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| Author | Ciulin, V.; Carter, S. G.; Sherwin, M. S. | ||||
Title  |
Terahertz optical mixing in biased GaAs single quantum wells | Type | Journal Article | ||
| Year | 2004 | Publication | Phys. Rev. B | Abbreviated Journal | Phys. Rev. B |
| Volume | 70 | Issue | 11 | Pages | 115312-(1-6) |
| Keywords | optical mixing | ||||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 1098-0121 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | Serial | 501 | |||
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| Author | Ozhegov, R. V.; Gorshkov, K. N.; Smirnov, K. V.; Gol’tsman, G. N.; Filippenko, L. V.; Koshelets, V. P. | ||||
| Title |
Terahertz imaging system based on superconducting integrated receiver | Type | Conference Article | ||
| Year | 2010 | Publication | Proc. 2-nd Int. Conf. Terahertz and Microwave radiation: Generation, Detection and Applications | Abbreviated Journal | Proc. 2-nd Int. Conf. Terahertz and Microwave radiation: Generation, Detection and Applications |
| Volume | Issue | Pages | 20-22 | ||
| Keywords | SIS mixer, SIR | ||||
| Abstract | The development of terahertz imaging instruments for security systems is on the cutting edge of terahertz technology. We are developing a THz imaging system based on a superconducting integrated receiver (SIR). An SIR is a new type of heterodyne receiver based on an SIS mixer integrated with a flux-flow oscillator (FFO) and a harmonic mixer which is used for phase-locking the FFO. Developing an array of SIRs would allow obtaining amplitude and phase characteristics of incident radiation in the plane of the receiver. Employing an SIR in an imaging system means building an entirely new instrument with many advantages compare to traditional systems: i) high temperature resolution, comparable to the best results for incoherent receivers; ii) high spectral resolution allowing spectral analysis of various substances; iii) the local oscillator frequency can be varied to obtain images at different frequencies, effectively providing “color” images; iv) since a heterodyne receiver preserves the phase of the radiation, it is possible to construct 3D images. The paper presents a prototype THz imaging system using an 1 pixel SIR. We have studied the dependence of the noise equivalent temperature difference (NETD) on the integration time and also possible ways of achieving best possible sensitivity. An NETD of 13 mK was obtained with an integration time of 1 sec a detection bandwidth of 4 GHz at a local oscillator frequency of 520 GHz. An important advantage of an FFO is its wide operation range: 300-700 GHz. | ||||
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| Notes | Approved | no | |||
| Call Number | ozhegov2010terahertz | Serial | 1397 | ||
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| Author | Ozhegov, R. V.; Gorshkov, K. N.; Vachtomin, Y. B.; Smirnov, K. V.; Finkel, M. I.; Goltsman, G. N.; Kiselev, O. S.; Kinev, N. V.; Filippenko, L. V.; Koshelets, V. P. | ||||
| Title |
Terahertz imaging system based on superconducting heterodyne integrated receiver | Type | Conference Article | ||
| Year | 2014 | Publication | Proc. THz and Security Applications | Abbreviated Journal | Proc. THz and Security Applications |
| Volume | Issue | Pages | 113-125 | ||
| Keywords | SIS mixer, SIR, THz imaging | ||||
| Abstract | The development of terahertz imaging instruments for security systems is on the cutting edge of terahertz technology. We are developing a THz imaging system based on a superconducting integrated receiver (SIR). An SIR is a new type of heterodyne receiver based on an SIS mixer integrated with a flux-flow oscillator (FFO) and a harmonic mixer which is used for phase-locking the FFO. Employing an SIR in an imaging system means building an entirely new instrument with many advantages compared to traditional systems. In this project we propose a prototype THz imaging system using an 1 pixel SIR and 2D scanner. At a local oscillator frequency of 500 GHz the best noise equivalent temperature difference (NETD) of the SIR is 10 mK at an integration time of 1 s and a detection bandwidth of 4 GHz. The scanner consists of two rotating flat mirrors placed in front of the antenna consisting of a spherical primary reflector and an aspherical secondary reflector. The diameter of the primary reflector is 0.3 m. The operating frequency of the imaging system is 600 GHz, the frame rate is 0.1 FPS, the scanning area is 0.5 × 0.5 m2, the image resolution is 50 × 50 pixels, the distance from an object to the scanner was 3 m. We have obtained THz images with a spatial resolution of 8 mm and a NETD of less than 2 K. |
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| Publisher | Springer Netherlands | Place of Publication | Dordrecht | Editor | Corsi, C.; Sizov, F. |
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| ISSN | 978-94-017-8828-1 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | Serial | 1368 | |||
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| Author | Pütz, P.; Honingh, C. E.; Jacobs, K.; Justen, M.; Schultz, M.; Stutzki, J. | ||||
| Title |
Terahertz hot electron bolometer waveguide mixers for GREAT | Type | Journal Article | ||
| Year | 2012 | Publication | Astron. Astrophys. | Abbreviated Journal | A&A |
| Volume | 542 | Issue | Pages | L2 | |
| Keywords | HEB mixer, applications | ||||
| Abstract | Context. Supplementing the publications based on the first-light observations with the German REceiver for Astronomy at Terahertz frequencies (GREAT) on SOFIA, we present background information on the underlying heterodyne detector technology. This Letter complements the GREAT instrument Letter and focuses on the mixers itself. Aims. We describe the superconducting hot electron bolometer (HEB) detectors that are used as frequency mixers in the L1 (1400 GHz), L2 (1900 GHz), and M (2500 GHz) channels of GREAT. Measured performance of the detectors is presented and background information on their operation in GREAT is given. Methods. Our mixer units are waveguide-based and couple to free-space radiation via a feedhorn antenna. The HEB mixers are designed, fabricated, characterized, and flight-qualified in-house. We are able to use the full intermediate frequency bandwidth of the mixers using silicon-germanium multi-octave cryogenic low-noise amplifiers with very low input return loss. Results. Superconducting HEB mixers have proven to be practical and sensitive detectors for high-resolution THz frequency spectroscopy on SOFIA. We show that our niobium-titanium-nitride (NbTiN) material HEBs on silicon nitride (SiN) membrane substrates have an intermediate frequency (IF) noise roll-off frequency above 2.8 GHz, which does not limit the current receiver IF bandwidth. Our mixer technology development efforts culminate in the first successful operation of a waveguide-based HEB mixer at 2.5 THz and deployment for radioastronomy. A significant contribution to the success of GREAT is made by technological development, thorough characterization and performance optimization of the mixer and its IF interface for receiver operation on SOFIA. In particular, the development of an optimized mixer IF interface contributes to the low passband ripple and excellent stability, which GREAT demonstrated during its initial successful astronomical observation runs. |
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| Notes | Approved | no | |||
| Call Number | Serial | 907 | |||
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| Author | Finkel, M. I.; Maslennikov, S. N.; Gol'tsman, G. N. | ||||
| Title |
Terahertz heterodyne receivers based on superconductive hot-electron bolometer mixers | Type | Journal Article | ||
| Year | 2005 | Publication | Radiophys. Quant. Electron. | Abbreviated Journal | Radiophys. Quant. Electron. |
| Volume | 48 | Issue | 10-11 | Pages | 859-864 |
| Keywords | HEB, applications | ||||
| Abstract | We consider recent results in development of hot-electron bolometer mixers. Special attention is paid to optimization of the contacts between the antenna and the active area of a superconducting film. An important result in the study of the parasitic effect of direct detection is obtained during the measurement of the noise temperatures by the hot/cold load method. The latest results of studies of the waveguide hot-electron bolometer mixers and their successful practical applications are considered. Progress in development of high-frequency (over 1.3 THz) heterodyne receivers for several important international projects is discussed and new submillimeter radio astronomy projects ESPRIT and SAFIR are described. | ||||
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| ISSN | 0033-8443 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | Serial | 381 | |||
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