SED Machine Bonding Woes

As reported on 6 Dec the lens bond of camera 1/2 was a success. A little Sylgard-184 ended up on the lens girdle, but the lens is clear and beautiful. I stored the lens away in our humidity-controlled environment. I'm still trying to deal with the fact that some of my CaF2 elements are now coated on both sides (I wanted only a coating on one side).

It turns out that an AR Coating tuned to operate on an air/glass interface performs about as well when going from a sylgard-184/glass interface over most of the wavelength range, but performs poorly at the red and blue ends. The realities of this project mean that we may just have to plow through and accept some throughput loss.

I was also excited to see the work of Trinh et al. (2012) posted on the arxiv. Their work is exciting and has the potential to dramatically increase the signal-to-noise of background limited observations on large telescopes. It seems as if the technology is not quite there yet and their abstract is refreshingly honest:

While these tests demonstrated high throughput and excellent suppression of the skylines by the OH suppression fibres, surprisingly GNOSIS produced no significant reduction in the interline background and the sensitivity of GNOSIS and IRIS2 is about the same as IRIS2.