W. M. Keck-Vanderbilt free-electron laser center facilities

The W.M. Keck-Vanderbilt Free-electron Laser Center operates a reliable free-electron laser (FEL) that is used in human surgical trials, as well as in basic and applied sciences. The wavelength of the FEL is tunable from 2.1 μm to 9.6 μm, delivering above 50 mJ per macropulse with a repetition rate of 30 Hz. For soft tissue surgery, especially neurosurgery and surgery on the optic nerve, a wavelength of 6.45 μm has been found to ablate with little collateral damage. The free-electron laser beam is delivered to experiments approximately 2000 hours each year. The Center also supports several other tools useful for biomedical experiments: an optical parametric generator laser system with tunable wavelength similar to the free-electron laser except it has much lower average power; a Fourier transform infrared spectrometer to characterize samples; several devices for in vivo imaging including an optical coherence tomography setup, a two-photon fluorescent confocal microscope, and a cooled, integrating camera capable of imaging luciferin-luciferase reactions within the body of a mouse. The Center also houses a tunable, monochromatic x-ray source based on Compton backscattering of a laser off of a relativistic electron beam.