Review of sensing and actuation technologies–from optical MEMS and nanophotonics to photonic nanosystems

Entering the era of the Internet of Things (IoT) and fifth-generation (5G) mobile networks, the demand for compact, cost-effective, and high-performance sensors and actuators is skyrocketing. Optical technologies as complements to conventional electrical technologies provide a versatile platform to construct sensors and actuators for widespread applications, showing advantages of high data rate, strong multiplexing capability, fast response, low crosstalk, and immunity to electromagnetic interference. In this paper, we provide a comprehensive review of the development progress of optical sensing and actuation technologies. Their applications in optical detectors, optical sensors (further divided into physical and chemical/biological sensors), and optical communication/computing/imaging are presented. For each category of the applications, progress is introduced following the technology evolution trend from optical microelectromechanical systems (MEMS) and nanophotonics to photonic nanosystems. Future development directions of optical sensing/actuation technologies are also proposed.