MTP/MPO Fiber Cable Testing Guide

With the rapid development of 5G networks, FTTX (Fiber to the X), and the Internet of Things (IoT), the demand for fiber optic cables is increasing, especially the widespread application of MTP/MPO fiber patch cords in high-speed and high-density data center cabling. In order to ensure the optimal performance of MTP/MPO cabling systems, necessary tests must be performed. This article will introduce the standards and specific test methods for MTP/MPO fiber optic cables in detail.

The fiber optic industry standards are constantly evolving, involving aspects such as fiber types (such as OM3, OM4, OS2, etc.), cable types (such as flame retardancy, bending resistance, etc.), connectors (such as LC, MPO/MTP), and optical security. Before testing, it is necessary to clarify the standards that the fiber optic cable should follow so that its performance can be measured by comparison.

The following are some well-known standard organizations that guide MTP/MPO fiber testing:

• IEC (International Electrotechnical Commission): International standards for fiber geometry, attenuation, macrobending loss, and dispersion.
• TIA/EIA (Telecommunications Industry Association and Electronics Industry Alliance): Develops important national standards for fiber optic test networks and equipment, such as installation certification requirements for fiber length, polarity, and link loss.

  

1. MTP/MPO Connector Testing and Cleaning Methods

The necessity of cleaning in fiber optic testing cannot be ignored. MTP/MPO connectors are very sensitive to dust and contaminants, so they need to be strictly inspected and cleaned before testing. About 80% of network failures are related to connector contamination. Connector cleanliness is a key factor in ensuring network reliability.

Each MPO connector port is a potential failure point, and more fibers mean more fiber end faces, and the risk of contamination and failure increases.

Poor quality or contaminated connectors will result in higher signal loss, and even one damaged connector may affect the performance of up to 24 fibers in the entire MPO link.

The following steps can help you ensure the cleanliness of the connector:

• Use a high-quality microscope to inspect the connector and components.
• If the connector is dirty, clean it first with a dry cleaning tool such as a box cleaner and MTP/MPO pen cleaner.
• If dirt is still present, use a cleaning wipe or foam swab for wet cleaning to ensure that there is no residue on the end face.
• Every time you connect an MTP/MPO cable, be sure to check and clean both ends.

2. MTP/MPO polarity type verification

The MTP/MPO polarity definition refers to the arrangement of optical fibers inside the optical cable to ensure that the transmitter (TX) corresponds correctly to the receiver (RX).

MTP/MPO polarity is very important. Incorrect polarity will cause the signal to be transmitted in the wrong direction, thus affecting network performance. Different polarity schemes (such as A, B, and C types) may flip during connection and installation. Testing is required to confirm the polarity type of the optical cable to ensure that the signal is transmitted along the correct channel.

Failure to identify polarity issues may lead to unnecessary equipment replacement, increased capital expenditures (CAPEX) and operating expenditures (OPEX), and may delay the normal operation of the network.

3. MTP/MPO fiber continuity test

The purpose of the MTP/MPO fiber continuity test is to confirm the integrity of the link, ensure that there is no fiber break, and the optical signal can be smoothly transmitted to the end of the link.

Test the fiber continuity of MTP/MPO cables using a visual fault locator. The visible light emitted by the visual fault locator can help identify and locate fiber link faults such as bends, breaks, and connection faults. When using it, pay attention to eye protection and avoid looking directly at the laser light source.

A simple continuity test with the MTP/MPO fiber continuity test method can quickly identify the problem and avoid wasting time in later troubleshooting.

4. MTP/MPO light source and optical power meter

Light sources and optical power meters are important tools for testing MTP/MPO fiber cables. The light source is used to stimulate the fiber, while the optical power meter is used to measure the power of the optical signal. This method can be used to quantify the insertion loss of the link and ensure the appropriate optical power budget.

Make sure to select an optical power meter that can meet current and future needs, especially in terms of channel count and spacing. For example, the fiber spacing of 12/24 fiber MPO is 2.75mm, while the spacing of 16/32 fiber is 3.75mm.

OTDR Testing

OTDR (Optical Time Domain Reflectometer) can detect, locate and measure events on a fiber link, simplifying the testing of MTP/MPO cables. Simply connect the OTDR device to one end of the fiber to calculate fiber attenuation, uniformity, joint and connector loss, and provide technicians with a graphical record of signal characteristics.

The consumption of MTP/MPO optical cables continues to grow, driven by new technologies and applications. Performing MTP/MPO optical cable testing is an important part of ensuring the performance of optical cables. As technology advances, the methods and equipment for fiber testing will continue to evolve, and more advanced and effective MTP/MPO patch cord testing solutions will appear in the future. In order to achieve high-quality network deployment, it is critical to follow the above best practices.