Intensity-modulated bend sensor by using a twin core fiber: theoretical and experimental studies

Area of Science:

• Photonics
• Optical Sensing
• Fiber Optics

Background:

• Optical fiber sensors are crucial for remote and precise measurements.
• Existing bend sensors face limitations in sensitivity and adaptability.
• Twin-core fiber (TCF) offers unique light-coupling properties for sensing applications.

Purpose of the Study:

• To propose and demonstrate a new optical fiber bend sensor.
• To investigate the bend sensing performance of a TCF-based sensor.
• To explore methods for adjusting sensor sensitivity and measurement range.

Main Methods:

• Fabrication of a sensor by splicing a TCF segment between two SMF segments.
• Utilizing an intensity-modulated method for bend detection.
• Analyzing light coupling and modulation within the TCF due to bending.

Main Results:

• The proposed sensor achieved a sensitivity of +0.671 /m^-1 and a resolution of 0.003 m^-1.
• The sensor demonstrated effective performance in the range of 0 to 1.25 m^-1.
• Sensitivity and measurement range were shown to be adjustable by altering TCF length and sensor configuration.

Conclusions:

• The TCF-based optical fiber bend sensor is a viable and effective sensing technology.
• The sensor's design allows for flexible adjustment of its performance characteristics.
• This sensor holds promise for future development in measuring both large and small bend ranges.