We consider the orientation of linear and symmetric-top molecules induced by laser and delayed terahertz (THz) pulses at high rotational temperatures (up to room temperature). We introduce an echo-assisted approach in which the achieved transient molecular orientation is an order of magnitude higher than the orientation produced by a single THz pulse. The laser pulse first dissects the wide molecular phase-space distribution into multiple narrow strips (filaments), each being cold and evolving separately. A subsequent THz pulse causes a substantial transient orientation of the individual filaments, which leads to an enhanced orientation of the whole molecular ensemble at later times via the echo mechanism. This enhanced degree of orientation is important in attosecond science, chemical reaction control, ultrafast molecular imaging, and other domains of physics.

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• Atomic & molecular processes in external fields
• Molecules
• Electric moment
• Polarizability
• Phase space methods
• Schroedinger equation