There is more I should say about the gold reflectors that make up the
walls of the oscillating cavity. I don't remember just now (though I
may have recorded it in my private diary) what the base metal is that
makes up the reflectors. The coating is gold.

The reflectors came to us the way all the other parts did, that is, in
a bucket that was placed on a shelf of left on a cart. The reflectors
were stacked on top of each other, with lens paper separating each
reflector half, and each half was identitical by design. Their smooth,
shiny, clean surfaces were beautiful. I had more of a chance to admire
their beauty as I had to clean each reflector with solvents prior to
assembly.

A third party originally gold-plated the reflectors, but my company
shifted to coating them in-house. I was impressed with the coating
quality, considering the trouble we had with the laser rods. But, I did
not have to examine the reflectos under a microscope for imperfections.
Even so, there were still issues with the coating.

There are tabs on the ends of the reflectors, which are supposed to fit
into slots set within the end pieces. Metal, mostly the gold-plating,
tended to build up on the tabs. Sometimes, the coatings were too thick
to allow the two halves to fit together inside the slot. In that case,
we had to file a little bit of the coating from the tabs. We had to be
careful not to file down to the deepest base level (I believe there
were three layers of metal making up the reflectors) or scratch the
inside surface of the reflectors. Fortunately, it was not difficult to
file down the reflectors according to specification, and I don't recall
any reflectors rejected due to filing.

I used a lens tissue to wipe up the filings from my workbench. I
thought the gold in them might eventually become a significant amount,
but it never did, as my supervisors had predicted.