PURPOSE: To provide an optical modulating element which has optical gain for a monolithic semiconductor structure diode optical switching array.

CONSTITUTION: A cutoff optical switching array formed on a waveguide for optical amplification is utilized to send ≥1 input beam to ≥1 selective optical channels or to cut it off. A passive optical waveguide 72 couples optical input with the amplifying optical waveguide 74. The passive optical waveguide 72 utilizes a monolithically formed optical splitter 66 to specify the path of a light signal to the array from a single fiber 76 to the amplifying optical waveguide 74.