A laser system capable of producing multiple groups of output wavelengths is disclosed. In one embodiment, an optical fiber bundle doped with erbium (Er) or erbium/ytterbium (Er/Yb) is perpendicularly attached to an optical device, which serves as a guided-mode resonance feedback mirror, to form a fiber laser matrix. The optical device contains a substrate layer, a waveguide layer, and a grating layer, with non-uniform device parameters. The wavelength of the resonant light and its corresponding laser light of an individual optical fiber depends upon the parameters in the location on the optical device where the fiber is attached. In another embodiment, a plurality of active waveguides in a body are attached to an optical device to form a diode-pumped crystal laser matrix with multi-group output wavelengths. The invented laser system is capable of generating laser sources of large channel capacity for the optical network especially for the dense wavelength division multiplexing (DWDM) system.