Abstract: The present invention provides a rough surface scattering method and solver for efficiently computing electromagnetic scattered fields resulting from an incident wave (12) being reflected from a surface slowly varying on the scale of the wavelength (10). The wavelength claimed approach to high-frequency scattering is based on the use of expansions of high order in parameter &lgr;, wavelength of the incident radiation. The resulting high-order expansion approach expands substantially on the range of applicability over low order methods, and can be used in some of the most challenging cases arising in applications. The surface current (14) induced by the incident wave (12) is represented as a high-order high-frequency expansion (20). The surface current ansatz is substituted into the surface current integral equation (22), wherein a surface current series expansion is formed (24) having, a high frequency order.

Abstract: A hybrid curvature/tilt wave front sensor (50) that employs both tilt measurements and curvature measurements of the wave front of a light beam (16). The light beam (16) is split into a first path and a second path. The light beam (16) on the first path is directed to a tilt sensor (12) employing a lenslet array (24) having a plurality of lenses (26). The lenses (26) focus separate portions (32) of the wave front onto a CCD (28) that provides local intensity measurements. A computer (30) receives electrical information of the intensity of the various beam portions (32) and computes a tilt measurement based on this information. The light beam (16) on the second path is directed to a curvature sensor (14) that includes a pair of CCDs (40, 42) positioned at the same distance before and after the focal plane of a lens (52). The intensity measurement of the beam (16) at these locations is sent to the computer (30) which performs curvature measurements on the beam wave front.