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Updated: Sep 24, 2025
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Synthesis of Nine-atom Deltahedral Zintl Ions of Germanium and their Functionalization with Organic Groups
Published on: February 11, 2012
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Chiral germanium micro-gears for tuning orbital angular momentum.
Abdelrahman Zaher Al-Attili1,2, Daniel Burt3, Zuo Li3
1Sustainable Electronic Technologies, Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ, UK. abdattili@ieee.org.
Scientific Reports
|May 6, 2022
Summary
Researchers developed germanium micro-gear cavities for vertical light emission with orbital-angular momentum (OAM). These cavities enable controlled generation of OAM signals, paving the way for new optical applications.
Area of Science:
- Optoelectronics
- Photonics
- Materials Science
Background:
- Group IV light sources with vertical emission and orbital-angular momentum (OAM) are crucial for novel applications.
- Whispering-gallery modes (WGMs) in microcavities are key to light manipulation.
Purpose of the Study:
- To demonstrate vertical emission of WGMs with non-zero OAM from germanium micro-gear cavities.
- To investigate the relationship between cavity design and OAM properties.
- To propose methods for controlling OAM chirality.
Main Methods:
- Fabrication of cylindrically symmetrical germanium micro-gear cavities by etching gratings on micro-disks.
- Photoluminescence (PL) measurements to identify WGMs.
- Finite-difference time-domain (FDTD) simulations to analyze modal profiles and characteristics.
Main Results:
- Demonstrated vertical emission of WGMs with non-zero OAM.
- Established a dependence of OAM order on WGM azimuthal order and the number of micro-gear periods.
- Proposed asymmetric cavity designs (staircase/triangular gears) to control OAM chirality.
Conclusions:
- Germanium micro-gear cavities are effective for generating vertically emitted OAM.
- Cavity geometry, including asymmetry, allows for tunable OAM order and chirality.
- This work offers a pathway to engineer OAM light sources for advanced applications.
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