Strong Optical Dipole Force Exerted on Molecules Having Low Rotational Temperature

Area of Science:

• Molecular Physics
• Laser-Matter Interactions

Background:

• Optical dipole force is crucial for manipulating neutral molecules.
• Controlling molecular alignment and rotational temperature impacts force.
• Previous studies explored laser-molecule interactions at various conditions.

Purpose of the Study:

• To investigate the enhancement of optical dipole force on molecules.
• To determine the effect of rotational cooling and molecular alignment on optical forces.
• To compare theoretical predictions with experimental measurements.

Main Methods:

• Utilized velocity map imaging techniques for measurements.
• Adjusted source pressure (2–81 bar) to decrease rotational temperature.
• Employed linearly polarized nonresonant laser beams for alignment.

Main Results:

• Reduced rotational temperature from 295 K to 1 K.
• Increased maximum molecular alignment from =0.33 to 0.92.
• Achieved a 74% enhancement in average optical dipole force.

Conclusions:

• Decreasing rotational temperature significantly enhances optical dipole force.
• Molecular alignment is strongly correlated with increased optical force.
• Experimental results validate theoretical calculations for optical dipole force.