Design and modeling of eye-shaped double-slot GaAs microring resonator for CO2 sensing

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Pakfetrat F., Bahadoran M., Dabagh S., Chiavaioli F.

Scientific Reports, cilt.15, sa.1, 2025 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 15 Sayı: 1
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1038/s41598-025-17208-6
  • Dergi Adı: Scientific Reports
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, Chemical Abstracts Core, MEDLINE, Veterinary Science Database, Directory of Open Access Journals
  • Anahtar Kelimeler: CO2 detection, Double-slot waveguide, Gas sensor, Microring resonator, Monitoring CO2 levels, VarFDTD method
  • Eskişehir Osmangazi Üniversitesi Adresli: Evet

Özet

Monitoring of CO2 is crucial because of its profound impact on both environmental and human health. A novel highly sensitive refractive index (RI) sensor, utilizing a double-slot microring resonating structure, has been designed and numerically assessed for the sensitive detection of gas media. The structure consisted of a circular microring resonator nested in a racetrack resonating configuration mimicking the structure of an eye-shaped microring resonator (ESMRR). This system was simulated and designed for a GaAs double-slot core waveguide deposited on a suitable Al0.5Ga0.5As substrate. Optical transfer function of ESMRR and related equations were derived using Mason rule, while the numerical analysis was performed using the variational finite difference time domain (var- FDTD) method. The free spectral range (FSR) was extended to 137.68 nm that led to a remarkable bulk sensitivity of 1217.39 nm/RIU and a resolution of 4.93 × 10−6 RIU. The proposed sensing structure was envisioned for CO2 sensing and demonstrated an impressive sensitivity of 24.4 pm/ppm for CO2 detection with an estimated detection limit of 0.82 ppm.