A low inductance structure for improving the integrity of data signals carried in an optical subassembly is disclosed. In one embodiment the optical subassembly comprises a housing containing a lens assembly and an optical isolator. The optical subassembly further includes an optoelectronic package having a base defining a mounting surface that cooperates with a cap to define a hermetic enclosure. First and second signal leads of the subassembly include ends that extend into the hermetic enclosure. A submount is disposed on the base mounting surface. A low inductance structure is integrally formed with the submount and includes a dielectric body interposed between the first and second leads. The body includes shaped edges and conductive pad structures in electrical communication with conductive traces disposed on the submount. Each pad structure is also in electrical communication with a respective one of the first and second signal leads via a plurality of wirebonds.