Simplified high-current measurement probe based on a single-mode optical fiber.

Area of Science:

• Optoelectronics
• Fiber Optics
• Current Measurement

Background:

• Accurate measurement of high currents is crucial in various industrial and research applications.
• Traditional current sensors can face limitations in terms of isolation, bandwidth, and electromagnetic interference.
• Fiber optic sensing offers potential advantages due to its inherent electrical isolation and immunity to electromagnetic interference.

Purpose of the Study:

• To design and demonstrate a novel fiber optic probe for measuring mega-ampere currents.
• To investigate the use of a twisted single-mode optical fiber for enhanced current sensing.
• To overcome the challenge of linear birefringence in optical fiber current probes.

Main Methods:

• A fiber optic probe utilizing a 658 nm wavelength light source was designed.
• Linearly polarized light was launched into a manually twisted single-mode optical fiber.
• Intensity variations of the modulated light were detected using a fast photodetector (100 nS rise-time).
• The optical fiber was twisted at a rate of 40 twists per meter to mitigate birefringence.

Main Results:

• The designed probe successfully measured mega-ampere currents.
• The sensitivity of the probe was determined to be 0.247° polarization rotation per kA current-turn product for a single optical fiber loop.
• Manual twisting of the optical fiber effectively compensated for undesired linear birefringence.

Conclusions:

• The developed fiber optic probe is a viable solution for mega-ampere current measurement.
• Twisted single-mode optical fiber is an effective method for overcoming birefringence in such probes.
• The probe demonstrates high sensitivity and potential for practical applications requiring precise high-current monitoring.