Optical microscopy is an indispensable tool for biomedical research. Yet, the same structures that make biological samples interesting to study under a microscope (such as cells, vasculature and subcellular organelles) scatter light and thus render tissues opaque. Tissue opacity poses a major challenge to all optical imaging and photo-stimulation methods, fundamentally limiting them to thin sections, cultured cells or superficial layers of tissue. A variety of methods for aberration correction in inhomogeneous media are known. However, these methods are rather slow and their applicability for practical biomedical imaging is limited. The objective of this innovative technology is to facilitate the implementation of aberration corrections in imaging systems.
The innovative method allows the identification and correction of optical aberrations. Thereto a nonlinear microscope is combined with an interferometric unit where the excitation laser beam is split into two arms: one arm acts as the conventional scanning beam that generates an image, the other beam is parked onto the sample. The two beams have significantly different intensities so that the scanning beam acts as a delta-like function that, due to interference with the stationary beam, probes the field of the stationary beam. The signal acquired on the photodetector can be shown to be proportional to the field of the aberrated point spread function (PSF) inside the inhomogeneous medium. The knowledge of the amplitude and phase of the light distribution inside the biological tissue allows the compensation of both optical aberrations and tissue-induced scattering.
The technology is available for in-licensing.
The proof of concept has been demonstrated.
A European priority claiming patent application was filed 2016 followed by an international PCT-application.
Papadopoulos, I. N., Jouhanneau, J.-S. B., Poulet, J. F. A. & Judkewitz, B. Scattering compensation by focus scanning holographic aberration probing (F-SHARP). Nature Photon. 11, 116-123 (2016).