Jefferson Lab is home to the world's most powerful tunable Free-Electron Laser. The FEL uses the same superconducting radiofrequency technology as Jefferson Lab's CEBAF accelerator. The FEL has been used to conduct an extensive range of applied and basic research.Unique to the FEL is the range of light it can produce. This tunability allows scientists to test multiple wavelengths of light. Another innovation that makes Jefferson Lab's FEL unique is its use of the energy-recovery linac, which allows the FEL to recycle energy from its electrons.