Extreme Broadband Transparent Optical Phase Change Materials for High-Performance Nonvolatile Photonics
Yifei Zhang (1), Jeffrey B. Chou (2), Junying Li (3), Huashan Li (4), Qingyang Du (1), Anupama Yadav (5), Si Zhou (6), Mikhail Y. Shalaginov (1), Zhuoran Fang (1), Huikai Zhong (1), Christopher Roberts (2), Paul Robinson (2), Bridget Bohlin (2), Carlos Ríos (1), Hongtao Lin (1), Myungkoo Kang (5), Tian Gu (1), Jamie Warner (6), Vladimir Liberman (2), Kathleen Richardson (5), Juejun Hu (1) ((1) Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA, (2) Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts, USA, (3) Shanghai Key Laboratory of Modern Optical Systems, College of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, China, (4) Sino-French Institute for Nuclear Energy and Technology, Sun Yat-sen University, Guangzhou, China, (5) The College of Optics & Photonics, Department of Materials Science and Engineering, University of Central Florida, Orlando, USA, (6) Department of Materials, University of Oxford, Oxford, U.K.)
(Submitted on 1 Nov 2018)
Optical phase change materials (O-PCMs), a unique group of materials featuring drastic optical property contrast upon solid-state phase transition, have found widespread adoption in photonic switches and routers, reconfigurable meta-optics, reflective display, and optical neuromorphic computers. Current phase change materials, such as Ge-Sb-Te (GST), exhibit large contrast of both refractive index (delta n) and optical loss (delta k), simultaneously. The coupling of both optical properties fundamentally limits the function and performance of many potential applications. In this article, we introduce a new class of O-PCMs, Ge-Sb-Se-Te (GSST) which breaks this traditional coupling, as demonstrated with an optical figure of merit improvement of more than two orders of magnitude. The first-principle computationally optimized alloy, Ge2Sb2Se4Te1, combines broadband low optical loss (1-18.5 micron), large optical contrast (delta n = 2.0), and significantly improved glass forming ability, enabling an entirely new field of infrared and thermal photonic devices. We further leverage the material to demonstrate nonvolatile integrated optical switches with record low loss and large contrast ratio, as well as an electrically addressed, microsecond switched pixel level spatial light modulator, thereby validating its promise as a platform material for scalable nonvolatile photonics.
