InGaAs/GaAs and InAs/GaAs quantum dots (QDs) have been identified as suitable candidates for various applications in the terahertz range by using their intraband carrier transitions. These applications include remote sensing of chemical and biological agents, infrared countermeasures, laser radar, pollution monitoring, molecular and solid-state spectroscopy, and noninvasive medical diagnostics. By adjusting the size, shape, and composition of QDs, the atomic-like optical and electronic properties of the QDs can be optimized for specific applications.