There is provided a method for fabricating an optical device having a light wave transmitting substrate with at least two major surfaces and edges, input and output reflecting surfaces carried by the substrate, for producing a substrate allowing light waves to traverse the substrate between the two major surfaces, the method including attaching to each other a plurality of substantially transparent flat plates arranged in a stack, slicing the stack to form a substrate with two major surfaces, and coupling-in and coupling-out reflecting surfaces, with major surfaces being parallel to each other and not parallel to the input or the output surfaces, grinding or polishing the substrate, and cutting the substrate to final dimensions.