Contents I. Introduction
Nowadays, the need for communication requires the transmission of a huge amount of information which leads to a great demand for the development and expansion of optical data transmission. The wavelength division multiplexing (WDM) process is used to increase the transmission capacity. With this process, multiple optical signals can be carried in a single optical fiber. The key components in the WDM system are the passive optical multiplexers/demultiplexers. Among all, the most suitable are arrayed waveguide gratings (AWG). WDM system uses an AWG multiplexer at the transmitter side to combine the optical signals onto the fiber and an AWG demultiplexer at the receiver side to split the signals again [1].
