Broadband and high-power microfiber switch driven by surface-charge-enhanced electrostatic force

The growth of high-performance computing and AI model training has driven the demand for optical switches with broad bandwidth and enhanced power-handling capabilities to support stable system operation. However, conventional silica-based fiber switches are limited by high operating voltages and material-induced absorption arising from the integrated functional layers. In this work, we propose and experimentally demonstrate an all-fiber switch driven by a surface-charge-enhanced electrostatic force. By injecting charges into the micro/nanofiber cantilever via a controlled triboelectric charging process, we shift the dominant actuation mechanism from weak polarization-gradient forces to robust Coulomb interactions within a localized electric field. Experimental results show that the device achieves a static switching voltage of 59.9 V and a resonant switching voltage of only 20.0 V, with sub-millisecond response times (<139 µs). Due to the all-fiber architecture and low-index substrate design, the switch exhibits ultra-broadband transparency from the visible to near-infrared regimes (450-1600 nm) and maintains stable performance under high optical power loads up to 0.6 W. This surface-charge engineering approach provides a practical solution for next-generation reconfigurable optical networks and high-power signal management.