Stark-induced adiabatic Raman passage for preparing polarized molecules

Area of Science:

• Molecular Physics
• Quantum Chemistry
• Laser Spectroscopy

Background:

• Preparing molecules in specific quantum states is crucial for controlling chemical reactions.
• Dynamical stereochemistry requires molecules with defined orientation and alignment.
• Existing methods have limitations in achieving precise control over molecular states.

Purpose of the Study:

• To propose and theoretically validate a novel method for preparing vibrationally excited molecules with controlled orientation and alignment.
• To enable future studies in dynamical stereochemistry by providing a reliable preparation technique.
• To investigate the feasibility of achieving complete population transfer to desired molecular states.

Main Methods:

• Utilizing Stark-induced adiabatic Raman passage (SARP) with tailored laser pulses.
• Employing delayed, overlapping pump and Stokes laser pulses of unequal intensities.
• Calculating (J, M)-state dependent dynamic Stark shifts of rovibrational levels in H(2).

Main Results:

• Demonstrated complete population transfer to excited vibrational levels (v > 0) of H(2) under collision-free conditions.
• Successfully prepared specific H(2) states (v=1, J=2, M=0 and M=±2) using SARP with different laser polarizations.
• Predicted feasibility of achieving complete population transfer to the v=4 vibrational level.

Conclusions:

• SARP is a viable method for preparing vibrationally excited H(2) molecules with precise orientation and alignment.
• The technique requires phase-coherent nanosecond pulses with specific intensity ratios and peak intensities.
• This method opens new avenues for controlling molecular dynamics and advancing stereochemistry research.