There are currently 3 terms in this directory beginning with the letter W.
A round piece of semiconductor material, such as silicon or InP. The larger the wafer sizes, the more devices can be produced (at a lower price). The consumer electronics industry uses 12 inch wafers to produce at a very high volume, but the lower volume telecom industry uses 3-6 inch wafers to produce its devices
A device that stabilizes and locks the emission of a lasers into a single wavelength. Without the locker, the laser's wavelength might drift with temperature and other mechanical instabilities.