Comparison between difference-frequency generation and parametric fluorescence in quasi-phase-matched lithium niobate stripe waveguides

Single WDM channel efficient wavelength shifting and/or amplification using counterpropagating optical parametric amplifiers

“…This indicates that the signal amplification bandwidth remains almost constant over a wide range of wavelengths. Such situation is completely different from the co-propagating configuration, for which 1 L dramatically increases when r 1 tends to 1 [14]. Furthermore, we have verified that the propagation losses do not change 1 L.…”

Parametric fluorescence in semiconductor waveguides

“…5 we compare two experimental emission spectra, at degeneracy and at 0.2 nm off degeneracy: in agreement with design predictions, wide tunability can be accomplished by slightly changing pump wavelength or sample temperature. By calculating the idler input as the vacuum fluctuations integrated on the phase-matching band [32], we may infer the parametric gain coefficient g = (4.0 ± 0.7) P p cm −1 from the experimental efficiency. To validate this value independently on the actual phase-matching spectrum, especially in a strongly temperature-sensitive device at high CW pumping intensities ( >1 MW cm −2 ), this crucial parameter was further evaluated by measuring frequency doubling conversion efficiency in the same waveguide.…”

Theory of spontaneous parametric down-conversion from photonic crystals

“…Recently, there has been much interest within the nonlinear-optics community in using periodically poled (PP) materials as a source of SPDC [5][6][7][8]. It is important to compare the use of PP structures with photonic-crystal devices as described here.…”

“…In particular, periodic modulation of the nonlinearity to assist in phase matching nonlinear processes has been coined quasiphase matching (QPM). QPM has been studied in the context of classical and quantum nonlinear optics [4][5][6][7][8]. The introduction of the periodic, nonlinear modulation leads to both flexibility in phase matching and also makes accessible a material's largest nonlinear coefficient.…”