Plasmonic‐Enhanced Polymer‐Stabilized Liquid Crystals Switching for Integrated Optical Attenuation

Abstract

Liquid crystals are widely used in photonics because of their profound electro–optic properties. However, the slow switching speeds (milliseconds) and the fluid nature of liquid crystals restrict their potential use in integrated photonics. In this work, polymer‐stabilized liquid crystals are utilized as the functional material to improve the response time with a polymer network that helps pre‐orientate the liquid crystal. Additionally, plasmonic slot structures are simultaneously employed to minimize the switch voltage by confining the optical field within the electrode spacing at subwavelength scales. Thanks to the large overlap of the optical and electric fields, the scattering states of the polymer‐stabilized liquid crystal can be effectively manipulated to modulate the loss of the propagating wave, resulting in strong optical attenuation in the integrated photonic platform. Specifically, a plasmonic enhanced polymer‐stabilized liquid crystal photonic device for operation at 1550 nm, which has a length of only 10 µm and shows an extinction ratio of 0.38 dB µm−1, with a power consumption of less than 6 µW and a response time ≈20 µs, resulting in a figure‐of‐merit of 0.012 mW.