Self-referenced temperature sensing with a lithium niobate microdisk resonator

Area of Science:

• Photonics
• Materials Science
• Sensing Technology

Background:

• Thermo-optic birefringence in materials is crucial for optical sensing applications.
• Lithium niobate microdisk resonators offer unique optical properties for device fabrication.
• Accurate and self-referenced temperature sensing is vital across various scientific and industrial fields.

Purpose of the Study:

• To demonstrate self-referenced temperature sensing using thermo-optic birefringence.
• To investigate the performance of a Z-cut lithium niobate microdisk resonator for temperature sensing.
• To achieve high sensitivity and low measurement uncertainty in optical temperature sensing.

Main Methods:

• Utilizing a Z-cut lithium niobate microdisk resonator.
• Exploiting the differential thermo-optic coefficients of ordinary and extraordinary light.
• Analyzing the relative cavity resonance shift of quasi-transverse magnetic (quasi-TM) and quasi-transverse electric (quasi-TE) modes.

Main Results:

• A temperature sensitivity of 0.834 GHz/K was achieved.
• A measurement uncertainty as low as 0.8 mK was demonstrated.
• Effective self-referenced temperature sensing was realized with low optical input power (1.5 μW).

Conclusions:

• The Z-cut lithium niobate microdisk resonator enables robust self-referenced temperature sensing.
• The differential response of quasi-TM and quasi-TE modes provides an intrinsic reference for temperature measurement.
• This approach offers a promising pathway for high-precision, low-power optical temperature sensors.