The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Hand gesture recognition is one of the secure natural user interface (NUI) mechanisms on wearable devices since it does not reveal user's intention in public domain unlike the speech recognition. However, its energy dissipation is very demanding as it requires compute-intensive machine vision processing. Recently, wake-up detectors have been proposed to improve the energy-efficiency of always-on sensing...
There has been significant advancement in photonic infrared (IR) detector technology in the past decade. In this tutorial, I will cover the basics of photonic IR detectors including the detection mechanisms and figures of merit. I will end with a survey of a few current technologies. Infrared imaging (3–25μm) has been an important technological tool for the past 60 years since the first report of...
In the last decade, the research on terahertz imaging systems in CMOS has attracted extensive attention and gained rapid progress. Detection theory and performance indicators are first analyzed in this paper. System structures are then compared from three aspects. Finally, research progresses are reviewed and certain research directions are indicated on account of existing problems.
Compton Scatter Imaging is a promising approach in imaging science. Since it employs scattered radiation that is otherwise rejected, it is claimed to improve the sensitivity of current radiation-based imaging systems. The Radon transform on V-lines models a Compton Camera and its inversion through filtered back-projection leads to an efficient way to reconstruct the density of a radiotracer. Recently,...
Issuing an alarm for power lines continues to be an important issue for low altitude aircraft safety. In this study, edge and gradient based methods are applied and compared according to their detection performances (in terms of Accuracy, F-Score, Speed and False Negative). It was observed that; despite being used genuinely for corners, HARRIS method provides significantly superior accuracy and F-Score...
A low-noise readout interface integrated with an antenna-coupled FET-based terahertz (THz) detector is designed and fabricated in a 0.15-μm CMOS standard technology. The implemented readout includes a cascade of a preamplification noise reduction stage based on a parametric chopper amplifier, and a direct analog-to-digital conversion by means of an incremental ΣΔ converter, substituting the lock-in...
We present two terahertz detectors composed of microbolometer sensors (vanadium oxide and silicon pn diode) and metamaterial absorbers monolithically integrated into a complementary metal oxide semiconductor (CMOS) process. The metamaterial absorbers were created using the metal-dielectric-metal layers of a commercial CMOS technology resulting in low-cost terahertz detectors. The scalability of this...
Brownout refers to dust cloud created by the rotor downwash of a helicopter. When it occurs, the visibility becomes limited, or even null. The pilot can be desorientated and accident may happen. No existing imaging systems can see through dust clouds, in real-time and with sufficient resolution. Using waves between 100GHz and 1THz seems to be a good solution to make a compact and suitable imaging...
A study of different pixel implementations working around 300 GHz is presented. They are monolithically integrated in a standard low-cost CMOS process with a high performances read-out chain for signal processing. All the different pixel configurations are compliant with the integrated metal stack and the imposed density rules of the technology. A test-chip, composed of a total of 17 cases of study,...
We demonstrate a novel architecture for a THz near-field probe, which enables coherent imaging with subwavelength spatial resolution using THz quantum cascade lasers. An InAs nanowire acting as a THz detector based on the field effect transistor concept is integrated inside a subwavelength input aperture of the near-field probe to detect intensity of the THz field and its phase. To determine the phase...
The design and performance analysis are presented for a passive uncooled radiometer pixel suitable for integration in 28nm CMOS technology. In the configuration a single wideband antenna, operating from 200 GHz to 600 GHz, is connected to a pn-junction diode. Including the antenna-detector impedance mismatch, the detector shows an average NEP of 2.71 pW/√Hz such that, together with the antenna, the...
We introduce a novel fast compressionless reconstruction algorithm for THz imaging. Based on Fourier imaging and a broadband THz spectrum, we demonstrate image reconstruction with high resolution using only 10s of pixels. First, we develop a mathematical framework based on polar Fourier optics and we demonstrate four cases where the fast reconstruction is possible. Second, we experimentally measure...
Terahertz technology is one of emerging technologies that has a potential to change our life. There is considerable interest in using electromagnetic terahertz pulses for imaging purposes. In this paper we presented initial results for improving the resolution of terahertz pulsed imaging system utilizing methodology of super-resolution reconstruction. We attempt to reconstruct an super-resolution(SR)...
Fermi-level managed barrier (FMB) diodes were applied to a terahertz (THz) wave linear detector array assembly for the first time. We incorporated the fabricated detector array that had 100 FMB diodes into a high-resolution THz imaging system and investigated its performance. Short-time THz-wave imaging at 315 GHz for a 120 × 120 mm2 area was accomplished in less than 0.5 sec by using the fabricated...
Spectral imaging is useful in a wide range of applications for non-invasive detection and classification. However, the massive amount of involved data increases its processing and storing costs. In contrast, compressive spectral imaging (CSI) establishes that the three-dimensional data cube can be recovered from a small set of projections, that are generally captured in 2-dimensional detectors. Furthermore,...
Two recently developed methods that allow visualizing the interaction of THz radiation with arbitrary structures, namely polaritonics and near-field imaging, are reviewed and compared. THz polaritonics, which relies on complex amplified laser systems, allows single-shot image acquisition in a plane perpendicular to the structures. THz near-field imaging, on the other hand, requires only femtosecond...
In this paper, we investigate active brain regions for motor execution and motor imagination tasks after training with a rehabilitation robot. Functional near-infrared spectroscopy (fNIRS) is used to measure the hemodynamic responses in the motor cortices of five subjects. An assistive robot (IMT 2.0, connected to the right hand) is used during the training session to make the subject to reach a target...
Single pixel detectors find applications ranging from multispectral imaging, through polarimetric, 3d, and holographic imaging, up to optical encryption and imaging through scattering media, which are however all hindered by the high measurement and reconstruction times. In this paper we propose to reduce the required signal acquisition time by using non-ergodic stationary sampling correlated with...
In this paper, an overview of main results concerning THz detection by nanometer field effect transistors (FETs) and heterojunction based transistors (HBTs) is presented. Different GaInAs/InP and GaN/AlGaN nanometer field effect transistors based detectors are presented. We present also first Silicon C-MOS transistors based integrated circuits for wireless communication in sub-THz range. Special attention...
Active spectral imaging in the mid-infrared can reveal absorption ‘fingerprints’ of different chemicals within a scene. The practicality of spectral imaging with active illumination is limited by the large number of images required (as the illumination wavelength or an interferometer mirror is scanned). Single pixel imaging uses the intensity reading from a single pixel detector while illuminating...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.