Related Experiment Video
Updated: Jan 15, 2026
10:52
Direct Imaging of Laser-driven Ultrafast Molecular Rotation
Published on: February 4, 2017
10.1K
Probing Cold Supersonic Jets with Optical Frequency Combs
Romain Dubroeucq1, Quentin Le Mignon1, Julien Lecomte1
1Université de Rennes, CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, F-35000 Rennes, France.
Molecules (Basel, Switzerland)
|October 16, 2025
Summary
We used cavity-enhanced spectroscopy to study cold acetylene molecules. This technique achieved high precision, revealing sharp spectral lines and a very low rotational temperature below 7 K.
Area of Science:
- Molecular Spectroscopy
- Physical Chemistry
- Quantum Optics
Background:
- Supersonic jet expansions are crucial for cooling molecules to study their fundamental properties.
- Cavity-enhanced spectroscopy offers high sensitivity for detecting weak molecular transitions.
Purpose of the Study:
- To apply cavity-enhanced direct frequency comb Fourier transform spectroscopy to cold acetylene molecules.
- To characterize the spectroscopic properties and rotational temperature of acetylene in a supersonic jet.
Main Methods:
- Utilized a near-infrared frequency comb spectrometer coupled with a high-finesse enhancement cavity.
- Achieved molecular cooling through expansion in argon carrier gas in a planar supersonic jet.
- Employed Pound-Drever-Hall locking and vibration damping for frequency comb and cavity stabilization.
Main Results:
- Obtained high-resolution, Doppler-limited absorption spectra of cold acetylene (C2H2).
- Determined a rotational temperature below 7 K in the jet core.
- Achieved spectral precision better than 2 MHz and a sensitivity of 7.8 × 10^-7 cm^-1.
Conclusions:
- Cavity-enhanced direct frequency comb spectroscopy is a powerful tool for precise characterization of cold supersonic expansions.
- The results have implications for molecular dynamics, reaction kinetics, and laboratory astrophysics.
- Demonstrated the potential for high-sensitivity molecular spectroscopy in fundamental research.
More Related Videos
Related Concept Videos
01:22Atomic Emission Spectroscopy: Instrumentation
1.2K
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
1.2K
01:26Inductively Coupled Plasma Atomic Emission Spectroscopy: Instrumentation
648
Inductively coupled plasma (ICP) is the common plasma source used in atomic emission spectroscopy (AES), a technique that detects and analyzes various elements in a sample. This method is often called inductively coupled plasma atomic emission spectroscopy (ICP-AES).
There are three main types of inductively coupled plasma atomic emission spectroscopy (ICP-AES) instruments: sequential, simultaneous multichannel, and Fourier transform instruments, with the latter being less commonly used....
There are three main types of inductively coupled plasma atomic emission spectroscopy (ICP-AES) instruments: sequential, simultaneous multichannel, and Fourier transform instruments, with the latter being less commonly used....
648
01:30Atomic Emission Spectroscopy: Interference
595
In atomic emission spectroscopy (AES), high-temperature atomizers excite a broad range of elements and molecules that generate complex emissions from sources such as oxides, hydroxides, and flame combustion products in the flame or plasma. Several strategies can be employed to minimize spectral interferences caused by overlapping emission lines or bands. These include increasing instrument resolution, choosing alternative emission lines, optimally placing the detector in low-background regions,...
595
01:29Plane Electromagnetic Waves II
4.0K
Consider a plane wavefront traveling in position x-direction with a constant speed. This wavefront can be utilized to obtain the relationship between electric and magnetic fields with the help of Faraday's law.
4.0K
01:11Atomic Nuclei: Larmor Precession Frequency
2.7K
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession,...
2.7K
01:30Plane Electromagnetic Waves I
4.9K
The existence of combined electric and magnetic fields that propagate through space as electromagnetic (EM) waves is the most significant prediction of Maxwell's equations. As Maxwell's equations hold in free space, the predicted electromagnetic waves do not require a medium for their propagation. An EM wave comprises an electric field, defined as the force per charge on a stationary charge, and a magnetic field, which is the force per charge on a moving charge.
The EM field is assumed to be a...
The EM field is assumed to be a...
4.9K