Low cost CWDM optical transceivers

Wavelength division multiplexing (WDM) techniques have been used in long-haul telecommunication systems for about 5 years in order to increase the amount of information carried over a single optical fiber. However, in shorter Premises and Enterprise connections, a single laser/detector transceiver has been the only solution that could meet the size, power, and cost targets. As single fiber connection bandwidth requirements increase in these shorter distance markets, it is difficult to meet these criteria with a single laser transceiver implementation. Course wave division multiplexing (CWDM) is one solution being implemented that has the potential to significantly increase both the capacity and distance of optical connections, while still maintaining a low cost, small form factor, and minimized power. Designing CWDM systems for integration into a small and low cost package suitable for LAN applications has many challenges. These challenges include producing multi-wavelength laser arrays, miniature multiplexers and demultiplexers, passive alignment, and thermal management. The first section of this paper will describe the laser wavelengths and thermal requirements necessary to achieve an 8-channel CWDM system. The second section will describe the optical multiplexer and demultiplexer technologies. The final section will discuss several specific applications and products that CWDM transceiver systems can address.