An on-package optical interconnect design is proposed for the first time, with silicon photonics in conjunction with the polymer-on-glass interposer technology to enable heterogeneous integration. Glass substrates are used for low-cost, high reliability packaging while silicon photonics allows for high-speed modulation and wavelength division multiplexing within a small footprint. By combining silicon-photonic and benzo-cyclobutene-on-glass interposer technologies, we propose a scalable on-package photonic interconnect that can provide data rates >224  Gb  /  s for medium-reach links. Our proposed interconnect considers microring modulators and high-speed detectors available in photonic-foundry processes. We present the power-budget analysis to identify the key limiting parameters toward achieving an energy consumption of   <  1  pJ  /  bit.