Non-Interferometric Tomography of Phase Objects Using Spatial Light Modulators

Abstract

Quantitative 3D phase retrieval techniques are based on either interferometric techniques such as holography or noninterferometric intensity-based techniques such as the transport of intensity equation (TIE). Interferometric techniques are vibration-sensitive and often use a reference beam requiring complicated optical alignment. In this work we develop a simple, fast, and noninterferometric tomographic 3D phase retrieval technique based on the TIE which does not suffer from such drawbacks. The optical setup is a modified 4f TIE system which uses an SLM to replace the slow translation of the CCD required to record several diffraction patterns in a traditional TIE system. This novel TIE setup is suitable for dynamical events such as imaging biological processes. A rotating mechanical stage is constructed to obtain tomographic phase images of the object. The tomographic reconstruction algorithm is based on the Fourier slice theorem (backprojection algorithm) which applies to objects with a small refractive index span. Simulation and experimental results are shown as part of this work. A graphical user interface is developed to perform the TIE tomographic reconstruction algorithm and to synchronize the captured intensities by the CCD, the phase patterns displayed on the SLM, and the Arduino controlled rotating stage assembly.

Spatial light interference microscopy: principle and applications to biomedicine

“…As we mentioned in section 1.2, tomographic methods such as OCT [123] and optical Doppler tomography [124] are interferometric techniques. Several non-interferometric tomographic methods based on the transport of intensity were also developed [125][126][127]. Fourier ptychographic tomography (FPM) and other synthetic aperture methods aim at improving the resolution in the 3D reconstruction [128][129][130].…”

Phase-unwrapping-free and iterative reconstruction methods for propagated refractive index tomography

“…The TIE retrieves the phase on the basis of intensity measurements without phase unwrapping. 13,19) By applying this advantage of the TIE to the reconstruction stage, phaseunwrapping-free propagated RI tomography is achieved.…”

“…The representative method is refractive index (RI) tomography. [6][7][8][9][10][11][12][13][14] RI tomography combines phase retrieval, such as digital holography, and the FBP method. Although RI tomography achieves noninvasive 3D measurement, its reconstruction accuracy is affected by many factors such as the thickness of specimens, the inhomogeneity of internal structures, and the difference in RI between a surrounding medium and a specimen.…”