Optical system and optical combination

An optical system comprising:

• an extended illumination source configured to emit light from an extended emission surface thereof toward a display panel, the emitted light comprising substantially distinct blue, green and red emission spectra comprising respective blue, green and red peaks at respective blue, green and red peak wavelengths and corresponding blue, green and red full widths at half maxima (FWHMs), the blue FWHM extending from a smaller blue wavelength to a longer blue wavelength;
• a reflective polarizer disposed on the emission surface of the extended illumination source and comprising a plurality of first polymeric layers numbering at least 10 in total;
• and
• an optical filter disposed between the reflective polarizer and the emission surface of the extended illumination source and comprising a plurality of second polymeric layers numbering at least 10 in total, each of the first and second polymeric layers having an average thickness of less than about 300 nm, such that for a substantially normally incident light:
• for each of the blue, green and red peak wavelengths, the plurality of first polymeric layers reflects greater than about 60% of the incident light having a first polarization state and transmits greater than about 60% of the incident light having an orthogonal second polarization state;
• for each of the green and red peak wavelengths and for each of the first and second polarization states, the plurality of second polymeric layers transmits greater than about 70% of the incident light;
• and
• for each of the first and second polarization states, the plurality of second polymeric layers transmits less at the smaller blue wavelength than at the longer blue wavelength by at least 30%.

An optical combination comprising:

• a reflective polarizer comprising a plurality of first polymeric layers numbering at least in total, each of the first polymeric layers having an average thickness of less than about 300 nm;
• and
• an optical filter disposed in optical communication with the reflective polarizer and comprising a plurality of second polymeric layers numbering at least 10 in total and disposed between opposing outermost polymeric layers, each of the opposing outermost polymeric layers and each second polymeric layer therebetween having an average thickness of less than about 300 nm, a thinnest second polymeric layer in the plurality of second polymeric layers disposed between and spaced apart from the opposing outermost polymeric layers, such that for a substantially normally incident light and a blue wavelength range extending from about 430 nm to about 480 nm, a green wavelength range extending from about 500 nm to about 570 nm, and a red wavelength range extending from about 600 nm to about 680 nm:
• for at least one wavelength in each of the blue, green and red wavelength ranges, the plurality of first polymeric layers reflects greater than about 60% of the incident light having a first polarization state and transmits greater than about 60% of the incident light having an orthogonal second polarization state;
• for each of the first and second polarization states, the plurality of second polymeric layers transmits greater than about 70% of the incident light for the at least one wavelength in each of the green and red wavelength ranges;
• and
• for a UV wavelength range extending from about 410 nm to about 420 nm and for the second polarization state, the pluralities of first and second polymeric layers have respective average transmittances T1 and T2, T1/T2≥1.5.