|
|
Hu, X., Dauler, E. A., Kerman, A. J., Yang, J. K. W., White, J. E., Herder, C. H., et al. (2009). Using surface plasmons to enhance the speed and efficiency of superconducting nanowire single-photon detectors. In Proceedings of the Conference on Lasers and Electro-Optics, 2009 and 2009 Conference on Quantum electronics and Laser Science Conference (pp. 1–2).
Abstract: We report our design and fabrication of superconducting nanowire single-photon detectors integrated with gold plasmonic nanostructures, which can enhance the absorption of TM-polarized light, and can enlarge the effective area without sacrificing detector speed.
|
|
|
|
Ozhegov, R. V., Gorshkov, K. N., Vachtomin, Y. B., Smirnov, K. V., Finkel, M. I., Goltsman, G. N., et al. (2014). Terahertz imaging system based on superconducting heterodyne integrated receiver. In C. Corsi, & F. Sizov (Eds.), Proc. THz and Security Applications (pp. 113–125). Dordrecht: Springer Netherlands.
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.
|
|
|
|
Chulkova, G., Milostnaya, I., Tarkhov, M., Korneev, A., Minaeva, O., Voronov, B., et al. (2006). Superconducting single-photon nanostructured detectors for advanced optical applications. In Proc. Symposium on Photonics Technologies for 7th Framework Program (Vol. 400).
Abstract: We present superconducting single-photon detectors (SSPDs) based on NbN thin-film nanostructures and operated at liquid helium temperatures. The SSPDs are made of ultrathin NbN films (2.5-4 nm thick, Tc= 9-11K) as meander-shaped nanowires covering the area of 10× 10 µm2. Our detectors are operated at the temperature well below the critical temperature Tc and are DC biased by a current Ib close to the meander critical current Ic. The operation principle of the detector is based on the use of the resistive region in a narrow ultra-thin superconducting stripe upon the absorption of an incident photon. The developed devices demonstrate high sensitivity and response speed in a broadband range from UV to mid-IR (up to 6 µm), making them very attractive for advanced optical technologies, which require efficient detectors of single quanta and low-density optical radiation.
|
|
|
|
Hovenier J.N., Adam A.J.L., Kašalynas I., Gao J.R., Klaassen T.O., Baryshev A., et al. (2006). Phase-locking on the beat signal of a two-mode 2.7 terahertz metal-metal quantum cascade laser. In Proc. Symp. IEEE/LEOS Benelux Chapter (pp. 125–128).
Abstract: We have studied the linewidth and phase-locking of a 2.7 THz quantum cascade laser by using a superconducting bolometer mixer. The 8 GHz beat signal is compared with a microwave reference with a feedback to the laser bias current. Phase locking has been demonstrated, resulting in an extremely narrow beat linewidth of less than 10 Hz. Under frequency-stabilization conditions we find that the line profile is virtually Lorentzian with a long-term minimum linewidth of the THz modes of about 6.3 kHz. Temperature dependent measurements suggestthat this linewidthdoes not approach the Schawlow-Townes limit.
|
|
|
|
de Graauw, T., Whyborn, N., Caux, E., Phillips, T., Stutzki, J., Tielens, X., et al. (2006). The Herschel-heterodyne instrument for the far-infrared (HIFI). In Proc. SPIE. Orlando.
|
|
