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Mode-coupling analysis of three-dimensional microdisk resonators by the finite-difference time-domain technique
Xian-Shu Luo1, Yong-Zhen Huang, Qin Chen
1State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China. xsluo@mail.semi.ac.cn
Optics Letters
|April 22, 2006
Summary
Mode coupling in microdisk resonators enhances quality factor. This study shows a peak quality factor for the HE72 mode at a specific substrate refractive index due to fundamental and first-order mode coupling.
Area of Science:
- Photonics and optical engineering
- Materials science
Background:
- Microdisk resonators are key components in integrated photonics.
- Substrate refractive index significantly influences optical mode behavior and quality factor.
Purpose of the Study:
- To investigate quality factor enhancement in a 3D microdisk resonator via mode coupling.
- To analyze the effect of substrate refractive index on resonant modes.
Main Methods:
- Finite-difference time-domain (FDTD) numerical simulation of a 1-microm radius, 0.2-microm thick microdisk.
- Systematic variation of substrate refractive index (n(sub)) from 2.0 to 3.17.
Main Results:
- Fundamental mode (HE71) quality factor decreases with increasing n(sub).
- First-order mode (HE72) quality factor peaks at n(sub) = 2.7 due to mode coupling.
- Observed variations in mode field distributions linked to mode coupling.
Conclusions:
- Mode coupling is a viable mechanism for achieving high-quality-factor modes in microdisks.
- This phenomenon offers potential for designing advanced optical devices with high-refractive-index substrates.
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