Teletrac Stabilized HeNe Laser Overview

Updated: 060110 - Views:
All content copyright © 2003-2009, B Vanderkolk

I picked this laser up in the '98 or '99 as part of a bulk buy of laser equipment from an electronics salvage company.

The tube itself has no markings. It's about 8 inches mirror to mirror. According to the user manual I found online it's manufactured by Zygo. Output is polarized. The OC end goes through a collimator to get a 1 cm low divergence beam. And it is LOW divergence. I once shot this thing out my window to a brick wall about 1/4 mile away, took a walk and found the beam to have barely grown, if at all. The HR side has what is obviously a mode detection assembly, but it's all covered in shrink tubing. There is a transistor of some sort glued face down onto the glass of the tube near the cathode end, probably for temp sensing. There are two low wattage filament lamps under the tube for heating. The HeNe supply is a standard brick made by Power Technology, Inc. Temperature regulation is done by two blades that vibrate, driven by a piezo. The vent is on the bottom of the laser so I have to make sure the 'tail' is sticking out in free space or it overheats and the fan blades really start clattering. From a cold start it reaches mode lock in about 11 minutes. Built into this laser is an optional interferometer receiver. This consists of a tiny 5mm beam splitter cube, polarizers, photodiodes, and amplifying electronics.

Clinking on the thumbnails below will take you to a large full sized image of 2272x1704 pixels.

This is the right side of the laser. The only side that has a logo. The left side of the laser. Note towards the left the connector for the interferometer receiver electronics.
A closeup of the interferometer electronics connector. The two little plasic caps are pluggin holes that allow access to the sin and cosine trimpots inside. The manufacturer's label. Made June, 1992. Serial 0897. The model number field is blank.
Right side view of the laser with the main cover off. On the left is the laser power supply 'brick' and mode control electronics. The white box is a cover for air flow control. A closeup of the front end of the laser, with collimating lens tube and interferometer components and electronics.
Closeup of HeNe power supply 'brick'.  Manufacturer is Power Technology, Inc. The HeNe tube underneath the white box. Note the temperature transistor glued to the tube and the small light bulb below the tube for adding heat to speed up warmup.
Front end components. The PCB is the interferometer electronics. On the right is the cathode end of the tube and the OC feeding the collimator. Left side of the power supply 'brick'. Below this is the piezo driven fan blades to control temperature once mode lock is achieved. Onthe right is the control electronics.
Closeup of the tube temperature sensor (transistor) and one of the low wattage filament heater lamps. Closeup of the collimator tube.
Further closeup of the interferometer optics and detectors. The beamsplitter cube is only 5mm!!! You can also see what appears to be either poloarizers of HeNe line filters. Another view of the piezo fan. The two blades vibrate in a side-to-side motion in opposite directions.
This is the vent hole underneath the laser, looking towards the back. Visible is the piezo fan. This is the same vent hole but looking towards the front of the laser.
This is a closeup of the HR end of the tube. Inside the black shrink wrap is the detector for sensing the mode of the laser output from the HR waste beam. Closeup of the interferometer receiver electronics. Very simple opamp circuits.
The laser on and in warmup mode. Note the filament lamps are on. Normally the white cover needs to be inplace to provide a controlled temperature environment. Closeup of the lit HeNe tube while in warmup mode. Without the flash you can really see the filament heaters and the soft salmon glow of ionized helium and neon.
An extreme closeup of the collimator output. I've reflected the beam back into the interferomter optics. I need to clean those opics!!! The laser warming up with the environment cover back in place. This will allow the laser to warm up and achieve mode lock.
Closeup of the piezo fan blades during warmup. Once mode lock is achieved these blades vibrate with a noticeable blur. We have mode lock!!!
Closeup of the piezo fan blades vibrating. The output of the laser is being redirected with a right angle prism back into the interferomter optics. The laser is coming out the hole in the center and going in the left.
Another closeup of the interferometer optics with laser light. The OC end of the tube feeding the collimator.
A view of the laser tube after warmup. Note that the filament heaters are off. The same view as at left but without the flash.
This is a 6.6 meg quicktime MOV movie of the laser warming up and showing the mode LED changing from red to green as the laser changes modes.