at each lattice point has each individual optical amplification function more specifically since the path from an input end to an output end is uniformly determined by which one s of the switch units at the lattice points turn on it suffices to unconditionally determine an amplification degree at each lattice point in accordance with the loss in this path in this embodiment in order to confirm this function the optical amplification degrees of four switch units 311 312 313 and 314 in the arrangement shown in fig7 were individually adjusted so that the optical signal input from the input end 711 was output to the output ends 731 732 733 and 734 with the same light intensity and so that the insertion loss was 5 db the values of the current required were 200 220 230 and 260 ma respectively similarly the optical amplification degrees of the remaining 12 switch units 321 322 323 324 331 332 333 334 341 342 343 and 344 were individually adjusted so that the optical signals input from the input ends 712 713 and 714 were output to the output ends 731 732 733 and 734 with the same light intensity and so that the insertion loss was 5 db as a result it was possible to confirm the novel function of the present invention that an optical signal input from any input end is output to any output end with the same light intensity with reference to fig9 one embodiment of an optical exchange that utilizes the optical signal monitor function of the present invention will be explained an optical signal input from the.