| 摘要 |
An infrared blurring array is formed of a substrate (42) having thereon a surface array of blurlets (38) whose foci (52) vary in distance from a nominal focal surface location (26), and/or whose optical phases at the nominal focal surface location (26) vary, in a pseudorandom but deterministic manner. The substrate (42) may be made of a meterial transmissive to a waveband of incident infrared energy, and the blurlets (38) are refractive lenslets (39) in the substrate (42), or the blurlets (38) may be mirrorlets (54) in a reflective substrate (42). The blurlets (38) are surfaces each defined by a curvature and an axial offset from a nominal focal surface location (26). At least one, and preferrably both, or the curvature and the axial offset of each blurlet (38) is a value that is randomly selected from a set of values defined by a respective distribution, preferably a truncated distribution. |
