Photonic Bandgap Fiber Microlaser with Dual-Band Emission for Integrated Optical Tagging and Sensing

Lasers are emerging as novel photonic tags for single-cell labeling, anticounterfeiting, and encryption technology due to their narrow linewidth, high spectral multiplexing capacity, and superior stimuli-responsiveness. These laser-encoded photonic tags mostly distinguish the heterogeneity but do not yet provide both tagging and sensing of biosamples, which is highly desirable for disease screening. Here, a photonic bandgap (PBG) fiber microlaser that works as a 2D tag and an immunosensor is developed. The tubular PBG structure allows strong light–matter interaction and supports dual-band lasing in the same optical fiber, enabling massive biosample tagging and sensitive biodetection. By encoding the random resonant peaks in the short-wave band and multiplexing in the spatial domain, a 2D laser tag is generated with a large encoding capacity (>2 8500 ). Immunosensing of microalbumin is realized by using the periodic resonant peaks in the long-wave band, and a limit of detection of 0.06 ng µL −1 is achieved. This work is inspiring for the development of high-performance, multifunctional integrated devices for disease screening.