Finisar Delivers World’s First Narrowly Tunable Long-Reach CMLTM Butterfly Transmitters for Metro, Regional, and Long-Haul DWDM Optical Networks

Transmission distance and optical output power are important performance parameters of DWDM optical transmitters. For applications requiring the longest reach, the DM200 transmits with an output power of 0 to 3 dBm and can transmit at 10Gbps over distances of 300 km without requiring costly optical dispersion compensation. For applications requiring high output power, the DM80 can transmit distances up to 120 km with an output power of 4-7 dBm.

Narrow tunability is an important differentiator for OEMs developing transponders for DWDM networks. A 40-channel DWDM link using single-wavelength transmitters, for example, requires that OEMs keep an inventory of 40 different lasers. In addition to increased purchasing and inventory management complexity, large numbers of individualized lasers require a longer lead time to replace when inventories run low, forcing OEMs to maintain large component reserves. Fully tunable transmitters, on the other hand, simplify inventory logistics but command the highest price since it requires the combination of an expensive fully tunable laser source and an external modulator. Narrowly tunable transmitters offer the best of inventory simplification and lower cost. Both the DM80 and DM200 transmitters offer narrow tunability at either 4-channel, 100 GHz DWDM spacing or 8-channel, 50 GHz DWDM spacing across both C-band and L-band, thus reducing the supply chain complexity by a factor of 4x or 8x compared to non-tunable sources.

“The production release of the narrowly tunable versions of both DM80 and DM200 shows Finisar’s commitment to building on its recent CML technology acquisition,” says Dr. Frank Fan, director of marketing at Finisar. “As the only company to offer 10 Gbps long-reach narrow tunability in a standard butterfly box format, Finisar is uniquely positioned to serve the specific needs of the high-end telecom market.”