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Related papers: Terahertz Pulse Shaping Using Diffractive Surfaces

200 papers

Pulse shaping is important for communications, spectroscopy, and other applications that require high peak power and pulsed operation, such as radar systems. Unfortunately, pulse shaping remains largely elusive for terahertz (THz)…

Optics · Physics 2021-06-23 Seyed Mohammadreza Razavizadeh

Replacing electrons with photons is a compelling route towards light-speed, highly parallel, and low-power artificial intelligence computing. Recently, all-optical diffractive neural deep neural networks have been demonstrated. However, the…

Signal Processing · Electrical Eng. & Systems 2021-07-19 Xuhao Luo , Yueqiang Hu , Xin Li , Xiangnian Ou , Jiajie Lai , Na Liu , Huigao Duan

Diffractive optical networks unify wave optics and deep learning to all-optically compute a given machine learning or computational imaging task as the light propagates from the input to the output plane. Here, we report the design of…

Optics · Physics 2022-05-23 Deniz Mengu , Muhammed Veli , Yair Rivenson , Aydogan Ozcan

A 2-D spatio-temporal analysis of terahertz generation by optical rectification of tilted-pulse-fronts is presented. Closed form expressions of terahertz transients and spectra in two spatial dimensions are furnished in the undepleted…

Optics · Physics 2019-02-04 Koustuban Ravi , Franz X. Kärtner

The effect of terahertz (THz) pulse generation has revolutionized broadband coherent spectroscopy and imaging at THz frequencies. However, THz pulses typically lack spatial structure, whereas structured beams are becoming essential for…

We demonstrate universal polarization transformers based on an engineered diffractive volume, which can synthesize a large set of arbitrarily-selected, complex-valued polarization scattering matrices between the polarization states at…

We consider the inverse problem of determining the geometry of penetrable objects from scattering data generated by one incident wave at a fixed frequency. We first study an orthogonality sampling type method which is fast, simple to…

Numerical Analysis · Mathematics 2022-07-21 Thu Le , Dinh-Liem Nguyen , Vu Nguyen , Trung Truong

Inverse design of nanoparticles for desired scattering spectra and dynamic switching between the two opposite scattering anomalies, i.e. superscattering and invisibility, is important in realizing cloaking, sensing and functional devices.…

Optics · Physics 2021-04-07 Jie Luo , Xun Li , Xinyuan Zhang , Jiajie Guo , Wei Liu , Yun Lai , Yaohui Zhan , Min Huang

The ability to manipulate the space-time structure of light waves diversifies light-matter interaction and light-driven applications. Conventionally, metasurfaces are employed to locally control the amplitude and phase of light fields by…

Sub-wavelength diffractive optics meta-optics present a multi-scale optical system, where the behavior of constituent sub-wavelength scatterers, or meta-atoms, need to be modelled by full-wave electromagnetic simulations, whereas the whole…

We propose a method to generate isolated relativistic terahertz (THz) pulses using a high-power laser irradiating a mirco-plasma-waveguide (MPW). When the laser pulse enters the MPW, high-charge electron bunches are produced and accelerated…

Plasma Physics · Physics 2019-09-04 Longqing Yi , Tünde Fülöp

Under spatially-coherent light, a diffractive optical network composed of structured surfaces can be designed to perform any arbitrary complex-valued linear transformation between its input and output fields-of-view (FOVs) if the total…

Optics · Physics 2023-08-17 Md Sadman Sakib Rahman , Xilin Yang , Jingxi Li , Bijie Bai , Aydogan Ozcan

Highly-efficient optical generation of narrowband terahertz (THz) radiation enables unexplored technologies and sciences from compact electron acceleration to charge manipulation in solids. State-of-the-art conversion efficiencies are…

Purpose: Some advanced RF pulses, like multi-dimensional RF pulses, are often long and require substantial computation time due to a number of constraints and requirements, sometimes hampering clinical use. However, the pulses offer…

Medical Physics · Physics 2019-01-08 Mads Sloth Vinding , Birk Skyum , Ryan Sangill , Torben Ellegaard Lund

The electromagnetic spectrum in the terahertz frequency region is of significant importance for understanding the formation and evolution of galaxies and stars throughout the history of the universe and the process of planet formation.…

Terahertz frequencies are an untapped resource for providing high-speed short-range communications. As a result, it is of interest to study the propagation characteristics of terahertz waves and to develop channel models. In previous work…

Signal Processing · Electrical Eng. & Systems 2022-10-17 Thanh Le , Ha Tran , Suresh Singh

Structural coloration is commonly modeled using wave optics for reliable and photorealistic rendering of natural, quasi-periodic and complex nanostructures. Such models often rely on dense, preliminary or preprocessed data to accurately…

Graphics · Computer Science 2025-07-03 Narayan Kandel , Daljit Singh J. S. Dhillon

The manipulation of solid states using intense infrared or terahertz light fields is a pivotal area in contemporary ultrafast photonics research. While conventional circular polarization has been well explored, the potential of…

Optics · Physics 2024-08-08 Kotaro Ogawa , Natsuki Kanda , Yuta Murotani , Ryusuke Matsunaga

Metasurfaces have attracted extensive interests due to their ability to locally manipulate optical parameters of light and easy integration to complex optical systems. Particularly, metasurfaces can provide a novel platform for splitting…

The stochastic formation of defects during Laser Powder Bed Fusion (L-PBF) negatively impacts its adoption for high-precision use cases. Optical monitoring techniques can be used to identify defects based on layer-wise imaging, but these…

Image and Video Processing · Electrical Eng. & Systems 2024-09-23 Francis Ogoke , Sumesh Kalambettu Suresh , Jesse Adamczyk , Dan Bolintineanu , Anthony Garland , Michael Heiden , Amir Barati Farimani