DIFF Subgroup
H01S 5/124 Full Title
Semiconductor lasers (superluminescent diodes H10H20/00) > Construction or shape of the optical resonator > the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers (comprising a photonic bandgap structure H01S5/11; surface-emitting lasers H01S5/18)
Of 2 combined children, 0 exist in both systems.
2 codes are CPC-only extensions.