System and Method for Polarization Compensation
Various implementations of the invention, improve an optical efficiency of an optical path comprising a polarizing beam splitter and a quarter wave plate. In some implementations of the invention, where an additional optical component introduces a phase retardance into the optical path, the quarter wave plate may be adjusted away from its nominal orientation relative to the optical path to improve an optical efficiency of the optical path.
1 . An circularly-polarized optical path comprising:
an optical component that introduces a phase retardance into the optical path; and
a quarter wave plate disposed within the optical path and adjusted off of a nominal orientation with respect to the optical path to compensate for the phase retardance introduced by the optical component, wherein the nominal orientation comprises a 45° angle relative to a polarization axis of the optical path and a 0° angle of incidence.
2 . An optical path comprising:
a polarizing beam splitter that defines a polarization axis of the optical path;
an optical component that introduces a phase retardance to the circularly polarized radiation in the optical path; and
a quarter wave plate disposed within the optical path and configured relative to the optical path to compensate for the phase retardance introduced by the optical component.
3 . The optical path of claim 2 , wherein the quarter wave plate is disposed within the optical path so as maximize an optical efficiency of the optical path.
4 . The optical path of claim 2 , wherein the quarter wave plate is configured at an angle other than a nominal 45° angle relative to a polarization axis defined by the polarization beam splitter.
5 . The optical path of claim 4 , wherein the quarter wave plate is configured at the angle other than a nominal 45° angle that maximizes an optical efficiency of the optical path.
6 . A method for improving an optical efficiency of an optical path, the optical path comprising a polarizing beam splitter, an optical component that introduces a phase retardance into the optical path, and a quarter wave plate, the method comprising:
adjusting a nominal orientation of the quarter wave plate relative to the polarizing beam splitter to improve an optical efficiency of the optical path.
7 . The method of claim 6 , wherein adjusting a nominal orientation of the quarter wave plate relative to the polarizing beam splitter comprises rotating the quarter wave plate relative to a polarization axis of the polarizing beam splitter off of a nominal 45° angle.
8 . The method of claim 6 , wherein adjusting a nominal orientation of the quarter wave plate relative to the polarizing beam splitter comprises tilting the quarter wave plate relative to an angle of incidence of the optical path off of a nominal 0° angle.
9 . The method of claim 6 , wherein adjusting a nominal orientation of the quarter wave plate relative to the polarizing beam splitter comprises tilting the quarter wave plate relative to an angle of incidence of the optical path off of a nominal 0° angle.
10 . The method of claim 6 , wherein adjusting a nominal orientation of the quarter wave plate relative to the polarizing beam splitter comprises:
detecting a reflected signal; and
adjusting a nominal orientation of the quarter wave plate relative to the polarizing beam splitter until a desired signal strength of the reflected signal is obtained.
11 . The method of claim 6 , wherein adjusting a nominal orientation of the quarter wave plate relative to the polarizing beam splitter comprises:
detecting a reflected signal; and
adjusting a nominal orientation of the quarter wave plate relative to the polarizing beam splitter until a signal strength of the reflected signal is maximized.
12 . The method of claim 6 , wherein adjusting a nominal orientation of the quarter wave plate relative to the polarizing beam splitter comprises:
adjusting the nominal orientation of the quarter wave plate based on the phase retardance introduced into the optical path by the optical component.