Patent ID: 7773842
Filing Date: 2010-08-10
Classification: G02B

Abstract:
1. An optical apparatus, comprising: an optical element having a set of at least two diffractive elements, wherein: each diffractive element is arranged to diffract a corresponding component of an incident optical field with a corresponding diffractive element transfer function so that the diffractive element set collectively provides an overall set transfer function between an entrance optical port and an exit optical port; each diffractive element comprises at least one diffracting region and is spatially defined with respect to a corresponding one of a set of diffractive element virtual contours, the diffracting regions having at least one altered optical property so as to enable diffraction of a portion of the incident optical field; the virtual contours of the diffractive element virtual contour set are spatially arranged so that, if diffracting regions of the corresponding diffractive elements were to spatially coincide with the virtual contours, a resulting superposition of the diffracted components at a design wavelength would exhibit maximal constructive interference at the exit port; the set of diffractive elements comprises at least one subset having at least two diffractive elements; and the overall set transfer function is determined at least in part by longitudinal displacement of at least two diffractive elements of at least one of the subsets relative to the corresponding virtual contours.