Compact, Highly Efficient, and Controllable Simultaneous 2 × 2 Three-Mode Silicon Photonic Switch in the Continuum Band

Abstract

Multimode switch (MMS) allows realizing multimode optical communication enabling high-speed communication. However, to develop such an ultrafast switch for simultaneous multimode with a compact size is very challenging. In this paper, we design and demonstrate a compact multimode $2\times 2$ MMS based on numerical simulation methods using silicon $\Psi $ -junctions and multimode interference (MMI) couplers. The switch is controlled by thermal-optic phase shifters which is able to switch simultaneously states of the optical signal between three quasi-transverse electric modes. The MMS exhibits a low insertion loss from −1.5 dB to −3 dB, low crosstalk below −22 dB, and high extinction ratio larger than 22 dB in 40-nm bandwidth in the third telecom window from 1520 to 1560 nm, respectively. With a compact footprint of $12\,\,\mu \text{m}\,\,\times 1300\,\,\mu \text{m}$ , the MMS exhibits relatively large dimensional tolerances. Besides, the MMS provides total electric power consumption levels smaller than 103 mW at an ultrafast switching time of $4.4~\mu \text{s}$ without the impact of the plasmonic effect. Furthermore, the conceptual principle of the proposed MMS can be reconfigurable and scalable in dimensional multifunctional on-chip mode-division multiplexing optical interconnects and promising potential for photonic large scale integration circuits in the continuum band.

Keywords

• Silicon photonics
• multimode waveguide switch
• thermo-optic effect
• controllable
• Ψ-junctions
• MMI couplers