Disclosed is an optical floating sub-assembly, comprising a thermally conductive non rigid substance between the heat sink carrier and external casing, to minimize mechanical stress on the optical assembly. Also disclosed is a printed circuit board as an electrical interface, comprising two modules capable of converting an electrical signal to an optical signal, transmitting the optical signal and then converting the optical signal back to an electrical signal. Also disclosed is an optical assembly, comprising a heat sink with mechanical features for optical alignment.