WINDOW

1. In fiber optics , a band of wavelengths at which an optical fiber is sufficiently transparent for practical use in communications applications. [After FAA ] Synonyms spectral window, transmission window. See first window , second window , third window . 2. In imagery , a portion of a display surface in which display images pertaining to a particular application can be presented. Note: Different applications can be displayed simultaneously in different windows. 3. A period during which an event can occur, can be expected to occur, or is allowed to occur.