APPLICATION OF DIFFRACTION GRATINGS IN THE LASER-DOPPLER ANEMOMETRY

Using diffraction gratings as beam splitters and achromatic imaging optics in LDA systems the fringe spacing becomes independent on the wavelength of the laser source. The possibilities of applying multiline laser diodes and new techniques for the directional velocity discrimination without employing frequency shift techniques are shown. The requirements on the imaging system as well as the advantages of the adjustment insensitivity of the system and reduced mode hopping influence are discussed.