In geometry, a paraboloid is a quadric surface that has exactly one axis of symmetry and no center of symmetry. The term "paraboloid" is derived from parabola, which refers to a conic section that has a similar property of symmetry. Every plane section of a paraboloid by a plane parallel to the axis of symmetry is a parabola. The paraboloid is hyperbolic if every other plane section is either a hyperbola, or two crossing lines (in the case of a section by a tangent plane).
A light guide module of optical mouse is disclosed. The light guide module comprises a LED die within a light guide input of light guide means. The light guide input comprises an internal paraboloid. Light emitted by the LED die and parallel reflected from the paraboloid is impinged on a light guide output.