An eyepiece for projecting an image to an eye of a viewer, the eyepiece comprising: a waveguide having a surface and configured to propagate light therein; and a diffractive optical element optically coupled to the waveguide , the diffractive optical element including: a plurality of first ridges protruding from the surface of the waveguide and arranged as a periodic array having a period ( D ), each respective first ridge of the plurality of first ridges having a first height (h 1 ) in a direction perpendicular to the surface of the waveguide and a respective first width (w 1 ) in a direction of the period (D); and a plurality of second ridges , each respective second ridge of the plurality of second ridges protruding from a respective first ridge and having a second height (h 2 ) greater than the first height (h 1 ) and a respective second width (w 2 ) less than the respective first width (w 1 ); wherein the diffractive optical element is configured to diffract a first portion of the light propagating in the waveguide toward the eye as a first order reflection , and to diffract a second portion of the light propagating in the waveguide away from the eye as a first order transmission , characterized in that the respective first width (w 1 ) and the respective second width (w 2 ) are selected such that the diffractive optical element has a first order reflection efficiency greater than a first order transmission efficiency. a waveguide having a surface and configured to propagate light therein; and a diffractive optical element optically coupled to the waveguide , the diffractive optical element including: a plurality of first ridges protruding from the surface of the waveguide and arranged as a periodic array having a period ( D ), each respective first ridge of the plurality of first ridges having a first height (h 1 ) in a direction perpendicular to the surface of the waveguide and a respective first width (w 1 ) in a direction of the period (D); and a plurality of second ridges , each respective second ridge of the plurality of second ridges protruding from a respective first ridge and having a second height (h 2 ) greater than the first height (h 1 ) and a respective second width (w 2 ) less than the respective first width (w 1 ); wherein the diffractive optical element is configured to diffract a first portion of the light propagating in the waveguide toward the eye as a first order reflection , and to diffract a second portion of the light propagating in the waveguide away from the eye as a first order transmission , characterized in that the respective first width (w 1 ) and the respective second width (w 2 ) are selected such that the diffractive optical element has a first order reflection efficiency greater than a first order transmission efficiency. a plurality of first ridges protruding from the surface of the waveguide and arranged as a periodic array having a period ( D ), each respective first ridge of the plurality of first ridges having a first height (h 1 ) in a direction perpendicular to the surface of the waveguide and a respective first width (w 1 ) in a direction of the period (D); and a plurality of second ridges , each respective second ridge of the plurality of second ridges protruding from a respective first ridge and having a second height (h 2 ) greater than the first height (h 1 ) and a respective second width (w 2 ) less than the respective first width (w 1 ); wherein the diffractive optical element is configured to diffract a first portion of the light propagating in the waveguide toward the eye as a first order reflection , and to diffract a second portion of the light propagating in the waveguide away from the eye as a first order transmission , characterized in that the respective first width (w 1 ) and the respective second width (w 2 ) are selected such that the diffractive optical element has a first order reflection efficiency greater than a first order transmission efficiency. <EOS>