2014/02/28 by Axel Heuer, Sebastian Raabe, Ralf Menzel +1 · 24 citations
Engineering · Physics and Astronomy · #Astronomical interferometer #Coherence (philosophical gambling strategy) #Coherence length #Computer science #Interference (communication) #Interferometry #Optics #Parametric statistics #Phase (matter) #Photon #Photonic and Optical Devices #Photorefractive and Nonlinear Optics #Physics #Quantum #Quantum entanglement #Quantum mechanics #Random lasers and scattering media #SIGNAL (programming language) #Spontaneous parametric down-conversion #Telecommunications #Visibility #Wavelength #quant-ph
paper · pdf · doi:10.1103/physreva.90.045803
published in Physical Review A 90(4) (American Physical Society) · 5 pages, 3 figures
openalex publication_date 2014/10/20 · arxiv created 2015/01/05 · arxiv updated 2015/01/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Spontaneous parametric down-conversion (SPDC) in a nonlinear crystal generates two single photons (signal and idler) with random phases. Thus, no first-order interference between them occurs. However, coherence can be induced in a cascaded setup of two crystals if, e.g., the idler modes of both crystals are aligned to be indistinguishable. Due to the effect of phase memory it is found that the first-order interference of the signal beams can be controlled by the phase delay between the pump beams. Even for pump photon delays much larger than the coherence length of the SPDC photons, the visibility is above 90%. The high visibilities reported here prove an almost perfect phase memory effect across the two interferometers for the pump and the signal photon modes.