Chirped InAs/InP quantum dot material platform enabling ultra-broad spectral tuning in external cavity lasers

We demonstrate a novel ultra-broadband tunable InAs/InP quantum dot (QD) external-cavity laser incorporating a chirped multilayer QD active region. By engineering the epitaxial material to feature chirped quantum dot layers, we broaden the photoluminescence spectrum. The influence of cavity length and facet coating conditions on the tuning range is also systematically investigated, enabling optimization of the laser’s spectral performance. Under an injection current of 1.5 A and using an anti-reflective (AR, R ≈ 0%)/high-reflective (HR, R ≈ 85%) facet coating configuration, a continuous tuning bandwidth of 160 nm spanning 1430–1590 nm is achieved. This result provides a promising route for next-generation broadband optical communication systems, high-resolution spectroscopy, and precision optical imaging technologies.