Single-Photon Detector With Wavelength-Selective Surface
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current superconducting nanowire single-photon detectors (SNSPDs) have limited spectral range, low detection efficiency for longer wavelength photons, and are difficult to manufacture, especially for large-scale arrays required in applications like quantum imaging and LIDAR.
Innovation Solution
A single-photon detector and array design featuring a substrate with a reflector and superconducting wire, covered by a dielectric layer and a surface-plasmon wavelength-selective nanostructure array, enabling surface plasmon resonances and improved light transmission across a broad spectral bandwidth from ultraviolet to infrared.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard SNSPD design is used, then detection efficiency is high for visible light, but detection efficiency decreases significantly for longer wavelength photons
Solution Approach 1:
The patent introduces a wavelength-selective surface with nanostructure array above the superconducting nanowire detector. This adds a spectral dimension to the detection system, enabling selective enhancement of specific wavelength ranges (UV, visible, or infrared) while maintaining the underlying SNSPD structure. The nanostructure array acts as a spectral filter that can be tuned to different wavelength bands.
Solution Approach 2:
The patent combines the superconducting nanowire material (e.g., NbN, TaN, TiN) with wavelength-selective optical materials in the nanostructure array. This composite structure integrates the high detection efficiency of SNSPDs with the spectral selectivity of plasmonic or photonic materials, achieving both high reliability and broad spectral adaptability.
2Ease of operation
If optical fiber is used to guide light to detector element, then light can be delivered to detector, but coupling loss occurs between fiber end and detector element
Solution Approach 1:
The wavelength-selective surface with nanostructure array serves as an intermediary between the optical fiber and the superconducting nanowire detector. It mediates the optical coupling by providing a transition zone that matches the optical modes, reducing reflection and improving light delivery efficiency to the detector element.
3Productivity
If large SNSPD arrays are manufactured, then detection capability for quantum imaging and LIDAR is improved, but manufacturing difficulty increases
Solution Approach 1:
The patent designs a universal platform where the same SNSPD structure with wavelength-selective surface can be replicated across multiple pixels. The standardized design enables scaling to large arrays while maintaining consistent performance characteristics. The system can be configured for different spectral ranges using the same base architecture.
Solution Approach 2:
The detector array is segmented into multiple independent pixels, each with its own superconducting nanowire and wavelength-selective surface. This segmentation allows for modular manufacturing and testing, reducing the complexity of producing large-scale arrays while maintaining high detection efficiency across all elements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances detection efficiency and scalability, allowing for high-performance large-scale detection arrays with improved uniformity and critical temperature, addressing the limitations of existing SNSPDs.
Implementation Method 1
The nanowire is cooled below its superconducting critical temperature and biased with a direct current less than the superconducting critical current of the nanowire. Once a single photon is absorbed in the meandering nanowire, the superconductivity of the nanowire is locally broken.
Implementation Method 2
Once a single photon is absorbed in the meandering nanowire, the superconductivity of the nanowire is locally broken. The localized non-superconducting area or hot spot with finite electrical resistance produces a measurable voltage pulse to be detected.
Implementation Method 3
a reflector disposed on or beneath the substrate, and at least one superconducting wire, preferably single-crystalline, disposed on the reflector or the substrate, wherein the incident light is irradiated on the at least one superconducting wire and/or is reflected to the at least one superconducting wire by the underlying reflector
Implementation Method 4
a surface-plasmon wavelength-selective surface comprising a nanostructure array on the dielectric layer, wherein the nanostructure array is configured to enable surface plasmon resonances stimulated by the incident light at one or more wavelengths, the surface-plasmon wavelength-selective surface resonantly transmits the incident light within a passband
Data Source
AI summary
The invention provides a single-photon detector that includes a superconducting wire made from a high quality and uniform superconducting film with a higher critical temperature. A reflector or a multilayered reflector with high reflectivity, preferably a nitride-based distributed Bragg reflector, is provided to reflect an incident light to the superconducting wire. A surface-plasmon wavelength-selective surface may be further provided above the superconducting wire to resonantly transmits the incident light within a selective passband, making the single-photon detector operable in the ultraviolet, visible, and infrared wavelength bands. In addition, a large area of superconducting film with high level of uniformity is grown to achieve the up scaling of the single-photon detector and a single-photon detector array.