Melles-Griot HeNe laser teardown

[wkb]

I just stumbled on the pictures of my teardown of a Melles-Griot helium-neon gas laser.  I got it from a friend of mine, it was
found defective in some chemical analysis lab instrument.  The friendly service guy who left it behind also replaced the high-voltage power supply, that one proved working without trouble.  Along with the defective laser tube I got a working one, with working power supply which was preventively swapped.

Anyway, it proved an entertaining project to take it apart.  The glass tube is housed in an aluminium tube, and is centered/mounted using some tar-like glue.  Thanks to Sam's Laser FAQ (http://www.repairfaq.org/sam/lasersam.htm) I got the right tip-off: slightly cook it in an oven in (I think it was) 80C or so.  The actual tube is doomed, due to sputtering effects (thanks Sam, for the explanation :-)

[wkb]

Some short movies of the laser tube under power

http://wkb.home.xs4all.nl/Laser-hacking/no-start-HeNe-laser.avi

http://wkb.home.xs4all.nl/Laser-hacking/non-starting-HeNe-laser.avi

With a slightly-higher value ballast resistor the tube looks better (but it does not laser, it is too far gone for that)

http://wkb.home.xs4all.nl/Laser-hacking/higher-ballast-R.avi

[alm]

Thanks for the pics. Nice to see a teardown of one.