JWST Tunable Filter Imager: Etalon Prototype Test Results

摘要

We present the prototyping results and laboratory characterization of a narrow band Fabry-Perot etalon flight model which is one of the wavelength selecting elements of the Tunable Filter Imager. The latter is a part of the Fine Guidance Sensor which represents the Canadian contribution to NASA's James Webb Space Telescope. The unique design of this etalon provides the JWST observatory with the ability to image at 30 Kelvin, a 2.2'×2.2' portion of its field of view in a narrow spectral bandwidth of R-100 at any wavelength ranging between 1.6 and 4.9μm (with a gap in coverage between 2.5 and 3.2μm). Extensive testing has resulted in better understanding of the thermal properties of the piezoelectric transducers used as an actuation system for the etalon gap tuning. Good throughput, spectral resolution and contrast have been demonstrated for the full wavelength range.