Analysis of birefringence modulation performance in RM-embedded CO-polymer waveguides

Uncontrolled birefringence causes measurement errors and signal distortion in high-precision optical systems, yet existing modulation methods suffer from complex fabrication or poor stability. Polymer waveguides serve as low-cost, flexible alternatives to traditional lithium niobate platforms. This work constructs an interferometer with reactive mesogen-embedded polymer waveguide arms to characterize polarization-dependent phase tuning performance via thermal excitation. Measured data reveal high phase modulation efficiencies for two orthogonal light polarizations, ultra-low heating power to generate full polarization phase retardation, and strong polarization tuning capability between modes. The results validate the excellent low-power, high-efficiency birefringence tuning capacity of the composite polymer waveguide architecture, offering a simple, compact route for advanced integrated photonic signal processing and precision interferometry.