In this work, we theoretically investigate the relative intensity noise (RIN) properties of quantum dot (QD) lasers through a rate equation model including the Langevin noises and the contribution from the off resonance energy levels. It is shown that the carrier noise significantly enhances the RIN which can be further reduced by properly controlling the energy separation between the first excited and the ground states. In addition, simulations also unveil that the RIN of QD lasers is rather temperature independent which is of prime importance for the development of power efficient light sources. Overall, these results indicate that QD lasers are excellent candidates for the realization of ultra-low noise oscillators hence being advantageous for fiber optics communication networks, short reach optical interconnects and integrated photonics systems.
In this paper, we investigate the temperature dependence of spectral linewidth of InAs/InP quantum dot distributed feedback lasers. In comparison with their quantum well counterparts, results show that quantum dot lasers have spectral linewidths rather insensitive to the temperature with minimum values below 200 kHz in the range of 283K to 303K. The experimental results are also well confirmed by numerical simulations. Overall, this work shows that quantum dot lasers are excellent candidates for various applications such as coherent communication systems, high-resolution spectroscopy, high purity photonic microwave generation and on-chip atomic clocks.