Semiconductor infrared up-conversion devices

Various infrared up-conversion techniques have been developed, driven by applications including lasing, laser cooling, and infrared imaging. In this review article, we first present a brief overview of existing up-conversion techniques and then discuss in detail one particular approach. Among all types of up-conversion techniques, an integrated semiconductor photodetector-light-emitting diode (PD-LED) up-conversion device is the most promising one for infrared imaging applications. By now, PD-LED devices relying on various mechanisms, using different materials and structures, aiming at different wavelength regions, have been developed, and pixelless infrared imaging prototype devices have been demonstrated. We report the progress of semiconductor PD-LED up-conversion devices, and point out directions for future improvement.