Highly sensitive silicon photonic temperature sensor based on liquid crystal filled slot waveguide directional...

Area of Science:

• Photonics
• Materials Science
• Sensor Technology

Background:

• Silicon photonic devices are crucial for integrated sensing applications.
• Liquid crystals (LCs) offer tunable optical properties for enhanced sensor performance.
• High-sensitivity temperature sensors are vital for various scientific and industrial fields.

Purpose of the Study:

• To propose and demonstrate a highly sensitive silicon photonic temperature sensor.
• To leverage the strong light-matter interaction in a nano-slot waveguide cladded with nematic liquid crystal (LC).
• To achieve unprecedented temperature sensitivity on a silicon-on-insulator (SOI) platform.

Main Methods:

• Fabrication of a two-mode nano-slot waveguide device on an SOI platform.
• Cladding the waveguide with a nematic liquid crystal (LC), specifically E7.
• Characterization via measurement of optical transmission spectra at varying ambient temperatures.

Main Results:

• Demonstrated high temperature sensitivities of 0.810 nm/°C (room temperature) and 1.619 nm/°C (near 50°C).
• Experimental results closely matched theoretical simulation predictions.
• Achieved the highest experimentally demonstrated temperature sensitivity for silicon-waveguide sensors on SOI.

Conclusions:

• The developed silicon photonic sensor offers exceptional temperature sensitivity.
• The nano-slot waveguide directional coupler design enables submicron spatial resolution and material flexibility.
• This technology is suitable for applications requiring tailored temperature sensitivity and operational ranges.