Extraction of group refractive index of silicon waveguide using two racetrack resonators
- Resource Type
- Conference
- Authors
- Zhu, Xiaoran; Zhang, Enge; Yang, Tongxin; Zhang, Shiqi; Chen, Liuwei; Liu, Zilong; Yang, Xu; Zhang, Lei
- Source
- 2023 21st International Conference on Optical Communications and Networks (ICOCN) Optical Communications and Networks (ICOCN), 2023 21st International Conference on. :1-3 Jul, 2023
- Subject
- Communication, Networking and Broadcast Technologies
Fields, Waves and Electromagnetics
Photonics and Electrooptics
Signal Processing and Analysis
Optical design
Wavelength measurement
Refractive index
Optical resonators
Delay lines
Optical variables control
Silicon
Group refractive index
Racetrack resonator
Free spectral range
Optical delay line
- Language
- ISSN
- 2771-3059
We present the extraction of group refractive index of a silicon waveguide of $450 \mathrm{~nm} \times 220 \mathrm{~nm}$ with a slab of 70 nm using the spectral responses of two racetrack resonators with perimeters of $405.66 \mu \mathrm{m}$ and $505.66 \mu \mathrm{m}$, respectively. We assume a cubic polynomial relation between the effective refractive index and the wavelength. An analytic expression for the group refractive indexes of both straight and bend waveguides can be obtained using the two measured spectra. The calculated $n_{\mathrm{g}}$ at 1550 nm is 3.922. This method offers a simple calibration tool in the optical delay line design.