Enhanced raster scanning assembly

An optical assembly comprising:

• (1) a tunable source of input radiation;
• (2) an optical element that receives at least a portion of the input radiation and comprises:
• a manifold having at least two independent surfaces, in which at least a portion of each independent surface is selected from the group consisting of a reflective structure and a diffractive structure other than a hologram, and the independent surfaces are geometrically configured so that a portion of incident radiation to the manifold is diffracted at least twice in an angular sense that increases a rate of change of an angular deviation of the incident radiation exiting the manifold with respect to optical frequency;
• and
• (3) a scanner which accepts and redirects a portion of the radiation output by the optical element for producing an illumination pattern,
• wherein a diffractive structure of one of said independent surfaces is different from that of another of said independent surfaces.

A method for scanning a radiation beam, the method comprising:

• (1) providing an optical element, the optical element comprising:
• a manifold having at least two independent surfaces, in which at least a portion of each independent surface is selected from the group consisting of a reflective structure and a diffractive structure other than a hologram, and the independent surfaces are geometrically configured so that a portion of incident radiation to the manifold is diffracted at least twice in an angular sense that increases a rate of change of an angular deviation of the incident radiation exiting the manifold with respect to optical frequency;
• and
• (2) directing toward the optical element a tunable source of input radiation so that radiation output from the optical element scans in angle as the source is tuned,
• wherein a diffractive structure of one of said independent surfaces is different from that of another of said independent surfaces.

An optical assembly comprising:

• (1) a tunable source of input radiation,
• (2) an optical element that receives at least a portion of the input radiation and comprises:
• a manifold having at least two independent surfaces, in which at least a portion of each independent surface is selected from the group consisting of a reflective structure and a diffractive structure other than a hologram, and the independent surfaces are geometrically configured so that a portion of incident radiation to the manifold is diffracted at least twice in an angular sense that increases a rate of change of an angular deviation of the incident radiation exiting the manifold with respect to optical frequency;
• and
• (3) a scanner which accepts and redirects a portion of the radiation output by the optical element for producing an illumination pattern,
• wherein one of said independent surfaces has a diffraction grating of 2400 lines/mm and another of said independent surfaces has a diffraction grating of 1800 lines/mm.