AN-147 Mechanical Shock Testing for Insertion Loss and Return Loss of Optical Connectors and Components

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AN-147 Mechanical Shock Testing for Insertion Loss and Return Loss of Optical Connectors and Components

Overview

 Shock monitoring allows us to evaluate the performance and connectivity of a mated pair of optical connectors through shock events. Many solutions require an optical power meter with an analog output (optical-to-electrical converter) and a sampling device, such as an oscilloscope, to digitally capture and analyze the transient signal. Such solutions require calibration practices to ensure the sampling device and analog signal accurately represent the optical signal levels. The OP740 and supporting software combines this functionality into an all-in-one solution with no need for an external capturing device or excessive focus on calibration.

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AN-146 Analyzing Dynamic Fiber Optic Components Using the OP740: Optical Switches

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  AN-146 Analyzing Dynamic Fiber Optic Components Using the OP740: Optical Switches

Overview

 The OP740 can be used to capture dynamic optical signals. In this example, the OP740 will be used to monitor the switching behavior of two types of optical switches: Mechanical and MEMs based.

AN-146 Figure 1 OP715 + OP720 + OP740 illustration

Figure 1: High-speed multichannel Optical Power Meter and two optical switches.

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AN-145 Measuring ILRL and Verifying Polarity

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  AN-145 Measuring Insertion Loss and Return Loss and Verifying Polarity

Overview

Polarity testing and Insertion Loss (IL) testing are crucial steps in the production and assessment of multi-stranded fiber optic cables. With certain setups, IL can be measured while verifying polarity.

The IL test measures the amount of light lost when traveling through the DUT en route to the detector. A test setup that uses a multichannel source and multichannel power meter evaluates the light paths of a multifiber device under test (DUT) one at a time. If any of the fibers are crossed or broken, light does not reach the OPM on the expected channel resulting in dark values. Using an Insertion Loss and Return Loss (RL) meter as the source instrument and a multichannel power meter as the detector allows for 3-in-1 IL, RL, and polarity evaluation.

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AN-143 Insertion Loss and Return Loss Testing of Short Cables and Assemblies (including TOSA and cassettes)

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AN-143 Insertion Loss and Return Loss Testing of Short Cables and Assemblies (including TOSA and cassettes)

Overview

As fiber optic infrastructure and components are designed more densely and more compactly, patch cords, cassettes, and optical subassembly cables have followed suit by becoming shorter and shorter. These short cables, which can sometimes be just 20cm in length, present certain problems for testing return loss (RL). Most RL meters, whether pulse-based or Optical Continuous Wave Reflectometer (OCWR) based, have difficulty accurately measuring the return loss of these cables. Often, the return loss from the back connector of the device under test interferes with the measurement of the front connector.

MTP saver cable
Figure 1: Short MTP®/MPO - MTP®/MPO cable
AN143 Cassette
Figure 2: LC breakout cassette
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AN-117 Measuring Insertion Loss and Return Loss of Hybrid Cables in OPL-MAX

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AN-117 Measuring Insertion Loss and Return Loss of Hybrid Cables in OPL-MAX

Overview

Obtaining connector-level insertion loss (IL) and return loss (RL) for hybrid cables is complicated by the different connector types on either end of the cable. Hybrid cables cannot simply be flipped to test the reverse direction when the reference and device under test (DUT) connectors are no longer compatible. A test setup comprised of the OP940 IL and RL Meter with two detectors, the OP725 Benchtop Optical Switch, and OPL-Max Application Software solves the compatibility issue and allows for hybrid cable testing with high speed, accuracy, and repeatability.

*Details on how to perform these measurements through the front panel of the OP940 can be found in Application Note AN-111 Measuring Insertion Loss and Return Loss on Hybrid Cables.

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AN-141 Bidirectional Multifiber Insertion and Return Loss Testing Using OP940 and OP721

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AN-141 Bidirectional Multifiber Insertion and Return Loss Testing Using OP940 and OP721

Overview

With 100G Ethernet and beyond quickly becoming the standard for the fiber optics communication industry, many cable manufacturers want to be able to test multifiber cables with relative speed and ease. Using an OP940 and OP721 with OPL-MAX, an operator can test bidirectional insertion loss and return loss on high-fiber-count cables.

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AN-116 Performing ILRL Measurements Using a Single-Channel OP940

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AN-116 Performing Insertion Loss and Return Loss Measurements Using a Single-Channel OP940

Overview

OptoTest’s OP940 allows operators to test Insertion Loss and Return Loss of fiber optic cables accurately and efficiently. Once Insertion Loss and Return Loss references are completed, the unit will automatically update test results on the screen in real-time.

Performing a Reference Measurement

Return Loss Reference

The OP940 references Return Loss by searching for the first large reflection in the reference cable. After such a reflection is found, measurements begin at a distance from the front panel to the unmated end of the cable. It is recommended that an unmated PC connector be used for RL reference (for more information see our White Paper) and that the number of connections between the front panel and the reference connector be minimized to reduce loss and reflectors to the OP940 front panel. The open PC connector should yield approximately 14dB reflection.

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AN-111 Measuring Insertion Loss and Return Loss on Hybrid Cables

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AN-111 Measuring IL/RL on Hybrid Cables

Overview

Testing simplex cables with unmatched connector types poses difficulties because the cable cannot simply be turned around to test the reverse direction. While hybrid bulkheads (SC-FC, ST-FC, etc.) are one option that can solve the problem with only minor issues, in some circumstances hybrid bulkheads will not provide sufficiently accurate measurements. SC-LC cables are one such example. SC-LC bulkheads have high loss and poor repeatability and, as a result, they should not be used in the testing process. Using an OP940 with two detector ports coupled with an OP725 will allow the operator to accurately test hybrid cables of all configurations with the highest accuracy possible.

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AN-137 Preventing Damage to Optical Connectors

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AN-137 Preventing Damage to Optical Connectors

Effects of Damaged Front Panels

"Dirt

Maintaining your equipment’s interface & connectors is absolutely critical to achieving quality results. Damaged instrumentation interfaces and reference cables can add loss and reflections as well as reduce stability, making it difficult to take accurate measurements. In addition to adhering to strict policies regarding cleaning and inspection, one way to maintain instrumentation interfaces and reference cords is to use SAVer cables and extension leads.

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AN-135 Launch Conditions for Multimode Testing

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AN-135 Launch Conditions for Multimode Testing

Overview

An LED light source is required per IEC 61300-3-4 for testing insertion loss on multimode cabling/connectors. When LASER sources are used, outside influences, such as movement and settling in cable as well as changes in temperature, can cause output power instability which can affect insertion loss test results.

Controlling launch conditions is an important part of insertion loss testing. If the launch conditions are not defined or known for the reference lead and optical source, then the results will tend to be skewed depending on whether the launch overfills or underfills the fiber.

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