Superconducting strip photon detector
A photon detector is an important device for detecting incident photons, and a superconducting strip photon detector detects photons by utilizing the resistance variation of a superconducting strip caused by incident photons. The nanostrip type is formed by a superconducting nanostrip with a strip width of 100 nm or less, and photon detection can be performed using the generation of a local resistive region upon photon incidence. It has sensitivity over a wide wavelength range from ultraviolet to mid-infrared, and is recognized as the highest-performance photon detector in the world, especially at the telecommunication wavelength band. It has been considered that the narrower the strip width of the superconducting strip photon detector, the higher the detection efficiency. Therefore, it has been said that development is quite difficult due to the wide strip width.
The fact that the detection efficiency of a photon detector varies with the polarization state of incident photons.
A shape in which a single very long strip is arranged as shown in Figure 2 (NICT-SNSPD).
High Critical Current Bank (HCCB) structure
When a current is applied to a superconducting strip, nonuniformity of the current distribution occurs in the strip width direction (see Figure 3(b)). In particular, high current densities are concentrated at the strip edges, resulting in non-uniformity in the ratio of applied current to superconducting critical current. A high critical current bank structure can avoid this non-uniform current ratio by forming a bank structure (see Figure 3) with a high critical current value at the strip edges.
Probability that the detector will produce a correct output signal for an incident photon.
Timing fluctuations detector output signal with respect to the photon incidence timing.