The coated optical flat
photoresist is then delivered to the pre-curing station.
"I've already completed the perforated 8-inch optical flat
and long-focus 6-inch primary for a Russell W.
Used to apply thin layers of coatings to increase or decrease the optical transmission on a lens or optical flat
, the SPECTOR-HT is equipped with a powerful ion source, a high-voltage extraction system and a large substrate holder.
Their material can be polished to the mirror finish of a quartz optical flat
, and has the optical reflectivity needed for interferometric calibration measurements.
The upper section is a detachable spar made from a 33-inch length of heavy-walled 1-inch-diameter steel tubing that connects the 3-inch-diameter tube to the housing of the optical flat
. Short lengths of precision-ground stainless-steel shafting pressed into the ends of the spar slide into mating sleeves located on the undersides of the 3-inch-diameter tube and the housing of the optical flat
, where they are retained by knurled thumbscrews that bear against milled flat surfaces.
I already had a 4 1/4-inch optical flat
for reflecting starlight upward to the refractor's objective.
The drive and optical flat
are protected from the elements by a 4-by-6-foot weather-stripped cover.
Surface [R.sub.5] need not be extremely flat; it can show up to about 30 interference fringes when placed in contact with an optical flat
, but these fringes should be fairly circular (within one or two fringe spacings).