Terahertz heterodyne imaging with InGaAs-based bow-tie diodes

Minkevičius, Linas; Tamošiūnas, V.; Kašalynas, Irmantas; Seliuta, D.; Valušis, Gintaras; Lisauskas, Alvydas; Boppel, Sebastian; Roskos, Hartmut G.; Köhler, K.

doi:10.1063/1.3641907

Cited by 55 publications

(47 citation statements)

References 15 publications

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“…It is known [13] that the spatial resolution improves by using shorter radiation wavelengths. For identification of small concealed objects the terahertz imaging is often used [13], [14]. Such terahertz radiation is strongly absorbed by water, so for detection of organic materials and passing moist barriers the microwave imaging is far more efficient.…”

Section: The Images Obtained Using the Systemmentioning

confidence: 99%

Microwave radiation imaging using inverse synthetic aperture radar technique

Ašmontas

Kiprijanovič

Levitas

et al. 2015

ElAEE

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Double-ridged horn antennas were used in ultra wideband radar system to create microwave radiation images. The images were obtained using inverse synthetic aperture radar technique. Transfer function of the calibrated radar system was close to one up to 22 GHz. High quality images of metallic and organic objects were created due to unique characteristic of ultra wideband radiated pulse. Metallic objects covered by visually opaque obstacles became detectable. The components of measurement setup and the data processing are both important for the formation of these images. The obtained results confirmed the ability of ultra wideband radar to form images for various practical applications including security systems. Higher frequency of such radar system can be raised up to 40 GHz-50 GHz.

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Section: The Images Obtained Using the Systemmentioning

confidence: 99%

Microwave radiation imaging using inverse synthetic aperture radar technique

Ašmontas

Kiprijanovič

Levitas

et al. 2015

ElAEE

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“…Bow-tie NEP was estimated to be of 4nW/√Hz [8], while that for silicon CMOS field effect transistors (FETs) -10pW/√Hz [15] and 43pW/√Hz [16]. The reported NEP value for commercial nanometric GaAs FETs transistors is about 10nW/√Hz [17].…”

Section: Bow-tie Diodes For Terahertz Imaging: a Comparative Studymentioning

confidence: 99%

“…As concerns room temperature solid-state THz detectors, one can mention Schottky diodes [2], nanometric field effect transistors [3,4] and microbolometers [5,6]. Very recent achievements in compact room temperature spectroscopic [7] and heterodyne THz imaging [8] allowed one to extend the family of compact THz sensors by adding a member of so-called InGaAs based bow-tie (BT) diodes. The sensors exhibit broadband operation as well as relatively simple device production and good reliability.…”

mentioning

confidence: 99%

Bow-tie diodes for terahertz imaging: Comparative study

Valušis¹,

Venckevičius²,

Kašalynas³

2012

Photon. Lett. Poland

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Abstract-The concept of broadband bow-tie diodes as terahertz sensors and their possible application for imaging is presented. Different bow-tie sensors fabricated of planar GaAs, modulation doped GaAs/AlGaAs structures and InGaAs layers are compared and discussed. It is demonstrated experimentally that the sensitivity of all studied devices at room temperature is nearly independent of frequency below 1THz and amounts to 0.3V/W for GaAs-based structures and 10V/W for InGaAs sensors. Room temperature terahertz images are recorded at 0.71THz and 1.4THz. Their parameters are considered in comparison with images taken by using commercially available pyroelectric sensors.The implementation of terahertz (THz) radiation in security applications and materials inspection requires reliable and compact solutions in the development of room temperature imaging systems. In these kinds of requirements, preference goes to solid-state-based solutions. A recent major breakthrough made in all-solidstate tunable sources has opened a promising route in the progress of room temperature THz emitters [1]. As concerns room temperature solid-state THz detectors, one can mention Schottky diodes [2], nanometric field effect transistors [3,4] and microbolometers [5,6]. Very recent achievements in compact room temperature spectroscopic [7] and heterodyne THz imaging [8] allowed one to extend the family of compact THz sensors by adding a member of so-called InGaAs based bow-tie (BT) diodes. The sensors exhibit broadband operation as well as relatively simple device production and good reliability.In this paper, we present a comparative study of different BT diode sensors. An operational principle and spectral features of the device is discussed, BT diode's parameters based on InGaAs layers, modulation doped GaAs/AlGaAs structures and planar GaAs are compared.Terahertz images recorded at room temperature using InGaAs BTs are compared with images taken by using commercially available pyro-electric sensors; feasibility for real-time THz imaging is considered, too.The bow-tie diode uses an idea to combine the performance of a bow-tie antenna as a coupler of incident * E-mail: irmantak@ktl.mii.lt, † E-mail: valusis@pfi.lt radiation and the semiconducting part as radiation sensing media. The diode displays structurally broken symmetry as depicted in Fig. 1: One of the two semiconductor leaves is metalized in order to couple incident radiation into the second one, where high mobility electrons are heated nonuniformly by incident THz radiation [9]. As a result, the voltage signal across the leaves is induced without any application of a bias voltage.Three different types of bow-tie diodes having the same geometry, but fabricated of different materials, were studied. The first one was GaAs/AlGaAs modulation doped structures consisting of a 20-nm-thick GaAs cap layer, Si-doped (1×10

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“…Their maximum responsivity was obtained for TiN absorber; it was 28 V/W at 2.52 THz radiation. Minkevicius et al (2011) published an InGaAs-based bow-type diode, it performed a responsivity of 6 V/W at 0.591 THz. (Ö jefors et al 2009) published a resonant on chip antenna and detector prepared by 0.25-lm CMOS technology for the 0.65 THz radiation.…”

Section: Measurementsmentioning

confidence: 99%

Thermopile-based THz antenna

Szentpali

Matyi²,

Fürjes

et al. 2011

Microsyst Technol

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This work is intended to describe the design aspects and to characterize the functionality of a novel thermopile structure applicable for detecting millimetre range and THz radiation. The proposed thermopile consists of a series of micromachined poly-crystalline silicon thermocouple strips arranged linearly. This device can act as a series of antennas; its antenna-like operation was demonstrated clearly by the strong polarization dependence when detecting microwave radiation. The sensing principle is similar to the basic operation of bolometers in that the absorbed radiation heats up the semiconductor strips, but the temperature increment is detected by the Seebeck effect instead of the resistance change. Therefore there is no readout current and the voltage output starts from zero. In the present work we are going to show the simulation of the current distribution. The fabrication of the device will also be outlined, as well as the results of measurements performed at 13, 100 GHz, and both in broad-band THz and in infrared radiation.

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Terahertz heterodyne imaging with InGaAs-based bow-tie diodes

Cited by 55 publications

References 15 publications

Microwave radiation imaging using inverse synthetic aperture radar technique

Microwave radiation imaging using inverse synthetic aperture radar technique

Bow-tie diodes for terahertz imaging: Comparative study

Thermopile-based THz antenna

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