OPTICAL ARITHMETIC UNIT

Japanese Patent JPH02271328

A

PURPOSE:To perform addition and subtraction by optical arithmetic according to the phase difference of light by varying the optical path length of each optical path divided by an optical path dividing means by an optical path length varying means and guiding each optical path onto one photodetecting element by an optical path direction changing means. CONSTITUTION:The optical arithmetic unit 1 divides the optical path 4 from a light source 2 into optical paths 5 and 6 by a beam splitter 3, and reflecting mirrors 7 and 8 change the directions of the optical paths 5 and 6 to make their light beams incident on deflecting elements 9 and 10. The angles theta1 and theta2 of incidence of light on condenser lenses 11 and 12 by varying electric fields applied to the deflecting elements 9 and 10 to accurately vary the optical path lengths of the optical paths 5 and 6, thereby making the light beams incident on the photodetecting element 13 by the condenser lenses 11 and 12. Then a light output is varied by the phase difference between the two incident light beams detected by the photodetecting element 13 to perform the optical arithmetic. The deflecting element 9 denotes the applied electric fields when a binary input is 0 and 1 as 0 and E1 and the deflecting element 10 denotes them as E2 and E1, so that the light output I is as shown in a table. When the threshold value Ith of the input light output is so set that I0