Impedance matched superconducting nanowire photodetector for single- and multi-photon detection
US11522115B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 4, 2020 |
| Grant date | Dec 6, 2022 |
| Priority date | — |
| Expiry date | Dec 17, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2001/442
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Conventional readout of a superconducting nanowire single-photon detector (SNSPD) sets an upper bound on the output voltage to be the product of the bias current and the load impedance, IB×Zload, where Zload is limited to 50Ω in standard RF electronics. This limit is broken/exceeded by interfacing the 50Ω load and the SNSPD using an integrated superconducting transmission line taper. The taper is a transformer that effectively loads the SNSPD with high impedance without latching. The taper increases the amplitude of the detector output while preserving the fast rising edge. Using a taper with a starting width of 500 nm, a 3.6× higher pulse amplitude, 3.7× faster slew rate, and 25.1 ps smaller timing jitter was observed. The taper also makes the detector's output voltage sensitive to the number of photon-induced hotspots and enables photon number resolution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.