Optical Networking Best Practices Handbook

14.3. RECOMMENDATIONS

Driven by the ever-increasing demand for bandwidth, optical networking is currently a highly attractive market space, and will remain so for several years to come. All along the value chain, from systems to optical components to semiconductors, the optical networking market is providing outstanding growth opportunities. DWDM is one of the key innovations facilitating this market explosion. DWDM allows many wavelengths of light to share the same fiber. Where previously one transmitter and receiver were required per fiber link, current DWDM deployments have as many as 180 wavelengths (laser transmitters and photodiodes) per fiber. Obviously, this translates to a great demand for the necessary optoelectronic devices. Optoelectronics are also used in the design of EDFA modules. An EDFA is an optical amplifier that is used to extensively eliminate the need for OEO signal regeneration within the network. Designers of optical component modules employing optoelectronic devices require effective solutions to their problems. These problems range from tight temperature tolerances for laser-diode modules to having to work with a very wide dynamic range on the input of an EDFA controller. This section will make recommendations with regard to several typical design problems encountered in optical networking, and will explore some of the pros and cons to the available recommendations [5].

14.3.1. Laser-Diode Modules

Figure 14.4 illustrates a simplified example of a DWDM ...