A coherent optical injection locking (COIL) apparatus generates multiple optical source outputs from a single optical source generated by a parent laser. The COIL apparatus includes a plurality of optical source generators each having a child laser, of lesser performance than the parent laser, that is injection locked to the single optical source. The optical source generators may have one or both of a shared configuration and a cascaded configuration that replicates the single optical source, or a single wavelength of the single optical source when it is a comb source.