1. Nonimaging Optical Systems and Their Uses -- 2. Some Basic Ideas in Geometrical Optics -- 3. Some Designs of Image-Forming Concentrators -- 4. Nonimaging Optical Systems -- 5. Developments and Modifications of the Compound -- Parabolic Concentrator -- 6. The Flow-line Method for Designing Nonimaging Optical Systems -- 7. Concentrators for Prescribed Irradiance -- 8. Simultaneous Multiple Surface Design Method -- 9. Imaging Applications of Nonimaging Concentrators -- 10. Consequences of Symmetry (by Narkis Shatz and John C. Bortz) -- 11. Global Optimization of High-Performance Concentrators (by Narkis Shatz and John C. Bortz) -- 12. A Paradigm for a Wave Description of Optical Measurements -- 13. Applications to Solar Energy Concentration -- 14. Manufacturing Tolerances -- Appendices A-M -- APPENDIX A: Derivation and Explanation of the Ætendue Invariant, Including the Dynamical Analogy; -- Derivation of the Skew Invariant -- APPENDIX B: The Edge-Ray Theorem -- APPENDIX C: Conservation of Skew and Linear Momentum -- APPENDIX D: Conservation of Etendue for -- Two-Parameter -- APPENDIX E: Perfect Off-Axis Imaging -- APPENDIX F: The Luneberg Lens -- APPENDIX G: The Geometry of the Basic Compound Parabolic Concentrator Bundles of Rays -- APPENDIX H: The qi/qo Concentrator -- APPENDIX I: The Truncated Compound Parabolic Concentrator -- APPENDIX J: The Differential Equation for the 2D Concentrator Profile with Nonplane Absorber -- APPENDIX K: Skew Rays in Hyperboloidal Concentrator -- APPENDIX L: Sine Relation for Hyperboloid/Lens Concentrator -- APPENDIX M: The Concentrator Design for Skew Rays.