Related Experiment Video
Updated: May 19, 2026
11:05
High-definition Fourier Transform Infrared (FT-IR) Spectroscopic Imaging of Human Tissue Sections towards Improving Pathology
Published on: January 21, 2015
Mid-infrared Fourier transform spectroscopy with a broadband frequency comb
Florian Adler1, Piotr Masłowski, Aleksandra Foltynowicz
1Department of Physics, JILA, National Institute of Standards and Technology,University of Colorado, Boulder, Colorado 80309-0440, USA. fadler@jila.colorado.edu
Optics Express
|October 14, 2010
Summary
We developed a new optical-frequency-comb method for fast trace gas detection in the mid-infrared molecular fingerprint region. This system achieves part-per-billion sensitivity for gases like methane in just 30 seconds.
Area of Science:
- Spectroscopy
- Analytical Chemistry
- Quantum Optics
Background:
- Trace gas detection is crucial for environmental monitoring and industrial process control.
- The mid-infrared molecular fingerprint region offers unique spectral signatures for many gases.
- Current methods can be slow or lack sensitivity for complex mixtures.
Purpose of the Study:
- To demonstrate the first implementation of optical-frequency-comb-based rapid trace gas detection.
- To achieve high-resolution broadband absorption spectroscopy in the mid-infrared.
- To enable sensitive and precise quantification of multiple trace gases.
Main Methods:
- Utilized a frequency comb Fourier transform spectrometer (FC-FTS) operating from 2100 to 3700 cm(-1).
- Acquired broadband absorption spectra in near-real-time with a maximum resolution of 0.0056 cm(-1).
- Applied simultaneous analysis of multiple spectral features for enhanced detection.
Main Results:
- Achieved part-per-billion (ppb) detection limits for methane, ethane, isoprene, and nitrous oxide.
- Demonstrated detection within 30 seconds of integration time.
- Enabled precise concentration measurements in gas mixtures with continuous absorption bands.
Conclusions:
- Optical-frequency-comb-based spectroscopy provides a powerful tool for rapid and sensitive trace gas analysis.
- The developed FC-FTS system successfully operates in the mid-infrared molecular fingerprint region.
- This technology allows for detection of molecules below the noise floor, even in complex gas mixtures.
Related Concept Videos
01:09Infrared (IR) Spectroscopy: Overview
When electromagnetic radiation passes through a material, atoms or molecules transition from a lower to a higher energy state by absorbing radiation corresponding to the energy difference between the two states. The absorption of infrared (IR) radiation causes transitions between vibrational energy levels in a molecule. Therefore, IR spectroscopy is a useful analytical tool for determining the molecular structure of molecules.
Different compounds display unique properties due to their...
Different compounds display unique properties due to their...
01:24IR Spectroscopy: Molecular Vibration Overview
When Infrared (IR) radiation passes through a covalently bonded molecule, the bonds transition from lower to higher vibrational levels. The fundamental vibrational motions that result in infrared absorption can be classified as stretching or bending vibrations.
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
01:25IR Spectrometers
There are two main infrared (IR) spectrophotometers: dispersive IR spectrometers and Fourier transform infrared (FTIR) spectrometers. In a dispersive IR spectrometer, a beam of infrared radiation produced by a hot wire is divided into two parallel equal-intensity beams using mirrors. One beam passes through the sample, while another is a reference beam. The beams then move through the monochromator, which separates the radiations into a continuous spectrum of different frequencies. The...
01:24IR Frequency Region: X–H Stretching
In IR spectroscopy, signals produced by the X−H bonds (such as C−H, O−H, or N−H) can be observed in the frequency range of 2700–4000 cm–1. The C−H stretching vibration forms sharp bands in the region 2850–3000 cm–1. The presence of the O−H stretching vibration leads to the forming of an absorption band in the frequency range 3650–3200 cm−1. At the same time, N−H stretching can be confirmed by absorption bands in the 3500–3100 cm−1 range. Even though both O−H and N−H bonds vibrate at a similar...
01:03IR Frequency Region: Fingerprint Region
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the C=O, C=N, and C=C occur between 1600–1850 cm−1.
The...
The...
01:11Applications of IR Spectroscopy: Overview
The non-destructive nature and ability to provide valuable chemical information make IR spectroscopy a versatile technique with broad applications in various scientific and industrial fields. IR spectroscopy is commonly used to identify and characterize organic and inorganic compounds. It provides information about the functional groups present in a molecule and the bonding between atoms. This helps in the structural elucidation of compounds during organic synthesis, pharmaceutical research,...