Fixing chiral molecules in space by intense two-color phase-locked laser fields

A new scheme is proposed to uniquely orient molecules of arbitrary symmetry with respect to the laboratory frame by the interaction of a phase-locked superposition of intense, ( ω , 2 ω ) two-color laser fields whose polarization directions cross each other obliquely with the polarizability and hyperpolarizability of molecules. Applicability of the present scheme is demonstrated for l-alanine by deriving theoretically the quasi-stationary states created adiabatically in a long laser pulse. The results show that a sufficiently high degree of 3D orientation can be achieved in the moderate laser-intensity range ( 10 12 – 10 13 W/cm 2 ) when the initial rotational temperature is as low as 10 - 1 K.