Abe, Marc
We put HWP with rotation mount before compensator and try to measure retardation of HWP as entry 2965.
We maximize p-pol power to rotate the HWP:
s = 19.9 mV
p = 648 mV
We rotate HWP and compensator to 45deg.(same direction)
we maximize p-pol power again and record value of the Vernier screw.
d = 6.84 mm
s = 766 mV
p = 16.8 mV
P-pol power was too low. It should be pure p-pol but p-pol power did not change even though we rotate the Vernier screw.
I think polarization direction was parallel to fast(slow) axis of compensator.
Retardation of HWP N_hwp is given by
N_hwp = 1-6.84/13.365
= 0.488
13.365 is calibration parameters measured in entry 2965.