Super-resolving phase measurement with short wavelength NOON states by quantum frequency up-conversion

摘要

Precise measurements are the key to advances in all fields of science.Quantum entanglement shows higher sensitivity than achievable by classicalmethods. Most physical quantities including position, displacement, distance,angle, and optical path length can be obtained by optical phase measurements.Reducing the photon wavelength of the interferometry can further enhance theoptical path length sensitivity and imaging resolution. By quantum frequency upconversion, we realized a short wavelength two photon number entangled state.Nearly perfect Hong Ou Mandel interference is achieved after both 1547-nmphotons are up converted to 525 nm. Optical phase measurement of two photonentanglement state yields a visibility greater than the threshold to surpassthe standard quantum limit. These results offer new ways for high precisionquantum metrology using short wavelength quantum entanglement number state.