Sensing performance improvement of resonating sensors based on knotting micro/nanofibers: A review

Compared with traditional optical fibers, optical micro/nanofibers can support the large proportion of evanescent fields, high efficiency optical coupling, low bending loss and high sensitivity, which have paved their way to all-optical transmission, environmental monitoring and life sciences. Because of the high quality factor, simple fabrication process and low cost, the microfiber knot resonator was used to explore some novel micro/nano-photonic devices, for example, micro-lasers and sensors. Where, the sensing performance was improved by elaborating the fiber surface or packaging the whole structures with the sensitive materials, enabling the sensors for determining the temperature, humidity, radiation intensity, current, gas concentration, etc. In this review, the microfiber knot resonators reported in the last decade have been reviewed, compared and analyzed. The future research has been prospected finally.

Automated summary

Optical micro/nanofibers have advantages such as high coupling efficiency, low loss, and high sensitivity, making them suitable for applications in all-optical transmission, environmental monitoring, and life sciences. Microfiber knot resonators are used to explore novel micro/nano-photonic devices and improve sensor performance through careful design and packaging with sensitive materials.