I used to actually do fun stuff when I was in school, but that was 17 years ago. Now, I am cleaning up the closet of shoe boxes and mailers that got collected when Ebay first opened and I got my first job at the local sandwich shop. Among them, I found my old TE N2 low-pressure laser, which I used to pump 20 different household items to lasing threshold for my Physics II class in high school, mostly laundry soaps and highlighters, some RIT dyes, etc. It was fun and I enjoyed it.
In a few boxes next to it, I have found the following items and want to construct a new laser, with the eventual end goal of a laser engraver for 0.010" deep engravings in some metals. Multiple passes are OK, and if the laser I end up building can't do that, well, that's OK too. The actual engraving machine part is no problem-I have built CNC machines before.
4 flashlamps, all Russian manufacture from the late 1980s looks like. INP3-7/80A, I can find a little data on them but they have some kind of UV-blocking coating on them. They are unused because I blasted the 5th and 6th ones I had into shards trying to pump laser dyes, before I found out about the UV-blocking coating.
Several good energy storage capacitors, 35uF at 5000V Maxwell (got 1) and 115uF at 2300V Aerovox (got 5). The Maxwell was part of a xenon strobe light collision avoidance system, and the aerovox caps were removed from out-of-date AED defibrillators. All are new, just have some dust on them.
A 6.35mm x 80mm Nd:Glass rod, marked R&G Serial 100283, Nd:Glass Laser Rod 3x1/4" Coated R100/R50%@1055nm Pack 1.4, 1pcs. I recently missed buying another one that was as far as I can tell identical to it on ebay, right down to the package and markings but it was serial number 101948.
A handful of crudely made, but probably acceptable mirror mounts (not that I need them if the above rod is really coated with mirrors already!) These were some of my first attempts at machining. Takes me back!
A couple of other things have come out of the boxes-a Heathkit 1mW HeNe laser, a few supermarket laser scanner tubes, and a few laser mirrors that may or may not have the matching information on the case they're in.
I want to build the Nd:glass rod into a small flashlamp pumped laser, and try to get some SHG going, and couple this into a bit of fibre optic cable. I want to also co-beam a low power laser (like one of the HeNe's or a visible diode laser) through the fibre for alignment/aiming.
Here's what I know:
The integral mirror laser rod won't be easily Q-switched, limiting it's abilities for my end goal.
My current laser safety goggles are not suitable. (they're only OD4 rated at 1055nm)
The total energy potentially stored in my Aerovox pulse caps is as much as 1500J, which should be more than overkill for both evaporating my fingers and my flashlamps, so caution here.
I have a full CNC machine shop at my disposal and plenty of bar material. (I teach machine tool and engineering at the local technical high school)
Here's what I DON'T know:
Where my copy of Kohcher's Solid State Lasers has gotten to.
How to calculate input energy to the flashlamp required to get the rod over the threshold, without blasting it to bits.
How to choose the right mirrors to suit whatever rod/lamp combo I replace this one with when it's time to go for engraving-level power, if this rod can't get me there.
I'd like to start with input pump energy. Can anyone help me figure how much lamp energy I need to have on hand to get the rod over the lasing threshold, with what appears to be a 50% reflective OC?