Related Experiment Video
Updated: Dec 25, 2025
12:18
Microwave Photonics Systems Based on Whispering-gallery-mode Resonators
Published on: August 5, 2013
17.4K
Major reshaping of narrow beams by resonant multilayer structures
Optics Express
|April 1, 2020
Summary
Electromagnetic millimeter-wave (MM-wave) beams significantly change shape when passing through multilayer structures. This reshaping is caused by exciting internal modes, impacting beam width and symmetry, especially with imperfections.
Area of Science:
- Physics
- Materials Science
- Electromagnetism
Background:
- High-quality multilayer structures exhibit unique electromagnetic properties at resonant frequencies.
- The interaction of electromagnetic beams with structured materials can lead to complex phenomena.
- Understanding beam propagation is crucial for developing advanced optical and electronic devices.
Purpose of the Study:
- To demonstrate and investigate the major reshaping of millimeter-wave (MM-wave) beams.
- To understand the underlying mechanism of beam reshaping in multilayer structures.
- To explore the sensitivity of this effect to structural imperfections.
Main Methods:
- Transmission of MM-wave beams through high-quality multilayer structures at resonant frequencies.
- Analysis of the spatial profiles of transmitted beams.
- Investigating the influence of incident beam characteristics and structural properties.
Main Results:
- Demonstrated significant reshaping of MM-wave beams, including increased width and shape distortion.
- Observed that beam reshaping is driven by the excitation of intrinsic quasi-optical modes with complex spatial profiles.
- Found that the effect intensifies with higher-order mode excitation and is highly sensitive to structural imperfections, leading to asymmetry.
Conclusions:
- The excitation of intrinsic modes in multilayer structures causes significant MM-wave beam reshaping.
- This phenomenon is critical for resonant MM-wave and Terahertz (THz) spectroscopy of low-loss dielectric materials.
- The sensitivity to imperfections highlights the need for precise fabrication in practical applications.
Related Concept Videos
01:23Design of Prismatic Beams for Bending
561
The design of prismatic beams, structural elements with a uniform cross-section, focuses on ensuring safety and structural integrity under load. The design process begins by determining the allowable stress, either from material properties tables, or by dividing the material's ultimate strength by a safety factor. This safety factor is essential for accommodating uncertainties, and varies depending on the material—timber, steel, or concrete—with each having unique strength and...
561
01:15Prismatic Beams: Problem Solving
389
In the design of a supported timber beam subjected to a distributed load, both the beam's physical dimensions and the timber's characteristics, such as its grade and species, are critical. These factors determine the allowable stress values, which are crucial for calculating the necessary beam depth to ensure structural integrity and safety.
The design begins with analyzing the beam as a free body to identify moments and force balances, thereby determining support reactions. Next, the...
The design begins with analyzing the beam as a free body to identify moments and force balances, thereby determining support reactions. Next, the...
389
01:11Distribution of Stresses in a Narrow Rectangular Beam
439
In studying beam stress distribution, examining an elemental section is essential. To determine the average shearing stress on this face, the calculated shear is divided by the surface area. Importantly, shearing stresses on the beam's transverse and horizontal planes mirror each other, indicating a consistent stress distribution along the upper region of the beam. Notably, shearing stresses are absent at the beam's upper and lower surfaces due to the absence of applied forces in these...
439
01:19Deflection of a Beam
600
Accurately determining beam deflection and slope under various loading conditions in structural engineering is crucial for ensuring safety and structural integrity. Singularity functions offer a streamlined approach to analyzing beams, especially when multiple loading functions complicate the bending moment equation.
Singularity functions, described in an earlier lesson, are powerful mathematical tools that represent discontinuities within a function commonly encountered in structural loading...
Singularity functions, described in an earlier lesson, are powerful mathematical tools that represent discontinuities within a function commonly encountered in structural loading...
600
02:16Resonance and Hybrid Structures
24.3K
According to the theory of resonance, if two or more Lewis structures with the same arrangement of atoms can be written for a molecule, ion, or radical, the actual distribution of electrons is an average of that shown by the various Lewis structures.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
24.3K
01:15Deformation of a Beam under Transverse Loading
635
Understanding beam deflection, particularly for indeterminate beams with overhanging segments and multiple concentrated loads, is crucial for ensuring structural integrity and functionality. The process begins with constructing an accurate free-body diagram, which helps identify the forces and moments acting on the beam. This diagram is vital for visualizing how bending moments vary along the beam's length, influencing its curvature.
The insights from the bending moment diagram extend to...
The insights from the bending moment diagram extend to...
635