Time Dependent Optical Phase and Imaginary Collision Kernels

John E. Thomas, P. J. Laverty, K. D. Stokes

Recently demonstrated techniques for measuring collision-induced phase in macroscopic optical coherence are described and analyzed in detail. The time-dependent phase measured by this method is used to study imaginary collision kernels for optical radiators that are related to the phase by Fourier transformation. The results indicate that classical velocity changes may make an important contribution to the imaginary kernel, in contrast to the real kernel, which is dominated by diffractive velocity changes.

Valerii S. Lisitsa, Sergey I. Yakovlenko

G. S. Agarwal

P. J. Laverty, K. D. Stokes, John E. Thomas

New techniques are demonstrated which measure, for the first time, collision-induced phase in macroscopic optical coherence. The shape of the phase versus time-delay curves obtained from the data yields the first information on imaginary velocity-changing collision kernels for optical radiators.

Jiehong Lao, Zheng Zhou, Xili Zhang +2 more

Abstract We study stability and collisions of quantum droplets (QDs) forming in a binary bosonic condensate trapped in parity-time (   )-symmetric optical lattices. It is found that the stability of QDs in the   -symmetric system depends strongly on the values of the imaginary part W 0 of the   -symmetric optical lattices, self-repulsion strength g , and the condensate norm N . As expected, the   -symmetric QDs are entirely unstable in the broken   -symmetric phase. However, the   -symmetric QDs exhibit oscillatory stability with the increase of N and g in the unbroken   -symmetric phase. Finally, collisions between   -symmetric QDs are considered. The collisions of droplets with unequal norms are completely different from that in free space. Besides, a stable   -symmetric QDs collides with an unstable ones tend to merge into breathers after the collision.

M. Dagenais