VCSEL-based technologies to interconnect optically XPUs and HBMs on an interposer chip

Multimode VCSEL light was coupled to a waveguide to interconnect XPUs and HBMs on an interposer chip. The average propagation loss transmitted through the cavity-type waveguide was measured 0.444 dB/cm. A GaP prism coupler and a polyimide micro-lens were developed to inject the multimode VCSEL light into the waveguide measuring the net coupling loss of 0.762 dB. The packaged size of VCSEL has an area of 0.4 mm and a height of 0.64 mm. MUX/DeMUX was designed on the bottom plane of the prism. A light source, a modulator, and MUX/DeMUX are all located on the same area of the prism bottom in VCSEL-based interconnections.