This series will discuss board and system level testing of high speed optical interfaces. Today these interfaces operate up to 10 Gbps over short, medium and long ranges. In the not too distant future, these interfaces will be operating in ranges up to 40 Gbps. There are several factors that can affect the performance of board/system level high speed, serial interfaces, including signal integrity issues in the optics and at the board level, power and other components such as clocks. The application series will provide background on high speed serial interfaces and techniques used to test these interfaces. This background will include a discussion about optical and electrical parameters that are tested and how they could impact the performance of these interfaces. The application series will continue with a discussion of the different test techniques. One aspect of this will include a discussion of the lack of standardization in the measurements that are taken by test equipment. The application series will conclude by talking about future interfaces and what it will take to effectively tests those interfaces.