Resonant cavity gas-phase polarimeter

Area of Science:

• Physical Chemistry
• Analytical Chemistry
• Spectroscopy

Background:

• Chirality is a fundamental property in chemistry and biology, crucial for molecular interactions.
• Gas-phase chirality measurements are challenging due to low concentrations and sensitivity requirements.
• Traditional polarimeters often lack the sensitivity needed for subtle optical activity detection in the gas phase.

Purpose of the Study:

• To demonstrate a high-sensitivity polarimeter for gas-phase chirality analysis.
• To leverage Fabry-Perot cavity physics for enhanced measurement sensitivity.
• To apply the device for monitoring enantiomeric racemization in the gas phase.

Main Methods:

• Development of a polarimeter based on the eigenstates of a Fabry-Perot cavity.
• Measurement of optical rotation induced by vapor-phase (R)-(+)-limonene and (S)-(-)-limonene.
• Experimental determination of the instrument's noise level.

Main Results:

• Demonstrated measurement of optical rotations as low as 50 (±1) × 10⁻⁵° for limonene enantiomers.
• Achieved and experimentally verified a noise level corresponding to a rotation of 10⁻⁶°.
• Successfully applied the polarimeter to monitor enantiomer mixing and racemization of limonene.

Conclusions:

• The demonstrated Fabry-Perot cavity-based polarimeter offers significantly improved sensitivity for gas-phase chirality measurements.
• The device enables precise detection of optical activity and monitoring of enantiomeric processes.
• This technology has potential applications in chiral analysis and reaction monitoring.