Related Experiment Video
Updated: Jul 7, 2026
10:39
Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating
Published on: October 11, 2016
Mutual coherence function for a double-passage retroreflected optical wave in atmospheric turbulence
L C Andrews1, R L Phillips, W B Miller
1Department of Mathematics, Center for Research and Education in Optics and Lasers, University of Central Florida, Orlando, Florida 32816, USA.
Applied Optics
|January 20, 1997
Summary
This study analyzes reflected Gaussian beam waves, revealing that spectral models with inner scales enhance amplitude more than Kolmogorov spectra. Finite outer scales reduce beam spreading and peak amplitude for retroreflectors, unlike plane mirrors.
Area of Science:
- Optics
- Wave Propagation
- Atmospheric Turbulence
Background:
- Gaussian beam waves are crucial in optical systems.
- Understanding wave propagation through turbulence is essential for remote sensing and communication.
- Retroreflectors offer unique reflection properties compared to plane mirrors.
Purpose of the Study:
- To calculate and analyze the mutual coherence function of a reflected Gaussian beam wave from a retroreflector.
- To compare results with a plane mirror reflector under different refractive-index spectral models.
- To investigate the impact of spectral model parameters (inner and outer scales) on wave characteristics.
Main Methods:
- Calculation of mutual coherence function using weak fluctuation theory.
- Application of generalized spectral representations with complex ABCD ray matrices.
- Analysis based on two refractive-index spectral models, including a modified spectrum and a pure power-law spectrum.
Main Results:
- Modified spectra with inner scales show greater amplitude enhancement than Kolmogorov spectra.
- Finite outer scales reduce beam spreading and peak amplitude enhancement on the optical axis for retroreflectors.
- Retroreflector coherence radius can be significantly larger than for plane mirrors.
Conclusions:
- Spectral model details, particularly inner and outer scales, significantly influence reflected Gaussian beam wave characteristics.
- Retroreflectors exhibit distinct turbulence-induced effects on beam spreading and coherence compared to plane mirrors.
- The study provides insights into wave propagation in turbulent media for optical system design.
Related Concept Videos
02:18Interference and Diffraction
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
01:07Propagation of Waves
When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
01:07Interference and Superposition of Waves
When two waves of the same nature occur in the same region simultaneously, they result in interference. Interference of waves implies that the net effect of the waves is the sum of the individual waves' effects. However, it does not imply that the individual waves affect the propagation of other waves.
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
01:07Reflection of Waves
When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at a distance from a cliff and hears the echo of their voice. The sound waves (longitudinal waves) traveling in the air are reflected from the bounding cliff. Similarly, flipping one end of a string whose other end is tied to a wall causes a pulse (transverse wave) to travel through the string, which gets reflected upon reaching the wall. In...
01:30Propagation Speed of Electromagnetic Waves
Electromagnetic waves are consistent with Ampere's law. Assuming there is no conduction current Ampere's law is given as:
01:05Doppler Effect - II
The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on the Doppler effect. Typically, a transmitter emits radio waves at a specific frequency toward the sky from a weather station. The radio waves bounce off the clouds and precipitation and travel back to the weather station. The radio frequency of the waves reflected back to the station appears to decrease if the clouds or precipitation are moving...