Broadband telecom emission from InP/InGaAs nano-ridge lasers on silicon-on-insulator substrate

Nanolasers directly grown on silicon substrates are ideal light sources for silicon-based photonic integrated circuits, benefiting from an ultra-small footprint and ultra-low energy consumption. However, constructing a compact laser source that covers a wide emission range is still challenging, especially for data-communication applications in the near-infrared region. Here, we explain a wavelength tuning strategy for InP/InGaAs nano-ridge lasers grown on silicon-on-insulator wafers through experimental measurements and detailed simulations. A wide tuning range of over 200 nm is achieved via tailoring the length of the on-chip Fabry-Perot nano-ridge lasers with identical epitaxial structures. With extensive mode and gain analyses of the nano-ridge lasers, we attribute the broadband tuning scheme to the enhanced band filling effect and the significant gain shift under high excitation levels. Our study provides a fresh perspective for the design of telecom nano-scale light emitters.