摘要

Fibre-optic fluorescent probes need special filtering; this allows them to reject the strong excitation light while transmitting the weak fluorescent light to the detector. In this paper, a seven-core fibre with optically coupled cores is proposed for fluorescent probes. Using core-to-core mode coupling for filtration instead of mounting conventional filters would decrease the number of necessary parts and the size of the probe, making it suitable for spectroscopic applications. The proposed probe was assembled with the central core being used to transmit and couple the excitation radiation to the outer six cores. Using all the cores for delivering the excitation light from the source to the sample reduces the risk of sample being photochemically damaged compared to excitation by a single-core fibre. Fluorescence emission feedback radiation at a higher wavelength can be collected in the outer six cores, and then the fluorescence signal can be coupled from these cores to the central core. The results from the numerical simulations of the 3D full-vectorial model show two cases corresponding to peak transmission at wavelengths of 410 nm and 480 nm. Therefore, the selectivity of the wavelength ensures that the light directed into the central core will pass through it and reach the end of the probe, except for certain wavelengths, where it will couple and appear at the end of the other cores.

  • 出版日期2017-3