Multilayer optical film, roll of multilayer optical film, backlight, and display system

A multilayer optical film comprising a plurality of alternating polymeric first and second layers numbering at least 20 in total, each of the polymeric first and second layers having an average thickness of less than about 500 nanometers (nm), the polymeric first layers comprising between about 10% and about 50% by weight of polyethylene terephthalate (PET) and between about 50% and about 90% by weight of polyethylene naphthalate (PEN), such that for a substantially normally incident light and for a visible wavelength range extending from about 420 nm to about 680 nm, the plurality of alternating polymeric first and second layers has:

• an average optical transmission of between about 10% and about 30% when the incident light is polarized along an in-plane first direction in the multilayer optical film;
• and
• an average optical transmission of greater than about 60% when the incident light is polarized along an in-plane orthogonal second direction in the multilayer optical film;
• wherein, for a p-polarized incident light propagating in an incident plane that comprises the first direction and for at least one wavelength in an infrared wavelength range extending from about 700 nm to about 960 nm, the plurality of alternating polymeric first and second layers has optical transmissions T1 and T2 for respective incident angles of less than about 10 degrees and greater than about 40 degrees, and wherein T2−T1 is less than about 40%.