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FrozenGate by Avery

476nm Laser Diode in old CNI GLP Pen Host!

Joined
Jun 13, 2007
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Years ago I got a lucky deal and picked up four Nichia "aqua" laser diodes rated at 20mW and around 476nm emission. These diodes were found to be really interesting, because when they are driven hard they emit a second 480nm line that is stronger than the 476nm line, and a diffraction grating can show this quite easily. I built one into a LeadLight and sold the rest off (both as handheld builds + one bare diode to a GB testing fund).

My aqua LeadLight quickly became my favorite laser and I used it for all of my important presentations, and everyone loved the soft blue color. I let my boss use it for his big conference talks, which usually ended up with physicists catching him afterwards and being astonished that it was direct diode, not DPSS. :D

The build eventually got some connection issues from the spring being compressed (a common LeadLight issue) so I intended on rebuilding it. Unfortunately, I couldn't find my beloved pointer for a few months, but just a couple weeks ago while sorting through my unmarked diodes with a variable PSU, I got a flash of sky blue light on my desk and realized it was my Nichia aqua diode!! I must have begun tearing it down and got sidetracked...so I soldered it to a Microboost drive to keep it save from ESD.

Onto the build... I bought some stuff from JLM months back and he sent me a torn down old school CNI pen as a gift. :) I decided to use this host for my build as I love the click of the GLP pens.
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I started by soldering a test load to a Flexdrive to set the current.
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I ended up setting it to about 84mA. Notice that you don't need a fancy testload to set a driver...I'm using some rectifier diodes and a 1ohm resistor, which probably cost me under 25¢.
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I pulled my diode from the anti-ESD bag and found my notes. This diode is case NEGATIVE, which means it CANNOT be used with a microboost in a host where the casing completes the connection (like the Leadlight)
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I made sure I was grounded, and pulled the microboost off of the diode. It is scary seeing my beloved diode exposed like that...
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I shorted my flexdrive and then soldered it on to my diode.
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Yup, it still works. :)
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Easy part is done, now it was time to crack into that pen...
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Everything but the head disassembled nicely. That module was really jammed in there, and I wanted to get it out without scratching it up too badly.
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I gave the adhesive inside a good splashing with my favorite ketone, but still couldn't pull it out.
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I ended up building an extractor using an empty cheapo laser host and the back half of an AixiZ module, which worked nicely.
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Next I had to modify the switch board from the CNI pointer. This is the original 532nm module that was inside, and notice that the PD pin was never hooked up. Even in the crappy pointers you see nowadays the PD pin is always hooked to something, so I was surprised to see this.
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I desoldered the board and removed all components except for the switch.
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I then soldered the switch to the input of the flexdrive. Notice anything wrong here???
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I started assembling it and realized I mixed up the polarity. This pen must be case NEGATIVE, not positive. Plus, I had nothing on the AixiZ module to keep it wedged in the host.
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I screwed on the back of an AixiZ module so the host had something to grab to, and I put the negative wire from the flexdrive into the threads of the AixiZ module to keep it case negative.
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Now I tried assembling it together again. I had trouble getting the button over the switch properly, and ended up tearing it down many times. This sucked and took forever.
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Aligning that damn switch still...
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Just getting to this part is a giant pain in the ass. Even then, after the first few clicks of the button it would begin to slide out of place and get stuck.
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After a bunch of time messing with it, I shimmed/braced the switchboard and button by packing in small pieces of paper. This ended up working very well, and it keeps everything locked into place.
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One final assembly...
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Ahh yes...those beautiful photons. :cool:
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Now I have a unique pointer for grad school. No laser scientist can be complete without an off the wall color of laser pointer. :p
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Hopefully y'all enjoyed the thread! This is what goes into pen builds, they are tricky and usually end up with me swearing a bunch and tearing them down multiple times before I finally get a good configuration. BUT they are rewarding in the end, and for a unique diode such as this there is no better build for them.

Haping lasing!!
 





Styro, nice seeing your detailed builds again; that 476nm is such a beautiful wavelength! :beer:
Looking at the finished product, you'd never imagine all work that was involved in getting it to that point.
Now that you have the hard part completed, the rest of grad school ought to be a breeze! ;)
:gj:
 
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Shiny host, awesome wavelength, good job! :beer:

Totally worth the effort.

BUT they are rewarding in the end, and for a unique diode such as this there is no better build for them.
 
I love that blue color, I wish I could find that 476nm diode. I would definitely buy one. Great build!
 
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Great build Styro! +rep!! I love the CNI hosts.

I love that blue color, I wish I could find that 476nm diode. I would definitely buy one. Great build!

Well, we may have 488nm diodes very soon! As for which is a nicer color, 488 or 476, it's a pretty tough call. They are both really great colors.
 
Great build Styro! +rep!! I love the CNI hosts.



Well, we may have 488nm diodes very soon! As for which is a nicer color, 488 or 476, it's a pretty tough call. They are both really great colors.

Link? Seller? Let me buy them all now :D:drool:
 
I could feel your pain as you went, step by step, first connecting the switch's polarity to the ground, I knew it had a case ground from your opening statements. After so many failures, SUCCESS! That is a beautiful color. It looks aquamarine to me. Thank you for sharing the whole process. It was very entertaining.
 
Thank you for sharing this great build styro! Like Sta said, hopefully these 488nm diodes flood the markets soon :)

-Alex
 
Us pen builders know how frustrating things can be at times but they honestly do get easier the more of them you build.
Yeah, nice color. I would like to see it next to a 473nm:)
 





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