High-speed polarization-resolved coherent Raman scattering imaging

Abstract

Polarization-resolved coherent Raman scattering (polar-CRS) provides rich information on molecular orientational organization, with the strong advantages of being a label-free and chemically specific imaging method. Its implementation, however, strongly reduces the imaging acquisition rate, due to limits imposed by polarization tuning. Here we demonstrate fast-polar-CRS imaging based on combined electro-optic polarization and acousto-optic amplitude modulations, applicable to both stimulated Raman scattering and coherent anti-Stokes Raman scattering imaging. The proposed scheme adds polarization information without compromising the capacities of regular CRS intensity imaging; increases the speed of orientational imaging by two orders of magnitude as compared with previous approaches; and does not require post-processing analyses. We show that this method permits sub-second time-scale imaging of lipid order packing and local lipid membrane deformations in artificial lipid multilayers, but also in red blood cell ghosts, demonstrating its high sensitivity down to a single lipid bilayer membrane.

Monitoring dynamic collagen reorganization during skin stretching with fast polarization‐resolved second harmonic generation imaging

“…It means that in collagenous tissues, the main limitation to decrease the acquisition duration is the relatively low SHG signal, not the polarization switching rate. Smart approaches to achieve video-rate polarization switching have been reported recently and proved efficient in samples exhibiting higher signals [23,25,35]. Nevertheless, in complex biological samples such as skin dermis, such imaging rates require to rely on subsequent frame averaging to achieve a sufficient signal-to-noise ratio and result in a similar acquisition duration as the one we obtained for full images.…”

“…The mean ± SEM of every parameter is also calculated samples, as demonstrated in Figure 2. Moreover, it works in thick samples where epi-detection is mandatory, which is not the case for many other approaches [22][23][24][25]35]. It may be further improved by synchronizing the EOM with pixel imaging in order to image tissues with faster motion.…”

Label-Free Non-linear Multimodal Optical Microscopy—Basics, Development, and Applications

“…Quantitative evaluation of high order lipid assembly in myelin sheath can be used for early diagnosis of neurodegenerative diseases [165]. Advances with hardware-based demodulation of P-CARS signal [166] and fast electro-optic polarization [167] have improved the speed of the technique to enable the study of dynamical changes in molecular assemblies. The fast polarization modulation technique is also sensitive enough to track changes in the lipid orientation of cell membrane as it moves freely, and it is a worthy alternative to polarization resolved fluorescence techniques in membrane studies.…”

“…These features make P-CARS a promising tool for imaging ex vivo and in vivo biological samples. Recent advances to improving the speed of polarization modulation and hardware-based demodulation have made it possible to study the dynamics of molecular assemblies on millisecond timescales [159,165,167]. Applications of P-CARS have so far been limited given its advantages, primarily because of lack of access to such advanced imaging tools but that should change the near future.…”

Ultrafast background-free ro-vibrational fs/ps-CARS thermometry using an Yb:YAG crystal-fiber amplified probe

“…In particular, coherent anti-Stokes Raman scattering (CARS) [3,4] is widely used to retrieve local information. It is applied to microscopy in condensed media [5,6], life sciences [7], metrology [8,9], but also to diagnose gaseous flows [10] such as combustion [1,11], plasma [12][13][14][15] and supersonic flows [16,17]. Especially in the case of reacting flows, these measurements are essential for the understanding and the reliable simulation of the physical processes taking place in presence of high temperature, pressure and turbulence.…”