A probe-type fiber optic ultraviolet photodetector

A probe-type all-fiber ultraviolet photodetector is proposed in this paper. A ZnO microwire is fixed on the end facet of a single-mode fiber through a glass tube with specific diameter to form a Fabry-Pérot interferometer. With this all-fiber structure, fast-response ultraviolet detection can be realized in an all-optical scheme. Since the refractive index of ZnO microwire increases under the illumination of ultraviolet, interference wavelengths of abovementioned device redshifts with the increase of ultraviolet light intensity. By employing a continuous 266-nm laser beam and chopping method, the sensitivity is obtained to be 0.268 nm/(W·cm-2 ) and the response time is only 0.56 ms. To be more specifically, the response speed of the device is further explored by a 266-nm pulsed laser, and the response time of the device is measured to be only 13 μs. The proposed device provides a new idea for the next generation of high-performance ultraviolet photodetectors and may find potential applications in the future.