| Superconducting nanowire single photon detectors(SNSPDs) have high detection efficiency, low dark counts, low jitter, and a broadband absorption spectrum. This makes them suitable for many application including quantum optics, quantum key distribution and interplanetary communication. Recently, integration of plasmonic structures with these devices has demonstrated single-surface-plasmon detection using SNSPDs. However, all these devices suffer from a fundamental trade-off between the need to maximize their detection efficiency and the need to minimize their reset time.This paper puts forward a new scheme to solve this defect. By adding resonant cavity structure and nano-antennas to our detector, the performance of the single photon detector can be optimized. This optical cavity structure allows the single photon detector be applied to the low-light, non-linear systems.We use Comsol software to do the simulation and find that the detection efficiency of the single cavity,3μm×3μm,9μm×9μm SNSPD can be greatly improved after adding the nano-antennas respectively. As the nanowire structure does not changed, the adding of nano-antennas can improve the detection efficiency of SNSPD without change its detection rate. In addition, we discuss the current, inductance and resistance of the SNSPD’s equivalent circuit and analyze latching in our device.Finally, we verify that the use of optical cavity structure can improve nanowire absorption rate due to resonance. Then we analyze a double cavity SNSPD structure with left-side illumination, the electromagnetically induced transparency (EIT) can be obtained between the two cavities. Quantum interference occurs at the wavelength of1310nm, where the absorption efficiency of single photon shows a peak value of88.5%,94.3%,95.1%with the nanowire thickness of4nm,8nm, and10nm, respectively. The new double-cavity SNSPD can achieve high absorption efficiency at1310nm and may have potential applications in plasmonic slow-light and non-linear systems. |
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