Related Experiment Video
Updated: Jul 11, 2026
07:33
Quantifying Mixing using Magnetic Resonance Imaging
Published on: January 25, 2012
Three-wave mixing in chiral liquids
1Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom and European Laboratory for Nonlinear Spectroscopy, Largo E. Fermi 2, 50125 Florence, Italy and and Istituto Nazionale per la Fisica della Mat.
Physical Review Letters
|November 4, 2000
Summary
Nonlinear optical frequency conversion in chiral media is dipole-allowed for sum- and difference-frequency generation. This study develops a chiral model and experimental evidence, revealing significantly smaller second-order susceptibility in chiral liquids than previously estimated.
Area of Science:
- Nonlinear Optics
- Chirality
- Quantum Chemistry
Background:
- Second-order nonlinear optical processes, such as sum- and difference-frequency generation, are restricted in isotropic systems.
- Chiral media allow these processes via dipole transitions, a phenomenon crucial for optical applications.
Purpose of the Study:
- To develop a theoretical model for three-wave mixing (sum-frequency generation) in chiral systems.
- To estimate the magnitude of the second-order nonlinear optical susceptibility in chiral media.
- To experimentally validate theoretical predictions using ab initio calculations and nonlinear optical experiments.
Main Methods:
- Development of a single-center chiral model for three-wave mixing.
- Ab initio quantum chemical calculations.
- Experimental measurements of three- and four-wave mixing in chiral liquids.
Main Results:
- The theoretical model provides an estimate for the nonlinear optical susceptibility.
- Ab initio calculations and experimental data support the theoretical estimates.
- The second-order susceptibility in chiral liquids was found to be substantially smaller than previously reported values.
Conclusions:
- The magnitude of second-order nonlinear optical effects in chiral liquids is significantly lower than anticipated.
- This finding has implications for the design and efficiency of optical devices utilizing chiral nonlinear materials.
Related Concept Videos
02:25Chirality
Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
02:24Properties of Enantiomers and Optical Activity
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
02:25Molecules with Multiple Chiral Centers
Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...
02:30Racemic Mixtures and the Resolution of Enantiomers
A racemic mixture, or racemate, is an equimolar mixture of enantiomers of a molecule that can be separated using their unique interaction with chiral molecules or media. Racemic mixtures are denoted by the (±)- prefix. This ‘optical rotation descriptor’ applies to the whole solution of a racemic mixture rather than a specific stereoisomer. Enantiomers typically have the same physical and chemical properties. Hence, they are not easily separable. However, enantiomers can exhibit different...
02:05Prochirality
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
02:30Chirality in Nature
Chirality is the most intriguing yet essential facet of nature, governing life’s biochemical processes and precision. It can be observed from a snail shell pattern in a macroscopic world to an amino acid, the minutest building block of life. Most of the snails around the world have right-coiled shells because of the intrinsic chirality in their genes. All the amino acids present in the human body exist in an enantiomerically pure state, except for glycine - the sole achiral amino acid. The...