Most of today’s commercial short-reach optical interconnects within datacentres employ Vertical-Cavity Surface-Emitting lasers (VCSELs), because of their low cost, small footprint, and capability for large-scale fabrication. Additionally, they can be directly modulated with a low modulation voltage so that power consumption can be further reduced. In order to cope with the increasing demands for higher capacity, dense wavelength division multiplexing (DWDM) of multi-wavelength VCSELs would be desirable, having the potential to support an aggregate datarate above 800 Gb/s within a single optical fiber. Within the current project, we will investigate a scalable solution for DWDM of VCSELs by injecting a low-power optical frequency comb in an array of strained VCSELs, providing a solution for VCSEL wavelength locking onto the DWDM grid. The assembly of VCSEL arrays on a 3D engineered glass interposer allows for precise straining of individual lasers within the VCSEL array, required for controlling the emission properties. Diffractive optical elements provide a compact and efficient solution for power splitting of a single comb to VCSEL arrays, and a solution for wavelength multiplexing of DWDM VCSELs in a single optical fiber. Assembly of an integrated photonics optical frequency comb, a strained VCSEL array, and diffractive optical elements on a common glass interposer will allow for a state-of-the-art DWDM VCSEL transmitter demonstration.