Digital optical microscopy using the MR-CSI method

Optical Imaging of the permittivity profile from optical diffraction tomography data is discussed. In order to arrive at sub-100 nm resolution it is necessary to employ nonlinear inversion methods that yield quantitative information of the permittivity distribution. Therefore, the so-called multiplicative regularized contrast source inversion (MR-CSI) method is adopted to solve the problem at hand. For a two-dimensional representative example, it is demonstrated that, using a wavelength of 400 nm, resolutions of the order of 20 to 30 nm can be achieved.