Investigation of the Optical Properties of Silicon-on-Insulator Microring Resonators Using Optical Backscatter Reflectometry

Introduction. Optical backscatter reflectometry is one of the most promising methods used to examine characteristic parameters relevant to the design of microring resonators. This method paves the way for experimental determination of the coupling coefficient and propagation loss. However, experimental verification of this technique by comparing the transmission characteristics obtained by reflectometry and those directly measured by an optical vector analyzer has not been carried out.

Aim. To determine the parameters of microring resonators by optical reflectometry and to calculate on their basis the transmission characteristics of microring resonators. To compare the calculated transmission characteristics with those obtained experimentally using a high-resolution vector analyzer.

Materials and methods. The characteristic parameters of silicon-on-insulator microring resonators were investigated using an ultra-high resolution reflectometer. An original algorithm was employed to derive the characteristic parameters of microring resonators from reflectograms. An optical vector analyzer was used to study the transmission characteristics of microring resonators. Numerical modeling of transmission characteristics considering the obtained parameters was carried out according an analytical approach based on partial wave analysis.

Results. The obtained values of the power coupling coefficient κ = 0.167 and propagation losses α = 3.25 dB/cm were used for numerical simulation of the transmission characteristics of a microring resonator. These characteristics were found to agree well with those obtained experimentally. The free spectral range of 88.8 GHz and Q-factor of 45 000 were determined.

Conclusion. An experimental study of the characteristic parameters of silicon-on-insulator microring resonators was conducted using an optical backscatter reflectometer. The performed comparison of the experimental and theoretical transmission characteristics showed good agreement, which indicates the high accuracy of the determined resonator parameters and, as a result, the relevance of the described method.

1. Blumenthal D. J., Heideman R., Geuzebroek D., Leinse A., Roeloffzen C. Silicon Nitride in Silicon Photonics. Proc. IEEE. 2018, vol. 106, no. 12, pp. 2209– 2231. doi: 10.1109/JPROC.2018.2861576

2. Marpaung D., Yao J., Capmany J. Integrated Microwave Photonics. Nature Photon. 2019, vol. 13, no. 2, pp. 80–90. doi: 10.1038/s41566-018-0310-5

3. Xu Q., Lipson M. All-Optical Logic Based on Silicon Micro-Ring Resonators. Optics Express. 2007, vol. 15, no. 3, pp. 924–929. doi: 10.1364/OE.15.000924

4. Van V., Ibrahim T. A., Ritter K., Absil P. P., John-son F. G., Grover R., Goldhar J., Ho P. T. All-Optical Nonlinear Switching in GaAs-AlGaAs Microring Resonators. IEEE Photonics Technology Letters. 2002, vol. 14, no. 1, pp. 74–76. doi: 10.1109/68.974166

5. Naweed A. Photonic Coherence Effects from Dual-Waveguide Coupled Pair of Co-Resonant Microring Resonators. Optics Express. 2015, vol. 23, no. 10, pp. 12573–12581. doi: 10.1364/OE.23.012573

6. Zhang B., Al Qubaisi K., Cherchi M., Harjanne M., Ehrlichman Y., Khilo A. N., Popović M. A. Compact Multi-Million Q Resonators and 100 MHz Passband Filter Bank in a Thick-SOI Photonics Platform. Optics Letters. 2020, vol. 45, no. 11, pp. 3005–3008. doi: 10.1364/OL.395203

7. Qiu H., Zhou F., Qie J., Yao Y., Hu X., Zhang Y., Xiao X., Yu Y., Dong J., Zhang X. A Continuously Tunable Sub-Gigahertz Microwave Photonic Bandpass Filter Based on an Ultra-High-Q Silicon Microring Resonator. J. of Lightwave Technology. 2018, vol. 36, no. 19, pp. 4312–4318. doi: 10.1109/JLT.2018.2822829

8. Qavi A. J., Washburn A. L., Byeon J. Y., Bailey R. C. Label-Free Technologies for Quantitative Multiparameter Biological Analysis. Analytical and Bioanalytical Chemistry. 2009, vol. 394, no. 1, pp. 121–135. doi: 10.1007/s00216-009-2637-8

9. Sinatkas G., Christopoulos T., Tsilipakos O., Kriezis E. E. Electro-Optic Modulation in Integrated Photonics. J. of Applied Physics. 2021, vol. 130, no. 1, p. 010901. doi: 10.1063/5.0048712

10. Xuan Z., Ma Y., Liu Y., Ding R., Li Y., Ophir N., Eu-Jin Lim A., Lo G.-Q., Magill P., Bergman K., Baehr-Jones T., Hochberg M. Silicon Microring Modulator for 40 Gb/s NRZ-OOK Metro Networks in O-Band. Optics Express. 2014, vol. 22, no. 23, pp. 28284–28291. doi: 10.1364/OE.22.028284

11. Dekker R., Usechak N., Först M., Driessen A. Ultra-fast Nonlinear All-Optical Processes in Silicon-on-Insulator Waveguides. J. of Physics D: Applied Physics. 2007, vol. 40, no. 14, p. R249. doi: 10.1088/0022-3727/40/14/R01

12. Nikitin A. A., Ryabcev I. A., Nikitin A. A., Kondrashov A. V., Semenov A. A., Konkin D. A., Kokolov A. A., Sheyerman F. I., Babak L. I., Ustinov A. B. Optical Bistable SOI Micro-Ring Resonators for Memory Applications. Optics Communications. 2022, vol. 511, p. 127929. doi: 10.1016/j.optcom.2022.127929

13. Nikitin A. A., Kondrashov A. V., Vitko V. V., Ryabcev I. A., Zaretskaya G. A., Cheplagin N. A., Konkin D. A., Kokolov A. A., Babak L. I., Ustinov A. B., Kalinikos B. A. Carrier-Induced Optical Bistability in the Silicon Micro-Ring Resonators under Continuous Wave Pumping. Optics Communications. 2021, vol. 480, p. 126456. doi: 10.1016/j.optcom.2020.126456

14. Zhuang S., Feng J., Liu H., Yuan S., Chen Y., Zeng H. Optical Multistability in a Cross-Coupled Double-Ring Resonator System. Optics Communications. 2022, vol. 507, p. 127637. doi: 10.1016/j.optcom.2021.127637

15. Mou B., Boxia Y., Yan Q., Yanwei W., Zhe H., Fan Y., Yu W. Ultrahigh Q SOI Ring Resonator with a Strip Waveguide. Optics Communications. 2022, vol. 505, p. 127437. doi: 10.1016/j.optcom.2021.127437

16. Gottesman Y., Rao E. V. K., Rabus D. G. New Methodology to Evaluate the Performance of Ring Resonators Using Optical Low-Coherence Reflectometry. J. of Lightwave Technology. 2004, vol. 22, no. 6, pp. 1566–1572. doi: 10.1109/JLT.2004.829216

17. Gottesman Y., Rabus D. G., Rao E. V. K., Benkelfat B. E. An Alternative Methodology Based on Spectral Analysis for a Direct Access to Ring Resonator Parameters. IEEE Photonics Technology Letters. 2009, vol. 21, no. 19, pp. 1399–1401. doi: 10.1109/LPT.2009.2025603

18. Van Laere F., Roelkens G., Ayre M., Schrauwen J., Taillaert, D., Van Thourhout D., Thomas Krauss F., Baets R. Compact and Highly Efficient Grating Couplers Between Optical Fiber and Nanophotonic Waveguides. J. of Light-wave Technology. 2007, vol. 25, no. 1, pp. 151–156.

19. Taillaert D., Bienstman P., Baets R. Compact Efficient Broadband Grating Coupler for Silicon-on-Insulator Waveguides. Optics Letters. 2004, vol. 29, no. 23, pp. 2749–2757. doi: 10.1364/OL.29.002749

20. Nikitin A. A., Vitko V. V., Cherkasskii M. A., Ustinov A. B., Kalinikos B. A. Nonlinear Frequency Response of the Multi-Resonant Ring Cavities. Results in Physics. 2020, vol. 18, p. 103279. doi: 10.1016/j.rinp.2020.103279

21. Gerhard D. Integrated Ring Resonators: a Compendium. Germany, Springer, 2021, 490 p.