Raman Imaging with a Fiber-Coupled Multichannel Spectrograph

Abstract

Until now, spatially resolved Raman Spectroscopy has required to scan a sample under investigation in a time-consuming step-by-step procedure. Here, we present a technique that allows the capture of an entire Raman image with only one single exposure. The Raman scattering arising from the sample was collected with a fiber-coupled high-performance astronomy spectrograph. The probe head consisting of an array of 20 × 20 multimode fibers was linked to the camera port of a microscope. To demonstrate the high potential of this new concept, Raman images of reference samples were recorded. Entire chemical maps were received without the need for a scanning procedure.

Label‐Free Molecular Imaging of Biological Cells and Tissues by Linear and Nonlinear Raman Spectroscopic Approaches

“…[279] Thekey elements were aprobe head consisting of an array of 20 20 multimode fibers and afibercoupled high-performance integral-field spectrograph originally developed for astronomical use.T he pitch between the fiber centers was 0.5 mm, resulting in asquare active surface with an edge length of 9.5 mm. Images can be registered by sequential acquisition of spectra and moving the Angewandte Chemie Reviews sample or the probe.T his procedure is time-consuming because the exposure time for each spectrum lies in the range of seconds,a nd the acquisition of hundreds of spectra takes several minutes.This is impractical in clinical settings.A technique was presented that allows for capturing an entire Raman image with only one exposure without the need for ascanning procedure.…”

Spermatozoa quality assessment: a combined holographic and Raman microscopy approach

“…Indeed, RS is a sensitive and non-invasive method with resolution in the sub-micrometer range that allows the chemical assessment of single cells by detecting their biomolecule vibrations, serving as a cellular intrinsic 'fingerprint' 3,[15][16][17][18][19][20][21][22][23][24][25][26] . It can be also used to provide pseudo-color images according to the Raman spectral band intensities allowing the identification of cell phenotype and physiological state [23][24][25][26][27][28][29][30][31][32] .…”

Ultrafast imaging Raman spectroscopy of large-area samples without stepwise scanning

“…The use of fiber bundle coupled IFS for imaging Raman spectroscopy was already reported (Ma and Ben-Amotz, 1997;Okuno and Hamaguchi, 2010;Roth et al, 2012;Stewart et al, 2012;Schmälzlin et al, 2014Schmälzlin et al, , 2015Brückner et al, 2015). However, previous setups were designed to examine samples with microscopic dimension, e.g., cells or tiny crystal fragments.…”

“…The employed astronomy spectrograph and the fiber bundle were presented previously (Schmälzlin et al, 2014). In brief: the MUSE spectrograph unit is a high-performance fully refractive optical system that covers a spectral range from 465 to 930 nm with about 0.25 nm resolution.…”