Nonvolatile multi-level adjustable optical switch based on the phase change material

Abstract

For the advantages of the faster computation speed and lower energy consumption, all-optical computation has attracted great attention compared with the traditional electric computation method. Optical switches are the critical elementary units of optical computation devices. However, the traditional optical switches have two shortcomings, expending the outside energy to keep the switch state and the weak multi-level adjustable ability, which greatly restrict the realization of the large-scale photonic integrated circuits and optical spiking neural networks. In this paper, we use a subwavelength grating slot-ridge (SWGSR) waveguides on the silicon platform to design a nonvolatile multi-level adjustable optical switch based on the phase change material Ge2Sb2Te5 (GST). Changing the phase state of GST can modulate the transmission of the optical switch, and the change of the optical transmittance of the optical switch is about 70%, which is much higher than that of previous optical switches. As no static power is required to maintain the phase state, it can find promising applications in optical switch matrices and reconfigurable optical spiking neural networks.