Tunable Optical Filters Using Phase Change Materials

Date of Award

8-1-2024

Degree Name

Ph.D. in Electro-Optics

Department

Department of Electro-Optics and Photonics

Advisor/Chair

Andrew Sarangan

Abstract

Tunable optical filters play a crucial role in various applications including telecommunications, spectroscopy, and sensing. Among different approaches for achieving tunability, phase change materials (PCMs) have garnered significant attention due to their reversible transition between amorphous and crystalline states in response to external stimuli such as temperature, electric field, or optical irradiation. The unique optical properties of PCMs, such as changes in refractive index, transmission, and absorption, during phase transition enable the creation of dynamically reconfigurable optical devices. By integrating PCMs into photonic structures such as Fabry-Perot cavities, photonic crystals, or metamaterials, researchers have demonstrated tunable filters with capabilities ranging from spectral filtering to wavelength-selective switching. In this work we have developed the fundamental principles underlying the operation of PCM-based thin film tunable optical filters, and highlight the key considerations in material selection, device design, and integration. Additionally, we systematically explore the incorporation of PCMs in optical thin film designs, and analyze the performance and conceptual gaps in conventional approaches. This dissertation addresses the design, fabrication, and testing of tunable filters for a few select applications to showcase their utility. It also addresses the initial implementation of electrical switching for multilayer thin-film stacks.

Keywords

Phase Change Materials, GSST, Tunable Optical Filters, GST

Rights Statement

Copyright © 2024, author.

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