All-fiber-optic mass sensor based on optomechanical nanofilm resonators

Mass detection plays an indispensable role in many fields like medical targeted therapy, biological cytology, and nanophysics. However, traditional mass detection faces the challenge of a complex system, expensive instruments, and long testing time. Here we report an all-fiber-optic mass sensor based on a nanofilm resonator. Using resonant frequency shifts as the readout of analyte mass, the sensor achieves the mass sensitivity of 0.920 kHz/pg with a mass resolution of 1.9×10 −14 g, for the first-order mode in the mass range up to 372 pg at room temperature. In this work, we transfer the excitation laser and detection laser to the micro-cavity structure at the end of the optical fiber. Combined with optical fibers, the sensor can be made extremely integrated, making it more stable and collimation-free compared with traditional bulky optical setups. Its good biocompatibility and anti-electromagnetism disturbance ability also make this mass sensor potentially a beneficial tool for cell biology and basic physics measurements.