Mid-'60s Ruby Laser

[Eidetic]

This c1968 Optics Technology model 130 pulsed ruby laser system took a lot to get together. The power supply was found in 2016 in a storage shed in Florida along with the oldest Spectra-Physics model 125 He-Ne I've seen. There were a few other lasers I could pick up throughout the country at the time, so I flew to Florida and drove it home.

It's had a rough life, but mostly survived. It's an air cooled laser, with a blower and air filter (from a Chevy Corvair) seen in the front center section. I love the drawer on the back for the head, but it was empty except for the manual, a spare lamp, and a box with a Trion ruby rod in it. I get the date for the system from the manual.

After posting about it on Facebook, I got a wonderful surprise. A message from Jeff Murray, an old friend and fellow San Francisco Bay Area holographer from the '80s, telling me he had the head to go with this power supply. A-freaking-mazing! It's things like this that convinces me I'm on a mission, and in contact with His Noodly Appendage.

Problem was, the head was buried deeply in storage on an island north of Seattle. So for the past two years, the supply sat alone in my garage. But then, a group of plasma tubes became available from previous incarnations of STI Optronics in the Seattle area so I planned a trip to get them all. Jeff's hospitality was as generous as his donation of the head to the archive. He actually used this laser to make a hologram of his face back in the day, but it wasn't very practical for that use. I asked what he used for to power it and was surprised to hear he had the supply for it as well. What?!?? Yeah, but it was buried much deeper so we couldn't get it out. But I saw it! Jeff .... holding out on me!

Anyway, here it is. A system again and probably operational with a bit of effort. The rod and lamps are good. Jeff kept the resonant output coupler to use with another ruby laser he has. A retro-reflecting prism is used for the high reflector. Jeff made his own mount for an iris diaphram and cell for a saturable dye Q-switch. An ad (Laser Focus September 1966) and a new product introduction (Laser Letter April 1965) describing the laser are also below.

[ronhip]

Optics technology also made the head in a hand-holdable version for eye surgery. We had one of them (in the late 60's early 70's) at the Exploratorium for public demonstration. It worked well until one of the flash tubes exploded. It slightly chipped the end of the ruby rod (which I still have.) In this hand-held version the mirrors were coated on the physical ends of the rod itself. No external optics, no alignment issues! (photo below)

[buffo]

the mirrors were coated on the physical ends of the rod itself. No external optics, no alignment issues!

Yup. Lots of the early ruby lasers had the mirrors bonded to the rod. The bare ruby boule was first shaped to the rough size, then the circumference was fine ground, then the ends were faced parallel (within 1/4 the wavelength of sodium light, no less!) and smooth-ground so they were nearly transparent. Then, and only then, was the silver applied to make the mirrors. Later on they used multiple layers of dielectric coating to make more efficient mirrors, of course, but the earliest rods used plain old silver.

Definitely a piece of history in that photo... (And in Eidetic's post too!) When I was a kid I read all I could about these lasers. Crazy to think about how far we've come since then!

Adam