Computational wavefront shaping for coherent nonlinear microscopy using the nonlinear distortion operator

Non-invasive imaging with high resolution deep within biological materials without the use of harmful ionizing radiation is of great interest in the field of medical imaging. Second- and third- harmonic generation are excellent mechanisms to circumvent this issue by providing outstanding contrast and optical sectioning 1. In general, these signals are weak and prone to scattering which introduce great challenges when imaging deep within turbid media. We will discuss recently demonstrated nonlinear distortion, which can detect very weak backscattered SHG optical fields in a widefield holography configuration, from which distortion from aberrations and scattering can be computationally estimated and corrected. This approach uses field phase information to allow diffraction limited imaging within deep tissue.