Diffractive optical element with off-axis incidence in a structured light application

An optical device, comprising:

• an emitter to emit light;
• and
• a diffractive optical element to transmit one or more diffracted orders of the light including a zero-order beam of the light,
• wherein the zero-order beam and the one or more diffracted orders have a same wavelength,
• wherein the diffractive optical element is arranged such that the light is to be incident on the diffractive optical element at a substantially non-normal angle of incidence,
• wherein the substantially non-normal angle of incidence is designed to cause the diffractive optical element to transmit the zero-order beam outside of a field of view defined by an angular range of the one or more diffracted orders, the angular range being defined with respect to, and inclusive of, a normal of an output surface of the diffractive optical element;
• and
• wherein the diffractive optical element includes a profile that causes the diffractive optical element to transmit the one or more diffracted orders asymmetrically with respect to the zero-order beam in a manner designed to minimize an amount of the light transmitted on a side of the zero-order beam that is opposite the field of view.

An optical system, comprising:

• an emitter to emit light;
• and
• a dot pattern generator to generate a dot pattern,
• wherein the dot pattern is to be generated by a diffractive optical element that transmits one or more diffracted orders of the light within a field of view defined by an angular range of the one or more diffracted orders, the angular range being defined with respect to, and inclusive of, a normal of an output surface of the diffractive optical element,
• wherein the light is to be incident on the diffractive optical element at a substantially non-normal angle of incidence,
• wherein the substantially non-normal angle of incidence is to cause a zero-order beam of the light to be transmitted outside of a field of view associated with the diffractive optical element,
• wherein the diffractive optical element includes a profile that causes the diffractive optical element to transmit the one or more diffracted orders asymmetrically with respect to the zero-order beam in a manner designed to minimize an amount of the light transmitted on a side of the zero-order beam that is opposite the field of view, and
• wherein the zero-order beam and the one or more diffracted orders have a same wavelength.