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Microwave Photonics Systems Based on Whispering-gallery-mode Resonators
Published on: August 5, 2013
Numerical characterization of whispering-gallery mode optical microcavities
Zhixiong Guo1, Haiyong Quan, Stanley Pau
1Department of Mechanical and Aerospace Engineering, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA. guo@jove.rutgers.edu
Applied Optics
|February 21, 2006
Summary
This study analyzes planar microcavities for optical resonances, finding microdisk size dictates frequency and gap width controls resonance quality. These silicon-based devices offer tunable optical properties for advanced applications.
Area of Science:
- Photonics and Optical Engineering
- Materials Science and Engineering
- Nanotechnology
Background:
- Whispering-gallery mode (WGM) optical resonances are crucial for various photonic devices.
- Planar microcavities offer a scalable platform for WGM resonators.
- Fabrication on Si-based thin films enables integration with microelectronics.
Purpose of the Study:
- To characterize planar microcavities composed of a waveguide and microdisk with a nanoscale gap.
- To investigate the impact of resonator configuration parameters on optical resonance properties.
- To understand the relationship between device geometry and WGM characteristics.
Main Methods:
- Utilized the finite-element method to solve Maxwell's equations for electromagnetic field analysis.
- Simulated electric field and energy density distributions for on-resonance and off-resonance conditions.
- Systematically varied microdisk size, gap width, and waveguide dimensions.
Main Results:
- Observed distinct electric field and energy density distributions for first and second-order resonances.
- Microdisk size was found to be the primary determinant of resonant frequencies and free spectral range.
- Gap width significantly influenced the full width at half-maximum (FWHM), finesse, and quality factor (Q value).
- Increasing gap width from 100 to 300 nm enhanced Q value and finesse while reducing FWHM.
Conclusions:
- Planar microcavities exhibit tunable optical resonances based on geometric parameters.
- Gap engineering is critical for optimizing resonator performance metrics like Q value and finesse.
- Waveguide dimensions also play a role in refining the resonance characteristics.
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