• Chinese Optics Letters
  • Vol. 23, Issue 4, 041402 (2025)
Jie Zhao1, Zhenxing Sun1,*, Pan Dai1,**, Jin Zhang2..., Yanqiu Xu2, Yue Zhang1, Zhuoying Wang1, Jiaqiang Nie1, Wenxuan Wang3, Rulei Xiao1 and Xiangfei Chen1|Show fewer author(s)
Author Affiliations
  • 1Key Laboratory of Intelligent Optical Sensing and Manipulation of the Ministry of Education & National Laboratory of Solid State Microstructures & College of Engineering and Applied Sciences & Institute of Optical Communication Engineering & Nanjing University-Tongding Joint Lab for Large-Scale Photonic Integrated Circuits, Nanjing University, Nanjing 210023, China
  • 2Nanjing Branch, China United Network Communications Corporation Limited, Nanjing 210002, China
  • 3Ocean College, Jiangsu University of Science and Technology, Zhenjiang 212003, China
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    DOI: 10.3788/COL202523.041402 Cite this Article Set citation alerts
    Jie Zhao, Zhenxing Sun, Pan Dai, Jin Zhang, Yanqiu Xu, Yue Zhang, Zhuoying Wang, Jiaqiang Nie, Wenxuan Wang, Rulei Xiao, Xiangfei Chen, "Flip-chip bonded 8-channel DFB laser array with highly uniform 400 GHz spacing and high output power for optical I/O technology," Chin. Opt. Lett. 23, 041402 (2025) Copy Citation Text show less

    Abstract

    In this paper, we proposed and experimentally demonstrated an 8-channel O-band distributed feedback (DFB) laser array with highly uniform 400 GHz spacing and high output power for optical input/output (I/O) technology. The grating phase is precisely controlled, and an equivalent π phase shift is implemented in the laser cavity via the reconstruction equivalent chirp (REC) technology. Anti-reflection (AR) and high-reflection (HR) films are coated on the front and rear facets, respectively, to enhance output power. The equivalent π phase shift is strategically placed near the HR film facet to improve the yield of the single longitudinal mode. Operating with a 400 GHz wavelength spacing, the proposed DFB laser array meets the continuous wave-wavelength division multiplexing multi-source agreement (CW-WDM MSA) specifications. The proposed DFB laser array is flip-chip bonded to a thin-film circuit with an aluminum nitride (AlN) submount to reduce the thermal resistance and enhance the output power. Compared to the p-side-up structure, the flip-chip bonding design significantly reduces junction temperature by 28% and increases maximum output power by approximately 20%. This design effectively lowers the thermal resistance of the chip and enhances its heat dissipation properties. At a bias current of 110 mA, the laser demonstrates wavelength deviations below 1.579 GHz and side-mode suppression ratios above 50 dB. The far-field divergence is measured at 25.8° × 30.1°, and the Lorentzian linewidth is 3.28 MHz. Increasing the bias current to 250 mA results in a laser output power exceeding 80 mW. Furthermore, the relative intensity noise (RIN) for all 8 channels is below -135.3 dB/Hz. The proposed flip-chip bonded 8-channel high-power DFB laser array demonstrates uniform wavelength spacing, high output power, and stable single longitudinal mode performance, making it a promising candidate for multiple wavelength laser sources in optical I/O technology.
    Δn(z)=12s(z)Δnexp(j2πzΛ0)+c.c,

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    s(z)=mFmexp(j2mπzP),

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    Δn(z)=m12ΔnFmexp(j2mπzP+j2πzΛ0)+c.c,

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    Δn(z)={Δn02mFmexp(j2πzΛ0+j2mπzP)+c.czz0Δn02mFmexp(j2πzΛ0+2mπzPj2mπΔPP)+c.cz>z0.

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    1Λ±1=1Λ0±1P,

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    Jie Zhao, Zhenxing Sun, Pan Dai, Jin Zhang, Yanqiu Xu, Yue Zhang, Zhuoying Wang, Jiaqiang Nie, Wenxuan Wang, Rulei Xiao, Xiangfei Chen, "Flip-chip bonded 8-channel DFB laser array with highly uniform 400 GHz spacing and high output power for optical I/O technology," Chin. Opt. Lett. 23, 041402 (2025)
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