Fiber End-Facet Integrated Non-Volatile Optical Switch Based On Ge₂Sb₂Te₅

The silicon photonic integrated network based on the thermo-optical or electro-optical effect generally has the disadvantages of volatile, large footprint, and significant energy loss. Here, we propose and demonstrate an all-optical controllable switch device with non-volatile, broadband adjustable, and bistable fast switching performance by integrating the phase-change material (Ge2Sb2Te5) on the optical fiber. By adjusting the energy of the laser pulse train exerting on the optical fiber, the phase state of the phase-change material can be switched, thereby realizing the 'ON' and 'OFF' function of the optical switch. As a result, a non-volatile optical switch with a wide bandwidth working range (up to 60 nm) and a significant transmission contrast (2 dB) is demonstrated. This device is expected to help realize fast and broadband optical routing in fiber optical communication networks as the optical switch. Furthermore, its logic operation function can impart optical fiber with new storage and computing functionalities except for transmission and sensing. It can be combined with an optical field-programmable gate array (OFPGA) and play a part in optical fiber photonic circuitry in the future.