Waveguide-integrated niobium-nitride detectors for on-chip quantum nanophotonics

NbN-based detectors can detect light from the granular regime (single or few photons) up toweak continuous photon fluxes at wavelengths ranging from visible light up to mid-IR. Thearticle reports our recent results on a novel linear detector, the waveguide-integrated hot electronbolometer (HEB) capable to measure photon fluxes of large coherent beams in a regime in whichsuperconducting nanowire single photon detectors (SNSPDs) are not efficient due to their strongnonlinearity. SNSPDs, photon number resolving detectors and amplitude multiplexing readoutschemes, all integrated on photonic circuits are also discussed in the paper. The compatibility ofthe integrated HEB detectors with the SNSPDs technology can allow the characterization ofcomplex non classical states of light within the same chip.