Holographic velocimetry of submicron particles

Abstract A new holographic arrangement allowing the recording of submicron particles has been designed. The laser beam is divided in two parts which are recombined so that they illuminate the hologram with the same orientation as with an inline system. Thus it is possible to balance the ratio of the beams and simultaneously to cancel the field aberrations in the image. The information concerning the particle sizes is lost but the use of double-exposure techniques allows to achieve accurate velocity measurements. Some pictures and results are presented. Other applications are described.