| Autor: |
Haosen Tan, Weida Zhang, Yudong Chen, Yuhe Xia, Chris Newey, Tso-Min Chou, Nai-Hsiang Sun, Jerome K. Butler, Gary A. Evans |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
IEEE Photonics Journal, Vol 14, Iss 6, Pp 1-10 (2022) |
| Druh dokumentu: |
article |
| ISSN: |
1943-0655 |
| DOI: |
10.1109/JPHOT.2022.3211456 |
| Popis: |
A simple thin film effective index analysis for first-order gratings in Si photonic waveguides is shown to provide highly accurate results for reflected and transmitted power spectrums as long as the waveguide remains single mode and non-radiating. A cover layer can be added to the grating region of a Si photonic waveguide to increase the strength of the grating, modify transition losses from the input waveguide to the grating waveguide region, and/or modify the width of the reflectivity spectrum. For a given grating period, the peak reflection and spectral width of the reflectivity decrease as the duty cycle is decreased or increased from ∼50%. For both radiating and multimode structures, the coupling between all modes, power radiated towards the superstrate (upwards), power radiated downwards (substrate) and transmitted power analyzed by Floquet-Bloch, Eigenmode Expansion and Finite Difference Time Domain methods show excellent agreement. Coupling coefficients calculated using analytic formulas are shown to be accurate only for shallow grating depths. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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