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Updated: Jun 15, 2026
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Microwave Photonics Systems Based on Whispering-gallery-mode Resonators
Published on: August 5, 2013
Mode losses in unstable resonators with rounded edges.
Applied Optics
|March 6, 2010
Summary
Edge rounding in unstable resonators significantly impacts eigenmode losses. Rounding causes mode detachment at lower Fresnel numbers, improving loss behavior and mode separation, especially in cylindrical and circular mirror configurations.
Area of Science:
- Optics and Photonics
- Laser Physics
- Resonator Design
Background:
- Unstable resonators are crucial in laser design.
- Understanding eigenmode losses is key to optimizing resonator performance.
- The effect of mirror edge geometry on resonator stability is not fully understood.
Purpose of the Study:
- To investigate the impact of round-edged mirrors on eigenmode losses in unstable resonators.
- To compare the behavior of round-edged versus sharp-edged mirrors in 2-D and 3-D configurations.
- To analyze the influence of edge rounding on mode detachment and loss characteristics.
Main Methods:
- Utilizing the waveguide approach for analyzing unstable resonators.
- Calculating eigenmode losses for 2-D and 3-D resonators with perfectly reflecting round-edged mirrors.
- Comparing results with sharp-edged mirror configurations.
Main Results:
- Edge rounding in cylindrical resonators leads to mode detachment at lower Fresnel numbers compared to sharp edges.
- Loss behavior in round-edged resonators more closely approximates the geometric optical limit for infinite mirrors.
- In circular resonators, sharp edges prevent mode detachment, while rounding introduces it.
- Edge rounding enhances the spectral separation between the fundamental detached mode and higher-order modes.
Conclusions:
- Mirror edge geometry, specifically rounding, plays a critical role in the stability and loss characteristics of unstable resonators.
- The waveguide approach effectively models these effects, providing insights into resonator design.
- Edge rounding offers a method to improve mode discrimination and potentially enhance laser performance.
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