On the basis of diffraction theory, quantum-mechanics and information theory, it is shown that the principle of coherent light recording is the theoretical ultimate in respect to information density and frequency bandwidth that can be achieved by any data-processing method. This rules out mechanical, magnetic or electric approaches. Photographic coherent light recording tests were made by the dynamic sweep tests on 16 mm Recordak Micro-File Special film SO 267 and AHU 5459. Evaluation of the test results shows that there is a relation between density, line width and recording rate for the various film materials. Averaging over a number of tests, the density of 2.0 which was considered to be a target density in regard to the required signal-to-noise ratio of the system yielded a line width of 15 microns on the SO 267 film, and 40 microns on the film AHU 5459. Preliminary efforts extended towards electro-optical and magneto-optical birefringence. Electro-optical deflection began with single prisms of alpha-quartz X, Y, Z cut, as well as ADP Z, J cut. Preliminary testing with ADP Z cut yielded an angular deflection of 180 seconds of arc before it was destroyed due to overdriving.