P. Ekstrom, R. Stokes, G. Stokes, J. Hackwell
Optical Engineering, Vol. 20, Issue 1, 200119, (February 1981) https://doi.org/10.1117/12.7972656
TOPICS: Astronomy, Polarimetry, Polarization, Visible radiation, Infrared detectors, Infrared radiation, Birefringence, Modulators, Infrared sensors, Sensors
We describe a new design for an astronomical polarimeter optimized for use in the 8 to 13p spectral region based on an earlier visible wavelength instrument. The combination of a special infrared ZnSe birefringence modulator and a background-limited fast photoconductive detector permits carry-over of many of the digital signal processing advantages of the earlier instrument. Within a single measurement sequence, this instrument will measure the photometric intensity, the circular polarization, and both components of the linear polarization. Used with a 2.5 meter class infrared telescope, the device should permit a 3u detection of 1% linear or circular polarization at 10u in less than 400 seconds of any compact source brighter than 1.2 mag.