# High Performance GaSb-Based DBR Laser with On-Chip Integrated Power Amplifier via Gain-Match Design
## 5 Conclusions  
We have fabricated a stable single-longitudinal-mode GaSb-based DBR laser emitting at 1950 nm. For a 1 mm long uncoated laser diode, the continuous-wave output power is 10 mW at room temperature, the maximum SMSR is as high as 42 dB, and the laser exhibited a stable single-mode emission from 15 \({}^{\circ}\)C to 40 \({}^{\circ}\)C. In addition, an on-chip integrated MOPA-DBR laser is obtained by calculating the fundamental mode transmission angles and carefully optimizing the match between the gain peak and Bragg wavelength. The optimal match is realized with 40 nm red-shifted between Bragg wavelength and photoluminescence (PL) peak. The best MOPA-DBR laser realizes 5.6 times the power amplification with a maximum output power of 45 mW in single-mode operation at room temperature. These results indicate that the perfect match of the gain peak in MOPA-DBR lasers significantly achieves the output power amplification, which puts up a new solution for the preparation of a high-performance single-mode laser source. Conceptualization, J.C. and C.Y. ; methodology, J.C.; formal analysis, J.C.; investigation, J.C., C.Y., Y.C., H.Y., J.S., Z.G., H.W. and Z.W. ; resources, C.Y. ; data curation, C.Y. and Z.N. ; writing--original draft preparation, J.C.; writing--review and editing, C.Y. and Z.N. ; visualization, H.T. and Y.Z. ; supervision, C.Y. and Z.N. ; project administration, C.Y. and Z.N. ; funding acquisition, C.Y., D.W., H.N., Y.X. and Z.N. All authors have read and agreed to the published version of the manuscript. This research was funded by the Innovation Program for Quantum Science and Technology under Grant 2021 ZD0300801, by the National Natural Science Foundation of China under Grant  
Figure 10: (**a**) Spectra of MOPA-DBR laser (#5) with period cycle of 537 nm. (**b**) The maximum output power, driving current range in single-mode operation, and the gain-peak drifting length of MOPA-DBR lasers (#4, #5, #6). 62204238, sponsored by Beijing Nova Program 20240484621, by the Chinese Academy of Sciences Project for Young Scientists in Basic Research, Grant No. YSBR-112, and by the \"Announce the list and take charge\" of the major special plan of science and technology in Shanxi Province under Grant 202201030201009. **Institutional Review Board Statement**: Not applicable. **Informed Consent Statement**: Not applicable. **Data Availability Statement**: The data presented in this study are available on request from the corresponding author. **Conflicts of Interest**: The authors declare no conflicts of interest. [PERSON], [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON], [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON]; [PERSON] _Diffraction Limited 1064 nm Monolithic DBR-Master Oscillator Power Amplifier with More Than 7W Output Power_; SPIE: Bellingham, WA, USA, 2018; Volume 10553. * [PERSON] et al. (2021) [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; et al. _Single Mode 660 nm Master-Oscillator Power-Amplifier with 500 mW Optical Output Power_; SPIE: Bellingham, WA, USA, 2021; Volume 11667. * [PERSON] et al. (2007) [PERSON]; [PERSON]; [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON] Tapered quantum cascade lasers. _Appl. Phys. Lett._**2007**, _91_, 181122. [CrossRef]
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