Forward-propagating surface-enhanced Raman scattering and intensity distribution in photonic crystal fiber with immobilized Ag nanoparticles

Abstract

A 30 cm long solid-core photonic crystal fiber (PCF) with immobilized and discrete Ag nanoparticles was used to obtain forward-propagating surface-enhanced Raman scattering (SERS) of 2 microM Rhodamine 6G (R6G) aqueous solution filled in the cladding air channels. The intensity distributions of characteristic Raman vibrational bands of silica and R6G in PCF were mapped for the first time to our knowledge by hyperspectral Raman imaging. We show that the measured SERS intensity arises exclusively from the forward-propagating core mode as a result of evanescent-field interaction with R6G in the innermost ring of the cladding air channels.

Towards Full‐Length Accumulative Surface‐Enhanced Raman Scattering‐Active Photonic Crystal Fibers

“…As a result, we have recommended and recently described in a brief study forward scattering as a more suitable detection mode to unambiguously assess the SERS-active nature of PCF. [18] To the best of our knowledge, this article is the first report of net accumulative SERS from the full-length Ag-nanoparticlefunctionalized PCFs. The finding has been enabled by a fine control of the coverage density of Ag nanoparticles and studies of a competitive interplay between SERS gain and light attenuation in the Raman intensity with PCFs of varying length.…”

[INVITED] New perspectives in photonic crystal fibre sensors

“…To carried out Raman spectroscopy with PCFs, they voids of the fibre are decorated with metal nanoparticles [74][75][76]. The deposition of nanoscale materials in the PCF voids can be carried out by chemical vapour deposition at high pressure or by using colloidal solutions [74][75][76][77][78][79]. Target molecules absorbed on the nanoparticles within the PCF couple to the surface plasmon modes, thus releasing Raman-scattered photons which are collected by the PCF.…”

Development of highly reliable SERS‐active photonic crystal fiber probe and its application in the detection of ovarian cancer biomarker in cyst fluid

“…Among the two classes of PCFs, hollow core PCFs allow direct interaction between the excitation light and the analyte but they suffer from rather narrow transmission bandwidth and spectral shift when they are filled with a liquid analyte . On the other hand, solid core PCFs provide fixed and broader transmission bandwidth, even when the fiber is filled with liquid and resulting in stronger Raman signal enhancement . In these fibers, the light is guided inside the solid core and the interaction between light and analyte occurs with the evanescent field that overlaps in the cladding.…”