Laser recording - A technology assessment

Wideband laser recording technology is an integral part of systems and concepts which deal with sensors, communications, and computerized data handling. Characteristics of these recorders include very wide bandwidths, high packing densities to reduce the total volume of recording media required, large dynamic range for handling analog signals, low distortion, and very good time base stability. A review of the state of the art in wideband recording indicates that the recording and reproduction of continuous wideband analog information can be carried out by three basic techniques: magnetic (longitudinal and rotary head), electron beam (silver halide film), and laser beam conventional and holographic (silver halide film). The advantages and shortcomings of each technique are discussed. Magnetic recording is bandwidth-limited, although it offers instant readout and erase and reusability of its medium. Electron beam technology offers an order of magnitude improvement in record capability and packing density, and limited multichannel capability. Laser beam technology is presently limited by mechanical scanning or deflection techniques as well as the shortcomings of silver halide film.