Wide-Range Bolometer With RF Readout TES

Abstract

To improve both scalability and noise-filtering capability of a Transition-Edge Sensor (TES), a new concept of a thin-film detector is suggested, which is based on embedding a microbridge TES into a high-Q planar GHz-range resonator weakly coupled to a 50-Ohm-readout transmission line. Such a TES element is designed as a hot-electron microbolometer coupled to a THz range antenna and as a load of the resonator at the same time. A weak THz signal coupled to the antenna heats the microbridge TES, thus reducing the quality factor of the resonator and leading to a power increment in the readout line. The power-to-power conversion gain, an essential figure of merit, is estimated to be above 10. To demonstrate the basic concept, we fabricated and tested a few submicron sized devices from Nb thin films for operation temperature about 5 K. The dc and rf characterization of the new device is made at a resonator frequency about 5.8 GHz. A low-noise HEMT amplifier is used in our TES experiments without the need for a SQUID readout. The optical sensitivity to blackbody radiation within the frequency band 600-700 GHz is measured as (2.7±0.9)×10 -14 W/√Hz at T c ≈ 5 K at bath temperature ≈ 1.5 K.  Index Terms-Transition edge sensor, TES, superconducting bolometer, HEB, HEB micro bolometer, electrothermal feedback, high-Q resonator, terahertz range, blackbody calibration, FDM readout .

Superconducting bolometer with high-frequency readout circuit at 400 mK

“…Recently, there has been an upsurge in interest on the part of the astrophysical community in ultrasensitive imaging direct terahertz detectors based on superconducting materials, especially in the form of integrated arrays with a number of pixels of ∼ 1000 [1][2][3][4][5][6][7], including those on orbital carriers. The monolithic detector proposed by us, which received the abbreviation RFTES (radio frequency transition edge sensor) [8][9][10][11][12][13][14][15][16], is a nonequilibrium thermal detector and retains the features of known superconducting detectors, having several advantages. The response of the detector is based on the high-frequency nonlinearity of the surface impedance of a superconductor [17], formed as a thin-film microbridge, included in a high-Q quarterwave resonator.…”

“…The most important parameter of the bolometer is the thermal insulation of the absorber, which is not a trivial task in the case of a detector with monolithic structure. Electrodynamic prototypes of RFTES have been tested in experiments with niobium bridges at liquid helium temperatures (∼ 4 K) [9][10][11][12].…”

Microwave Radiation Detection with an Ultrathin Free-Standing Superconducting Niobium Nanohelix

“…Miniaturized superconductor technologies have attracted a lot of attention since the first superconducting quantum interference device (SQUID) was invented in 1964 by a group at the Ford Motor Co . Continuing research in recent years has led to superconducting nanobolometers − and nano-SQUIDs. − The generic major problem in previously developed structures is a strong thermal coupling to the underlying substrate, , which sets the lower limit for the sensor’s response time. Hence, it is natural to anticipate that free-standing nanostructures with few contact points to the supporting substrates should allow for overcoming this bottleneck.…”

Сверхпроводящий резонатор с микромостиком из гафния при температурах 50-350 mK

“…При переходе к температурам ниже 1 K электронная под-система многих материалов слабо взаимодействует с кристаллической решеткой и может быть разогрета относительно независимо, особен-но вблизи сверхпроводящего перехода [5]. Появление неравновесного нано-HEB-детектора (HEB -болометр на горячих электронах) [6,7], который можно условно отнести к разновидности TES с саморазо-гревом, подтолкнуло нас к разработке концепции RFTES (RFTES -болометр на краю сверхпроводящего перехода с высокочастотным счи-тыванием) [8][9][10]. Мы предложили измерять такой разогрев на частотах резонатора в несколько GHz, считая возможным реализовать вариа-бельность импеданса мостика на сравнительно высоких частотах.…”