Observation of amplitude squeezing in a constant-current-driven distributed feedback quantum dot laser with optical feedback

We illustrate the generation of single-mode amplitude squeezing in a distributed feedback quantum dot laser driven by a constant-current pump. Achieving broadband amplitude squeezing of 1.7 dB over a 10 GHz range at room temperature is realized by suppressing carrier noise and implementing optical feedback. The noise-corrected squeezing level reached 5.1 dB. Furthermore, the examination of the zero-delay second-order correlation function demonstrates the robust feedback stability of the amplitude-squeezed state in the quantum dot laser compared to a reference quantum well laser. This investigation lays the groundwork for future advancements in integrated optical quantum chips.