Pairwise comparison device

Apparatus for comparing first and second sets of voltages having one-to-one correspondence, and providing an indication responsive to the magnitudes of the pairwise differences of the voltages;

• comprising
• a plurality of channel waveguides, each having a first electrode on one side of the channel and a second electrode on the opposite side of the channel;
• means for connecting each voltage of the first set to the first electrode of one waveguide;
• means for connecting each voltage of the second set to the second electrode of the waveguide to the first electrode of which the corresponding voltage of the first set is connected;
• means for directing to the input end of each waveguide a substantially plane wave of coherent light having predetermined relative intensity and phase;
• and
• means responsive to the light emerging from the output end of the waveguides for providing an indication that is a function of the pairwise relative magnitudes of the first set of voltages and the second set of voltages, and
• wherein the channel waveguides, electrodes, voltage connecting means, and light directing means comprise a device for guiding the input wave of coherent light, segmenting it into a plurality of waves, and reassembling them into a single output wave that may be similar to the input wave or may have a phase shift pattern imposed upon it;
• comprising
• a thin film waveguide whose width is relatively broad at its input end, positioned to receive the input wave;
• comprising
• a relatively short input end portion comprising a continuous region of thin material, having a relatively high index of refraction and of substantially uniform width, extending in a predetermined direction;
• a first longer transitional portion comprising a continuation of the same material extending from the input end portion in approximately the same direction in a plurality of narrower first transitional strips of which adjacent ones are contiguous at the input end, each strip tapering away from the adjacent strips approximately as a long, narrow parabola to a substantially narrower width at its other end;
• a middle portion comprising a further continuation of the same material extending from the narrower ends of the first transitional strips in approximately the same direction, at least for a substantial length, in still longer middle strips of substantially uniform width and spacing;
• a second transitional portion, similar to the first, comprising a further continuation of the same material extending from the middle strips in approximately the same direction in second transitional strips, each tapering from the narrow width of the middle strips approximately as a long narrow parabola to the width where it becomes contiguous to the adjacent strips;
• and
• a relatively short output end portion, similar to the input end portion, comprising a further continuation of the same material in a continuous region extending from the second transitional portion in approximately the same direction.

Apparatus for guiding a substantially plane input wave of coherent light, segmenting it into a plurality of waves, and reassembling them into a single output wave, comprising a thin film waveguide whose width is relatively broad at its input end, positioned to receive the input wave;

• comprising
• a relatively short input end portion comprising a continuous region of thin material, having a relatively high index of refraction and of substantially uniform width, extending in a predetermined direction;
• a first longer transitional portion comprising a continuation of the same material extending from the input end portion in approximately the same direction in a plurality of narrower first transitional strips of which adjacent ones are contiguous at the input end, each strip tapering away from the adjacent strips approximately as a long, narrow parabola to a substantially narrower width at its other end;
• a middle portion comprising a further continuation of the same material extending from the narrower ends of the first transitional strips in approximately the same direction, at least for a substantial length, in still longer middle strips of substantially uniform width and spacing;
• a second transitional portion, similar to the first, comprising a further continuation of the same material extending from the middle strips in approximately the same direction in second transitional strips, each tapering from the narrow width of the middle strips approximately as a long, narrow parabola to the width where it becomes contiguous to the adjacent strips;
• and
• a relatively short output end portion, similar to the input end portion, comprising a further continuation of the same material in a continuous region extending from the second transitional portion in approximately the same direction.