Abstract

Two classical, coincident light pulses propagating through two different dispersive media will become broadened and their degree of coincidence will be reduced. The width of the coincidence curve can be shown to be proportional to $\left({\beta }_1^2+{\beta }_2^2\right)x^2$, where β₁, and β₂ are the dispersion coefficients in the two media and x is the distance traveled. When entangled photon pairs from parametric down conversion are considered instead, it is found that the width of the coincidence curve is then proportional to (β₁ + β₂)²x², which gives an interference term of 2β₁β₁. If β₁ = β₂, the dispersion experienced by one photon can exactly cancel the dispersion experienced by the other in such a way that their coincidence is maintained.

© 1991 Optical Society of America