Tunable Polarization Encoder Capable of Polarization Conversion and Separation Based on a Layered Photonic Structure

In this paper, a polarization encoder with a polarization conversion function is investigated using a layered photonic structure comprising nonlinear materials and indium antimonide. The electric field of the incident linear polarization waves considered are parallel to the x-y plane at an angle of 45° to the x-axis, and can be decomposed into components directed along the x- and y-axes, generating two polarized waves: transverse electric and transverse magnetic waves. Due to the nonlinear effect and the temperature and magnetic flux density tunable properties of indium antimonide, the light intensity, temperature, and magnetic flux density can be used to adjust the reflection phase difference and polarization form. Discussing the influences of these three physical quantities on the phase difference, the incident linear polarization wave and reflected circular polarization wave conversion, the circular polarization conversion of two different rotations and the circular polarization separation of a certain bandwidth can be simultaneously realized with the specific modification of the light intensity or temperature. Moreover, four disparate input logic levels composed of temperature and magnetic flux density achieve specific encoding outputs for all polarization forms. This signifies that polarization selection through control of the logic codes can be easily attained. The consequences show that this form of polarization conversion and encoding is tailored and can be accurately manipulated. Hence, this provides a novel foundation for tunable and diverse polarization splitters and selectors.