Energy-Efficiency Switchable Grating Coupler for Intra-Chip Wireless Optical Interconnection

A switchable compact plasmonic grating coupler is proposed and demonstrated theoretically. It is excited by TM standing waves and can be used to modulate the intensity of radiated light by moving the position of standing waves. The coupler used for connection is composed of five gold strips and a reflector, and it's footprint is only 2.19 μm × 3.19 μm. The calculation results show that the bandwidth of coupler is 110 nm from 1.5 to 1.61 μm, and the extinction ratio can reach 20 dB at λ = 1.55 μm with the ON-radiation efficiency bigger than 82%. Meanwhile, the thermal loss rate is no more than 8%. The switchable coupler, with features of compact size, high energy efficiency, fast response, and ability of vertical light emission, can be used for dense optical interconnection systems. It provides a new approach for intra-chip wireless optical interconnection.