Highly sensitive and reconfigurable fiber optic current sensor by optical recirculating in a fiber loop

Area of Science:

• Optoelectronics
• Fiber optic sensing technology
• Electromagnetism

Background:

• Traditional current sensors face limitations in sensitivity and reconfigurability.
• Fiber optic current sensors (FOCS) offer advantages but require further sensitivity enhancement.
• Existing FOCS designs often involve complex structures and higher insertion losses.

Purpose of the Study:

• To propose and experimentally validate an advanced fiber optic current sensor (FOCS) with significantly enhanced current sensitivity.
• To demonstrate a coupler-free FOCS design utilizing a recirculating fiber loop architecture.
• To achieve reconfigurable operation for the FOCS, enabling adaptation to various current measurement conditions.

Main Methods:

• Implementation of a recirculating fiber loop architecture using a 2X2 optical switch.
• Utilization of standard single mode fiber (SSMF) as the sensing head.
• Experimental measurement of current sensitivity with different lengths of SSMF (1-Km and 500-m).

Main Results:

• Achieved a current sensitivity of 11.5 degrees/A for a 1-Km SSMF FOCS.
• Obtained a current sensitivity of 21.2 degrees/A for a 500-m SSMF FOCS, representing more than a tenfold enhancement.
• Demonstrated reconfigurable operation through flexible switch control of the recirculating loop.

Conclusions:

• The proposed coupler-free FOCS design significantly enhances current sensitivity through a recirculating fiber loop.
• The sensor's reconfigurable capability allows for versatile application in different current scenarios.
• This advanced FOCS presents a promising solution for practical, high-sensitivity current measurement applications.