Dispersion cancellation with phase-sensitive Gaussian-state light

Abstract

CitationShapiro, Jeffrey H. "Dispersion cancellation with phase-sensitive Gaussian-state light." Physical Review A 81.2 (2010): 023824.Franson's paradigm for nonlocal dispersion cancellation [J. D. Franson, Phys. Rev. A 45, 3126 (1992)] is studied using two kinds of jointly Gaussian-state signal and reference beams with phase-sensitive cross correlations. The first joint signal-reference state is nonclassical, with a phase-sensitive cross correlation that is at the ultimate quantum-mechanical limit. It models the outputs obtained from continuous-wave spontaneous parametric downconversion. The second joint signal-reference state is classical-it has a proper P representation-with a phasesensitive cross correlation that is at the limit set by classical physics. Using these states we show that a version of Franson's nonlocal dispersion cancellation configuration has essentially identical quantum and classical explanations except for the contrast obtained, which is much higher in the quantum case than it is in the classical case. This work bears on Franson's recent article [J. D. Franson, Phys. Rev. A 80, 032119 (2009)], which asserts that there is no classical explanation for all the features seen in quantum nonlocal dispersion cancellation.for J = S or R and K = S or R. The photodetectors in Fig. 1 produce classical photocurrents, i J (t) for J = S or R, whose measurement statistics are equivalent to those of the photocurrent operators, i J (t) ≡ q duÊ † J (u)Ê J (u)g(t − u), for J = S or R, (8)

Observations of Dispersion Cancellation of Entangled Photon Pairs

“…A classical calculation [14], based on detector crosscorrelation, has claimed to predict Franson cancellation. Elsewhere, this interpretation has been criticized [15].…”

Cancellation of dispersion and temporal modulation with nonentangled frequency-correlated photons

“…Several authors have shown that similar dispersion cancellation effects can be obtained with nonentangled light [12,13]. In particular, the work in [12] considers classical thermal light equally split in two dispersive arms and demonstrates that the broadening of the second-order correlation function increases as ( 1 − 2 ) 2 , so that it remains unaffected if 1 = 2 .…”

“…Later, the work in [13] shows that by introducing a phase conjugator element in one of the arms, the broadening of the correlation function increases as ( 1 + 2 ) 2 , similar to the case of the signal-idler photon pairs generated in SPDC, and thus the same dispersion compensation rules apply [14].…”

Nine-frequency-path quantum interferometry over 60 km of optical fiber

“…Research is still on-going about the classical or quantum nature of the non-local dispersion approach [21,22]. We show here that the dispersion can be canceled nonlocally, thereby restoring the original interference pattern after the twin-photons are propagated in long-haul optical fibers.…”