The International Year of Light and Light-Based Technologies 2015 was a global initiative adopted by the United Nations. Numerous cultural, academic, industrial and governmental organizations around the world joined forces to celebrate the light and raise awareness about the many ways in which photonics impact our lives in areas such as energy, education, climate change, health and social welfare. The initiative resulted in thousands of activities that involved millions of people in more than 100 countries around the world. The themes of this volume emerged throughout 2015 as the most relevant and with the greatest interest. It is hoped that this book will become a basic consultation document and an indelible legacy.