The Stanford FEL facility has been serving users since 1986. The Center has grown and matured considerably since then, but the goal has always been to provide the highest-quality beam possible for use as a scientific tool. The data presented here will show the exceptional quality and stability of our FEL beam, and the ease with which it can be adjusted to suit user requirements. The physical infrastructure has also been expanded to provide users with the laboratory space and support they need.
To provide experimenters with precise and stable beams, we have installed feedback loops to control the optical pulse wavelength and amplitude. Variations in wavelength can be reduced to less than 1 part in 10,000 rms, a small fraction of the transform-limited linewidth. Amplitude variations are reduced to less than 2% rms. The micropulse width can be varied to suit the experiment. Pulse lengths from 700 fs to 3 ps have been delivered to users. Since the beam is transform-limited the spectral width varies accordingly. A real-time diagnostic display in every lab room shows the pulse length, spectrum, power, beam position and pointing, all of which are critical for crossed-beam nonlinear optics experiments.
There are 10 experimental rooms at the Stanford Center, each provided with an optical bench and some basic electronics. In addition, the Center has a picosecond dye laser and a sub-picosecond Ti:Sapphire laser which are synchronized to the FEL, a Fourier Transform Infrared Spectrometer and a multi-beam microscope. These facilities, along with a biological sample preparation lab and a modest pool of electronics and optics, greatly reduce the time required for experimenters to gather useful data.