A&A Supplement Series, Vol. 123, June II 1997, 589-592
Received September 5; accepted October 21, 1996
E. Oliva
Simultaneous measurements of the polarized flux at angles 0, 45, 90 and 135
degrees can be performed by inserting a
simple combination of two Wollaston prisms and two wedges (cf. Fig. 1 (click here))
in the pupil plane of a camera/spectrometer multimode astronomical
instrument.
The first three elements of the Stokes vector can be therefore
determined from data taken at the same time and
without any need of rotating 
plates or other
moving elements which could be difficult to incorporate in
multimode astronomical instruments.
This paper describes the working principles of the wedged double Wollaston
and presents detailed parameters for prism combinations optimized for
imaging-polarimetry and spectro-polarimetry at "visual" (0.3 - 1.0 
m)
and near IR (1.0-2.5 
m) wavelengths.
The devices described here could significantly simplify the implementation of imaging and spectro-polarimetric modes in astronomical multimode focal reducers.
keywords: instrumentation: miscellaneous, instrumentation: polarimeters