Theoretical Investigation of Material Properties Affecting Coherent Anti-Stokes Raman Scattering Microendoscopy
Kelly, Kevin F.
Master of Science
Physicians in clinical settings are constantly seeking label-free imaging modalities with superior sensitivity and resolution. Coherent anti-Stokes Raman scattering (CARS) has demonstrated great clinical potential, but complicated optics and poor conversion efficiency of CARS signal photons has limited the use of endoscopic CARS. Optimization of optical systems for maximal signal collection for rapid, low noise endoscopic imaging is essential. In vivo CARS imaging collects a large backscattered signal from forward CARS, obscuring structures with dimensions similar to the excitation wavelength. This is the first model to accurately determine the effect of scattering in multiple tissue types on CARS imaging. By characterizing the radial location of the backward CARS signal from sub-wavelength features and backscattered forward CARS signals from larger scatterers, methods are developed to collect both images simultaneously. Numerical methods are utilized to demonstrate how the focusing objective, focal depth, collection method, and object of interest impact CARS imaging.