Direct Three-Dimensional Measurement of Refractive Index via Dual Photon-Phonon Scattering.

ABSTRACT: We developed a microscopy technique that can measure the local refractive index without sampling the optical phase delay of the electromagnetic radiation. To do this, we designed and experimentally demonstrated a setup with two colocalized Brillouin scattering interactions that couple to a common acoustic phonon axis; in this scenario, the ratio of Brillouin frequency shifts depends on the refractive index, but not on any other mechanical and/or optical properties of the sample. Integrating the spectral measurement within a confocal microscope, the refractive index is mapped at micron-scale three-dimensional resolution. As the refractive index is probed in epidetection and without assumptions on the geometrical dimensions of the sample, this method may prove useful to characterize biologic

SUBMITTER: Fiore A 

PROVIDER: S-EPMC6530466 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature