Spatio-Temporal Cleaning Of A Femtosecond Laser Pulse By A Filament Conjugate Mirror

Abstract

Optical phase conjugation is well known for its time reversal properties [1]. A phase conjugate mirror is formed when two laser beams of same frequency w meet from opposite directions in a transparent nonlinear medium. When a probe beam is retro-reflected by an optical phase conjugate mirror, wavefront distortions induced by a phase object are removed after re-crossing this object [2, 3]. In this presentation, we use two counter-propagating filaments to create a conjugate mirror with air as a non linear medium [4]. We demonstrate that it operates differently from a usual conjugate mirror. With a filament conjugate mirror, the reflected signal has essentially a perfect spatial mode independent of the initial probe beam profile. © 2013 IEEE