Another episode of "What is it"

[macona]

Got a couple more goodies that I cant identify.

First is what I think is a little DPSS head from Spectra Physics, Part# 7950-L104. I called them and they have no info, as usual. It seems this happens more and more. It has a SMA 905 on one end with an aperture with a AR coated window on the other. It came with a 100um fiber.


IMG_3154 by macona, on Flickr

The other thing is something I have no clue what it is. It Has a small box that plugs into 120 AC. This powers a cylinder which holds a crystal in the center. There is no connection to the crystal, it just sits wrapped in foil in a couple aluminum blocks which slide in the cylinder. It does not seem to do anything right now, the led on the box does not come on. Any clue what it might be before I take it apart any further?


IMG_3155 by macona, on Flickr


IMG_3157 by macona, on Flickr


IMG_3156 by macona, on Flickr

[tribble]

Google says the 7950 is a "Q-switched laser head." You probably knew that already. Maybe this patent filing will speak to you more than me...

http://www.freepatentsonline.com/5022043.html

"To solve this problem, laser systems have been developed in which resonators are fiber optically coupled to an array of laser diodes. Such systems are typified by the Spectra-Physics model 7200 Laser Diode module coupled with the model 7950 Q switched laser head. This system uses a low power folded cavity stable resonator laser, with a fiber optic coupling mechanism using circular optical fibers. The model 7200 provides for coupling a pump beam from the laser diodes of up to 500 milliwatts."

[shrad]

the other device could be a pulsed laser second harmonic generator with the black cylinder being an oven and the electronic circuit the temperature controller... should be worth something as its a long crystal!

[mixedgas]

The Black tube is a doubler for low rep rate (like 10-20 Hz) very very high power lasers. Its angle tuned KTP or KDP. That generation ran at 1064 (YAG) or 1047 (YLF) for the most part. Looks like the doubler head for a SP that used a EO Q-switched Yag oscillator, then a massive Yag amplifier rod. Take a SP 2050 like long white head and stick two flashlamp pumped yag resonators in it, and you have the beast. Massive laser.

I was introduced to one many years ago. By a fellow who set me up good. He charged the cap banks before I got in the room, put a lens in front, and hit the single shot button. It snapped a BIG air breakdown 6 inches from my nose. I'm told I jumped six feet up, six feet back, and turned ashen white before I hit the ground. (Dick, you BA$*^d! Dont do that again! ) I'd never seen a laser induced air breakdown before. I'll remember the model number in a day or two.... DCR series something with a extended cavity. The thing is intense enough that you did not really have to tune the KTP much. He just set a 1" long cube of KTP in the beam on a dixie cup, voila... massive green.

The little round SP dpss is their first or one of the first SP commercial DPSS head from the late 90s. Came in cw 1064, q-switched green, and q-switched 1064 flavors. I remember the adverts.They did not sell too many of them. Its a collectors item more then anything else. (cue Edetic). Their head DPSS scientist, Dr Byer, would recognize it, but not too many other people there would. They used passive Q-switches, so just add 808 to the fiber and they run. I've seen the heads on Ebay but I've never seen the drivers.

Steve

[macona]

Thanks for the info. It is a heater. I popped the black thing apart and there are heating elements. I noticed one of the terminals was arced out so it looks like something happened and may be why it is not working. I will have to play a bit and see if I can get it working again. Not like I have anything that could pump it though.

The little head has a coax that terminates to a BNC. What else would that be if not a q-switch?

[mixedgas]

Welcome to the Photon Game Show Network!

Today on PGSN, This Epic Epiosde of WHAT IS IT?

Starts with the statement, "The BNC MOST LIKELY IS A TINY QSWITCH!"

For 1000 points, correctly identity the center frequency using a friend's VNA....

I'm betting -J x 1 cent on 80 Mhz....

Thank you for playing WHAT IS IT?

Steve

[shrad]

coudn't it be 40-ish Mhz?

[mixedgas]

Welcome to the Photon Game Show Network!

Today on PGSN, This Epic Epiosde of WHAT IS IT?

Starts with the statement, "The BNC MOST LIKELY IS A TINY QSWITCH!"

For 1000 points, correctly identity the center frequency using a friend's VNA....

I'm betting -J x 1 cent on 80 Mhz....

If its not a Q-switch, its a photodiode

Thank you for playing WHAT IS IT?

Steve

[shrad]

wouldn't there be a reverse bias close to the PD in that case?

the q-switch is a better option I think

[Stoney3K]

wouldn't there be a reverse bias close to the PD in that case?

the q-switch is a better option I think

Since we've already determined the 7950 is in fact a Q-switched laser head... that doesn't Q-switch all by itself, does it? You'd need some way to connect it to the outside world, and the BNC seems to be its only connection.

Sounds like you need a 7200 to go with that fiber connected to the 7950 on the other end. I'd guess the large red cap would be the exit aperture...