1:30 PM - 3:30 PM
▲ [19p-PA3-5] Fabrication of High-Q Ring Resonator using n-type GeOI wafer
Keywords:silicon photonics
In the past decades, germanium (Ge) has become one of the most prospective candidates for electronic-photonic integrated circuits because of its superior properties in both electronic and photonic applications compared with silicon (Si). Smaller bandgap of Ge made it suitable for a low-cost photodetector in C-band, and Ge also has good transmission properties in mid-infrared (MIR) range. We demonstrated the Ge CMOS photonics platform which uses a Ge-on-Insulator (GeOI) wafer. With its large refractive index contrast we realized a low bending loss of 0.2 dB/90° even when the radius was 5 mm. A 7-µm-radius ring resonator was also fabricated with an unexpected low Q factor of 170 which was attributed to high propagation loss caused by the free-carrier absorption in p-type Ge. In this work, we used n-type Ge to improve properties of an n-GeOI ring resonator.
We fabricated a 7-µm-radius ring with width of 500 nm for single mode transmission. The Q factor was over 5000 which was around 30 times larger than our previous result. The extinction ratio was over 18 dB. We measured the Ge ring with varied temperatures of 20.0, 25.0, 30.0, 35.0 and 40.0 ℃. The resonance peak shift of the Ge micro ring proportional to the temperature change with dλ/dT of 0.182±0.002 nm/℃ with keeping similar Q factors. This result indicated the feasibility of a high-quality GeOI ring resonator operating at a wavelength of 1.95µm, which will be useful for future MIR communication and sensing systems.
We fabricated a 7-µm-radius ring with width of 500 nm for single mode transmission. The Q factor was over 5000 which was around 30 times larger than our previous result. The extinction ratio was over 18 dB. We measured the Ge ring with varied temperatures of 20.0, 25.0, 30.0, 35.0 and 40.0 ℃. The resonance peak shift of the Ge micro ring proportional to the temperature change with dλ/dT of 0.182±0.002 nm/℃ with keeping similar Q factors. This result indicated the feasibility of a high-quality GeOI ring resonator operating at a wavelength of 1.95µm, which will be useful for future MIR communication and sensing systems.