LC:PDMS optical waveguides: a new proposal for flexible photonics

We demonstrated optical waveguides made of polydimethylsiloxane (PDMS) channels filled with nematic liquid crystals (LC), referred as LC:PDMS waveguides [1], inspired by optofluidic devices demonstrated by Psaltis et al. [2]. PDMS is in fact largely used in microfluidics to fabricate microsystems by means of soft lithography. Standard cast and molding technique allows to easily make passive optical waveguides by combining different kinds of PDMS for effective packaging of flexible photonic chips [3]. In this paper we propose electro-optic integrated devices based on LC:PDMS waveguides such as optical switches based on sub-micron long directional couplers for flexible low power photonic chips. Design and fabrication of LC:PDMS waveguides and devices will be presented operating at the fiber optic communication wavelength of 1550 nm. Monte Carlo simulations will be also reported to show molecular reorientation in a LC:PDMS with an applied electric field in an in-plane switching electrode configuration and how this affects directional coupler behavior to obtain electro-optical LC:PDMS switches. [1] A. d’Alessandro, L. Martini, G. Gilardi, R. Beccherelli, and R. Asquini, IEEE Photonics Technology Letters, 27, 1709 (2015). [2] D. Psaltis, S. R. Quake, and C. H. Yang, Nature, 442, 381 (2006). [3] J. Missinne, S. Kalathimekkad, B. Van Hoe, E. Bosman, J. Vanfleteren, and G. Van Steenberge, Opt. Expr., 22, 4168 (2014).