WOptical attenuator
WBeam splitter
WDiaphragm (optics)
WDiffractive beam splitter
WGround glass
WLens
WMultifocal diffractive lens
WOptical circulator
WOptical isolator
WOptical microcavity
WPinhole (optics)
WPolarizer
WPrimary mirror
WPrism
WQ-plate
WRetroreflector
WSpatial filter
WSpatial light modulator
WVirtually imaged phased array
WWaveplate
WZone plate