Danish component maker Ibsen Photonics has developed a monitor for real-time measurement of channel power in dense wavelength-division multiplexing (DWDM) systems. The D-MON uses a diffraction grating to split incoming signals onto a custom diode array, simultaneously measuring the individual intensities of up to 80 optical channels at 50 GHz spacing.
The power monitor is based on Ibsen's Diffractor platform, a patent-pending optical design that enables parallel processing of individual channels. "The secret of the D-MON lies in a combination of compact optical design and grating manufacture," explained Ibsen's vice-president of sales and marketing, Dirk Jessen.
The company manufactures the diffraction gratings in-house using a holographic fabrication technique. Jessen claims the method yields gratings that are fundamentally more noise-free than those produced using rival technologies. Ibsen is currently focusing its efforts on meeting Telcordia criteria and plans to offer qualified devices towards the year's end.
Jessen added: "The gratings are made in pure fused silica; no polymer or sol-gel materials are used. This provides environmentally stable gratings that will easily pass Telcordia tests."
The D-MON, which measures just 70 x 46 x 18 mm, including all control electronics, records the power levels of all channels simultaneously in less than 6 ms. Jessen says the device's athermal design eliminates the need for active temperature compensation, resulting in a power consumption of less than 1 W (as opposed to the 5-10 W typically required for products using active temperature compensation).
Designed for integration into network elements such as amplifiers or dynamic optical add-drop multiplexers, the D-MON enables functions such as gain-tilt monitoring, dynamic gain equalization and channel inventory control.
Ibsen has plans to develop more products based on its Diffractor technology. "The Diffractor platform opens up possibilities for a number of competitive DWDM modules," said Jessen. "We have patents pending on a number of concepts and are actively pursuing partnerships in this respect."
By Tami Freeman, Technology Editor, FibreSystems Europe magazine
• This article originally appeared in FibreSystems Europe June 2002 p11