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We have developed a calorimeter for a metrology standard for measuring the power of terahertz (THz) waves. Since the THz calorimeter is based on the thermal balance between heat produced by THz waves and direct current (DC), it requires an equivalent factor for converting from THz to DC power. The DC equivalent factor, which is defined as the ratio between the thermal efficiency of THz and DC powers,...
The frequency characteristics of commercially available pyro-electric detectors have been compared in the range from 0.9 to 2.8 THz by using an intense continuously-tunable terahertz (THz)-wave source. We have found that the THz-wave interference inside the detector has considerable effect on the performance.
To evaluate terahertz emission from intrinsic Josephson junctions, we used a YBa2Cu3O7−δ (YBCO) grain boundary Josephson junction as a terahertz detector. Shapiro steps have been clearly seen on the current-voltage curves of the YBCO junction irradiated with the emission from either a VDI-Tx-S140 transmitter (tens of μW at 620 GHz) or a Bi2Sr2CaCu2O8−x stack (25 μW at 500 GHz). While the harmonic...
A terahertz detector using an InAlAs/InGaAs high-electron-mobility-transistor (HEMT) integrated with a bow-tie antenna was proposed and fabricated. By utilizing ballistic transport in the short-channel, a current sensitivity of 1.5 A/W at 280 GHz was achieved by the detector having 70-nm T-gate HEMT without applying drain bias. We also measured the drain bias dependence of current sensitivity on the...
Approaches based on thinning down the substrate under the antenna are often used in order to increase efficiency of detectors built with MOSFETs and antennae printed on thick substrates. Such detectors have relatively low responsivity. In applications where cheap individual pixels are required, standard silicon lenses used to increase the responsivity are prohibitively expensive. In this paper an...
We report on the development of a tunable antenna coupled intersubband terahertz (TACIT) detector based on GaAs/AlGaAs two dimensional electron gas. A successful device design and micro-fabrication process have been developed which maintain the high mobility (1.1×106 cm2/V-s at 10K) of a 2DEG channel in the presence of a highly conducting backgate. Gate voltage-controlled device resistance and direct...
High quality Mn-Co-Ni-O (MCN) spinel films are prepared on Al2O3 substrate by RF magnetron sputtering (RF) and chemical solution deposition (CSD). The microstructural characterizations reveal the films present excellent crystallization and compact surface. The variable temperature electrical results show the films have temperature coefficient of resistance (TCR) of −3.8 %/K at 295 K. Based on the...
A FET detector, fabricated in a standard CMOS technology and coupled to a bow-tie antenna is characterized in terms of spatial response by using a deconvolution method. An optical setup is used to produce a predictable impulse response. The resulting spatial response shows interaction with other structures present on the chip, while the measured shape is in agreement with the antenna effective area...
Bow-tie antenna coupled field-effect transistors have been implemented in 0.25 μm AlGaN/GaN process technology and have been mounted on an aplanatic hemispherical silicon substrate lens. By asymmetric coupling of 590-GHz radiation to the channel, the transistors are used as direct power detectors, achieving system noise-equivalent power values of 166 pW/√Hz at 590 GHz (referred to the total beam power)...
This paper presents a 153–162 GHz pre-amplified power detector receiver based on a 250 nm InP/InGaAs/InP double heterojunction bipolar transistor (DHBT) process. The front end consists of a double slot antenna followed by a five stage low noise amplifier and a detector. The receiver is characterized through measurements of its response to broadband hot and cold terminations. A simplified method is...
The realization of large format fully sampled sensitive focal plane arrays of direct detectors is a long standing development goal for advanced astrophysical instrumentation for submillimeter wavelengths. Recently a superconducting microwave kinetic inductors detector (MKID) technology has been developed which offers high sensitivity and unprecedented multiplexing ratio. We report on development of...
We developed a THz imaging system based on a broadband thermal source (at 500 °C) and an asymmetric semiconductor nanochannel, the self-switching nanodiode (SSD), as a room-temperature detector. The maximum resolution was better than 0.5 mm full width at half maximum. The radiation was coupled to the SSD through a microantenna, whose geometry determined the frequency bandwidth of the system. While...
We present Terahertz imaging with a 1D multichannel time-domain spectroscopy system (TDS) which operates with a photoconductive array of 15 detection channels excited by a 1030 nm femtosecond fiber laser. The emitter and detector are photoconductive antennas based on InGaAs/InAlAs multi-layer heterostructures (MLHS). The simultaneous measurement of 15 THz pulses with a pixel pitch of 1 mm increases...
X-Spec is a moderate-resolution (R=400–700), multi-beam survey spectrometer covering the 190–520 GHz band under development for CCAT. It will employ a superconducting lithographically-patterned on-chip spectrometer technology, called SuperSpec. The spectrometer employs a filterbank architecture, and consists of a series of half-wave resonators formed by lithographically-patterned superconducting transmission...
This paper presents a measurement-based analysis of operation of an example MOSFET detector integrated with a narrow-band patch antenna. First, responsivity of the detector was measured versus frequency of incident wave revealing two responsivity peaks, and then the antenna and the transistor were on-wafer probed to extract their impedances and antenna resonances in order to better explain the behavior...
We report on room-temperature detection of sub-terahertz radiation by InP double heterojunction bipolar transistors designed for 100 Gbit/s circuit applications. Maximum responsivity of 250 V/W around 272 GHz were achieved at room-temperature under unbiased base-emitter and base-collector conditions. We show also that these detectors can operate as sensitive broadband THz detectors in THz imaging...
We present measurements from a prototype array of superconducting kinetic inductance detectors optimized for 150 GHz radiation and commercially fabricated from 20 nm aluminum films on silicon wafers.
Terahertz (THz) photo-detectors, consisting of a r graphene nano-bridge and a plane antenna have been fabricated c and characterized. Hot electrons in graphene-bridge (GB) are generated after absorbing the incident THz photons. We measured the amplified thermal noise power from hot electrons to sense the absorbed THz power. By using this noise-thermometric technique, a THz photodetector with temperature...
We have proposed and fabricated an antenna-coupled microbolometer with a Joule-heating resistor at the center of a half-wave antenna on a Si substrate to achieve a high-performance sensing in 1 THz frequency region at a room-temperature. The heater is directly connected to a half-wave antenna at its center and the thermistor is thermally contacted to but electrically isolated from the heater by a...
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