August 7, 2007 -- Panduit announced that it has earned accreditation from Underwriters Laboratories Inc. (UL) for its capability to measure Differential Mode Delay (DMD) and calculate the Effective Modal Bandwidth (EMBc) of laser optimized multimode fiber.

DMD is the difference in arrival times of the various optical modes that pass through fibers, and is the main parameter by which the performance of a multimode optical fiber system is measured. Fibers with low DMD provide optimal laser bandwidth to support longer distances and higher bit rates required across today's network backbones and storage areas.

Passing DMD testing assures fiber performance for applications such as 10 Gigabit Ethernet and Fibre Channel, which specify the use of low-cost 850-nm laser transmitters with laser-optimized multimode fibers. High-accuracy DMD measurements result in more accurate calculations of EMBc to characterize fiber bandwidth.

Panduit Labs says it conducted significant research into DMD testing to develop a measurement system that would characterize the DMD performance and EMBc of multimode fibers beyond the level achieved by commercially available systems.

During its audit of the new DMD test stand, UL certified that Panduit Labs meets the performance and tolerance specifications outlined by TIA-455-220-A and IEC 60793-1-49 for measuring DMD of multimode fiber.

With its DMD test system, Panduit Labs says it has determined that a good correlation exists between EMBc and measured Bit Error Rate (BER) of multimode fibers operating over 10 Gigabit Ethernet channels.

Panduit will present preliminary results of its research at the International Wire & Cable Symposium (IWCS) in November 2007.