Tunable Bloch surface waves devices

TL;DR

This thesis develops tunable Bloch surface wave devices using 1D photonic crystals, demonstrating polarization control, active layer tunability with lithium niobate, and electro-optic tuning for advanced photonic applications.

Contribution

It introduces novel methods for controlling BSW propagation and tunability using passive gratings and active lithium niobate layers in 1D photonic crystals.

Findings

Polarization-controlled BSW directionality achieved with gratings

Demonstration of BSW tunability via lithium niobate layers

Electro-optic tuning of BSW demonstrated

Abstract

This thesis is devoted to develop tunable devices on the base of one-dimensional photonic crystals (1DPhC) which can sustain Bloch surface waves (BSWs). First, we explore the possibilities to control the BSW propagation direction with polarization of incident light. In this case we manufacture additional passive structures such as gratings on the top of the 1DPhC, which are working both as a BSW launcher and polarization-controlled wave-splitters. We test this type of launcher in air and in water as an external medium. Then, we demonstrate the tunability of the BSW by adding an active layers into the multilayer stack. Here a crystalline X-cut thin film lithium niobate (TFLN) is used to introduce anisotropic properties to the whole 1DPhC. Different ways to manufacture 1D PhCs with LiNbO3 on the top would be described. Finally, we explore the concept of the electro-optically tuned BSW.