Single-fiber probe based on surface enhanced Raman scattering (SERS)

Fiber SERS probes have great potential in chemical and biological sensing. To our knowledge, there has been no demonstration of any single-fiber SERS probes where both the excitation beam and SERS signals are transmitted through the same fiber with a significant length, which is required for a flexible probe. In this paper, we report our proof-of-concept demonstration of a single-fiber SERS probe with a 1 m long fiber. We demonstrate various configurations of the fiber probe, where the SERS substrate is coated on either a side-polished or end-polished fiber surface. While the side-polished fibers provide a large platform for signal generation, the end polished fibers are easy to manipulate and can transmit SERS signals back through the fiber. In our experiments, we have successfully detected SERS signals both at the end where the fiber is polished and coated with the SERS substrate and at the end where the excitation light is coupled into the fiber, using R6G as a testing sample