Method of fabricating a light-guide optical element

A method of fabricating a light-guide optical element having a plurality of partially reflecting surfaces comprising:

• providing a plurality of transparent plates, each plate polished on two opposite surfaces such that said surfaces are parallel to each other;
• for each plate of a subset of said plates, coating a first of said surfaces with a first coating and a second of said surfaces with a second coating, each of said first coating and said second coating being a multi-layer dielectric coating configured to provide partially reflective properties;
• bonding together the plurality of transparent plates to form a stack comprising an alternating arrangement of a plurality of coated plates of the subset of plates and uncoated plates such that a partially reflective multi-layer dielectric coating is present at each interface between adjacent plates of said stack;
• and
• cutting the stack along parallel planes non-parallel to said surfaces of the transparent plates so as to form the optical element.

A light-guide optical element comprising:

• a transparent body bounded by a pair of mutually parallel major surfaces that support propagation of light within the body by internal reflection at said major surfaces;
• and
• a plurality of mutually parallel planar partial reflectors, internal to the transparent body, located between said major surfaces and non-parallel to said major surfaces,
• wherein at least part of said body is formed from a sequence of plate portions bonded together at planar interfaces, and wherein said partial reflectors are implemented as multi-layer dielectric coatings at said planar interfaces,
• wherein, for a subset of said plate portions, two interface surfaces of the plate portion have multi-layer dielectric coatings that form two sequential partial reflectors, each of said interface surfaces being bonded at a corresponding planar interface to an adjacent uncoated plate portion.