Variable optical attenuator for use in the visible spectrum

A method for attenuating a laser beam based on the excitation of a surface plasmon is described. This attenuator is continuously variable, has a dynamic range of 10^2, has a spectral range covering the visible, does not steer the beam or distort its profile, and can handle powers of at least 1-W cw. Some preliminary results obtained on a crude prototype are presented; final device design and predicted performance are discussed.