Ultra‐low background Raman sensing using a negative‐curvature fibre and no distal optics. Issue 3 (19th November 2018)

• Record Type: Journal Article
• Authors: Yerolatsitis, Stephanos; Yu, Fei; McAughtrie, Sarah; Tanner, Michael G.; Fleming, Holly; Stone, James M.; Campbell, Colin J.; Birks, Tim A.; Knight, Jonathan C.
• Is Part Of: Journal of biophotonics. Volume 12:Issue 3(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-11-19
• Subjects: fibre fabrication -- hollow‐core fibre -- Raman fibre probe -- Raman sensing; Photonics -- Periodicals; Optical materials -- Periodicals; Optics -- Periodicals; Medical instruments and apparatus -- Periodicals; 621.3605
• DOI: 10.1002/jbio.201800239
• Languages: English
• ISSNs: 1864-063X

Abstract

Abstract : Measuring Raman spectra through an optical fibre is usually complicated by the high intrinsic Raman scatter of the fibre material. Common solutions such as the use of multiple fibres and distal optics are complex and bulky. We demonstrate the use of single novel hollow‐core negative‐curvature fibres (NCFs) for Raman and surface‐enhanced Raman spectroscopy (SERS) sensing using no distal optics. The background Raman emission from the silica in the NCF was at least 1000× smaller than in a conventional solid fibre, while maintaining the same collection efficiency. We transmitted pump light from a 785‐nm laser through the NCF, and we collected back the weak Raman spectra of different distal samples, demonstrating the fibre probe can be used for measurements of weak Raman and SERS signals that would otherwise overlap spectrally with the silica background. The lack of distal optics and consequent small probe diameter (<0.25 mm) enable applications that were not previously possible. Abstract : Measuring Raman spectra through an optical fibre is usually complicated by the high intrinsic Raman scatter of the fibre material. Common solutions such as the use of multiple fibres and distal optics are complex and bulky. A single hollow‐core negative‐curvature fibre is used for Raman and surface‐enhanced Raman spectroscopy sensing with no distal optics. This new optical fibre shows a 1000× background reduction compared with conventional fibres.