Optical devices having dichroic beam combiners, optical devices for use with dichroic beam combiners, and methods of manufacture therefor

A method for manufacturing an optical device, the method comprising:

• obtaining a plurality of transparent plates;
• applying a polarization-selective coating to a plurality of surfaces associated with the transparent plates to form a plurality of coated surfaces that transmit incident light to the coated surfaces that is polarized in a first polarization direction and reflect incident light to the coated surfaces that is polarized in a second polarization direction orthogonal to the first polarization direction;
• arranging the plates in a stack such that the coated surfaces are mutually parallel;
• slicing the stack to form a slice including at least a first and a second major external surface and a plurality of adjacent sections, each section including exactly two of the coated surfaces between the first and second major external surfaces;
• attaching a first array of retardation plates to the first or second major external surface such that, for each section, a first of the two coated surfaces of the section is associated with a respective one of the retardation plates of the first array of retardation plates;
• attaching a second array of retardation plates to the second or first major external surface such that, for each section, a second of the two coated surfaces of the section is associated with a respective one of the retardation plates of the second array of retardation plates;
• attaching a first array of lenses, deployed in a first orientation, to the first array of retardation plates such that, for each section, the first of the two coated surfaces of the section is associated with a respective one of the lenses of the first array of lenses;
• and
• attaching a second array of lenses, deployed in a second orientation orthogonal to the first orientation, to the second array of retardation plates such that, for each section, the second of the two coated surfaces of the section is associated with at least one first lens, at least one second lens, and at least one third lens of the second array of lenses.

A method for manufacturing an optical device, the method comprising:

• arranging a plurality of coated surfaces in a stack so as to assume a periodic formation that includes a sequence of segments, the sequence of segments including a first segment, and the periodic formation formed by repeating the first segment a set number of times, the first segment including a first coated surface and a second coated surface, each of the coated surfaces configured to transmit certain types of light and reflect other types of light;
• slicing the stack at an oblique angle to the coated surfaces to form a slice having at least two major external surfaces and a plurality of adjacent sections, each section having coated surfaces from one segment of the periodic formation between the two major external surfaces and oblique to the two major external surfaces;
• and
• cutting the slice at least once to form at least one substrate from each section, each substrate of the at least one substrate having at least two major surfaces and coated surfaces from a single segment of the periodic formation embedded between the two major surfaces, wherein coatings used to produce the coated surfaces and the oblique angle are such that, for each substrate of the at least one substrate, light that is transmitted and reflected by the coated surfaces propagates as unguided light through the substrate.