Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Infrared (IR) Spectroscopy: Overview

Infrared (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...

Propagation Speed of Electromagnetic Waves

Propagation Speed of Electromagnetic Waves

Electromagnetic waves are consistent with Ampere's law. Assuming there is no conduction current Ampere's law is given as:

IR Spectrum

IR Spectrum

When infrared (IR) radiation passes through a molecule, the bonds stretch or bend by absorbing the radiation. This absorption creates the molecule's absorption spectrum, which is the plot of its percentage transmittance versus wavenumber.
Transmittance is defined as the ratio of the radiant power passing through a sample to that from the radiation's source. Multiplying the transmittance by 100 gives the percent transmittance (%T), which varies between 100% (no absorption) and 0% (complete...

IR Frequency Region: Fingerprint Region

IR 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...

IR Spectrometers

IR 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...

IR Spectroscopy: Molecular Vibration Overview

IR 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...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Detection range enhancement using circularly polarized light in scattering environments for infrared wavelengths.

Applied optics·2015

Same author

Wave-front sensing by pseudo-phase-conjugate interferometry.

Applied optics·2010

Same author

Improved compensation of atmospheric turbulence effects by multiple adaptive mirror systems.

Applied optics·2010

Same author

Sidelobe reduction in optical signal processing.

Applied optics·2010

Same author

Effect of detector noise on the positioning accuracy of an autofocus system.

Applied optics·2010

Same author

Error-free image compression algorithm using classifying-sequencing techniques.

Applied optics·2010

Search research articles

Related Experiment Video

Updated: Jun 15, 2026

The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements

The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements

Published on: December 5, 2025

Infrared propagation and performance modeling at the Electro-Optical Test Facility.

D G Crowe, D K Cohen, E L Dereniak

|March 12, 2010

Summary

Atmospheric emission significantly impacts infrared (IR) system performance. The 9.5-11.5-micrometer band shows superior performance in fog compared to shorter infrared bands.

Area of Science:

Electro-optical engineering
Atmospheric physics
Infrared optics

Background:

Infrared (IR) system performance is crucial for various applications.
Atmospheric conditions, particularly fog, significantly affect IR signal propagation.
Accurate modeling of atmospheric effects is essential for predicting IR system performance.

Purpose of the Study:

To present fog spectral transmission data and propagation models.
To evaluate the impact of atmospheric emission on IR system performance.
To compare the performance of different infrared bands under various atmospheric conditions, including fog.

Main Methods:

Data generation using the Electro-Optical Test Facility.
Development and application of atmospheric propagation models.

More Related Videos

Fabrication and Testing of Photonic Thermometers

Fabrication and Testing of Photonic Thermometers

Published on: October 24, 2018

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Published on: May 29, 2014

Related Experiment Videos

Last Updated: Jun 15, 2026

The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements

The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements

Published on: December 5, 2025

Fabrication and Testing of Photonic Thermometers

Fabrication and Testing of Photonic Thermometers

Published on: October 24, 2018

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Published on: May 29, 2014

Analysis of spectral transmission data in the 3-5, 3.5-4.1, and 9.5-11.5 micrometer bands.

Main Results:

Atmospheric emission is identified as a major, often overlooked, factor in IR system performance.
The 3.5-4.1 micrometer band demonstrates superior performance over the 3-5 band at both short and long ranges.
The 9.5-11.5 micrometer band significantly outperforms both the 3-5 and 3.5-4.1 micrometer bands in foggy conditions.

Conclusions:

Incorporating atmospheric emission into models is critical for accurate IR system performance prediction.
Specific infrared spectral bands offer distinct advantages depending on range and atmospheric conditions.
The longer wavelength 9.5-11.5 micrometer band is optimal for IR system operation in fog.