Microscopy without lenses: Rethinking illumination, computation, and polarization DLHM
Science & Engineering Building (SENG), Room 212
: Zoom Link: https://umassd.zoom.us/j/91838904870 Meeting ID: 918 3890 4870 Passcode: 442819
Ana Doblas
5089998471
adoblas@umassd.edu
https://umassd.zoom.us/j/91838904870
Topic: “Microscopy without lenses: Rethinking illumination, computation, and polarization DLHM”
Abstract: Lensless microscopy trades the objective lens for computation. In digital lensless holographic microscopy (DLHM), a point source, sample, and digital camera are sufficient to record a hologram from which amplitude and phase information can be numerically retrieved, enabling compact and low-cost microscopy systems. However, achieving reliable quantitative imaging requires careful development of both the optical hardware and computational methods. In this talk, I will review our advances in DLHM from both perspectives. On the hardware side, I will discuss the evolution of illumination from conventional pinhole-based systems to holographic optical elements and high-numerical-aperture freeform illumination, highlighting the tradeoffs among resolution, field of view, noise, and coherence. I will also present polarization-sensitive approaches, including diattenuation and Mueller-matrix imaging, as well as portable systems designed for field applications. On the computational side, I will discuss reconstruction, preprocessing, simulation, noise reduction, and methods for improving image quality. I will also show how deep learning can reduce computational requirements by detecting cells directly from raw holograms and automatically estimating their focusing distance. Finally, I will introduce recent lensless architectures combining off-axis interferometry and polarization sensitivity. Together, these developments demonstrate the potential of DLHM as a compact, quantitative, and polarization-aware imaging platform for laboratory and field applications.
Biography: Carlos Trujillo is a Full Professor at Universidad EAFIT (Medellín, Colombia) in the Fundamental Sciences area. He is affiliated with the Optics and Photonics Laboratory, and heads the Master's program in Applied Physics. He received his Ph.D. in Physics (2018, Summa Cum Laude), M.Sc. in Computational Sciences (2013, Magna Cum Laude), and B.Sc. in Engineering Physics (2010, top of his class), all from Universidad Nacional de Colombia, Medellín. His research focuses on digital holographic and lensless holographic microscopy. It combines optical design, computational imaging, polarimetry, and deep learning to develop accessible, quantitative microscopes.
The Seminars is open to the public free of charge.
*For further information, please contact Dr. Ana Doblas via email at adoblas@umassd.edu.