Abstract: An optical system includes an oriented polymeric multilayer optical film having a first reflection band, and a light source configured to produce light in an output band and/or a sensor configured to receive light in an input band. The light source and/or sensor is in optical communication with the oriented polymeric multilayer optical film. In some cases, the first reflection band overlaps the input and/or output band at normal incidence, but not at an oblique incidence angle. In some cases, the first reflection band overlaps the input and/or output band at an oblique incidence angle, but not at normal incidence. The optical system can further include a non-birefringent optical filter having a first blocking band where the first blocking band overlaps the first reflection band for at least one of normal incidence or an oblique incidence angle.

Abstract: An optical stack including an oriented polymeric multilayer optical film and a non-birefringent optical filter is described. The oriented polymeric multilayer optical film has a first reflection band with a first band edge and the non-birefringent optical filter has a first blocking band. In some cases, the first blocking band contains the first band edge and the first blocking band provides a reduction in variation of a band edge of an overall blocking band of the optical stack.

Abstract: A lightguide having opposing first and second major surfaces where the first major surface includes a plurality of extended features and a plurality of discrete features is described. The lightguide has a viewable area having a length at least 100 times a thickness of the lightguide. The extended features extend in a first in-plane direction across at least 90 percent of the length L of the viewable area. The discrete features are spaced apart along the length and width of the viewable area. The discrete features may be disposed in spaces between the extended features. The discrete features may have faces extending between and connecting adjacent extended features.

Abstract: A lightguide having opposing first and second major surfaces where the first major surface includes a plurality of extended features and a plurality of discrete features is described. The lightguide has a viewable area having a length at least 100 times a thickness of the lightguide. The extended features extend in a first in-plane direction across at least 90 percent of the length L of the viewable area. The discrete features are spaced apart along the length and width of the viewable area. The discrete features may be disposed in spaces between the extended features. The discrete features may have faces extending between and connecting adjacent extended features.

Abstract: An optical stack including an oriented polymeric multilayer optical film and a non-birefringent optical filter is described. The oriented polymeric multilayer optical film has a first reflection band with a first band edge and the non-birefringent optical filter has a first blocking band. In some cases, the first blocking band contains the first band edge and the first blocking band provides a reduction in variation of a band edge of an overall blocking band of the optical stack.