Nonimaging optical transformers and their potential applications in fiber optics are dis-cussed. A newly discovered nonimaging optical design is described in detail. The new design known as 01/02 transformer, transforms a Lambertian source with an angular divergence 01 to a Lambertian source with an angular divergence Θ2, while preserving the phase space volume. Its potential applications are in launching light into multi-mode fibers as well as inter-connecting optical fibers. It is particularly in the interconnect problem that very low losses are of critical importance.