Pump-and-probe optical transmission phase shift as a quantitative probe of the Bogoliubov dispersion relation in a nonlinear channel waveguide 
P.-E. Larrè, S. Biasi, F. Ramiro-Manzano, L. Pavesi, I. Carusotto
Eur. Phys. J. D (2017) 71: 146, DOI: 10.1140/epjd/e2017-80208-5