Speaker: Wei Luo
Affiliation: Ph.D. Candidate UCLA
Abstract: To achieve high-resolution and wide field-of-view, digital holographic imaging techniques need to tackle two major challenges: phase recovery and spatial undersampling. Previously, these challenges were separately addressed using phase retrieval and pixel super-resolution algorithms, which utilize the diversity of different imaging parameters. Although existing holographic imaging methods can achieve large space-bandwidth-products by performing pixel super-resolution and phase retrieval sequentially, they require large amounts of data, which might be a limitation in high-speed or cost-effective imaging applications. I will introduce a propagation phasor approach, which for the first time combines phase retrieval and pixel super-resolution into a unified mathematical framework and enables the synthesis of new holographic image reconstruction methods with significantly improved data efficiency. In this approach, twin-image and spatial aliasing signals, along with other digital artifacts, are interpreted as noise terms that are modulated by phasors that analytically depend on the lateral displacement between hologram and sensor planes, sample-to-sensor distance, wavelength, and the illumination angle. Compared to previous holographic reconstruction techniques, this new framework results in five- to seven-fold reduced number of raw measurements, while still achieving a competitive resolution and space-bandwidth-product. I will also demonstrate the success of this approach on conventional lens-based microscopy, achieving a similar level of improvement in the space-bandwidth product of the imaging system.
Biography: Wei Luo received his BS and MS degrees in Electrical Engineering from Tsinghua University, China. In 2011, he joined Professor Aydogan Ozcan’s Bio-Nanophotonics Lab in Electrical Engineering Department at UCLA to pursue his Ph.D. degree. His research focuses on high-resolution, wide-field holographic microscopes. Wei Luo has received fellowships including the Chancellor’s Award at UCLA and SPIE Optics and Photonics Education Scholarship. During his research at UCLA, Wei has authored or co-authored over 35 peer reviewed research articles in major journals and conferences.
Date(s) - Mar 01, 2016
12:30 pm - 2:30 pm
E-IV Tesla Room #53-125
420 Westwood Plaza - 5th Flr., Los Angeles CA 90095