a similar topic.

Back when I did photoshop competitions, I was tested and was able to notice color purity tests at levels as low as 2% impurity...specifically in reds, greens, and of course, grey tones.

 

[kilter]

Kay. I get it now. Thanks!