Optical connection structures for a photonic assembly and methods for forming the same

A photonic assembly comprising:

• a composite die including a photonic integrated circuits (PIC) die and an electronic integrated circuits (EIC) die, the PIC die comprising waveguides and photonic devices therein, and the EIC die comprising semiconductor devices therein;
• an optical connector unit comprising a first connector-side mirror reflector and a first transition edge coupler, wherein the first connector-side mirror reflector is configured to change a beam direction between a vertically-extending beam path through the composite die and a horizontally-extending beam path through the first transition edge coupler;
• and
• a heat sink overlying the composite die and attached to the composite die.

A method of forming a photonic assembly, the method comprising:

• forming a composite die including a photonic integrated circuits (PIC) die and an electronic integrated circuits (EIC) die, the PIC die comprising waveguides and photonic devices therein, and the EIC die comprising semiconductor devices therein;
• forming an optical connector unit comprising a first connector-side mirror reflector and a first transition edge coupler within, or on, the composite die, wherein the first connector-side mirror reflector is configured to change a beam direction between a vertically-extending beam path through the composite die and a horizontally-extending beam path through the first transition edge coupler;
• and
• attaching a fiber array units assembly comprising a plurality of optical fibers to the optical connector unit, wherein the horizontally-extending beam path laterally extends into an optical fiber within the plurality of optical fibers.