Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Web-Based Tools for Quantum Networks

NIST develops new measurement techniques that can be useful for quantum network development. Here we provide links to algorithms and software widgets that can be readily applied in any laboratory in the world to establish or improve characterization of quantum network components.

  • The spontaneous parametric down-conversion phase matching (web version)  (Fortran90 source code and standalone executable) -- is a design tool for bulk spontaneous down-conversion sources. The software outputs the joint mode structure of twin beams based on a phase-matching calculation in both collinear and noncollinear cases. It allows a large set of nonlinear crystals and configurations to be examined.
  • Mode reconstructor – (source code in C) – is a source characterization tool that computes the mode structure of single beams of multimode light or conjugated multimode beams using only photon counting data as an input. (Demo available at
  • Detector self-characterization via autocorrelation (algorithm) -- is a simple and highly sensitive algorithm for characterizing a large class of single-photon detectors. This method is based on analyzing multi-order correlations among time-tagged detection events from a single-photon-detection device such as single photon avalanche photodiode or a superconducting nanowire single-photon detector under continuous-wave illumination. (Demo available at
  • Poisson-Influenced K-Means Algorithm or PIKA -- is a machine learning algorithm used to assign numbers of photons to pulses arising from TES detectors. To use the software, download the notebook, and follow the instructions in Section 1, "Run PIKA here". It may also be necessary to download and unzip one or both of the data sets in the section "Additional Material" near the end of the notebook. Mathematica is required to run the *.nb file, but the free Mathematica Player may be used to run the *.cdf version.
Created February 10, 2022, Updated August 24, 2022