High-efficiency wide-angle beam steering system

A beam steering system comprising:

• an optical assembly that includes at least one cycloidal diffractive waveplate, each cycloidal diffractive waveplate having three functional layers, in all of which an optical anisotropy axis is parallel to a surface of the cycloidal diffractive waveplate;
• in outer two layers of at least one cycloidal diffractive waveplate, the optical anisotropy axis has an orientation varying linearly with position in a direction perpendicular to the surface of the cycloidal diffractive waveplate;
• in an inner layer of at least one cycloidal diffractive waveplate, the optical anisotropy axis orientation having no variation with position in the direction perpendicular to the surface of the cycloidal diffractive waveplate;
• a twist angle of the optical anisotropy axis orientation in one of the two outer layers of at least one cycloidal diffractive waveplate being equal in magnitude and opposite in sign to the twist angle of the optical anisotropy axis orientation of the other outer layer of the cycloidal diffractive waveplate;
• and
• a controller assembly configured and arranged such that propagation direction of a beam of optical radiation traversing the optical assembly is changed by a selected angle, wherein the optical assembly comprises:
• a first set of N non-switchable cycloidal diffractive waveplates, all of which include lines of constant optical anisotropy axis orientation, the lines being parallel to each other both over an entire area of each non-switchable cycloidal diffractive waveplate, and among all members of the first set of N non-switchable cycloidal diffractive waveplates;
• each member of the first set of N non-switchable cycloidal diffractive waveplates being preceded along a path of optical radiation propagating through the beam steering system by a switchable polarization converter that in one state converts left-hand circularly-polarized optical radiation to right-hand circularly-polarized optical radiation, and right-hand circularly-polarized optical radiation to left-hand circularly polarized optical radiation, and in the other state passes optical radiation without changing its polarization;
• the number N being a positive integer equal to or greater than one.

An optical lens system comprising:

• at least one diffractive waveplate lens having three functional layers, in all of which an optical anisotropy axis is parallel to a surface of the at least one diffractive waveplate lens
• in outer two layers of the at least one of the diffractive waveplate lenses, the optical anisotropy axis orientation varying linearly with position in a direction perpendicular to a surface of the diffractive waveplate lens;
• in an inner layer of the at least one diffractive waveplate lens, the optical anisotropy axis orientation having no variation with position in a direction perpendicular to a surface of the at least one diffractive waveplate lens;
• a twist angle of the optical anisotropy axis orientation in one of the two outer layers of the at least one of the diffractive waveplate lenses being equal in magnitude and opposite in sign to a twist angle of the optical anisotropy axis orientation of the other outer layer of the at least one diffractive waveplate lens;
• a product of thickness and birefringence of the outer two layers of the at least one diffractive waveplate lens being about 30% of a selected operating wavelength of the optical lens system;
• a product of thickness and birefringence of the inner layer of the at least one diffractive waveplate lens being about 63% of the selected operating wavelength of the optical lens system;
• and
• an absolute value of an angle through which the optical anisotropy axis twists in the two outer layers of the at least one diffractive waveplate lens being about 82 degrees.