The ssy-1 as it known is a flashlamp pumped q-switched Nd:YAG laser that was used as a part of a laser rangefinder, which has found its way onto the surplus market. As of 2017 the supplies of these are dwindling, but they do still turn up occasionally at the usual vendors.
A shot of the system the yag head is currently in, which was originally planned to be a CNC laser engraver, but after I damaged the flashlamp on my ssy-1 it got mothballed. The setup that damaged the flashlamp is also shown, the large bank of capacitors (about 200J worth) were just a little to much for the poor flashlamp and one day it exploded quite violently.
A shot of the laser not focused on anything which, due to the extremely high peak power of the head, causes a small spark to form out of mid air, which makes a 'snap' sound. Also, a shot of the laser on a piece of copper plate which gives a green hue to the fireball.
A shot of a piece of black anodized aluminum just past the focal length so both the air ionization and the fireball caused by the aluminum vaporizing, and a shot with the aluminum right at the focal point.
A shot of a piece of black foam and a LM555 time IC that was cause to hours of debugging.
The ssy-1 head is quite well documented, and a ton of information about it can be found on Sam's FAQ. One comment I will make is that there are a few factors limiting power for this laser. The pulse energy is limited to a few tens of millijoules by the internal q-switch (shots over about 25J input energy will damage the q-switch after a relatively small number of shots), but the q-switch can easily be removed to allow shots of to a few hundred joules in (which should give well over 1J output energy) before the flashlamp explodes. The average power is limited only by the cooling, and when I used the rod/q-switch out of my ssy-1 in my VersaPulse laser I was able to get well over a watt of output power without stressing the rod.
Additionally, I received an e-mail from a Joseph W. Ruhl, Jr, who works for Elbit, who adds:
I have seen the SSY-1 designation before and really do not know where it came from. I do not believe any of our liceneese used that designation. The SSY-1 that you talk about is really the Hughes Aircraft Company production part number 12272643 laser transmitter, developed originally for the XM-1 Program in the 1970's. It went into production for the M1 Laser Rangefinder. I was most likely the youngest member of the M1 laser design team in those days and retired from Hughes (Raytheon by the time I retired) after 30 years. The M1 transmitter is a flashlamp pumped, Dye Q-switched, ND:YAG laser with an output of about 50 mJ in a 10 nsec pulse (with the original M1 PFN). The laser transmitter in your photo actually appears to be a P/N12272885 which was a product improvement over the 12272643. The "-885" utilized spring steel retainers for the output coupler and end reflector. The unit was also used in a number of foreign tanks like the Korean K1. We modified the basic design some 15 years after we developed it to add an inter-cavity RAMAN cell shifting the wavelength to 1540 nm. We also limited the output energy of the RAMAN shifted transmitter to 7 mJ so that the end LRF was eyesafe (per military standards). This version of the transmitter went into the IBAS modification of the Bradley Integrated Sight Unit and was also used on the USMC LAV and several other vehicles.
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