A novel method of using hollow-core photonic crystal fiber as a Raman biosensor

A new method for using a non-selectively filled hollow-core photonic crystal fiber (HC-PCF) as a sensitive Raman spectroscopy platform suitable for biosensing applications is presented. A 1550 HC-PCF was completely filled with ethanol (core and cladding holes). Using a 785nm excitation laser, the Raman spectrum of ethanol in the fiber core was obtained and compared with the equivalent Raman spectrum of an ethanol-filled cuvette. Using a relatively short 9.5cm length of HC-PCF, a Raman signal enhancement factor of 40 over a bulk solution of ethanol was observed under the same excitation conditions. The small sample volume utilized and longer interaction length provides the potential for compact, sensitive, and low-power Raman sensing of biological materials