Computational Phase Imaging with a Spatial Light Modulator

Keywords: Computational Imaging, Phase Retrieval, Fourier Optics, Phase Contrast

Project Overview Traditional imaging using a lens and a standard light source falls short in recovering the complex amplitude of the electrical field (the optical wave). In the case of weakly scattering samples, such as cells, a bright-field microscope fails to unveil the fine details of the cell structure. On the other hand, phase-contrast imaging not only makes the phase shift caused by refractive index differences visible but also facilitates label-free imaging of biological specimens.

Our Solution Our approach to addressing the optical phase problem incorporates the use of a Spatial Light Modulator (SLM) to modulate a laser beam. The modulated wave interacts with the sample, generating distinct diffraction patterns. Through a mathematical optimization process, we not only reconstruct the structure of the laser beam but also successfully recover the complex transmission function of the sample.

What You’ll Explore The appeal of our setup lies in its simplicity. Your assignment involves constructing and testing such a setup. Once assembled, we can initiate the acquisition of experimental data and proceed to test its recovery using our reconstruction code. We already possess a functional source code written in Julia Language, a cutting-edge high-performance programming language. Building on this existing codebase, our goal is to explore the boundaries of what is achievable in the realm of phase imaging.

Figure 1: Source:

Why Join Us?
• Explore the cutting edge of computational phase imaging
• Gain hands-on experience in building and operating optical laser setups
• Explore new fields of algorithmic improvements for phase imaging
• You already gained some experience with optical setups before
• You are familiar with at least one high level programming language (Julia, Python, Matlab)
• Our lab name is LAPD (is there a cooler name?)
For more details contact me ([email protected]) or stop by my office (BM 4108).

Further References
• Park, Y., Depeursinge, C. & Popescu, G. Quantitative phase imaging in biomedicine. Nature Photon 12, 578–589 (2018)
• Goodman, J. W. Introduction to Fourier optics. Roberts and Company publishers, 2005