Diameter measurement of single-mode fiber by using interferometric and imaging techniques.

Area of Science:

• Optics and Photonics
• Fiber Optics Technology
• Metrology

Background:

• Accurate measurement of optical fiber dimensions is critical for telecommunications and sensing applications.
• Existing methods for cladding diameter measurement may lack precision or require specialized equipment.
• Single-mode fibers require precise characterization for optimal performance.

Purpose of the Study:

• To present two novel, accurate, and accessible methods for measuring the cladding diameter of single-mode fibers.
• To theoretically analyze the fringe formation in an interferometric setup for fiber metrology.
• To demonstrate the potential for high-accuracy measurements with minimal error.

Main Methods:

• Interference fringe measurement: Analyzing fringe spacing at two planes using an interferometeric arrangement.
• Lens-based imaging: Utilizing a lens to image point sources and their magnification for diameter estimation.
• Theoretical analysis: Investigating Gaussian field distribution effects on fringe patterns and Lloyd mirror arrangements.

Main Results:

• Consistent fiber cladding diameter measurements were obtained using both proposed methods.
• The interference method theoretically accounts for Gaussian field distribution effects on fringe maxima and minima.
• The lens-based method demonstrated enhanced accuracy with multiple point sources.
• Standard error for cladding diameter measurements was less than 0.15 µm.

Conclusions:

• The presented interference fringe and lens-based imaging techniques offer reliable and accurate methods for single-mode fiber cladding diameter measurement.
• These methods provide a practical approach for fiber characterization with high precision.
• The findings contribute to advancements in optical fiber metrology and quality control.