Ultracompact High‐Extinction‐Ratio Nonvolatile On‐Chip Switches Based on Structured Phase Change Materials
Wenfei Li, Xiyuan Cao, Sannian Song, Longsheng Wu, Ruobing Wang, Yi Jin, Zhitang Song, Aimin Wu
Abstract
Abstract Adopting phase change material (PCM) in constructing nonvolatile on‐chip photonic switches has received intensive attention recently. Usually, a large‐area thin PCM film is directly used to construct a switch. Here, subwavelength structured PCM supporting localized resonance are adopted to efficiently improve the switching performance in a moderate bandwidth to obtain an optimal switch of higher switching contrast, smaller footprint, lower energy consumption, and better structure stability. Such a switch consisting of three cascaded Ge 2 Sb 2 Te nanodisks with a total volume of only 0.229 µm 35 nm on top of a single mode strip silicon waveguide is demonstrated. In the experimental verification, a high extinction ratio up to 27 dB is supported by the fabricated device as a high performance switch. The proposed design methodology will find its great potential in various large‐scale integration in optical interconnection and optical computing with new architectures or applications.