ModCon Mode Controller – Aerospace

For source independent mode control fit the ModCon to your light source and

  • Improve measurement accuracy
  • Ensure stable launch conditions for multimode fiber measurements
  • Meet 85/85 launch conditions required in some aerospace applications.

The ModCon Mode Controller is designed to ensure that whatever source you use to test the loss and bandwidth of your multimode optical fiber network, LED, Laser, OTDR or white light, you launch the same distribution of modes into the fiber. As a result you can eliminate the variations due to the widely different modal characteristics of the sources commonly used in fiber optic measurements and networks.

Measurements of loss and bandwidth in multimode fibers are known to be highly dependent on the modal condition of the light source used for the measurement. For example, OTDR and LS/PM loss measurements can differ significantly simply because an OTDR uses a laser source and not an LED.

Now there is a way to dramatically improve agreement AND ensure you meet international standards at the same time – the ModCon. The ModCon is a passive device which ensures that the correct launch conditions are achieved independent of the light source used. This results in more accurate measurements, better agreement between different test sets, and compliance with international standards. Every ModCon is rigorously tested using Arden’s MPX Modal Explorer to ensure that its output meets the standard regardless of the modal distribution of the input.

ModCon – Aerospace

Our Modal Controllers for Aerospace are available in 50/125µm and 62.5/125µm Graded Index fiber, with either FC, ST, SC or LC connectors.

The Modal Launch Condition for our Aerospace modal controllers is specified in terms of the width of the Near Field Pattern at 5, 15 and 75% of the maximum. The specification limits are shown below. A Certificate of Conformance or a Test Certificate (850 and 1300nm) giving details of how it was measured are available as options.

Launch condition for Modal Controllers in 62.5/125µm fiber

Intensity (% of max)Maximum value (µm)Minimum value (µm)

Launch condition for Modal Controllers in 50/125µm fiber

Intensity (% of max)Maximum value (µm)Minimum value (µm)


EF plot

Plot of typical source showing compliance with the Near Field Width requirements for 85/85 launch condition

70/70% Limited Phase Space ModCons are also available. The Near Field Width of the intensity profile at the 5% level is 70% of the nominal core diamater.

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