Tomographic diffractive microscopy of transparent samples

Abstract

We report a tomographic diffractive microscope, which permits imaging non-labelled transparent or semi-transparent samples. Based on a combination of microholography with a tomographic illumination, our setup creates 3-D images of the index of refraction distribution within the sample. One acquires successively interferograms, rotating the illumination (the specimen being static) and using phase-shifting holography. Within the first Born approximation, each interferogram is interpreted as a subset of the Fourier transform of the specimen index of refraction distribution. The reconstruction is therefore similar to synthetic aperture imaging: one recombines the information in the Fourier space, and a final Fourier transform gives a 3-D image of the specimen. First recalling the theoretical foundations, we then describe our experiment, and show initial results obtained on biological samples.

Tomographic diffractive microscopy: basics, techniques and perspectives

“…Microscopy, while having a rather good lateral resolution exhibits a limited sectioning capability along the optical axis [10,26,27].…”

Parametric Blind Deconvolution for Confocal Laser Scanning Microscopy

“…However, the PSF cannot be numerically computed if this variation is unknown. In Kam, et al [2001], a ray tracing method was proposed to obtain the PSFs, while in Simon, et al [2008], a combination of microholography and tomographic illumination was used to obtain this variation. Once this information is known, these aberrations could be compensated from the observation.…”

Influence of incident beam polarization on intensity and polarization distributions of tight focusing spot

“…Thus, the experimental intensity profile is a convolution size of an ideal (theoretical) focusing spot and the gold nanosphere size. The experimental data can be further optimized by applying the image deconvolution method 20 to fit the theoretical calculation. However, it is not necessary in our case, since the polarization dependence of the focusing spot is clearly evidenced.…”