How do SPD-Smart dimmable aircraft cabin windows work?
SPD-Smart aircraft windows use SPD film enclosed between thin plastic layers. Within this film are microscopic particles. When no electrical voltage is present, the particles absorb light and block it from passing through the film. When an electrical voltage is applied, the particles align so that light can pass through. Adjusting the voltage to the film provides a range of transparencies (i.e. very dark to fully clear) where light transmission can be rapidly varied to any degree desired depending upon preference or pre-programmed requirements.