Abstract: A system, method, and computer program for preserving design intent of a Non-Uniform Rational B-spline (NURBS) surface without representation of a parent surface, comprising representing an output surface having control points that is independent from a refinement of the surface; interpolating a base surface from the output surface; calculating a delta vector that is a difference between the output surface and the base surface; and transforming the delta vector based upon a local coordinate system of a normal vector and a tangent plane of the base surface and appropriate means and computer-readable instructions.

Abstract: A system, method, and computer program for preserving design intent of a Non-Uniform Rational B-spline (NURBS) surface without representation of a parent surface, comprising representing an output surface having control points that is independent from a refinement of the surface; interpolating a base surface from the output surface; calculating a delta vector that is a difference between the output surface and the base surface; and transforming the delta vector based upon a local coordinate system of a normal vector and a tangent plane of the base surface and appropriate means and computer-readable instructions.

Abstract: A method for designing an avalanche photodiode for high bit rate or high speed applications is disclosed. The photodiode is made up of a multiplication layer of a first semiconductor material, an absorption layer of a second semiconductor material and a field control layer of a third semiconductor material having. The field control layer has a moderate doping of a first type dopant and is intermediate between the multiplication and absorption layers. A central region of the multiplication layer is diffused with a second type dopant which results in a diffused region having a greater thickness in the center than in the periphery of the diffused region.