Optical fibers for miniaturized surface-enhanced Raman-scattering probes

A range of optical fibers with surface-enhanced Raman scattering (SERS) functionalized tips have been evaluated for use as micro-scale sensing devices. In order to optimize the sensitivity of the optical fiber probe, the relationship between SERS intensity and different fiber parameters was investigated. It was found that the numerical aperture, core size, mode structure, and core material have a major effect on the probe performance, as does the numerical aperture of the microscope objective. The results suggest that an ideal fiber for SERS sensing should be single mode at the excitation wavelength and have low-background core material.