Ultra-broadband silicon waveguide micro-electro-mechanical systems (MEMS) photonic switch

An ultra-broadband silicon waveguide micro-electro-mechanical systems (MEMS) photonic switch, wherein the photonic switch comprises three parts:

• a SiO2 layer and two input waveguides arranged on the SiO2 layer, a waveguide crossing with a nano-gap, and two output waveguides;
• the waveguide crossing with the nano-gap comprises a waveguide crossing and a nano-gap disposed on the waveguide crossing, the waveguide crossing is composed of two overlapped elliptical cylinders with the same size and shape, and centers of the two elliptical cylinders are overlapped and long axes are perpendicularly overlapped with each other to form a four-petal shape;
• a center of the waveguide crossing is etched with the nano-gap, specifically, the nano-gap is fully etched and disposed between symmetrical concaves on two sides formed by the two overlapped elliptical cylinders, and the nano-gap divides the waveguide crossing into two sub-waveguide crossings;
• both ends of the long axes of the two elliptical cylinders of the waveguide crossing serve as ports, a total of four ports are formed, the four ports are respectively connected to four single-mode strip waveguides, the two adjacent ports are respectively connected to the first input-waveguide and the second input-waveguide, and the other two ports are respectively connected to the first output-waveguide and the second output-waveguide, the first input-waveguide and the second output-waveguide are symmetrically arranged at both ends of a long axis of the first elliptical cylinder of the waveguide crossing, and the second input-waveguide and the first output-waveguide are symmetrically arranged at both ends of a long axis of the second elliptical cylinder of the waveguide crossing;
• an end of the nano-gap extends through a concave edge of the waveguide crossing between the first output-waveguide and the second output-waveguide, and another end of the nano-gap extends through the concave edge of the waveguide crossing between the first input-waveguide and the second input-waveguide;
• a middle of the second input-waveguide and the first output-waveguide are fully etched to respectively form a first nano-groove and a second nano-groove, and the two nano-grooves are arranged perpendicular to extending directions of own waveguides;
• the SiO2 layer around and under the waveguide crossing with the nano-gap is removed to form an air gap, an outward radial direction of the air gap covers the first nano-groove and the second nano-groove to ensure that the SiO2 layer under the first nano-groove and the second nano-groove is removed, so that the waveguide crossing with the nano-gap is bent and deformed within a plane surface of the SiO2 layer;
• the two sub-waveguide crossings are connected to an external circuit, and a width of the nano-gap is adjusted through adjusting a magnitude of a bias voltage applied across the two sub-waveguide crossings, thereby controlling a light propagation direction, so as to implement switching of a light propagation path.