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Numerical investigation on photonic microwave generation by a sole excited-state emitting quantum dot laser with optical injection and optical feedback

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Chinese Physics B 2021年第5期30卷 255-261页

作者： Zai-Fu Jiang Zheng-Mao Wu Wen-Yan Yang Chun-Xia Hu Yan-Hong Jin Zhen-Zhen Xiao Guang-Qiong Xia School of Physical Science and Technology Southwest UniversityChongqing 400715China School of Mathematics and Physics Jingchu University of TechnologyJingmen 448000China School of Physics Chongqing University of Science and TechnologyChongqing 401331China College of Mobile Telecommunications Chongqing University of Posts and TelecomChongqing 401520China

Based on three-level exciton model,the enhanced photonic microwave signal generation by using a sole excited-state(ES)emitting quantum dot(QD)laser under both optical injection and optical feedback is numerically *** the range of period-one(P1)dynamics caused by the optical injection,the variations of microwave frequency and microwave intensity with the parameters of frequency detuning and injection strength are *** is found that the microwave frequency can be continuously tuned by adjusting the injection parameters,and the microwave intensity can be enhanced by changing the injection ***,considering that the generated microwave has a wide linewidth,an optical feedback loop is further employed to compress the linewidth,and the effect of feedback parameters on the linewidth is *** is found that with the increase of feedback strength or delay time,the linewidth is evidently decreased due to the locking ***,for the relatively large feedback strength or delay time,the linewidth compression effect becomes worse due to the gradually destroyed P1 ***,through optimizing the feedback parameters,the linewidth can be reduced by up to more than one order of magnitude for different microwave frequencies.

关键词： photonic microwave quantum dot laser optical injection optical feedback

Polarization switching in a quasi-isotropic microchip Nd:YAG laser induced by optical feedback

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Chinese Physics B 2010年第2期19卷 274-279页

作者：任成谈宜东张书练 State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instruments&MechanologyTsinghua University

This paper demonstrates the influence of external optical feedback on the polarization state of longitudinal modes in quasi-isotropic microchip Nd：YAG lasers. Under optical feedback, the polarization state of longitudinal modes in quasi-isotropic lasers relies strongly on the intracavity anisotropy loss and mode competition. When the intracavity anisotropy loss is small, external optical feedback can cause polarization switching and strong mode competition between two orthogonal linearly polarized eigenstates of one laser longitudinal mode, which leads to the distortion of laser intensity modulation waveform. The polarization switching is independent of the initial external cavity length. By increasing the intracavity anisotropy loss, one polarization eigenstate can be suppressed and the laser works in single-polarization state. A theoretical analysis based on the compound cavity model is presented, which is in good agreement with the experimental results. The results offer guidance to the development of laser feedback interferometers.

关键词： microchip Nd:YAG laser optical feedback polarization switching laser feedback interferometer

Low-frequency fluctuation in multimode semiconductor laser subject to optical feedback

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Chinese Optics Letters 2008年第2期6卷 120-123页

作者：张旭叶会英宋兆欣 Information Engineering College of Zhengzhou University

Dynamics of a semiconductor laser subject to moderate optical feedback operating in the low-frequency fluctuation regime is numerically investigated. Multimode Lang-Kobayashi （LK） equations show that the low-frequency intensity dropout including the total intensity and sub-modes intensity is accompanied by sudden dropout simultaneously, which is in good agreement with experimental observation. The power fluctuation is quite annoying in practical applications, therefore it becomes important to study the mech- anism of power fluctuation. It is also shown that many factors, such as spontaneous emission noise and feedback parameter, may influence power fluctuation larger than previously expected.

关键词： optical feedback Spontaneous emission

Distortion of optical feedback signals in microchip Nd:YAG lasers subjected to external multi-beam interference feedback

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Chinese Physics B 2010年第3期19卷 319-323页

作者：谈宜东张书练任舟任成张亦男 The State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentsTsinghua University

This paper proposes a theoretical analysis for the characteristics of an external cavity Nd：YAG laser with feedback of multiple-beam interference, which is induced by the multi-reentrance of the light from the external Fabry-Perot cavity. The theoretical model considers the multiple beam interference of the external Fabry-Perot cavity. It is found that the optical feedback signals are distorted to pulse waveforms instead of the sinusoidal ones in conventional feedback. The experimental results are in good agreement with the theoretical analysis. The obtained theoretical and experimental results can advance the development of a laser feedback interferometer.

关键词： optical feedback multi-beam interference

Sensitivity to external optical feedback of circular-side hexagonal resonator microcavity laser

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Chinese Physics B 2021年第12期30卷 74-80页

作者： Tong Zhao Zhi-Ru Shen Wen-Li Xie Yan-Qiang Guo An-Bang Wang Yun-Cai Wang Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceTaiyuan University of TechnologyTaiyuan 030024China College of Physics and Optoelectronics Taiyuan University of TechnologyTaiyuan 030024China Guangdong Provincial Key Laboratory of Photonics Information Technology Guangzhou 510006China School of Information Engineering Guangdong University of TechnologyGuangzhou 510006China

The sensitivity to fault reflection is very important for larger dynamic range in fiber fault detection *** time delay signature(TDS)of chaotic laser formed by optical feedback can solve the sensitivity limitation of photodetector in fiber fault *** TDS corresponds to the feedback position and the fault reflection can be detected by the laser *** sensitivity to feedback level of circular-side hexagonal resonator(CSHR)microcavity laser is numerically simulated and the feedback level boundaries of each output dynamic state are *** peak level of TDS is utilized to analyze the *** demonstration is presented in two aspects:the minimum feedback level when the TDS emerges and the variation degree of TDS level on feedback level *** results show that the CSHR microcavity laser can respond to the feedback level of 0.07%,corresponding to-63-dB feedback *** to conventional distributed feedback laser,the sensitivity improves almost 20 dB due to the shorter internal cavity length of CSHR microcavity ***,1%feedback level changing will induce 1.001 variation on TDS level,and this variation degree can be influenced by other critical internal parameters(active region side length,damping rate,and linewidth enhancement factor).

关键词： sensitivity optical feedback microcavity laser nonlinear dynamic

Intensity modulation characters of orthogonally polarized HeNe lasers with different optical feedback level

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Chinese Physics B 2008年第2期17卷 644-648页

作者：崔柳张书练万新军 The State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentsTsinghua University

This paper demonstrates the intensity modulation characters of orthogonally polarized HeNe lasers with different optical feedback level generated by the variable reflectivity of external reflector. The modulation depths of the orthogonally polarized frequencies are increased when the optical feedback level becomes strong. It also observes that the modulation amplitudes are different for different external cavity length. Based on the vectorial extension of Lamb＇s semi-classical theory, it finds that the calculations are consistent with the experimental results.

关键词： intensity modulation optical feedback frequency split

optical feedback characteristics in a dual-frequency laser during laser cavity tuning

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Chinese Physics B 2005年第10期14卷 1984-1989页

作者：刘刚张书练李岩朱钧 State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instruments Tsinghua University Beijing 100084 China

The optical feedback characteristics in a Zeeman-birefringence dual-frequency laser are studied during the laser cavity tuning in three different kinds of optical feedback conditions：（i） only //-light is fed back; （ii） only ⊥-light is fed back; （iii） both lights are fed back. A compact displacement sensor is designed using the experimental result that there is a nearly 90 degrees phase delay between the two lights＇ cosine optical feedback signals when both lights are fed back into the laser cavity. The priority order that the two lights＇ intensity curves appear can be used for direction discrimination. The resolution of the displacement sensor is at least 79 rim, and the sensor can discriminate the target＇s moving direction easily.

关键词： dual-frequency laser optical feedback self-mixing displacement sensor

optical feedback characteristics in a helium neon laser with a birefringent internal cavity

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Chinese Physics B 2007年第11期16卷 3416-3422页

作者：毛威张书练徐亭万新军刘刚 The State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentsTsinghua UniversityBeijing100084China

The output characteristics of optical feedback in a helium neon laser with a birefringent internal cavity are studied systematically in five different regions of the gain curve for the two orthogonally polarized modes. When the laser operates in the two end regions of the laser gain curve, one of the two orthogonally polarized modes will be a leading one in optical feedback. Strong mode competition can be observed. However, when the laser operates in the middle region of the laser gain curve, the two modes can oscillate equally with optical feedback. Besides the intensity of the two polarized lights, the total light intensity is also studied at the same time. M-shaped optical feedback curves are found. Particularly, when the average intensities of the two lights are comparable, the intensity modulation curve of the total light is doubled, which can be used to improve the resolution of an optical feedback system.

关键词： optical feedback birefringent internal cavity self-mixing interference mode competition

Time-Domain Traveling Wave Model of Single-Section Quantum Dot Mode-Locked Lasers with optical feedback

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Journal of Harbin Institute of Technology(New Series) 2021年第3期28卷 45-52页

作者： Xuefang Xiao Zewang Zhang Xiupu Zhang School of Opto-electronic and Communication Engineering Xiamen University of TechnologyXiamen 361024FujianChina Key Laboratory of Communication Network and Information Processing in Fujian Province Xiamen 361024FujianChina Photonics Labs. Department of Electrical and Computer EngineeringConcordia UniversityMontreal QC H3G 1M8Canada

The optical feedback modulations of a passively mode-locked semiconductor laser with quantum dot structure were investigated in this study. The delay-induced dynamics of QD MLL under the condition of optical feedback have been studied by exploiting a time domain traveling wave(TDTW) model. The conventional TDTW model was improved to make it suitable for studying optical feedback system, especially the system with long external cavity structure. Combing the TDTW model with optical feedback and carrier rate equations, the pulse variation of a single section QD MLL was studied. This new model shows good agreement with the published experimental data. The roundtrip time and local light intensity modulation to the pulse evolution of QD MLL were studied. The results show that when the time for a light to go to and return from external cavity is equal to the integral times of the period of laser pulse without external feedback, resonance will be formed, and the period of pulse sequence is the shortest. The results also show that the stronger the local light intensity modulation is, the shorter the pulse period is.

关键词： quantum dot structure passively mode-locked laser optical feedback