Stacks of optical structures and methods and apparatus for making same

摘要: Stacked optical structures and methods apparatus for making them are provided. The stack has a uniform gap between adjacent in which (1) mixture of adhesive mechanical spacers (2) an filler, or adhesive, is placed. Each stacked structure includes at least two substructures, each mating surface. thickness the equal to maximum diameter spacers. distributed away from axis filler such that passes through it.