"Optoelectronics is making an impact multiple times as the semiconductor revolution made on the quality of our life. In telecommunication, entertainment devices, computational techniques, clean energy harvesting, medical instrumentation, materials and device characterization and scores of other areas of R&D the science of optics and electronics get coupled by fine technology advances to make incredibly large strides. Measurements of semiconductor photocurrent (PC) spectra have a long and rich history. During the 1960s and 1970s, the topic became one of the most studied phenomena in semiconductor research so that entire textbooks were dedicated to the subject. In spite these considerable activities, only a few theoretical efforts were published in order to fit PC spectra. Over the recent years, high power diode lasers have seen a tremendous evolution in material epitaxial growth technology, epistructure optimization technique, cavity surface- passivation technology etc. Epitaxial structure is designed for a specific range of operation to optimize a combination of optical, electrical and thermal performance, generally minimizing both operating voltage and internal loss to achieve high efficiency with long cavities for high-average-power and high-brightness applications. Semiconductor Optoelectronic Devices covers recent achievements by specialists around the world. Smart materials and devices are fast emerging and being tested and applications developed in an unimaginable pace and speed. In this book, an attempt is made to capture some of the materials and techniques and underlying physical and technical phenomena that make such developments possible. The wide range of topics related to semiconductor optoelectronics and photonics presented in this book will be of useful to students and other stake holders in the field such as researchers and device designers. "