An apparatus for use in replicating an image associated with an input-pupil to an output-pupil, the apparatus comprising: an optical waveguide including a bulk-substrate, an input-coupler and an output-coupler; the bulk-substrate of the optical waveguide including a first major side, a second major side opposite the first major side, and peripheral sides; the input-coupler of the optical waveguide configured to couple, into the bulk-substrate of the optical waveguide, light corresponding to the image associated with the input-pupil; and the output-coupler of the optical waveguide configured to couple, out of the bulk-substrate of the optical waveguide, light corresponding to the image that has traveled through the optical waveguide from the input-coupler to the output-coupler at least in part by way of total internal reflection; wherein one or more of the peripheral sides of the bulk-substrate of the optical waveguide includes first and second surfaces (502 and 504, 602 and 604, 702 and 704) that define first and second planes (512 and 514, 612 and 614, 712 and 714) angled 45 degrees relative to one another, wherein the first surface (502, 602, 702) defines a first chamfered or beveled edge that is between the peripheral side and the first major side; and the second surface (504, 604, 704) defines a second chamfered or beveled edge that is between the peripheral side and the second major side, wherein the output-coupler is configured to diffract a portion of the light corresponding to the image, that is incident on one of the peripheral sides that includes first and second surfaces, out of the output-coupler, wherein, for at least one peripheral side which includes first and second surfaces (702 and 704) that define first and second planes (712 and 714) angled 45 degrees relative to one another: the first surface comprises a multifaceted surface that includes a plurality of peaks and a plurality of valleys; each of the peaks is formed by a pair of adjacent facets of the multifaceted surface that are 90 degrees relative to one another; each of the valleys is formed by a pair of adjacent facets of the multifaceted surface that are 90 degrees relative to one another; the peaks collectively define the first plane; and the second surface is planar and defines the second plane. an optical waveguide including a bulk-substrate, an input-coupler and an output-coupler; the bulk-substrate of the optical waveguide including a first major side, a second major side opposite the first major side, and peripheral sides; the input-coupler of the optical waveguide configured to couple, into the bulk-substrate of the optical waveguide, light corresponding to the image associated with the input-pupil; and the output-coupler of the optical waveguide configured to couple, out of the bulk-substrate of the optical waveguide, light corresponding to the image that has traveled through the optical waveguide from the input-coupler to the output-coupler at least in part by way of total internal reflection; wherein one or more of the peripheral sides of the bulk-substrate of the optical waveguide includes first and second surfaces (502 and 504, 602 and 604, 702 and 704) that define first and second planes (512 and 514, 612 and 614, 712 and 714) angled 45 degrees relative to one another, wherein the first surface (502, 602, 702) defines a first chamfered or beveled edge that is between the peripheral side and the first major side; and the second surface (504, 604, 704) defines a second chamfered or beveled edge that is between the peripheral side and the second major side, wherein the output-coupler is configured to diffract a portion of the light corresponding to the image, that is incident on one of the peripheral sides that includes first and second surfaces, out of the output-coupler, wherein, for at least one peripheral side which includes first and second surfaces (702 and 704) that define first and second planes (712 and 714) angled 45 degrees relative to one another: the first surface comprises a multifaceted surface that includes a plurality of peaks and a plurality of valleys; each of the peaks is formed by a pair of adjacent facets of the multifaceted surface that are 90 degrees relative to one another; each of the valleys is formed by a pair of adjacent facets of the multifaceted surface that are 90 degrees relative to one another; the peaks collectively define the first plane; and the second surface is planar and defines the second plane. the first surface comprises a multifaceted surface that includes a plurality of peaks and a plurality of valleys; each of the peaks is formed by a pair of adjacent facets of the multifaceted surface that are 90 degrees relative to one another; each of the valleys is formed by a pair of adjacent facets of the multifaceted surface that are 90 degrees relative to one another; the peaks collectively define the first plane; and the second surface is planar and defines the second plane.