Collimating optical device and system

A light-guide, compact imaging optical system, comprising:

• at least one display light source for producing light waves;
• an optical device composed of a light-waves transmitting material for collimating light waves, the device having at least one light-waves entrance surface, at least two light-waves exit surfaces and a plurality of external surfaces;
• at least two retardation plates each one carried by the optical device on at least a portion of an external surface of the plurality of external surfaces;
• at least one light-waves polarizing beamsplitter disposed at an angle to the at least one of the light-waves entrance or exit surfaces;
• at least two light-waves collimating components, each one covering at least a portion of at least one of the retardation plates;
• at least two light-transmitting substrates, each substrate having at least two major surfaces parallel to each other, edges, light-waves input aperture and at least one partially reflecting surface located in one of the substrates;
• and
• at least one optical element for coupling light-waves from the optical device into the substrates by internal reflection;
• wherein the display light source is positioned adjacent to the entrance surface of the optical device for producing image light-waves to be coupled through the entrance surface into the optical device, and the input aperture of the light-transmitting substrates are positioned adjacent to an exit surface of the optical device.