Patent ID: 8213070

Claim:
A wave-plate structure, comprising: a first substantially zero-order, zero-wave plate; and a second substantially zero-order, zero-wave plate arranged in series with the first substantially zero-order, zero-wave plate and oriented at a selected angle relative to the first substantially zero-order, zero-wave plate, the first and second substantially zero-order, zero-wave plates configured to alter a polarization state of an input signal passing therethrough in a manner that is dependent on the power of the input signal, each of the first and second substantially zero-order, zero-wave plates including, an entry wave plate having a slow axis and a fast axis; and an exit wave plate having a slow axis and a fast axis; wherein the fast axis of the entry wave plate is oriented substantially perpendicular to the fast axis of the exit wave plate; and wherein the slow axis of the exit wave plate of the first substantially zero-order, zero-wave plate is oriented at about 40 degrees to about 50 degrees relative to the slow axis of the entry wave plate of the second substantially zero-order, zero-wave plate.