Abstract: An improved method and system of monitoring and identifying microbiota swimming in a fluid or moving across surfaces in a fluid provides a sensitive method for rapidly measuring very small changes in activity, and detecting and identifying individual microbes in relatively large volumes of fluid, even in the presence of detritus. The system comprises a laser station, a sample collector station, a picture taking station and a monitoring station.

Abstract: A holographic head including a collimating element for receiving a coherent beam of radiation non-circular in cross section, an objective element for receiving a radiation beam and focusing it to a spot, and a holographic unit also disposed in the path of the beam. The holographic unit includes a first hologram element for passing the beam at a predetermined diffractive order and sign. The holographic unit further includes a second hologram element inclined at an angle to the first hologram element for providing a beam substantially circular in cross section and at the same diffractive order and opposite sign to compensate for dispersion. The first and second holograms may additionally compensate for collimating or objective element aberrations, respectively.

Abstract: A series of pulses are transmitted to a first laser and the same series of ulses through a time delay network to a second laser. Each laser provides pulses of light through separate diagonal mirrors and through respective transparent holograms. Each light beam is then brought into convergence by respective sides of a wedge shaped reflector and brought into spacially coincident focus by an imaging lens onto the surface of a sample under test. The two hologram transparencies are imaged spacially coincident but separated in time on the face of the sample. Thermal elastic waves produced by laser heating at the sample surface transform into a desired acoustic beam pattern determined by the nature of the wavefronts which the hologram transparency represents. The position of the coincident image on the sample may be moved by varying the time between the two pulses.

Abstract: A two-dimensional serial and field multiplexing holographic scanner is provided which is provided with multiple rows of holograms on the disk to achieve serial multiplexing and with means to shift or tilt an auxiliary reflector to focus the scanning beam on entirely new field points so as to achieve field multiplexing. The provision of both serial and field multiplexing provides a higher resolution scan of the object than otherwise obtainable. The scanner comprises a rotating disc that has recorded on it a plurality of holograms positioned on the disc face in multiple rows. Each hologram is particularly placed on the disc and focused to a specific object point. In a given row, each hologram is focused at a different longitudinal point on the object to be scanned. An auxiliary reflector is also provided, which is positioned in front of the rotating disc and within the outside diameter of the outermost holograms on the disc. The auxiliary reflector may be tilted or shifted by means of a piezo-electric drive.