Patent ID: 9612161
Date: 2017-04-04
CPC Classifications: G01J

Claim:
1. A method of measuring a phase difference between a first set of photons and a second set of photons, the method comprising: directing the first set of photons to a first parametric downconverter; directing the second set of photons to a second parametric downconverter; directing photons output from an exotic photon source to the first downconverter; directing photons output from the first parametric downconverter to a first beam splitter; directing photons output from an exotic photon source to the first beam splitter; directing photons output from the second parametric downconverter to a second beam splitter; directing photons output from the first beam splitter to the second beam splitter; detecting photons output from the second beam splitter; deriving, from the detecting, a phase difference between the first set of photons and the second set of photons; and outputting the phase difference.