Question

explain mechanism of wedge depolarizer and lyot depolarizer

Answer 1

Wedge depolarizer :-

the quartz - silica wedge depolarizer is a common commercial design and is similar to the corner depolarizer, however the angle between the two components is much smaller (is typical) and only first component is birifringent. The second component is made of fused silica.

As with the corner depolarizer, there is some seperation of the output as a function of polarization as well as some beam deviation due to the imperfect match in referactive index between quartz and silica. The output is periodic across the depolarizer, because the wedge angle is so much smaller than in a cornu depolarizer the period is larger often around 6mm.