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We demonstrate the operation of coupled-cavity terahertz frequency quantum-cascade lasers composed two sub-cavities separated by an air gap realized optical lithography and dry etching. This geometry allows stable, single mode with typical side suppression ratios in 30–40 dB range. employ a transfer matrix method to model selection mechanism. The obtained results are good agreement measurements allow prediction operating frequency.

Light-field (LF) refers to the spatio-directional light flow in space. In LF imaging, rays are recorded along different positions and directions, a 3-D scene is reconstructed with back-propagation [1]. Modern visible-light cameras assemble lens array atop megapixel (Mpx) count focal-plane (FPA), such that each (macro-pixel) provides spatial sampling while FPA pixels within (sub-pixels) provide angular [2]. Likewise, THz can allow real-time 3D see-through imaging for inspection screening...

We demonstrate a coherent imaging system based on terahertz (THz) frequency quantum cascade laser (QCL) phase-locked to near-infrared fs-laser comb. The phase locking enables electro-optic sampling of the continuous-wave radiation emitted by QCL through generation heterodyne beat-note signal. use this signal raster scan using emitting at 2.5 THz. At detection noise floor our is 3 pW/Hz and long-term stability <3 degrees/h, limited mechanical apparatus.

Abstract Resistive switching in oxide‐based structures is intensively studied for the development of ultra‐fast non‐volatile memories with low consumption and neuromorphic electronic devices. Here, evidence interface‐controlled, reversible, bi‐polar resistance switch prototype multiferroic BaTiO 3 /La 0.75 Sr 0.25 MnO (BTO/LSMO) system given. The analysis current–voltage hysteresis curves a thick Au/BTO/LSMO structure reveals existence 2.55 nm‐thick barrier layer at bottom BTO/LSMO...

Integrated THz systems comprising index matched optical media introduce discontinuities in the propagation path leading to an etaloning effect. The hinders absolute accuracy of a measuring instrument thereby limiting its applicability. A methodology using computational notch filtering is implemented here extract true performance instrument. Specifically, responsivity and NEP portable room temperature 1k-pixel terahertz CMOS camera have been investigated continuously tunable broadband...

YBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">6+x</sub> compounds are well known to exhibit superconducting properties for <i xmlns:xlink="http://www.w3.org/1999/xlink">x</i> > 0.5 and semiconducting lower oxygen content. Superconducting YBCO was obtained commercially; the material deposited by sputtering close room temperature...

This article presents the concept of a lens-integrated CMOS camera-type terahertz (THz) compact antenna test range (CATR) to determine far-field characteristics transmitters (TX), including radiation pattern, directivity, half-power beam-width (HPBW), and power. For validation, frequency-dependent pattern 0.6-1.1 THz TX equipped with 23.7-28.2 dBi standard gain horn was measured using CATR. Directivity, HPBW, power have been extracted from CATR measurements. The first two parameters are...

In order to develop radiation thermal detectors, oxygen-depleted amorphous YBa2Cu3O7−δ (YBCO) thin films were grown at low temperature (< 150¡C) on SiO2/Si substrates by direct-current hollow cathode sputtering, which allows envisage further integration of detectors a readout electronics silicon chip. Planar and metal/YBCO/metal tri-layer sensing structures then processed. The near-infrared optical response showed evidence transition from bolometric pyroelectric behavior planar devices, but...

In this paper, a silicon lens-integrated CMOS THz camera is employed as compact antenna test range. The far-field radiation pattern of 26-dBi 0.852-THz standard gain horn source characterized. Both single-frame low-resolution and multi-frame super-resolution acquisition are performed. latter to measure with enhanced angular resolution. directivity the determined from both measured patterns. maximum in respective patterns 25 dBi 25.8 dBi, respectively, an accuracy 1 dB 0.2 dB. Improved due better

YBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">6+x</sub> (YBCO) oxides are semiconductors (SC) at low oxygen content. IR detectors were processed with amorphous SC films, either planar or metal/YBCO/metal tri-layers. The response 850 nm exhibited a noise and fast pyroelectric behavior. THz antennas considered.

CEA-Leti has developed a real-time reflection imaging system: it combines illumination by QCL sources and telescope that focuses the reflected radiation onto camera houses an uncooled 320×240 antenna-coupled micro-bolometer array driven FPGA card. We present first high resolution images of illuminated surfaces acquired in real-time.

Hot electron bolometers (HEB) made from high-TC superconducting YBa2Cu3O7–x (YBCO) oxide nano-constrictions are promising THz mixers, due to their expected wide bandwidth, large mixing gain, and low intrinsic noise. The challenge for YBCO resides, however, in the chemical reactivity of material related aging effects. In this paper, we model simulate frequency dependent performance HEBs operating as mixers. We recall first main hypotheses our hot spot taking into account both RF effects...

YBa2Cu3O6+x (YBCO) oxides, well known as superconductors for x > 0. 5, are semiconductors (SC) lower oxygen content. SC films DC sputtered at 150 °C in amorphous form (a-YBCO) exhibited a temperature coefficient of resistance competitive with other bolometric sensing materials. Such deposition conditions highly beneficial to integrate radiation detector on silicon chip bearing already processed readout electronics. IR structures have been processed: simple planar or more advanced...

YBa₂Cu₃O_6+x compounds are well known to exhibit superconducting properties for <i>x</i> &gt; 0.5 and semiconducting lower oxygen content. Superconducting YBCO was obtained commercially; the material deposited by sputtering at room temperature. In order migrate from uncooled far-infrared bolometer technologies, we have first realized compared performance of 2 &times; pixel arrays made both materials on MgO substrates. Pixels were in shape meanders, embedded an...

This paper presents a CMOS camera-type THz compact antenna test range (CATR) to facilitate convenient means measure far-field radiation patterns of transmitters (TXs). For concept validation, we measured the pattern 26-dBi 0.852-THz standard gain horn antenna-type TX with known characteristics CATR. With help geometrical multi-frame super-resolution imaging, directivity determination accuracy achieved at peak signal-to-noise ratio (PSNR) 34.8 dB is 0.2 dB. Further, investigated...

The yttrium-barium-copper oxide cuprate (YBCO) is well-known to exhibit superconducting properties in its YBa₂Cu₃O_(6+x) phase for x close 1. Oxygen depletion (x ≈ 0.3–0.5) of this compound leads, however, a semiconductor. An unusual although promising application YBCO semiconducting form can be sought the field uncooled thermal detectors bolometer type due large temperature coefficient resistance (TCR = 1/R (dR/dT) –3 –4 %/K). Besides, films deposited without...

Semiconducting Y-Ba-Cu-O based devices for room temperature infrared detection are investigated. The coupling conditions of incident radiation to the sensing film examined first, with relation absorption coefficient in THz frequency range. readout circuitry then examined, Schottky nature metal/Y-Ba-Cu-O contacts. We conclude some device performances. In near-infrared instance, noise equivalent power values below 10 pW/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

Decoupling the desired spectral signal from scattering events and also sporadic signals background has been a challenge for fulfilling promise of real-time applications exhibited by present broadband terahertz devices. Performing imaging in conjunction with spectroscopy will circumvent this issue, thereby improving accuracy measurement. In work, spatial profiles widely used CW antenna coupled photomixer are experimentally investigated using well-calibrated 32×32 pixel CMOS camera broad...

Voltage bistability is demonstrated at low temperature in a biased unipolar GaAs/AlGaAs superlattice, using design based on tunneling from charge reservoir into Wannier-Stark ladder and competition between nearest next-nearest neighbor coherent injection channels. The static conduction characteristics are accounted for by density matrix approach of an inhomogeneous three-level system with resistive load. Electrostatic retroaction the energy levels shown to provide adequate nonlinear feedback...