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

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 mu m and shows an extinction ratio of 0.38 dB mu m-1, with a power consumption of less than 6 mu W and a response time approximate to 20 mu s, resulting in a figure-of-merit of 0.012 mW. A scheme of on-chip integrated optical attenuators for plasmonic slot waveguide-enhanced electro-optical properties of polymer-stabilized liquid crystal film is proposed. This prototype reduces the response time and improves the modulation efficiency of the liquid crystal-based integrated photonic device, resulting in a compact and energy-efficient platform for on-chip optical modulation. image