We have performed Raman spectroscopy using a near-field scanning optical microscope. This avoids the diffraction limit inherent with conventional optical microscopy techniques involving far-field optical components, and allows volumes significantly smaller than the cube of the wavelength to be investigated. The small sample volume coupled with the light-starved nature of the Raman effect itself...

Microalgae are extensively researched as potential feedstocks for biofuel production. Energy-rich compounds in microalgae, such as lipids, require efficient characterization techniques to investigate the metabolic pathways and the environmental factors influencing their accumulation. The model green alga Coccomyxa accumulates significant amounts of triacylglycerols (TAGs) under nitrogen depleti...

Bioactive materials including glass and glass-ceramics are nowadays used as medical implants for orthopedic applications. In this study several samples of glass-ceramics have been prepared using both heat treatment and sol-gel processes. The structure and bioactivity of these samples based on their interaction with simulated body fluid (SBF) have been determined. In-vitor, using the Raman s...

Surface-enhanced Raman spectroscopy (SERS) and femtosecond stimulated Raman spectroscopy (FSRS) have revolutionized the Raman spectroscopy field. SERS provides spectroscopic detection of single molecules, and FSRS enables the acquisition of Raman spectra on the ultrafast time scale of molecular motion. Here, we present the first successful combination of these two techniques, demonstrating surf...

The intensity ratio between two major Raman bands in graphene is one of the most important information for physics of graphene and has been believed to represent various intrinsic properties of graphene without critical assessment of extrinsic effects. We report a micro Raman spectroscopy study on the Raman intensity ratio of the 2D band to the G Raman band of graphene varying the thickness of ...

Fast and sensitive Raman spectroscopy measurements are imperative for a large number of applications in biomedical imaging, remote sensing and material characterization. Stimulated Raman spectroscopy offers a substantial improvement in the signal-to-noise ratio but is often limited to a discrete number of wavelengths. In this report, by introducing an electronically-tunable acousto-optical filt...

Introduction Raman spectroscopy is one of the most common techniques for materials identification and characterization. Based on inelastic scattering of a monochromatic excitation source, Raman measures vibrational, rotational and other low-frequency modes in a system. It’s not only characteristic for functional groups, but also sensitive to backbone and crystalline structures. Therefore, Raman...

We have carried out absolute calibrations of the LHD YAG Thomson scattering system by using Raman scattering and Rayleigh scattering in order to verify the applicability of Rayleigh calibration in the LHD Thomson scattering, and make a comparative study of Raman and Rayleigh calibrations. In the LHD Thomson scattering device, Rayleigh calibration is expected to give more reliable calibration fa...

We report on the development of a novel multiplexing Raman spectroscopy technique using a single laser light together with a volume phase holographic (VPH) grating that simultaneously acquires both fingerprint (FP) and high wavenumber (HW) tissue Raman spectra at endoscopy. We utilize a customized VPH dual-transmission grating, which disperses the incident Raman scattered light vertically onto ...

The cascading polarization contributing to the femtosecond fifth-and seventh-order coherent Raman scattering processes is obtained in terms of the third-and fifth-order Raman response functions. It is found that four cascading processes contribute to the fifth-order Raman scattering signal. In the case of the seventh-order Raman scattering, there are 34 possible cascading processes contributing...