In-Vivo functional optical-resolution photoacoustic microscopy with stimulated Raman scattering fiber-laser source

In this paper a multi-wavelength optical-resolution photoacoustic microscopy (OR-PAM) system using stimulated Raman scattering is demonstrated for both phantom and in vivo imaging.A 1-ns pulse width ytterbium-doped fiber laser is coupled into a single-mode polarization maintaining fiber.Discrete Raman-shifted wavelength peaks extending to nearly 800 nm are generated with pulse energies sufficient for OR-PAM imaging.Bandpass filters are used to select imaging wavelengths.A dualmirror galvanometer system was used to scan the focused outputs across samples of carbon fiber networks, 200μm dye-filled tubes, and Swiss Webster mouse ears.Photoacoustic signals were collected in transmission mode and used to create maximum amplitude projection C-scan images.Double dye experiments and in vivo oxygen saturation estimation confirmed functional imaging potential.