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Updated: Jun 5, 2025
12:18
Microwave Photonics Systems Based on Whispering-gallery-mode Resonators
Published on: August 5, 2013
16.9K
Free-space-coupled wavelength-scale disk resonators
Babak Mirzapourbeinekalaye1, Sarath Samudrala1, Mahdad Mansouree1
1Department of Electrical and Computer Engineering, University of Massachusetts Amherst, 151 Holdsworth Way, Amherst, MA 01003, USA.
Nanophotonics (Berlin, Germany)
|December 5, 2024
Summary
Researchers developed a new model for optical microresonators, showing stored energy depends on quality factor and directivity. This led to a microdisk design efficiently coupled to free-space waves for applications like sensing and micro-lasers.
Area of Science:
- Optics and Photonics
- Materials Science
Background:
- Optical microresonators with high quality factors are typically difficult to excite with freely propagating optical waves.
- Efficient coupling is crucial for many photonic applications.
Purpose of the Study:
- To present a universal model for optical resonators interacting with freely propagating waves.
- To design and demonstrate a microdisk resonator with efficient free-space coupling.
Main Methods:
- Developed a theoretical model relating resonator stored energy to quality factor and directivity.
- Designed microdisk resonators with periodic protrusions on their circumference.
- Experimentally fabricated and characterized microdisk resonators with high quality factors.
Main Results:
- Demonstrated that stored energy is proportional to the product of quality factor and directivity.
- Showcased microdisk designs with efficient coupling to normally incident plane waves.
- Observed thermally-induced bistability at low input powers (0.7 mW) in a microdisk with Q = 15,000.
Conclusions:
- Wavelength-scale, free-space-coupled microdisks offer strong excitation and are suitable for sensing, emission enhancement, and nonlinear optics.
- The developed model provides a guideline for designing efficient microresonators.
- These microdisks are promising for integrated photonic devices and micro-laser cavities.
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