We present a multilevel pulse-area theorem for generating infrared pulses in combination with two time-delayed terahertz pulses, offering an advanced method for manipulating molecular quantum states. This approach enables precise control over molecules, starting from the ground state and driving them into a well-defined superposition of three rotational states within an excited vibrational level. To validate our theoretical model, we perform detailed time-dependent quantum wave-packet simulations of lithium hydride (LiH) molecules in their ground electronic state, accounting for both vibrational and rotational degrees of freedom. By jointly determining the optimal values of multiple pulse parameters (amplitudes, phases, and delays), we demonstrate highly accurate control over rotational superpositions at the chosen vibrational level and achieve the desired molecular orientation. Furthermore, we extend the theorem to encompass rotational excitations spanning two different vibrational subspaces and design optimized terahertz pulses tailored to control molecular orientations in excited vibrational states. We also investigate the influence of these customized terahertz pulses on rotational excitations within the ground vibrational level. This work establishes a theoretical framework for the precise and flexible control of both vibrational and rotational quantum states in molecular systems, with potential applications in quantum technologies and molecular spectroscopy.

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• Atomic & molecular processes in external fields
• Coherent control
• Rotational states
• Vibrational states