1Mount Stromlo and Siding Spring Observatories
Private Bag, Weston Creek P.O., ACT 2611, Australia
P.O. Box 296, Epping NSW 2121, Australia
The TAURUS Tunable Filter (TTF1) is a Fabry-Perot cavity with an adjustable plate spacing of 2 to 13 m. The parallelism measurement involves repeated imaging through a focal plane slit and a series of pupil plane masks. This approach is particularly efficient when the plate scanning is synchronized with movement of charge on the CCD. We assess the effects of wavelength-dependent phase changes within the inner surface coatings of the plates. These become important as the plates approach a spacing comparable in size to the thickness of the coatings.
instrumentation: Fabry-Perot interferometers -- detectors: charge-coupled devices