Quantum cascade lasers (QCLs) are semiconductor lasers that are especially good at emitting laser light in the mid-IR to far-IR spectrum. QCL’s have existed since the mid-90’s, and offer enormous potential in biomedical, sensing, R&D, military, and homeland security areas. This report looks at the many applications available for quantum cascade lasers, and provides market assessments and five-year forecasts for these applications.