IEC 61755-2-4:2015

Overview

IEC 61755-2-4:2015 is an international standard published by the International Electrotechnical Commission (IEC) that defines connection parameters for non-dispersion shifted single-mode physically contacting fibre optic connectors. Specifically, it focuses on non-angled polished reference connection applications used for attenuation measurements. The standard prescribes dimensional and optical fibre requirements to ensure reliable performance of reference plugs and adaptors in fibre optic interconnecting devices, crucial for consistent and accurate attenuation testing in optical fibre networks.

This standard establishes defined performance grades for reference connectors to be used with single-mode fibres (B1.1, B1.3, and B6 types) according to IEC 60793-2-50. IEC 61755-2-4:2015 is intended primarily for use in quality assurance processes such as shipping and acceptance inspections, where minimal measurement uncertainty is critical.

Key Topics

• Non-angled polished reference connections: Specifies mechanical and optical conditions for reference connectors without angled polishing, ensuring stable low attenuation in connections.
• Performance grades: Defines two attenuation grades (R1 and R2) with maximum permissible insertion losses (≤ 0.1 dB and ≤ 0.2 dB respectively), correlating to specific measurement uncertainty contributions.
• Dimensional limits and fibre specifications: Restricts fibre core locations and angular misalignments, with mode field diameter (MFD) tightly controlled between 9.1 µm and 9.3 µm at 1310 nm wavelength.
• Gaussian light intensity model: Uses Gaussian mode field distribution for evaluating coupling efficiency, ensuring precise assessment of connection quality and attenuation.
• Measurement uncertainty: Provides guidelines for calculating attenuation measurement uncertainty from reference connectors, critical for quality assurance in optical fibre attenuation tests.
• Compatibility: Reference connector plugs comply with fibre types specified in IEC 60793-2-50 but are not recommended for fibre classification difficulties, such as in cable plant construction or maintenance.

Applications

IEC 61755-2-4:2015 is vital for:

• Attenuation measurement setups: Use of reference connector plugs and adaptors to reduce uncertainties in loss measurements of fibre optic links.
• Quality control and inspection: Shipping inspections and acceptance tests where consistency of fibre optic connector performance must be verified.
• Manufacturing calibration: Calibration of testing equipment and reference standards in fibre optic device manufacturing to ensure internationally recognized performance criteria.
• Research and development: Development of new fibre optic connectors meeting stringent low-loss criteria based on well-defined optical interfaces.
• Optical network deployment and maintenance: Ensures optical connectors meet benchmark quality for testing, although the standard advises against use in difficult fibre classification scenarios common in field cable plant works.

By following IEC 61755-2-4:2015, organizations can achieve precision in attenuation testing, aiding in maintaining high-performance optical communication networks worldwide.

Related Standards

• IEC 60793-2-50: Defines product specifications for class B single-mode optical fibres (B1.1, B1.3, B6), used in reference connector plugs.
• IEC 61300-3-4 and IEC 61300-3-42: Provide basic test procedures for attenuation and measurement of single-mode optical connectors and adaptors.
• IEC 61755-2-1 and IEC 61755-2-2: Define connection parameters for non-angled and angled polished single-mode physically contacting fibres, with a broader scope including statistical performance grades.
• IEC TR 62627-04: Technical report illustrating uncertainty calculations in optical connector attenuation measurements.
• IEC 61755-3 (all parts): Covers additional connector parameters for non-dispersion shifted single-mode physically contacting fibres.

Keywords

• Fibre optic interconnecting devices
• Non-angled polished reference connections
• Single-mode connectors
• Reference connector plugs
• Attenuation measurement uncertainty
• Mode field diameter (MFD)
• Physically contacting fibres
• IEC 61755-2-4
• Optical fibre testing
• Fibre optic standards

By adhering to IEC 61755-2-4:2015, manufacturers, testers, and operators of fibre optic systems can ensure precise, repeatable, and internationally harmonized performance of single-mode non-angled reference connectors, facilitating reliable optical network measurement and operation.