Tomographic Diffraction Microscopy (TDM) is a technique that makes it possible to assess for 3D complex refractive index of the investigated sample without fluorescent labeling. Therefore, TDM is a method of choice for the characterization of biological samples or functionalized surfaces. TDM is a generalization of Digital Holographic Microscopy with a full control of the angle of illumination over the object. Angle can be modified either by sweeping the illumination on the object, or by rotating the object while maintaining the angle of illumination. Combining several hundreds of acquisition, it is possible to retrieve a full 3D information about both refraction and absorption of the object. Nevertheless, the time needed for data acquisition might become prohibitive for routine investigations, or dynamic sample imaging. Moreover, simultaneous reflection and transmission characterization of sample remains an experimental challenge. Recently a method called “Mirror-Assisted Tomographic Diffraction Microscopy” (MA-TDM) have been proposed [Opt. Lett. 35, 1857 (2010)], which theoretically allows to achieved isotropic 3D resolution by combining, in a simpler fashion, reflection and transmission modes. When transparent sample are considered, one can take benefits of this mirroring effect to limit the amount of acquired holograms, while maintaining the resolution of TDM. We propose to demonstrate this concept, using a specific preparation of the sample. It will be shown that, using an adequate data processing scheme, it is possible to reconstruct 3D objects using an annular illumination sweep, thus limiting the amount of acquisition. This study paves the way to a versatile TDM configuration allowing for both reflection and transmission acquisitions from a single image acquisition.
Tomographic diffractive microscopy (TDM), also known as phase tomography, synthetic aperture microscopy… is becoming a more and more mature technique. It is an extension of holographic microscopy, with controlled conditions of illumination. Several views of the sample are numerically combined to reconstruct a 3-D image. Commercial implementations are even already available, but there are still challenges to be addressed to improve the method. We present possible approaches to further speed up acquisitions, simplify reconstructions and/or improve sensitivity/contrast.
Tomographic diffractive microscopy (TDM) is an imaging technique, which allows for recording the refractive index of unlabelled transparent specimens. Based on diffraction theory, it can be implemented in transmission or in reflection. In this paper, a new TDM data acquisition and reconstruction method is proposed. The purpose is to use the mirror effect of a reflecting material to establish a double illumination system. Neglecting backward-diffracted fields, the setup reduces to a double-transmission TDM, which combined with an azimuthal rotation of the illumination, allows for faster and simplified acquisitions. We also point out a new demodulation method based only on Fourier transforms.
Tomographic diffractive microscopy (TDM) is an imaging technique which allows for recording the complex optical index of unlabelled specimens. It is based on diffraction theory with a spatially coherent illumination and interference demodulation. Different methods have been developped like illumination rotation with fixed sample or sample rotation with fixed illumination. However this last technique is difficult to set up. Hence, we propose a novel reconstruction technique applicable to axisymmetric unlabelled specimens. It consists in a numerical rotation of the Ewald cap of sphere generated by a zero-degree illumination on the sample. Due to the specimen symmetry, we show that the Fourier space can be filled in the direction perpendicular to the axis of symmetry.
Proceedings Volume Editor (1)
This will count as one of your downloads.
You will have access to both the presentation and article (if available).