| opt. |
light chopper; radiation chopper; chopper (provides modulated light); optical modulator; reticle (patterned chopping disk, which consists of opaque and transparent sections; it breaks up the incoming radiation and converts the incident dc signal into an ac signal; the reticle generates error signals and discriminates between large background sources and smaller target signals); light modulator (imposing on a light beam a phase modulation in time and space); light valve (which lets light through or shuts it off according to the state of a cell) |
