Columbia Free Electron Laser In the past, our group has pioneered the development of free electron lasers (FELs) which have been shown to generate very large amounts of power, tunable from the microwave to the visible spectrum. FEL physics has a close relationship with laser and accelerator physics, and it is the latter which is receiving most of my attention now. In recent years, we have investigated FEL photonics (an important topic in connection with an X-Ray FEL, which starts from photon and particle noise), the production of TW-level FEL short pulses, novel methods of seventh harmonic upconversion of lower frequency FEL radiation, and the "Inverse" FEL, which is a new accelerator that uses a powerful CO2 laser as a drive beam to accelerate electrons. This latter work has been done at Brookhaven National Laboratory, which has a unique accelerator test facility associated with the National Synchrotron Light Source. We have collaborated several times with Brookhaven in the past in projects of mutual interest.