Related Experiment Video
Updated: Jun 15, 2026

Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
Abstract:
Formulas are derived for the rms noise power and power spectrum observed by an ir detector adjacent to a turbulent flow layer. The power spectrum seen by a finite aperture is conveniently expressed in terms of the power spectrum observed by a point detector. Using a simple idealization of experimental results for the latter, the spectrum observed by a finite circular aperture is calculated. Aperture averaging appears to be surprisingly ineffective in limiting the noise spectrum unless wide apertures can be employed.
Related Concept Videos
Infrared (IR) Spectroscopy: Overview
Different compounds display unique properties due to their...
Turbulent Flow
Irrotational Flow
Laminar and Turbulent Flow
IR Spectroscopy: Molecular Vibration Overview
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...
Viscosity
The SI unit of viscosity is...

