SED Machine Col 1/2

SED Machine Collimator 1/2 Doublet

I sound like a repeating record. Marin Anderson [CIT] and I bonded SED machine doublet camera elements 3/4 today. The collimator is a 95-mm f/4 lens with a telectrinc input.

Collimator 1/2

Collimator 1/2

Above is a stop motion video of the col 1/2 bonding performed by Marin Anderson and Nick Konidaris [Caltech]. The positive element is a CaF2 (ISP Optical), while the negative element is a fused silica (Heraeus suprasil). You'll note that there are several key elements in order of appearance: a checklist, blue tape, pink lens cleaner, kapton-tape shims applied with a tongue depressor, Sylgard-184 applied with pipettes, and q-tips for cleaning the lens.

New Parts in Hand

In addition to bonding, some parts have completed fabrication. So far we now have the lens barrels that hold the rainbow camera, collimator, and camera!

The Rainbow Camera delrin barrel

The rainbow camera barrel that contains a doublet, triplet, and singlet is shown. The barrel is made using delrin of a well-measured coefficient of thermal expansion, in order to control aberrations that appear at different temperatures.

The collimator aluminum barrel

The 95-mm f/4 collimator barrel is shown. The barrel sits in a V-block and is held down with springs (inspired by the OSMOS spectrograph). The barrel contains six elements, with most of the positive power produced by CaF2, and negative power and residual-aberration correction provided by Ohara Corporation i-line glasses. The mix of fragile materials and large expansion differences makes for some interesting mechanical engineering challenges.