| CPC G02B 5/305 (2013.01) | 13 Claims |

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1. An optical stack comprising:
a reflective polarizer comprising a plurality of interference layers; and
an absorbing polarizer disposed on and substantially co-extensive with the reflective polarizer, such that for a substantially normally incident light and for at least a first wavelength between about 450 nm and about 670 nm:
each interference layer reflects or transmits light primarily by optical interference;
the plurality of interference layers transmits at least about 85% of the incident light having a first polarization state, reflects at least about 80% of the incident light having an orthogonal second polarization state, and transmits less than about 0.1% of the incident light having the second polarization state;
the absorbing polarizer has a first optical transmittance for the first polarization state, an optical absorption greater than about 50% for the second polarization state, and a second optical transmittance for the second polarization state, an average of the first and second optical transmittances greater than about 0.46, the second optical transmittance having a first standard deviation across at least 80% of the absorbing polarizer, the first standard deviation greater than about 0.004; and
the optical stack has an optical transmittance for the second polarization state having a second standard deviation across at least 80% of the optical stack, the second standard deviation less than about 0.001.
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