Liquid crystal tunable claddings for polymer integrated optical waveguides

Abstract

Optical waveguides in photonic integrated circuits are traditionally passive elements merely carrying optical signals from one point to another. These elements could contribute to the integrated circuit functionality if they were modulated either by variations of the core optical properties, or by using tunable claddings. In this work, the use of liquid crystals as electro-optically active claddings for driving integrated waveguides has been explored. Tunable waveguides have been modeled and fabricated using polymers. Optical functions such as variable coupling and optical switching have been demonstrated.

Active Optical Beam Shaping Based on Liquid Crystals and Polymer Micro-Structures

“…Their unique characteristics lead to a dominant position in products of the current display industry, such as thin film transistor (TFT) liquid crystal displays (LCDs). Beside the well-established applications in displays, LCs with their unique electro-optical properties have been the subject of continued research in other application areas, such as LC light intensity attenuators [11][12][13], LC phase shifters [14][15][16], LC wavelength selectors [17][18][19], LC beam shaping devices [20][21][22] etc. The tunable optical refractive index of LC materials, along with the quite mature LCD fabrication technologies, are reasons to believe that the LC-based beam shaping components have a huge potential to eliminate the disadvantages that are inherent to many existing solutions in the tunable and active optical applications.…”