The invention relates to the soybean variety designated D2011908. In a WDM system, light detection monitors are provided in the light signal input part of an AWG module, and the number of wavelengths to be multiplexed is determined based on the light input powers. The mechanical one-dimensional scanner reflects the transformed light beam from the lens set onto the holographic optical element in one dimension at a time. A bottom contact is formed in the second dielectric layer to electrically connect to the metal layer. In the whole process, a power of a previous timeslot does not need to be introduced, therefore, error accumulation can be avoided, thereby reducing a power control error and improving control precision. An example of a system can allow a user to enter or start a product search request for a relatively broad term in a search engine and quickly start looking for relevant information by assisting the user in narrowing the product search results in a more efficient guided search.