Polarization-independent electro-optic phase modulator based on trilayer birefringent materials

Manipulating the phase and amplitude of light led to many important breakthroughs in optics, and it is still considered one of the most critical technologies in emerging optical systems. However, conventional phase modulators generally suffer from the strong polarisation dependence that stems from the anisotropic optical property of the base material. Here, we report a phase modulator that is polarisation-independent and is based on the trilayer of birefringent materials which have their optical axes aligned at specific angles. The proposed structure effectively eliminates the polarisation dependence of the phase modulator without compromising its electro-optic properties. This technology provides a simple but significant method for developing a polarisation-independent phase modulator without fabrication complexity.