Optical Analog Computers

Certain applications of optical devices in digital computers are described, and a general theory of optical analog computers is developed. Certain characteristics of the photographic process make it possible to perform mathematical operations with photosensitive materials, as well as with photocells. These characteristics are: (1) the modulation of light intensities by optically dense films; (2) the addition of densities of superimposed layers; (3) the multiplication of transparencies of superimposed layers; (4) the ability of the photographic emulsion to integrate exposures occurring throughout time or from several sources.Examples of optical methods of calculation are described, and the construction of an optical analog computer for synthesizing the two-dimensional Fourier transform of a function for use in crystal structure determination is described. A new machine giving immediate presentation of the results of two-dimensional Fourier transforms is proposed.

[1]  V. Bush,et al.  A continuous integraph , .

[2]  Vannevar Bush,et al.  Integraph solution of differential equations , 1927 .

[3]  T. S. Gray.  A photo-electric integraph , 1931 .

[4]  A Curve Tracer for Two, Three or Four Variables , 1937 .

[5]  H. C. Montgomery.  An optical harmonic analyzer , 1938 .

[6]  W. Bragg,et al.  A New Type of ‘X-Ray Microscope’ , 1939, Nature.

[7]  M. Buerger.  The Photography of Interatomic Distance Vectors and of Crystal Patterns. , 1939, Proceedings of the National Academy of Sciences of the United States of America.

[8]  Photographic Fourier Syntheses , 1941 .

[9]  Optically Reciprocal Gratings and Their Application to Synthesis of Fourier Series. , 1941, Proceedings of the National Academy of Sciences of the United States of America.

[10]  W. Bragg,et al.  The X-Ray Microscope , 1942, Nature.

[11]  LAWRENCE BRAGG,et al.  Lightning Calculations With Light , 1944, Nature.

[12]  PHOTOGRAPHY OF CRYSTAL STRUCTURES. , 1944, Science.

[13]  Photographic Fourier Synthesis , 1945, Nature.

[14]  P. J. G. D. Vos.  The use of the `fly's eye' apparatus to study crystal structures containing atoms of different scattering powers , 1948 .

[15]  J. Kasper,et al.  Phases of Fourier coefficients directly from crystal diffraction data , 1948 .

[16]  The photography of atoms in crystals. , 1950, Proceedings of the National Academy of Sciences of the United States of America.

[17]  Optical Evaluation of Molecular Structure Factors , 1950 .

[18]  A Multiple Projector for the Huggins Masks , 1951 .

[19]  The Determination of Crystal Structures from X-Ray Data Without a Knowledge of the Phases of the Fourier Coefficients. , 1951, Proceedings of the National Academy of Sciences of the United States of America.

[20]  A Method for Making Accurately Reproducible Masks of the Huggins Type , 1951, Nature.

[21]  Perforated plates for optical interference experiments Optical Fourier summation by means of the "X-ray microscope" , 1951 .

[22]  An Isophotal Contour Densitometer , 1953 .

[23]  D. Mclachlan,et al.  A Versatile Projector for Assisting in Crystal Structure Determinations , 1954 .

[24]  P. Lindberg.  Measurement of Contrast Transmission Characteristics in Optical Image Formation , 1954 .

[25]  R. Clark Jones,et al.  New Method of Describing and Measuring the Granularity of Photographic Materials , 1955 .

[26]  Table Model Projector for the Bragg‐Huggins Masks , 1955 .

[27]  Wave Synthesizing Light Chopper , 1955 .

[28]  L. Kovasznay,et al.  Optical Autocorrelation Measurement of Two‐Dimensional Random Patterns , 1957 .

[29]  A synthesizer for triangular wave functions , 1957 .

[30]  C. Aravindakshan.  CORRESPONDENCE: A simple arrangement for obtaining optical trnsforms of crystal structures , 1957 .