OSE Dissertation Defense by Mr. Sayed Hassan Dibaji Foroushani on Volumetric Imaging Using the Pupil-Matched Remote Focusing Technique in Light-Sheet Microscopy

Departmental News

Mr. Sayed Hassan Dibaji Foroushani

Posted: October 17, 2023

Date: Monday, October 23, 2023

Examination Time: 1:00 PM Mountain Time (US and Canada) 

Location: PAIS Budling, Room #3205

Dissertation Committee:

Dr. Tonmoy Chakraborty, Committee Chair, Physics and Astronomy Department

Dr. Keith Lidke, Physics and Astronomy Department

Dr. Diane Lidke, Pathology Research Department

Dr. Sheng Liu, Physics and Astronomy Department


The dissertation explores innovative techniques in light sheet microscopy, a pivotal tool in biomedical imaging, to enhance its speed, resolution, and efficiency in capturing dynamic biological processes. Light sheet microscopy allows for quick 3D imaging of biological specimens ranging from cells to organs with high spatiotemporal resolution, large field-of-view, and minimal damage, making it vital for in vivo imaging. The first project introduces a novel optical concept designed to optimize Axially Swept Light Sheet Microscopy (ASLM). This technique is crucial for imaging specimens ranging from live cells to chemically cleared organs due to its versatility across different immersion media. The project presents an innovative approach that enhances the performance of ASLM-based microscopes by scanning two staggered light sheets while synchronizing the rolling shutter of a scientific camera. This method allows ASLMs to image twice as fast without compromising the detection signal, providing a gentler illumination scheme and improving the imaging speed and detection signal of ASLM-based microscopes. The demonstrated technique is validated through imaging experiments on fluorescent beads and a chemically cleared mouse brain, showcasing its potential in advancing the field of light sheet microscopy. The second project focuses on axial de-scanning using remote focusing in the detection arm of light-sheet microscopy. This technique is essential for high-speed, high-resolution volumetric imaging without disturbing the biological sample. The project introduces a unique optical design that can descan the axial focus movement in the detection arm of a microscope by overcoming the challenges associated with the polarization of emitted fluorescence. This technique allows for aberration-free, multi-color, volumetric imaging without compromising the fluorescent signal. It is demonstrated by acquiring fast dual-color 4D image stacks, highlighting its potential applications in various microscopy techniques that require adjustable Z-stages for volumetric imaging, such as confocal, 2-photon, and other light sheet variants.



Hassan Dibaji received a B.S. in Physics from Ferdowsi University of Mashhad, Iran in 2002 and an M.Sc. in Solid State Physics from the K.N.Toosi University of Technology Tehran, Iran in 2005. He has been a Ph.D. student in Optical Science and Engineering at the University of New Mexico since 2017. In graduate school, he researched the microfabrication of optoelectronic devices and material characterization. With Dr. Chakraborty, he pursued his dissertation work where he developed a remote focusing technique in light sheet microscopy.