Abstract: Optical paths to propagate a plurality of optical information signals intersect optical paths to transmit light signals to a plurality of subscribers. Light power dividing and propagation direction changing devices for separating requested optical information signals are arranged at the intersecting points. Losses of the optical information signals, due to the separation, are compensated by optical amplification, so that the signals can be distributed to all of the subscribers while maintaining a predetermined intensity. Thus, the same photosignal can be distributed to a plurality of subscribers. The system can be easily expanded in correspondence to an increase in the number of optical information signals and an increase in the number of subscribers.

Abstract: Optical paths to propagate a plurality of optical information signals intersect optical paths to transmit light signals to a plurality of subscribers. Light power dividing and propagation direction changing devices for separating requested optical information signals are arranged at the intersecting points. Losses of the optical information signals due to the separation, are compensated by optical amplification, so that the signals can be distributed to all of the subscribers while maintaining a predetermined intensity. Thus, the same photosignal can be distributed to a plurality of subscribers. The system can be easily expanded in correspondence to an increase in the number of optical information signals and an increase in the number of subscribers.

Abstract: There is provided a self-routing optical switch array formed by connecting m stages of optical switches and set so as to satisfy the relation:.lambda..sub.a1 <.lambda..sub.1 <.lambda..sub.a2 .lambda..sub.2 <. . . <.lambda..sub.an <.lambda..sub.n. . . <.lambda..sub.am <.lambda..sub.m <.lambda..sub.swhere .lambda..sub.n is wavelength of an absorption edge of a switching region of an nth stage of the optical switch array; .lambda..sub.an is wavelength of destination signal light multiplexed with information signal light used in an optical switch located at the nth stage, and .lambda..sub.s is wavelength of the information signal light.