Related Experiment Video
Updated: Jan 30, 2026

07:28
Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor
Published on: August 30, 2012
11.2K
Efficient coupling to a waveguide by combined gratings in a holographic waveguide display system
Applied Optics
|January 16, 2019
Summary
This study introduces combined gratings for holographic waveguide displays, improving diffraction efficiency. A VHG+Ag grating design significantly enhances light coupling for more compact and efficient display systems.
Area of Science:
- Optics and Photonics
- Materials Science
- Display Technology
Background:
- Waveguide displays offer compact and lightweight solutions but require improved grating diffraction efficiency.
- Current incoupler and outcoupler designs face limitations in maximizing light energy transfer.
Purpose of the Study:
- To enhance diffraction efficiency in holographic waveguide display systems.
- To investigate combined grating structures for optimized light coupling.
Main Methods:
- Simulated waveguide display systems using a finite element method.
- Developed and applied two design rules: grating vector matching and refractive index matching.
- Investigated combined subwavelength binary gratings and volume holographic gratings (VHGs).
Main Results:
- A VHG+Ag combined grating demonstrated significantly higher diffraction efficiency than other materials.
- Identified optimal design parameters including Bragg wavelength, VHG index modulation, and binary grating properties.
- VHG+Ag-VHG+Ag combined gratings as incouplers and outcouplers further boosted system efficiency.
Conclusions:
- Combined gratings, particularly VHG+Ag, offer a viable path to higher diffraction efficiency in waveguide displays.
- The proposed design rules and material selection are critical for maximizing light energy transfer.
- This research contributes to the development of more efficient and advanced holographic waveguide display systems.
Related Concept Videos
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
1.7K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.7K
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
1.5K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
1.5K
G-protein Coupled Receptors
132.0K
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
132.0K
Spin–Spin Coupling: One-Bond Coupling
1.5K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.5K
Couple
996
A couple is a pair of parallel forces equal in magnitude but in opposite directions. The forces are separated by a perpendicular distance, known as the couple's arm. The couple causes a rotation force or moment that rotates the body about an axis perpendicular to the plane of the forces. The resulting moment is referred to as the couple moment. The SI unit of a couple moment is the Newton-meter (N-m).
A typical example to understand this concept is tightening a bolt with a lug wrench. A...
A typical example to understand this concept is tightening a bolt with a lug wrench. A...
996
Work of a Couple Moment
1.1K
Mechanical engineering involves the study of motion, energy, and force, and is concerned with designing, manufacturing, and maintaining mechanical systems. One important concept in this field is the couple moment, produced by two equal and opposite forces acting at two points in a rigid body separated by a certain distance.
When the rigid body undergoes a differential displacement due to a couple, its motion can be divided into two parts: equal translation of the two points to their final...
When the rigid body undergoes a differential displacement due to a couple, its motion can be divided into two parts: equal translation of the two points to their final...
1.1K

