Abstract: A holographic recording of the interference between an object laser beam and a reference laser beam is used to combine the amplitudes of multiple laser beams which are conjugates of the reference beam into a single laser beam which is conjugate of the object beam. An optical device in the form of a prism has an entrance face with a diffusion surface, and an exit face with a light sensitive recording medium. An object beam incident on the diffusion surface is scattered over the recording medium, in interference with a reference beam simultaneously incident at an angle .theta. onto the same medium. Multiple beams, conjugate to the reference beam, incident at angles .theta..+-.4.degree. on the hologram thus created on the recording medium are diffracted by the hologram and caused to combine at the diffusion surface to form a signal output beam, conjugate to the original object beam and having an amplitude which is proportional to the sum of the separate amplitudes of the combined beams.

Abstract: A holographic recording of the interference between an object laser beam and a reference laser beam is used to combine the amplitudes of multiple input laser beams which are conjugates of the reference beam, into a single output laser beam which is a conjugate of the object beam. An optical device in the form of a trapezoidal prism has an entrance top face with a diffusion surface, and an exit base face with a holographic recording made on a light sensitive recording medium of an interference pattern of an object beam incident on the diffusion surface and scattered over the recording medium, in interference with a reference beam simultaneously incident to a side of the prism onto the same medium.

Abstract: Bismaleimide resins based on indane bisphenol and composites formed from such resins.