SHIM and TPEM: getting more information from non linear excitation

Several endogenous protein structures give rise to second harmonic generation (SHG) - second order nonabsorbative energy doubling of an excitation laser line. The orientation of collagen fibers within tissues such as tendons or ligaments is of primary importance. In this study, we propose a method to map the orientation of collagen fibers of a tendon. The method uses only few images acquired at specific polarizations of the input laser beam by rotating the sample on the stage. This procedure is implemented both in backward and forward scattering pathways. The improved details should clarify the backscattered signal nature