Optical design for LED solid state lighting : a guide

has been involved for over 50 years in lens design, optical systems design, electro-optical systems engineering, and photonics. He has been a faculty member at three academic institutions engaged in optics education and research, employed by a number of companies, and provided consulting services. Dr Johnson is an IOP Fellow, SPIE Fellow and Life Member, OSA Fellow, and was the 1987 President of SPIE. He serves on the editorial board of Infrared Physics & Technology and Advances in Optical Technologies. Dr Johnson has been awarded many patents, has published numerous papers and several books and book chapters, and was awarded the 2012 OSA/SPIE Joseph W Goodman Book Writing Award for Lens Design Fundamentals (second edition). He is a perennial co-chair of the annual SPIE Current Developments in Lens Design and Optical Engineering Conference. ## Foreword Until the 1960s the field of optics was primarily concentrated in the classical areas of photography, cameras, binoculars, telescopes, spectrometers, colorimeters, radiometers, etc. In the late 1960s optics began to blossom with the advent of new types of infrared detectors, liquid crystal displays (LCDs), light emitting diodes (LEDs), charge coupled devices (CCDs), lasers, holography, fiber optics, new optical materials, advances in optical and mechanical fabrication, new optical design programs, and many more technologies. With the development of the LED, LCD, CCD, and other electro-optical devices, the term 'photonics' came into vogue in the 1980s to describe the science of using light in the development of new technologies and the performance of a myriad of applications. Today optics and photonics are truly pervasive throughout society and new technologies are continuing to emerge. The objective of this series is to provide students, researchers, and those who enjoy self-education with a wide-ranging collection of books that each focus on a relevant topic in the technologies and applications of optics and photonics. These books will provide knowledge to prepare the reader to be better able to participate in these exciting areas now and in the future. The title of this series is Emerging Technologies in Optics and Photonics where 'emerging' is taken to mean 'coming into existence', 'coming into maturity', and 'coming into prominence'. IOP Publishing and I hope that you find this series of significant value to you and your career. PRELIMS.pdf Preface Author biographies Ching-Cherng Sun Tsung-Xian Lee CH001.pdf Chapter 1 Introduction of LED solid-state lighting 1.1 The past, present, and future of LEDs 1.2 Working principle of LEDs 1.3 Luminous efficiency evaluation of LEDs 1.4 LED die and its package 1.5 Radiometry and photometry 1.6 Four-level optical designs and considerations References CH002.pdf Chapter 2 Basic optics 2.1 Propagation of light 2.2 Complex representation of light waves 2.3 Huygens’ principle 2.4 The speed of light 2.5 Wavefront 2.6 Polarization 2.7 Fresnel equations of reflection Total reflection Total transmission Example 2.1 2.8 Interaction between light and matter Example 2.2 2.9 Basic principle of geometrical optics 2.10 Mirrors and lenses Planar mirrors Elliptical mirrors Hyperbolic mirrors Parabolic mirrors Spherical mirrors Spherical lenses 2.11 Prisms Minimum deviation Reflecting prisms The right-angle prism The Dove prism The Porro prism The penta prism The rhomboid prism 2.12 Gaussian optics Spherical refracting surface 2.13 Thin lens 2.14 Thick lens 2.15 Spherical mirror 2.16 Paraxial ray tracing Example 2.3 Example 2.4 References CH003.pdf Chapter 3 LED die-level light extraction optics 3.1 Challenge in LED light extraction efficiency 3.1.1 Total internal reflection loss 3.1.2 Fresnel reflection loss 3.1.3 Material absorption loss 3.2 Effective solutions for LEE enhancement 3.2.1 Die shaping 3.2.2 Surface roughening/texturing 3.2.3 Patterned sapphire substrate 3.2.4 Photonics crystal 3.3 LED light extraction analytical method and simulation 3.4 Case studies of LEE simulation 3.5 Quantum photon recycling mechanism on LEE 3.6 Current crowding effect on LEE 3.7 Microstructure and light-scattering on LEE References CH004.pdf Chapter 4 LED package-level primary optics 4.1 Optical considerations in LED packaging 4.2 Primary optics for high luminous efficiency 4.3 Primary optics to shape light distribution 4.4 Primary optics for low spatial color deviation 4.5 Phosphor modelling References CH005.pdf Chapter 5 Light source modeling 5.1 Light source characteristics 5.2 The propagation fields 5.3 LED light source modelling 5.4 Case studies of light source modeling References CH006.pdf Chapter 6 LED component-level secondary optics 6.1 Essential principle of optical flux transfer 6.2 Typical optical elements for secondary optics 6.3 High-directional LED illumination 6.4 Angular radiation extension by a diffuser References CH007.pdf Chapter 7 LED system-level LED lighting optics 7.1 LED street/roadway lighting 7.2 LED headlamps 7.3 LED backlight 7.4 Optical design for other applications References Light-emitting diodes (LEDs) are considered the most important light source of the 21st century owing to advantages of energy saving, long life, fast response, high colour performance, and environmental benefit. We believe that accurately understanding the light performances of LEDs and using them skilfully is an important capability for optical designers. This book provides an overview of the light performance of LED SSL and can further effectively apply optical design to SSL at different levels. Optical Design for SSL is classified into four levels including LED die, package, component, and system. All approaches are aimed at teaching readers to precisely determine the spatial and chromatic light performance of an LED and increasing the optical utilization factor of an LED luminaire to achieve optical energy efficiency. Recommended for optical designers, illumination designers, LED optical engineers, students - upper level undergraduate and graduates. Key Features: - Presents an essential guidebook for optical design in LED Lighting - Includes thorough explanations of LED light performance and limitations - Proposes four-level optical design in LED lighting - Includes chapter summaries - Provides a reader-friendly approach to ensure precision