Patent ID: 11927783
Assignee: 3M INNOVATIVE PROPERTIES COMPANY
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 8:
9. The optical system of claim 7, wherein the plurality of polymeric layers comprises a plurality of alternating first and second polymeric layers, for each pair of adjacent first and second polymeric layers:
the first layer has an index n1x along the first polarization state, an index of refraction my along the second polarization state, and an index n1z along a z-axis orthogonal to the first and second polarization states; and
the second layer has an index n2x along the first polarization state, an index of refraction n2y along the second polarization state, and an index n2z along the z-axis, such that for at least one wavelength in a predetermined wavelength range extending at least from about 450 nm to about 600 nm:
a maximum difference between n1x, my and n1z is less than about 0.002; and
a difference between n2x and n1x is greater than about 0.2.