non imaging light transformer 120 which directs light emanating from a fiber optic cable bundle 122 in a particular pattern the function of the light transformer 120 is to reduce 34 transform 34 the divergence angle of the light emerging from the optical fiber 122 to a value that is appropriate for optimal performance in a particular application the principle of operation of a non imaging light transformer is based on the optical 34 etendu 34 principle which states that the product of the area and the square of the sine of the divergence angle is a constant known as the liouville invariant in a closed non absorbing optical system where a and a are the areas of the optical beam and u03b8 1 and u03b8 2 are the divergence angles of the beam at any two points along its propagation path the basic surface contour used in non imaging optics is that of a parabola however in cases with narrow divergence angles a combination of a lens and a modified hyperbolic parabolic surface contour can be used to reduce the length for certain geometries a simple conical surface can be substituted for the hyperbola parabola contour with minimal loss in collection efficiency the light transformer is fabricated from optical grade clear plastic acrylic or other polymethyl methacrylate pmma material depending upon the required surface accuracy four manufacturing techniques can be used in production of a transformer machining thermoforming casting and injection molding preferably the transformer 120 produces a cone shaped light output having a solid angle smaller than.