RESUMO
The rapid development of infrared spectroscopy, observational astronomy, and scanning near-field microscopy has been enabled by the emergence of sensitive mid- and far-infrared photodetectors. Superconducting hot-electron bolometers (HEBs), known for their exceptional signal-to-noise ratio and fast photoresponse, play a crucial role in these applications. While superconducting HEBs are traditionally crafted from sputtered thin films such as NbN, the potential of layered van der Waals (vdW) superconductors is untapped at THz frequencies. Here, we introduce superconducting HEBs made from few-layer NbSe2 microwires. By improving the interface between NbSe2 and metal leads, we overcome impedance mismatch with RF readout, enabling large responsivity THz detection (0.13 to 2.5 THz) with a minimal noise equivalent power of 7 pW/ Hz and nanosecond-range response time. Our work highlights NbSe2 as a promising platform for HEB technology and presents a reliable vdW assembly protocol for custom bolometer production.
RESUMO
NbN-based detectors can detect light from the granular regime (single or few photons) up to weak continuous photon fluxes at wavelengths ranging from visible light up to mid-IR. The article reports our recent results on a novel linear detector, the waveguide-integrated hot electron bolometer (HEB) capable to measure photon fluxes of large coherent beams in a regime in which superconducting nanowire single photon detectors (SNSPDs) are not efficient due to their strong nonlinearity. SNSPDs, photon number resolving detectors and amplitude multiplexing readout schemes, all integrated on photonic circuits are also discussed in the paper. The compatibility of the integrated HEB detectors with the SNSPDs technology can allow the characterization of complex non classical states of light within the same chip.