Nikon NKL-85 Helium-Neon Laser (Gallery)
The Nikon NKL-85 is probably a Lamb-Dip stabilized HeNe laser similar in
its principles of operation to those of the Spectra-Physics 119. I do not know
the manufacturing date, but it is probably slightly more recent based
on the transistors and ICs in the HeNe laser and PZT power supplies.
Much more information on these lasers can be found in the chapter:
Commercial Stabilized HeNe Lasers
of Sam's Laser FAQ.
View 01 - Left front view. I believe that there are supposed to be
three adjustable feet, but I don't have them. There are also no safety
stickers, though I suppose it's possible they fell off. This laser is
HEAVY - at least 15 pounds, with most of that in the baseplate and cover,
and massive laser resonator frame.
View 02 - Front interior view. The black cover simply conceals another
semi-transparent plastic cover. It's hard to tell if that holds the OC
mirror or is simply protection. The two ballast resistors can be seen
standing up on the right.
View 03 - Right back view. All power and signals enter via the 27
pin military-style round connector except for one input to the mini-coax
above it. That goes to what is probably an amplifier whose output
connects to a pin on the round connector. The only wiring to that
circuitry is DC power - nothing else inside the laser head.
View 04 - Back interior view. The two (2) redundant micro-switches
for the cover interlock are visible at the lower left.
View 05 - Left front interior view. The sheet metal cover for the PZT
power supply has been removed for the photo. The glass bulb with the
large gas reservoir and cathode of the HeNe laser tube is at the top,
with a perfect silvery/dark getter spot. The bore of the tube is totally
concealed below within a metal enclosure, probably for both mechanical
support, and thermal and/or magnetic isolation.
View 06 - Right back interior view. The metal covers for the HeNe
laser power supply has been removed for the photo. The circular black cover
conceals the photodiode preamp PCB (which uses an IC in a TO5 can).
There is only a single photodiode monitoring the waste beam from the
laser tube. The box above the connector contains some additional
circuitry, purpose unknown.
View 07 - Left side interior view. This shows the PZT power supply
which includes a 7404 TTL hex inverter (just visible at the upper
right) probably configured as an oscillator driving transistors (not
vacuum tubes, can you believe it?!!!). The inverter transformer is
in the metal case and the voltage multiplier is on the left.
View 08 - Right side interior view. This shows the HeNe laser power
supply which is also a transistor-based inverter. The inverter transformer
is in the metal case and the voltage multiplier is on the right.
View 09 - Tube powered. My digital camera does a terrible job of
rendering HeNe laser bore discharges but it really is perfect. :)
View 10 - Label. I doubt 24041 of these were built, so that's
probably number 41. :) There were no safety labels on this laser head,
but I suppose they could have fallen off.