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A novel balanced air-biased coherent detection scheme for capturing ultrabroadband terahertz (THz) waveforms is implemented. The balanced detection scheme allows for coherent detection at the full repetition rate of the laser system without…

The invisibility cloak has been a long-standing dream for many researchers over the decades. The introduction of transformational optics has revitalized this field by providing a general method to design material distributions to hide the…

Optics · Physics 2011-05-03 Fan Zhou , Yongjun Bao , Wei Cao , Colin T. Stuart , Jianqiang Gu , Weili Zhang , Cheng Sun

Phase imaging is widely used in biomedical imaging, sensing, and material characterization, among other fields. However, direct imaging of phase objects with subwavelength resolution remains a challenge. Here, we demonstrate subwavelength…

We achieve high detectivity terahertz sensing using a silicon nitride nanomechanical resonator functionalized with a metasurface absorber. High performances are achieved by striking a fine balance between the frequency stability of the…

Coherent diffractive imaging is a technique that recovers the sample image by numerically inverting its diffraction pattern. We propose a generalization of this method for the inversion of multi-wavelength data. Using this approach, we show…

Optics · Physics 2020-05-08 Erik Malm , Edwin Fohtung , Anders Mikkelsen

A semiconductor-based terahertz-detector strategy, exploiting a bound-to-bound-to-continuum architecture, is presented and investigated. In particular, a ladder of equidistant energy levels is employed, whose step is tuned to the desired…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 F. Castellano , R. C. Iotti , F. Rossi

We demonstrate Fourier single-pixel imaging in the terahertz regime. The experimental system is implemented with a photo-induced coded aperture setup, where a monolayer graphene on a high-resistance silicon substrate illuminated by a coded…

Applied Physics · Physics 2019-07-24 Rongbin She , Wenquan Liu , Yuanfu Lu , Zhisheng Zhou , Guangyuan Li

Visual inspection of industrial products is used to determine the control quality for these products. This paper deals with the problem of visual inspection of ceramic tiles industry using Wavelet Transform. The third level the coefficients…

Other Computer Science · Computer Science 2010-03-10 Samir Elmougy , Ibrahim El-Henawy , Ahmed El-Azab

We propose a polarimetric microwave imaging technique that exploits recent advances in computational imaging. We utilize a frequency-diverse cavity-backed metasurface, allowing us to demonstrate high-resolution polarimetric imaging using a…

The goal of synthetic aperture imaging is to estimate the reflectivity of a remote region of interest by processing data gathered with a moving sensor which emits periodically a signal and records the backscattered wave. We introduce and…

Image and Video Processing · Electrical Eng. & Systems 2019-07-05 Liliana Borcea , Josselin Garnier

We report the development of new terahertz techniques for rapidly measuring the complex Faraday angle in systems with broken time-reversal symmetry using the cyclotron resonance of a GaAs two-dimensional electron gas in a magnetic field as…

Materials Science · Physics 2015-06-03 D. K. George , A. V. Stier , C. T. Ellis , B. D. McCombe , J. Černe , A. G. Markelz

We report a Mueller matrix ellipsometer design using dual continuously rotating anisotropic meta wave plates which determines the full set of Mueller matrix elements in the terahertz spectral range. The instrument operates in the frequency…

Instrumentation and Detectors · Physics 2025-03-31 Viktor Rindert , Alexander Ruder , Steffen Richter , Philipp Kühne , Mark Bauer , Vanya Darakchieva , Mathias Schubert

We present a temporally-multiplexed dual-colour terahertz (THz) imaging technique using THz-to-optical conversion in atomic vapour. By rapidly alternating the pump laser frequency, we sequentially excite two atomic states, each absorbing a…

Atomic Physics · Physics 2025-07-16 Lucy A. Downes , C. Stuart Adams , Kevin J. Weatherill

We demonstrate structured illumination super-resolution imaging in the Terahertz (THz) frequency band using the Virtually Structured Detection (VSD) method. Leveraging our previously reported high-speed, high-sensitivity atomic-based THz…

The detection of spatial or temporal variations in very thin samples has important applications in the biological sciences. For example, cellular membranes exhibit changes in lipid composition and order, which in turn modulate their…

A full (2$\pi$) phase modulation is critical for efficient wavefront manipulation. In this article, a metasurface based on graphene long/short-strip resonators is used to implement a dynamic 2$\pi$ phase modulation by applying different…

Optics · Physics 2016-01-22 Liming Liu , Yair Zarate , Haroldo T. Hattori

Terahertz fields can be dramatically enhanced as they propagate through nanometer-sized slits. The enhancement is mediated by significant accumulation of the induced surface charges on the surrounding metal. This enhancement is shown here…

Terahertz subwavelength imaging aims at developing THz microscopes able to resolve deeply subwavelength features. To improve the spatial resolution beyond the diffraction limit, a current trend is to use various subwavelength probes to…

Coherent diffractive imaging is unique as the only route for achieving diffraction-limited spatial resolution in the extreme ultraviolet and X-ray regions, limited only by the wavelength of the light. Recently, advances in coherent short…

Terahertz spectral range (frequencies of 0.1-1 THz) has recently emerged as the next frontier for non-destructive imaging, industrial sensing and ultra-fast wireless communications. Here, we review several classes of materials such as…

Optics · Physics 2019-11-07 Mathieu Poulin , Steven Giannacopoulos , Maksim Skorobogatiy