For 10 points, name this quantity that measures the ability of a lens to collect light.
If using immersion lithography, one can realistically have values for this quantity that are greater than 1, in which case you might prefix it with "hyper-". In optical lithography, the resolution is inversely 3 proportional to this quantity while the depth of focus is inversely proportional to its square. The V number can be simplified to this quantity times core diameter times pi over wavelength. For an optical fiber, this quantity is the square root of the difference between the squared (*) indices of refraction for 6 the core and cladding. In general, it's equal to the index of refraction times the sine of half the cone angle ofthe lens. For 10 points, name this quantity that measures the ability of a lens to collect light.
If using immersion lithography, one can realistically have values for this quantity that are greater than 1, in which case you might prefix it with "hyper-".
numerical aperture [or: NA] 