High-Stable Electric Field Integrated Optical Sensor Based on Reduced Lithium Niobate

Area of Science:

• Photonics and Materials Science
• Integrated Optics
• Sensor Technology

Background:

• Lithium niobate (LN) integrated optical devices are crucial for navigation, telecommunications, and sensing.
• Their performance is limited by temperature-dependent instability due to the pyroelectric effect in LN.
• This instability hinders long-term operational reliability.

Purpose of the Study:

• To investigate thermally reduced lithium niobate (LN) as a stable material platform for integrated optical circuits.
• To enhance the stability of integrated optical electric field sensors (IOES).
• To address the limitations imposed by the pyroelectric effect in LN.

Main Methods:

• Fabrication of an integrated optical electric field sensor (IOES) using a Michelson interferometer design.
• Characterization of key performance metrics: optical loss, free spectral range, electro-optical sensitivity, and optical path difference.
• Evaluation of device stability under applied voltage and assessment of calibration accuracy.

Main Results:

• The IOES demonstrated exceptional optical path difference stability with no observable drift over time under normal climatic conditions (0-5 V applied voltage).
• Device calibration showed a predominantly linear response, with a third-degree polynomial model offering a more precise fit.
• A minimum relative error of 0.47% was achieved during calibration, indicating high device accuracy.

Conclusions:

• Thermally reduced LN is a promising material for next-generation integrated optical devices, significantly improving long-term stability.
• Mitigating the pyroelectric effect in LN enhances the reliability of IOES and other photonic components.
• This approach enables the deployment of stable integrated optical systems in demanding, environmentally sensitive applications.