Design and Optimization of Silicon Photonics Integrated Optical Ring Resonator for Ultra-High Sensitivity Refractive Index Sensor
Keywords:
Optical Ring Resonator, Silicon Photonics, Refractive Index Sensor, FDTD Simulation, High Q-factorAbstract
This study presents the design and optimization of a high-performance optical ring resonator (ORR) integrated on a silicon photonics platform for ultra-sensitive refractive index sensing applications. The research aims to enhance sensitivity, improve the quality factor (Q-factor), and increase the figure-of-merit (FOM) through systematic numerical simulations and geometry optimization. The ORR structure is modeled on a silicon-on-insulator (SOI) platform with a 220-nm silicon device layer and a 2-μm buried oxide (BOX), while key geometrical parameters such as ring radius, waveguide width, and coupling gap are varied to identify optimal operational conditions. Numerical analysis is performed using Finite-Difference Time-Domain (FDTD) and Finite Element Method (FEM), enabling accurate calculation of resonance wavelength, effective index, evanescent-field interaction, transmission spectrum, and mode profile. The simulation results show that a configuration with a 10-μm radius, 450-nm waveguide width, and 180-nm coupling gap achieves an optimal balance between free spectral range, resonance sharpness, and sensing performance. The optimized structure demonstrates a high Q-factor of approximately 25,930 and a narrow full width at half maximum (FWHM) of about 59.8 pm, producing a sensitivity of 350–450 nm/RIU and a high FOM suitable for high-resolution refractometric sensing. The strong evanescent-field confinement provided by the high-index contrast of SOI enables efficient interaction with analytes, resulting in enhanced responsiveness. These findings confirm that the proposed ORR design offers significant performance improvements compared to conventional silicon resonators and holds strong potential for integration in compact biosensing, chemical detection, and environmental monitoring systems. Overall, the optimized ORR structure provides a promising foundation for next-generation ultra-sensitive photonic sensors.
References
Ahmed, S. Z., Hasan, M., Kim, K., et al. (2024). Zero-crosstalk silicon photonic refractive index sensor with subwavelength gratings. Nano Convergence. https://doi.org/10.1186/s40580-024-00446-1
Butt, M. A., et al. (2023). A review of photonic sensors based on ring resonator structures: platforms and sensing applications.
Claes, T., Bogaerts, W & Bienstman, P. (2010). Experimental characterization of a silicon photonic biosensor consisting of two cascaded ring resonators based on the Vernier-effect and introduction of a curve fitting method for an improved detection limit. Optics Express, 18 (22): 22747-22761. https://doi.org/10.1364/OE.18.022747
Erkamim, M., &; Sudipa, I. G. I. (2023). Implementation of Analytic Hierarchy Process Method for Land Selection of Oil Palm Plantations in Riau. 3(October), 76–82.
Fathurrohman, Gilang, and Suparman, H. (2023). Sprayer Tool Design using Mini Misfogger with Solar Panel Power. Agricultural Engineering Innovation Journal, 1(01), 1–11.
Fallahi, V., Kordrostami, Z., & Hosseini, M. (2024). Sensitivity and quality factor improvement of photonic crystal micro-ring resonator sensors by geometrical optimization. Scientific Reports.
Gangwar, R. K., Qin, J & Wang, X. (2022). Porous Silicon–Based Microring Resonator for Temperature and Cancer Cell Detection. Frontiers Physics, 10;1-8. https://doi.org/10.3389/fphy.2022.929033
Guo, R., et al. (2024). High-Q silicon microring resonator with ultrathin sub-structures. APL Photonics, 11(2), 021417.
Hasanuddin, Zahrul, F., Rusdi, M., &; Aryani, S, D. (2021). Weed control equipment on food crops using portable mechanical drives for farmers in Lieue Village, Darussalam Ace Besar District. PEPADU Journal, 2(2), 144–148.
Hu, T., Zhang, W., & Chen, X. (2020). High figure-of-merit optical sensors: A review. Sensors, 20(12), 3416.
Irawan, D., Azhar, A., &; Sahal, M. (2022). Ergonomic design of weeds sprayer based on recycle energy to support palm oil replanting. Journal of Innovation and..., 1(1), 13–20.
Kazanskiy, N. L., Khonina, S. N., & Butt, M. A. (2020). Subwavelength Grating Double Slot Waveguide Racetrack Ring Resonator for Refractive Index Sensing Application. Sensors, 20(12), 3416. https://doi.org/10.3390/s20123416
Kundal, S., et al. (2025). Modeling and enhancing sensing performance of slotted ring resonators using coupled-mode theory. Applied Optics / AO (2025).
Kotb, A., et al. (2025). Silicon-on-silica microring resonators for high-quality applications. Nanomaterials.
Lu, K., Huang, B., Lv, X., Zhang, Z., & Ma, Z. (2024). Ultrasensitive silicon photonic refractive index sensor based on hybrid double slot subwavelength grating microring resonator. Sensors, 24(6), 1929. https://doi.org/10.3390/s24061929
Purba, H. J., &; Tungkot, S. (2022). Indonesian oil palm plantations in the perspective of sustainable development. Indonesian Journal of Social Sciences, 43(1), 81–94. Retrieved from http://jmi.ipsk.lipi.go.id/index.php/jmiipsk/article/view/717/521
Sarkaleh, A. K., Lahijani, B. V., Saberkari, H., & Esmaeeli, A. (2017). Optical Ring Resonators: A Platform for Biological Sensing Applications. Journal of medical signals and sensors, 7(3), 185–191.
Sarwono, E., Subiyanto, Primadiyono, Y., &; Putri, M. (2022). Solar pesticide remover. Electrician-JUrnal Engineering and Technology and Electrical Technology, 16(1), 66–72. https://doi.org/10.23960/elc.v16n1.2228
Sun, S., Chang, M., & Kong, M. (2024). Two-peak envelope spectrum of a subwavelength grating microring resonator for wide-range and high-sensitivity refractive index sensing. Photonics and Nanostructures.
Surya, S. A., Santosa, &; Putri, R. E. (2023). Analysis of the selection of alternative weed control in maize crops in Nagari Aia Gadang, West Pasaman Regency. Andalas Journal of Agricultural Technology, 27(1), 126–135.
Tavakoli, A., Taghizadeh, A., & Mørk, J. (2020). Double-slot subwavelength grating racetrack resonator for ultra-sensitive refractive index sensing. Sensors, 20(12), 3416.
Thomson, D., Zilkie, A., Bowers, J. E., Komljenovic, T., Reed, G. T., & Vivien, L. (2016). Roadmap on silicon photonics. Journal of Optics, 18(7), 073003
Vos, K. D., Bartolozzi, I., Schacht, E., Bienstman, P & Baets, R. (2007). Silicon-On-Insulator Microring Resonator for Sensitive and Label-free Biosensing. Optics Express, 15 (12): 7610-7615.
Wahid, A., Munir, M., &; Hidayatulloh, A. R. (2020). Work Accident Risk Analysis Using HIRARC Method PT. SPI. Journal of Industrial View, 2(2), 45–52. https://doi.org/10.26905/4880
Wang, Z., Xu, X., Fan, D., Wang, Y., & Chen, R. T. (2016). High quality factor subwavelength grating waveguide micro-ring resonator based on trapezoidal silicon pillars. Optics letters, 41(14), 3375–3378. https://doi.org/10.1364/OL.41.003375
Widiyastuti, D A and Kurniawan, A. (2018). Weed Control on Oil Palm (Eaeis gueneensis Jack) Yielding Crops at PT Kharisma Alam Persada Tapin Regency. Journal of Plant Cultivation Perkebubab Panganur Polytechnic, 4(1), 21–26.
Wu, Y., et al. (2023). Design of highly sensitive refractive index sensor based on resonator structures. Optics & Laser Technology (2023).
Xu, Y., Fu, C., & Sun, S. (2022). Wide-range refractive index sensing based on dispersive subwavelength grating microring resonator. Optical and Laser Technology, 154, 108304.
Yang, M., et al. (2024). High-sensitivity and wide-range refractive index sensing with SWG waveguide racetrack microring resonator on SOI. Optics Letters, 49(19), 5603.
Zhu, H., White, I. M., & Suter, J. (2010). High-sensitivity label-free biosensing using optical ring resonators. Biosensors and Bioelectronics, 25(12), 2235–2239.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2025 Wahyu Satrio, Mutiara Dier, Annisa Al Hasna Kurnia
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
