Optical stack including a grating

A polarizer stack, comprising:

• a grating assembly comprising a first layer and a second layer;
• and
• a polarizer disposed adjacent the grating assembly,
• wherein a first interface between the first layer and the second layer defines a first grating, the first layer has a refractive index n1, the second layer has a refractive index n2, the first grating has a peak to valley height of h1, wherein |n1-n2| multiplied by h1 is between 150 nm and 350 nm and the first grating has a first pitch in a range of 2 micrometers to 50 micrometers, and
• wherein each of the first and second layers are selected from the group consisting of viscoelastic or elastomeric adhesive layers, crosslinked resin layers, and soluble resin layers, and
• wherein the polarizer stack is an integral stack.

An optical stack, comprising:

• a first grating;
• and
• a periodically varying optical film layer disposed adjacent the first grating,
• wherein the first grating has a periodically modulated refractive index, the first grating comprising alternating first and second regions, the first region having a refractive index n1, the second region having a refractive index n2, the first grating having a thickness of h, wherein |n1-n2| multiplied by h is between 150 nm and 10 micrometers, and the first grating has a first pitch in a first direction in a range of 2 micrometers to 50 micrometers, and
• wherein the optical stack is configured to be placed over a display or placed between a backlight and a display panel.

An optical stack, comprising:

• a louver film;
• and
• a first grating adjacent the louver film,
• wherein the first grating has a periodically modulated refractive index, the first grating comprising alternating first and second regions, the first region having a refractive index n1, the second region having a refractive index n2, the first grating has a thickness of h, wherein |n1-n2| multiplied by h is between 150 nm and 10 micrometers and the first grating has a first pitch in a first direction in a range of 2 micrometers to 50 micrometers, and
• wherein the optical stack is an integral stack.