Optical Fiber Geometry: Accurate Measurement of Cladding Diameter

Area of Science:

• Metrology
• Optical Engineering
• Materials Science

Background:

• Accurate measurement of optical fiber cladding diameter is critical for telecommunications and data transmission.
• Existing metrology techniques may lack the required precision for advanced fiber optic applications.

Purpose of the Study:

• To develop and validate novel instruments for high-accuracy optical fiber cladding diameter measurement.
• To establish traceable measurement standards for optical fiber dimensions.

Main Methods:

• Development of a contact micrometer for direct diameter measurement.
• Implementation of a scanning confocal microscope for non-contact surface profiling.
• Utilisation of a white-light interference microscope for high-resolution topographical analysis.

Main Results:

• All three developed instruments achieved an estimated uncertainty (3 standard deviations) of 50 nm or less.
• The contact micrometer serves as a primary standard for generating commercially available Standard Reference Materials.
• A potential systematic error of 20 nm was identified for the scanning confocal microscope.

Conclusions:

• The developed instruments provide highly accurate and reliable methods for optical fiber cladding diameter measurement.
• The availability of Standard Reference Materials generated by the micrometer facilitates inter-laboratory comparisons and calibration.
• Further investigation into the systematic error of the confocal microscope is warranted for enhanced metrological traceability.