Broadband nonvolatile electrically programmable silicon photonic switches

TL;DR

This paper introduces a broadband, nonvolatile, electrically programmable silicon photonic 2 x 2 switch using phase-change material, offering zero static power, compact size, and high endurance for scalable photonic systems.

Contribution

The authors develop a novel nonvolatile silicon photonic switch based on Ge2Sb2Te5, achieving broadband operation, low loss, minimal crosstalk, and high endurance, advancing programmable PIC technology.

Findings

Record-high endurance of over 2,800 switching cycles

Compact coupling length of 64 um with low insertion loss

Effective broadband operation across the telecommunication C-band

Abstract

Programmable photonic integrated circuits (PICs) have recently gained significant interest due to their potential in creating next-generation technologies ranging from artificial neural networks and microwave photonics to quantum information processing. The fundamental building block of such programmable PICs is a tunable 2 x 2 switch, traditionally controlled by the thermo-optic or free-carrier dispersion. Yet, these implementations are power-hungry, volatile, and have a large footprint (typically > 100 um). Therefore, a truly 'set-and-forget' type 2 x 2 switch with zero static power consumption is highly desirable for large-scale PICs. Here, we report a broadband nonvolatile electrically programmable 2 x 2 silicon photonic switch based on the phase-change material Ge2Sb2Te5. The directional coupler switch exhibits a compact coupling length (64 um), small insertion loss (<2 dB), and minimal crosstalk (<-8 dB) across the entire telecommunication C-band while maintaining a record-high endurance of over 2,800 switching cycles. This demonstrated switch constitutes a critical component for realizing future generic programmable silicon photonic systems.