Compact on-chip temperature sensors based on dielectric-loaded plasmonic waveguide-ring resonators

Area of Science:

• Photonics and Plasmonics
• Optical Sensing Technologies

Background:

• Surface plasmon-polariton (SPP) waveguides offer unique light confinement properties.
• Ring resonators are sensitive to changes in their optical environment.
• Integrating SPP waveguides with ring resonators creates novel sensing platforms.

Purpose of the Study:

• To demonstrate and analyze a dielectric-loaded SPP waveguide-ring resonator as a temperature sensor.
• To investigate the impact of temperature variations on the transmission characteristics of the system.
• To evaluate the performance and sensitivity of the proposed temperature sensor.

Main Methods:

• Fabrication of a waveguide-ring resonator system using dielectric-loaded SPP waveguides.
• Comprehensive analysis of transmission spectra under varying temperature conditions.
• Characterization of the sensor's footprint and sensitivity at a specific input power.

Main Results:

• Temperature changes induce significant variations in the roundtrip phase within the ring resonator, altering transmission.
• The primary mechanism for transmission variation is the temperature-induced phase shift.
• A sensor with a ~5 μm resonator radius and 500 nm gap achieved a temperature sensitivity of ~10⁻² K.

Conclusions:

• The demonstrated waveguide-ring resonator is an effective platform for high-sensitivity temperature sensing.
• The sensor's performance is suitable for practical optical detection limits with moderate input power.
• This technology holds promise for miniaturized and efficient optical temperature measurement devices.