In terahertz digital holography, the off-axis configuration is the appropriate choice when the investigated object is non-sparse and complex. The limitation of recording distance in the off-axis configuration restricts the imaging quality. Either low-resolution or spectra overlap can potentially occur. We propose an iterative phase-retrieval approach to improve the quality of reconstruction results obtained from an off-axis hologram. One additional capture of object wave intensity is recorded to perform iterative phase retrieval with off-axis reconstruction as the initial guess. Apodization operation can be applied to the object wave intensity capture to suppress undesired border diffraction effects. The image quality using the proposed method has been improved both from simulation and experimental verification.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/AO.58.009208 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Design of a graphene-based chiral trifunctional tunable terahertz metasurface.
Phys Chem Chem Phys
January 2025
College of Mechanics and Engineering Science, Hohai University, Nanjing, 211100, China.
Driven by the pressing demand for integration and miniaturization within the terahertz (THz) spectrum, this research introduces an innovative approach to construct chiral structures using dichroism as the target function. This initiative aims to tackle the prevalent issues of single-functionality, narrow application scope, and intricate design in conventional metasurfaces. The proposed multifunctional tunable metasurface employs a graphene-metal hybrid structure to address the critical constraints found in existing designs.
View Article and Find Full Text PDFPhotoreconfigurable Metasurface for Independent Full-Space Control of Terahertz Waves.
Sensors (Basel)
December 2024
Research Center of Applied Electromagnetics, Nanjing University of Information Science and Technology, Nanjing 210044, China.
We present a novel photoreconfigurable metasurface designed for independent and efficient control of electromagnetic waves with identical incident polarization and frequency across the entire spatial domain. The proposed metasurface features a three-layer architecture: a top layer incorporating a gold circular split ring resonator (CSRR) filled with perovskite material and dual -shaped perovskite resonators; a middle layer of polyimide dielectric; and a bottom layer comprising a perovskite substrate with an oppositely oriented circular split ring resonator filled with gold. By modulating the intensity of a laser beam, we achieve autonomous manipulation of incident circularly polarized terahertz waves in both transmission and reflection modes.
View Article and Find Full Text PDFA Room-Temperature Terahertz Photodetector Imaging with High Stability and Polarization-Sensitive Based on Perovskite/Metasurface.
Adv Sci (Weinh)
December 2024
School of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072, China.
Terahertz (THz) polarization detection facilitates the capture of multidimensional data, including intensity, phase, and polarization state, with broad applicability in high-resolution imaging, communication, and remote sensing. However, conventional semiconductor materials are limited by energy band limitations, rendering them unsuitable for THz detection. Overcoming this challenge, the realization of high-stability, room-temperature polarization-sensitive THz photodetectors (PDs) leveraging the thermoelectric effect of Cs(FAMA)Pb(IBr) (CsFAMA)/metasurfaces is presented.
View Article and Find Full Text PDFChalcogenide phase-change material advances programmable terahertz metamaterials: a non-volatile perspective for reconfigurable intelligent surfaces.
Nanophotonics
May 2024
Shandong Technology Center of Nanodevices and Integration, School of Integrated Circuits, Shandong University, Jinan, 250100, China.
Terahertz (THz) waves have gained considerable attention in the rising 6G communication due to their large bandwidth. However, the cost and power consumption become the major constraints for the commercialization of 6G THz systems as the frequency increases. Reconfigurable intelligent surface (RIS) comprising active metasurfaces and digital controllers has been proposed for beamforming in the 6G multiple-input-multiple-output systems, showing good potential to suppress the system size, weight, and power consumption (SWaP).
View Article and Find Full Text PDFDeep learning-driven macroscopic AI segmentation model for brain tumor detection via digital pathology: Foundations for terahertz imaging-based AI diagnostics.
Heliyon
November 2024
Advanced Photonics Research Institute (APRI), Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea.
We used deep learning methods to develop an AI model capable of autonomously delineating cancerous regions in digital pathology images (H&E-stained images). By using a transgenic brain tumor model derived from the TS13-64 brain tumor cell line, we digitized a total of 187 H&E-stained images and annotated the cancerous regions in these images to compile a dataset. A deep learning approach was executed through DEEP:PHI, which abstracts Python coding complexities, thereby simplifying the execution of AI training protocols for users.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!