Our Filters

We are about to start posting some very exciting results, so I thought we should provide some information about our filter system.  We are using Sloan Digital Sky Survey (SDSS) standard r’, i’, and z’ filters as our main bandpasses.  These filters were provided by Asahi Spectra.  Our CCD47 has a near-IR coating to maximize its long wavelength quantum efficiency (QE).   The below plot shows the combined QE of our system (taking into account only the CCD and filters), as well as the mean wavelengths of the filters.

Magellan VisAO Filter Curves
The tranmission of our SDSS bandpass filters and CCD.

Update 22 July 2011: added the transmission of our 950 Long Pass (950 LP) filter. This should be treated with a little caution, as it is from a catalog page, and not a measurement of our actual filter. Also note that these calculations were done assuming our CCD47 QE goes to 0 at 1.1 microns, since the manufacturer’s curve stops at 1.05.