Experimental ultrafast (femtosecond) continuous dye laser system designed by the Laser Optics group in the Department of Physics at Imperial College, London. Photographed in 1987. The image shows the first continuous femtosecond dye laser operating in the blue green (1987), and the first passively mode-locked colliding pulse Coumarin 102 ring dye laser giving a 90 femtosecond pulse at a wavelength of 497 nanometers - frequency doubling yields seeding pulses for a terawatt KrF amplifier system.