Limiting Optical Diodes Enabled by the Phase Transition of Vanadium Dioxide

作者：Chenghao Wan, Erik H. Horak, Jonathan L. F. King, Jad Salman, Zhen Zhang, You Zhou, Patrick Roney, Bradley S. Gundlach, Shriram Ramanathan, Randall H. Goldsmith, Mikhail A. Kats · 发表于：ACS Photonics · 年份：2018 · DOI：10.1021/acsphotonics.8b00313 · 被引用次数：76 · 研究领域：Magneto-Optical Properties and Applications、Transition Metal Oxide Nanomaterials、Advanced Fiber Optic Sensors

A limiting optical diode is an asymmetric nonlinear device that is bidirectionally transparent at low power but becomes opaque when illuminated by sufficiently intense light incident from a particular direction. We explore the use of a phase-transition material, vanadium dioxide (VO 2 ), as an active element of limiting optical diodes. The VO 2 phase transition can be triggered by optical absorption, resulting in a change in refractive index orders of magnitude larger than what can be achieved with conventional nonlinearities. As a result, a limiting optical diode based on incident-direction-dependent absorption in a VO 2 layer can be very thin, and can function at low powers without field enhancement, resulting in broadband operation. We demonstrate a simple thin-film limiting optical diode comprising a transparent substrate, a VO 2 film, and a semitransparent metallic layer. For sufficiently high incident intensity, our proof-of-concept device realizes broadband asymmetric transmission across the near-infrared, and is approximately ten times thinner than the free-space wavelength.