A Tellurium Oxide Microcavity Resonator Sensor Integrated On-Chip with a Silicon Waveguide

Area of Science:

• Photonics
• Materials Science
• Sensor Technology

Background:

• Optical microcavity resonators are crucial for sensitive detection.
• Silicon photonics offers a robust platform for integrated photonic devices.
• Tellurium oxide is an emerging material with unique optical properties.

Purpose of the Study:

• To demonstrate thermal and evanescent field sensing using a tellurium oxide optical microcavity resonator.
• To characterize the sensitivity and limit of detection of the fabricated sensor.
• To explore the integration of tellurium oxide into silicon photonics for sensing applications.

Main Methods:

• Fabrication of a silicon-on-insulator waveguide with a circular trench coated in tellurium oxide.
• Characterization of the microcavity resonator's response to temperature changes.
• Measurement of the device's sensitivity to refractive index changes using an evanescent field.

Main Results:

• Achieved a thermal sensitivity of up to 47 pm/°C.
• Obtained an evanescent field sensitivity of 10.6 nm/RIU.
• Demonstrated a limit of detection of 2.2 × 10^-3 RIU.

Conclusions:

• The tellurium oxide microcavity resonator on silicon photonics shows significant potential for integrated sensing.
• The device is suitable for both thermal and biochemical sensing applications.
• This work paves the way for incorporating novel materials into silicon photonic platforms for advanced sensors.