Ultra-compact, high-Q silicon microdisk reflectors

• Published in: Optics express Vol. 20; no. 20; pp. 21840 - 21846
• Main Authors: Shi, Wei, Yun, Han, Zhang, Wen, Lin, Charlie, Chang, Ting Kai, Wang, Yun, Jaeger, Nicolas A F, Chrostowski, Lukas
• Format: Journal Article
• Language: English
• Published: United States 24.09.2012
• Subjects: Computer-Aided Design; Equipment Design; Equipment Failure Analysis; Lenses; Miniaturization; Refractometry - instrumentation; Silicon - chemistry; Silicon - radiation effects; Surface Plasmon Resonance - instrumentation
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.20.021840

We demonstrate wavelength-selective reflectors based on silicon microdisk resonators integrated with compact Y-branch splitters, using a CMOS-photonics technology. A high quality factor (Q) of ~ 88,000 was measured in the reflection spectrum for a 2.5-μm-radius device with a small footprint of 6 × 17 μm(2) and a wide free-spectral range (FSR) of over 41 nm. As the radius is reduced to 1.5 μm, corresponding to a device footprint of 4 × 15 μm(2), the spectrum shows an ultra-wide FSR of over 71 nm with the compromise of having a reduced Q of ~ 4000. The coupling between a microdisk and a waveguide is numerically investigated. We further propose a multichannel sensing system using cascaded microdisk reflectors.