Compact folded-optics illumination lens

A method for generating an optical beam, comprising the steps of:

• refracting initial light;
• internally reflecting the light;
• again reflecting the light;
• and
• refracting the light producing an output light that is at least partially collimated.

A folded-optics apparatus, comprising:

• a transparent body including a first surface, a second surface and a cavity formed within at least the second surface;
• the cavity having a third surface;
• the second surface comprising a reflective region extending radially away from the cavity;
• and
• the first surface comprising an annular zone configured to provide internal reflection folding and a refractive transition between the transparent body and an exterior of the transparent body.

A method of manufacturing an optical device that convert a first distribution of an input radiation to a second distribution of output radiation, comprising:

• providing a two-dimensional model that describes a first distribution of an input radiation as an input bundle of edge rays and the second distribution of an output radiation as an output bundle of edge rays, and representing the input and output edge ray bundles each in a phase-space representation in terms of the position of each ray in space;
• defining a two-dimensional representation of three active optical surfaces responsive to the boundary conditions of the phase-space representations, including successively calculating segments of at least a first and second surfaces;
• and
• symmetrically extending said two-dimensional representation of said optical surfaces to provide a three-dimensional optical device.