The Complete Guide to MTP/MPO Fiber Optic Cable Tests
Introduction:MTP/MPO (Multifiber Push-On/Pull-Off) fiber optic cables have become the standard choice for high-density data center and telecommunication applications due to their ability to accommodate multiple fibers within a single connector. Proper testing of MTP/MPO cables is crucial to ensure reliable and efficient data transmission. In this guide, we will provide a comprehensive overview of the tests commonly performed on MTP/MPO fiber optic cables, their purpose, and best practices for accurate and effective testing.
Visual Inspection:
Visual inspection is the initial step in testing MTP/MPO fiber optic cables and involves examining the physical condition of the connectors and cable assemblies. The purpose of visual inspection is to identify any visible defects, contamination, or damage that may affect the performance of the cable. Key aspects of visual inspection include:
Checking the cleanliness of connector end faces using fiber inspection tools.
Inspecting the alignment pins and guide pins for proper alignment and integrity.
Verifying the physical condition of the cable, including strain relief, jacket integrity, and overall cable assembly quality.
Insertion Loss (IL) Measurement:
Insertion loss measurement is a critical test to evaluate the attenuation introduced by the MTP/MPO cable assembly. The purpose of this test is to determine the signal loss incurred during transmission through the cable. The IL measurement involves the following steps:
Connecting the MTP/MPO cable assembly between a calibrated light source and a power meter.
Measuring the power level of the transmitted light and comparing it with the power level received at the other end.
Calculating the insertion loss as the difference between the transmitted and received power levels.
Ensuring that the measured insertion loss falls within acceptable limits specified by industry standards or specific project requirements.
Return Loss (RL) Measurement:
Return loss measurement evaluates the amount of light reflected back towards the source due to reflections and mismatches within the MTP/MPO cable assembly. The purpose of this test is to assess the quality of the connector interface and the overall performance of the cable. The RL measurement involves the following steps:
Connecting the MTP/MPO cable assembly to an optical time-domain reflectometer (OTDR) or a return loss test set.
Emitting a light pulse into the cable and measuring the amount of light reflected back.
Calculating the return loss as the ratio of the reflected power to the incident power, typically expressed in decibels (dB).
Verifying that the measured return loss meets the specified requirements to ensure minimal signal reflections.
Polarization Extinction Ratio (PER) Measurement:
Polarization extinction ratio measurement is specific to MTP/MPO cables used in polarization-dependent applications, such as parallel optics. The purpose of this test is to assess the uniformity of polarization across the fiber cores within the MTP/MPO cable assembly. The PER measurement involves the following steps:
Utilizing a polarization-sensitive device, such as a polarimeter or an optical spectrum analyzer.
Measuring the power level of light transmitted through the cable while rotating the input polarization.
Calculating the polarization extinction ratio as the ratio of the maximum power to the minimum power, typically expressed in decibels (dB).
Verifying that the measured polarization extinction ratio meets the specified requirements to ensure consistent polarization performance.
End-face Geometry Inspection:
End-face geometry inspection assesses the physical condition and geometric characteristics of the connector end faces within the MTP/MPO cable assembly. The purpose of this test is to evaluate the connector's compliance with industry standards and ensure optimal mating and performance.
