Torrioli G, Forrer A, Beck M, Carelli P, Chiarello F, Faist J, Gaggero A, Giovine E, Martini F, Senica U, Leoni R, Scalari G, Cibella S. THz optical beat-note detection with a fast superconducting hot electron bolometer operating up to 31 GHz.
OPTICS EXPRESS 2023;
31:15942-15952. [PMID:
37157684 DOI:
10.1364/oe.481081]
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Abstract
We study the performance of a hot-electron bolometer (HEB) operating at THz frequencies based on superconducting niobium nitride films. We report on the voltage response of the detector over a large electrical detection bandwidth carried out with different THz sources. We show that the impulse response of the fully packaged HEB at 7.5 K has a 3 dB cutoff around 2 GHz. Remarkably, detection capability is still observed above 30 GHz in an heterodyne beating experiment using a THz quantum cascade laser frequency comb. Additionally, the HEB sensitivity has been evaluated and an optical noise equivalent power NEP of 0.8 pW/√H z has been measured at 1 MHz.
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