Simultaneous measurement of in-plane and out-of-plane displacement fields in scattering media using phase-contrast spectral optical coherence tomography

The use of phase contrast spectral optical coherence tomography to measure two orthogonal displacement components on a slice within a scattering medium is demonstrated. This is achieved by combining sequential oblique illumination of the object and recording two interferograms before plus two after the deformation. The proposed technique is illustrated with results from a sample undergoing simple shear. Depth-resolved out-of-plane and in-plane sensitivities of 0.14 and 4.2 μm per fringe are demonstrated up to a depth of 400 μm in a water based polymer.