Ultra-compact hybrid silicon:chalcogenide waveguide temperature sensor

Area of Science:

• Materials Science
• Optical Engineering
• Sensor Technology

Background:

• Harsh environments require robust temperature monitoring solutions.
• Integrated optical sensors offer high sensitivity and remote sensing capabilities.
• Chalcogenide glasses (ChG) exhibit unique phase change properties useful for sensing applications.

Purpose of the Study:

• To demonstrate a real-time, reusable, and reversible integrated optical sensor for temperature monitoring in harsh environments.
• To leverage the phase change properties of ChG integrated with silicon waveguides for temperature sensing.
• To validate the sensor's performance through experimental measurements.

Main Methods:

• Depositing Ge40S60 ChG onto a single-mode optical waveguide.
• Utilizing the amorphous-to-crystalline phase transition of ChG around 415 °C.
• Measuring transmission power loss changes due to ChG phase transition.
• Demonstrating reversibility by applying an electrical pulse to restore the amorphous phase.

Main Results:

• A significant transmission power drop of over 40dB was observed when Ge40S60 transitioned to its crystalline phase.
• The sensor demonstrated real-time temperature monitoring capabilities.
• The reversible nature of the sensor was confirmed by restoring the amorphous phase using electrical pulses.

Conclusions:

• The integrated optical sensor based on ChG and silicon waveguides is feasible for real-time temperature monitoring in harsh environments.
• The sensor's distinct optical loss change upon phase transition allows for accurate temperature detection.
• The reusability and reversibility of the sensor enhance its practicality for applications such as nuclear reactor cladding monitoring.