Spatial Heterodyne Offset Raman Spectroscopy Enabling Rapid, High Sensitivity Characterization of Materials' Interfaces

Spatially offset Raman spectroscopy is integrated with a fiber-coupled spatial heterodyne spectrometer to collect Raman spectra from deep within opaque or scattering materials. The method, named spatial heterodyne offset Raman spectroscopy generates a wavenumber-dependent spatial phase shift of the optical signal as a spectral image on a charge-coupled device detector. The image can be readily processed from the spatial domain using a single, simple, and on-the-fly Fourier transform to generate Raman spectra, in the frequency domain. By collecting all of the spatially offset Raman scattered photons that pass through the microscope's collection objective lens, the methodology gives an improvement in the Raman sensitivity by an order of magnitude. The instrumentation is both mechanically robust and movement-free, which when coupled with the associated advantages of highly efficient signal collection and ease of data processing, enables rapid interfacial analysis of complex constructs based on established biomaterials models.

Automated summary

Spatially offset Raman spectroscopy, when integrated with a fiber-coupled spatial heterodyne spectrometer, generates a wavenumber-dependent spatial phase shift to collect Raman spectra from deep within opaque or scattering materials. By processing the spectral image using a single Fourier transform, an order of magnitude improvement in Raman sensitivity is achieved, allowing rapid interfacial analysis of complex constructs based on established biomaterials models.