Feasibility of nonlinear reflection of light by a collisionless molecular beam

Numerical solutions of the Maxwell-Bloch equations describing the nonlinear absorption of an IR laser field as it propagates across a collisionless molecular beam are presented. Calculations show the possibility that the laser field experiences a self-reflection inside the molecular beam while it is being absorbed. Since the density of the molecular beam changes smoothly in the radial direction, there are no reflections induced by its boundaries, and it constitutes an ideal system to study the self-reflected wave. The reflectivity of the molecular beam is predicted to be vanishingly small at low intensities but to increase dramatically as the nonlinear effects become significant.