Abstract

In the visible region of the spectrum most glasses have positive group-velocity dispersion. The availability of optical elements having adjustable negative dispersion is therefore important to many applications involving extremely short pulses. Such elements, essentially free from loss, can be achieved using prisms.¹ Consider, for example, a pair of identical prisms, arranged antiparallel so that the second one undoes the ray bending of the first. Loss can be minimized by operating so that the rays of interest pass through all the prism faces approximately at Brewster’s angle. This requires that tan(a) = 1/n, where 2a is the apex angle of the prisms and that tan(e) = n, where e is the external angle of incidence of the beam on the prism faces.

© 1984 Optical Society of America