Theoretical Study on Low-Chirp Directly Modulated DFB Lasers with (110)-Oriented Quantum Well

The low-chirp operation of distributed feedback lasers is highly desirable in high-speed and high-bit rate optical transmission. In this article, we address this issue by theoretically investigating the possibility of further a reduction in the linewidth enhancement factor (LEF) of a quantum well (Q...

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Main Authors: Jianwei Li, Mengzhu Hu, Xinyang Su, Yanting Liu, Ke Zhan
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Photonics
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Online Access:https://www.mdpi.com/2304-6732/12/7/647
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author Jianwei Li
Mengzhu Hu
Xinyang Su
Yanting Liu
Ke Zhan
author_facet Jianwei Li
Mengzhu Hu
Xinyang Su
Yanting Liu
Ke Zhan
author_sort Jianwei Li
collection DOAJ
description The low-chirp operation of distributed feedback lasers is highly desirable in high-speed and high-bit rate optical transmission. In this article, we address this issue by theoretically investigating the possibility of further a reduction in the linewidth enhancement factor (LEF) of a quantum well (QW). The energy band structure of AlGaInAs quantum-well DFB lasers grown with a (110) crystal orientation in the active region of the L-band has been theoretically analyzed using multi-band k.p perturbation theory, by reducing the asymmetry of conduction bands and valence bands and thus the linewidth enhancement factor parameter, which is related to the frequency chirp. Simulation results show that the LEF of the directly modulated DFB laser is reduced from 2.434 to 1.408 by designing the (110)-oriented compression-strained Al<sub>0.06</sub>Ga<sub>0.24</sub>InAs multiple-quantum-well structure, and the eye diagram of the (110)-oriented quantum-well DFB laser with a digital signal transmission of 20 km is significantly better than the (001) crystal-oriented quantum-well DFB laser for the 10Gbps optical fiber communication system, thus achieving a longer distance and higher-quality optical signal transmission.
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spelling doaj-art-2c2a7832905b4b13ae7fe987c9ab89a12025-08-20T02:47:17ZengMDPI AGPhotonics2304-67322025-06-0112764710.3390/photonics12070647Theoretical Study on Low-Chirp Directly Modulated DFB Lasers with (110)-Oriented Quantum WellJianwei Li0Mengzhu Hu1Xinyang Su2Yanting Liu3Ke Zhan4Zhejiang Provincial Innovation Center of Laser Intelligent Equipment Technology, Wenzhou 325200, ChinaZhejiang Provincial Innovation Center of Laser Intelligent Equipment Technology, Wenzhou 325200, ChinaSchool of Physical Science and Engineering, Beijing Jiaotong University, Beijing 100044, ChinaZhejiang Provincial Innovation Center of Laser Intelligent Equipment Technology, Wenzhou 325200, ChinaZhejiang Provincial Innovation Center of Laser Intelligent Equipment Technology, Wenzhou 325200, ChinaThe low-chirp operation of distributed feedback lasers is highly desirable in high-speed and high-bit rate optical transmission. In this article, we address this issue by theoretically investigating the possibility of further a reduction in the linewidth enhancement factor (LEF) of a quantum well (QW). The energy band structure of AlGaInAs quantum-well DFB lasers grown with a (110) crystal orientation in the active region of the L-band has been theoretically analyzed using multi-band k.p perturbation theory, by reducing the asymmetry of conduction bands and valence bands and thus the linewidth enhancement factor parameter, which is related to the frequency chirp. Simulation results show that the LEF of the directly modulated DFB laser is reduced from 2.434 to 1.408 by designing the (110)-oriented compression-strained Al<sub>0.06</sub>Ga<sub>0.24</sub>InAs multiple-quantum-well structure, and the eye diagram of the (110)-oriented quantum-well DFB laser with a digital signal transmission of 20 km is significantly better than the (001) crystal-oriented quantum-well DFB laser for the 10Gbps optical fiber communication system, thus achieving a longer distance and higher-quality optical signal transmission.https://www.mdpi.com/2304-6732/12/7/647linewidth enhancement factorfrequency chirpcrystal orientationAlGaInAs quantum well
spellingShingle Jianwei Li
Mengzhu Hu
Xinyang Su
Yanting Liu
Ke Zhan
Theoretical Study on Low-Chirp Directly Modulated DFB Lasers with (110)-Oriented Quantum Well
Photonics
linewidth enhancement factor
frequency chirp
crystal orientation
AlGaInAs quantum well
title Theoretical Study on Low-Chirp Directly Modulated DFB Lasers with (110)-Oriented Quantum Well
title_full Theoretical Study on Low-Chirp Directly Modulated DFB Lasers with (110)-Oriented Quantum Well
title_fullStr Theoretical Study on Low-Chirp Directly Modulated DFB Lasers with (110)-Oriented Quantum Well
title_full_unstemmed Theoretical Study on Low-Chirp Directly Modulated DFB Lasers with (110)-Oriented Quantum Well
title_short Theoretical Study on Low-Chirp Directly Modulated DFB Lasers with (110)-Oriented Quantum Well
title_sort theoretical study on low chirp directly modulated dfb lasers with 110 oriented quantum well
topic linewidth enhancement factor
frequency chirp
crystal orientation
AlGaInAs quantum well
url https://www.mdpi.com/2304-6732/12/7/647
work_keys_str_mv AT jianweili theoreticalstudyonlowchirpdirectlymodulateddfblaserswith110orientedquantumwell
AT mengzhuhu theoreticalstudyonlowchirpdirectlymodulateddfblaserswith110orientedquantumwell
AT xinyangsu theoreticalstudyonlowchirpdirectlymodulateddfblaserswith110orientedquantumwell
AT yantingliu theoreticalstudyonlowchirpdirectlymodulateddfblaserswith110orientedquantumwell
AT kezhan theoreticalstudyonlowchirpdirectlymodulateddfblaserswith110orientedquantumwell