Efficient photonic circuits for liquid-cooled high-density datacenters

Abstract

Photonic circuits are disclosed having an efficient optical power distribution network. Laser chips (InP) having different wavelengths are flip-chip assembled near the center of a silicon photonic chip. Each InP die has multiple optical lanes, but a given die has only one wavelength. Waveguides formed in the photonic chip are optically connected to the lanes, and fan out to form multiple waveguide sets, where each waveguide set has one of the waveguides from each of the different wavelengths, i.e., one waveguide from each InP die. The waveguide network is optimized to minimize the number of crossings that any given waveguide may have, and no waveguide having a particular wavelength crosses another waveguide of the same wavelength. The unique arrangements of light sources and waveguides allows the use of a smaller number of more intense laser sources, particularly in applications such as performance-optimized datacenters where liquid cooling systems may be leveraged.