Return the Jones matrix for a linear retarder with long axis
rotation of 0 degrees.
- - p is the phase delay in radiant units, i.e. p is
ranging between 0 and 2*pi(). If not given or set to [] the default
value 0 is used.
 - - mode is a string defining the units for the phase
delay: ’radiant’ (default), ’degree’ (0..360) or ’wavelength’
(0..1).
 
Argument p can be passed as a scalar or as a matrix or as a
cell array. In the two latter cases, a cell array JM of
Jones matrices of the same size is returned.
References:
-  E. Collett, Field Guide to Polarization,
      SPIE Field Guides vol. FG05, SPIE (2005). ISBN 0-8194-5868-6.
 -  R. A. Chipman, "Polarimetry," chapter 22 in Handbook of Optics II,
      2nd Ed, M. Bass, editor in chief (McGraw-Hill, New York, 1995)
 -  "Jones calculus",
      last retrieved on Jan 13, 2014.
 
See also: Jones_waveplate.