Optimized interferometric setup for chiral and achiral ultrafast IR spectroscopy
Optics Express
|July 21, 2015
Summary
We developed a stabilized interferometer for detecting vibrational circular dichroism (VCD) and optical rotatory dispersion (VORD) using femtosecond laser pulses. This setup can selectively measure chiral signals or artifacts like linear birefringence (LB) and linear dichroism (LD).
Area of Science:
- Spectroscopy
- Physical Chemistry
- Quantum Optics
Background:
- Chiral molecules exhibit unique optical properties like VCD and VORD.
- Accurate measurement of these properties is challenged by artifacts such as LB and LD.
- Previous methods lacked the stability and selectivity for precise transient measurements.
Purpose of the Study:
- To report a novel, actively stabilized interferometer for sensitive VCD and VORD detection.
- To improve upon existing techniques by integrating advanced optical and detection strategies.
- To enable selective measurement of chiral signals and dominant artifacts.
Main Methods:
- Utilized an interferometer with femtosecond laser pulses.
- Implemented signal amplification via crossed polarizers.
- Employed precise polarization control, phase stability, tight focusing, and broad-band detection.
- Applied spectral interferometry for simultaneous LB and LD detection.
Main Results:
- Demonstrated selective detection of transient VCD/VORD or LB/LD based on pump-beam polarization.
- Presented simultaneous transient LB and LD data for an achiral Rhenium carbonyl complex.
- Analyzed residual background signals in the experimental configuration.
Conclusions:
- The developed setup offers enhanced sensitivity and selectivity for chiral spectroscopy.
- This method allows for the disentanglement of chiral signals from polarization artifacts.
- The findings are crucial for advancing static and transient measurements of molecular chirality.
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