An apparatus for handling an optical signal includes: an optical transmitting unit transmitting the optical signal from an input locus to an output locus. The optical transmitting unit includes a plurality of optical transmitting sections. Each respective optical transmitting section of the plurality of optical transmitting sections has a respective length and a respective attenuation gradient to establish a respective length-and-attenuation gradient configuration. Each respective optical transmitting section effects attenuation of the optical signal according to its respective length-and-attenuation gradient configuration.