## 5 Conclusions  
This work presented the experimental characterization of three single-gain hybrid integrated lasers for dual local oscillator generation. The optical power versus current curve of the three lasers used in the heterodyne system revealed that the maximum power achieved for laser 3, by only biasing the gain section, was 2 mW. This finding highlights the need for further investigation into the coupling losses between the InP and Si\({}_{3}\)N\({}_{4}\) chips of these lasers, as the output power of laser 2 and laser 4 were eleven and nine times higher than this, respectively. Addressing these coupling losses will be a key focus of future studies aimed at enhancing overall system efficiency.  
However, through careful control of the current injected into the gain section and precise fine-tuning of the voltages applied to the heaters within the laser cavity, the performance of each laser can be optimized to achieve high output powers and low optical linewidths. These optimizations improved stability, which is a critical factor for the successful implementation of dual local oscillator generation in advanced microwave photonics systems.  
It is important to note that while this work presents the wavelength maps for laser 3 and laser 4, all five integrated lasers exhibited a tuning range greater than 70 nm when varying the heater voltages applied to the micro-ring resonators. This extensive tuning range underscores the versatility and adaptability of the system for diverse applications.  
In conclusion, this hybrid multi-laser module demonstrates exceptional promise for satellite communication applications, offering enhanced performance, scalability, and reliability. Its ability to generate stable, tunable signals across multiple frequency bands positions it as a transformative technology for next-generation communication networks.  
**Author Contributions:** Conceptualization, C.G.H.R., C.M., I.V., and G.C.; methodology, C.G.H.R., R.B.T., J.C.-C., A.Z., R.C.G., and G.C.; validation, R.B.T., J.C.-C., A.Z., and R.C.G.; writing--original draft preparation, J.C.-C. and A.Z.; writing--review and editing, all the authors; supervision, L.G. and J.M.D.M.; project administration, P.W.L.V.D., C.M., and G.C. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work has been supported by the European Space Agency through the TRP program \"Tuneable Photonic RF Demultiplexer for Broadband Satellites--THORMUX\" (GA 870421), by the European Union through the projects TERA6G (GA 101096949), SPRINTER (GA 101070581), and POLYNCES (G.A. 101070549), and by a Spanish national project, \"6G-Xtreme\" (Ref. TSI-063000-2021-136).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** No new data were created during the construction of the manuscript.  
**Acknowledgments:** We thank [PERSON] for her help with the control software.  
**Conflicts of Interest:** Authors [PERSON], [PERSON], [PERSON], [PERSON], and [PERSON] were employed by the company Lionix International B.V. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.