How do frequency, speed, wavelength and amplitude change in polarimetry?

[mcwhk]

i just saw a post which explain the principle of polarimetry here:
https://www.physicsforums.com/showthread.php?t=52941

and i got few questions on my head:

movies said: frequency of the light is changed when pass through the isomer.
so, how do the speed of light, and wavelength of light changed? and how about amplitude?

after changing the intersecting point of 2 perpendicular wave, how is the resultant vector look like?

thanks

 

[mcwhk]

really no one knows?

please help me...