Compensation of Verdet Constant Temperature Dependence by Crystal Core Temperature Measurement

Area of Science:

• Optoelectronics
• Materials Science
• Sensor Technology

Background:

• The Verdet constant in magneto-optical sensors exhibits temperature dependence, impacting AC current and magnetic field measurements.
• Accurate temperature compensation is crucial for reliable extrinsic Faraday sensor performance.

Purpose of the Study:

• To develop and present a method for compensating the temperature dependence of the Verdet constant in polarimetric extrinsic Faraday sensors.
• To enhance the accuracy of AC current and magnetic field sensing by addressing temperature-induced errors.

Main Methods:

• Utilizes the optical activity of a Bismuth Germanate (Bi₁₂GeO₂₀) crystal to sense temperature.
• Measures the temperature of the crystal volume directly influencing the light beam's polarization.
• Integrates temperature sensing within an existing Δ/Σ configuration without requiring major modifications.

Main Results:

• Achieves accurate temperature compensation by directly measuring the temperature of the sensing element.
• Eliminates errors caused by temperature differences inherent in indirect compensation methods.
• Demonstrates applicability to existing sensing devices, improving their performance.

Conclusions:

• The proposed method offers a direct and effective way to compensate for temperature effects on the Verdet constant.
• This technique enhances the precision of magneto-optical sensors for AC current and magnetic field applications.
• The method is compatible with current sensor designs, facilitating performance upgrades.