Phase Retrieval in Ultrafast Optics: Single-shot Imaging & Temporal Characterization of Vectorial Pulses |
| TYPE | Solid State Institute Seminar |
| Speaker: | Gil Ilan Haham |
| Affiliation: | Department of Physics and the Solid State Institute, Technion |
| Date: | 02.04.2025 |
| Time: | 12:30 - 13:30 |
| Location: | Solid State Auditorium(Entrance) |
| Remark: | Ph.D. Student of Prof. Oren Cohen |
| Abstract: | Abstract Coherent diffraction imaging (CDI) is a lensless microscopy technique. In CDI, the intensity of a diffracted electromagnetic field (or electron beam) is recorded after interacting with an object, which is computationally reconstructed via phase retrieval. Since the foundational numerical work of the Gerchberg and Saxton more than 50 years ago and the later experimental demonstration in 1999, extensive research has focused on improving the quality, speed, and robustness of phase retrieval. However, single-shot reconstructions remain challenging due to sensitivity to noise, limited dynamic range, and the inherent ill-posedness of the problem. More recent work has focused on scanning CDI, known as Ptychography, which overcomes most of the challenges of traditional CDI but comes at a cost of more complicated setups and time-consuming 2D scanning. These techniques have also inspired related methods in temporal pulse reconstruction, and especially Frequency Resolved Optical Gating (FROG). I will present 3 related phase-retrieval methods. The first is Single-Shot Coded-Aperture Ptychography, which enables high-NA single-shot microscopy as well as time-resolved imaging at ps-resolutions at the visible wavelength range. The second method is Mixed-State Coherent Diffractive Imaging, which resolves many of CDI’s challenges while still relying on a single-measurement. Finally, I will present Single-Scan Vectorial FROG, a method which recovers ultrafast pulses with time varying polarization from a single scan. גם בזום Join Zoom Meeting
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