communication and metrology. Here we present a compact energy–time entangled photon
pair source at telecom wavelengths realized through cascaded second harmonic generation
and spontaneous parametric down conversion in a single periodically poled lithium niobate
waveguide. We introduce and characterize methods to diminish the effects of Raman
scattering, the principal being quasi-CW pumping. The quality of energy–time entanglement …