AWG is another way of making into DWDM. A grating formed by a set of optical waveguides arranged in a specific length is used to have the ability to split waves. It is mainly used in the production of high-density wavelength multi-T./demultiplexer (DWDM). Its principle is: first the light source to start using (including a variety of wavelengths of light modulation signal) through the splitting element into several to dozens of roughly equal amplitude sub-sources, and then these sub-sources into the pre-designed length of the array waveguide, so that each white has a specific output phase, and then through the multiple output coupling elements, for a specific wavelength of the light source will be at a specific location to form constructive interference and output The light source of a specific wavelength will form constructive interference at a specific position and output. In this way, the light source (signal) of different wavelengths can be allocated or captured to achieve the purpose of wavelength multi-up / solution multi-up.

AWG is the first component to commercialize the Planar Lightwave Circuit technology. Its approach is to deposit a silicon dioxide (Si02) film layer on a silicon wafer, and then use the micro-imaging process (Photolithography) and reactive ion etching (Reactive lon Etch) to define an array of waveguide and beamsplitting components, etc., and then to cover the uppermost layer with a protective layer to complete. Since AWG uses the same process as general semiconductors, the production cost of multi-channel number is similar to that of low-channel number, but it is more suitable for mass production, and the degree of integration is higher, so it has considerable potential for multi-channel components and future development.