| 题名 | 基于光纤器件的超短脉冲波形变换技术研究 |
| 作者 | 徐钦峰 |
| 学位类别 | 博士 |
| 答辩日期 | 2010 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 瞿荣辉 |
| 关键词 | 脉冲波形变换技术 锁模光纤激光器 光纤自相关仪 光纤光栅 级联GT干涉仪 毫米波光脉冲产生 |
| 其他题名 | Study of ultra-short pulse waveform transform technology based on fiber elements |
| 中文摘要 | 激光脉冲整形技术在高速光通信系统、激光与物质相互作用、量子动力学控制、超短放大脉冲源、生物医学，全光开关、超快激光光谱学、非线性光纤光学和激光核聚变等领域有着巨大的应用前景，是当前国际上激光科学技术中一个非常重要的前沿领域。随着光纤器件技术的快速发展和成熟，基于光纤器件的超短脉冲产生技术和波形变换技术已经被提出和报道。与其它技术相比，基于光纤器件的脉冲整形技术具有和种子源光纤激光器的天然相容性，不存在耦合问题；并且装置简单、稳定性高、价格低廉等优点。基于上述研究背景，本文设计了超短脉冲光纤激光器和利用光纤器件对超短脉冲进行了波形变换技术的研究，主要研究内容如下： 详细研究了非线性偏振旋转超短脉冲光纤激光器和基于可饱和吸收体的被动锁模光纤激光器，比较分析了各自的优缺点。其中非线性偏振旋转锁模光纤激光器可以产生几ps宽度的超短脉冲，中心波长具有调谐宽带调谐功能，调谐范围达到30nm以上；实验中也发现了通过调谐偏振控制器获得双波长激光输出，双波长的特性与腔内双折射和增益谱线有关；基于可饱和吸收体的锁模光纤激光器可以产生400-700fs左右的超短脉冲，产生的超短脉冲相对于非线性偏振旋转更加稳定，且在低泵浦功率下更容易实现锁模。此外，在同一泵浦功率下，基于可饱和吸收体的锁模光纤激光器通过调谐偏振控制器可以产生多种脉冲输出状态，如调Q、调Q 锁模、完全锁模、二次谐波锁模、双脉冲、三个脉冲等，文中对此进行了详细分析。 研制了基于光纤器件的超短脉冲宽度测量自相关仪，测量范围为fs至百ps量级。与体光学系统相比，光纤自相关仪与被测的光纤激光系统具有良好的兼容性，且价格廉价、体积小、重量轻等优点。利用自相关仪对锁模光纤激光器的输出的脉冲宽度进行了测量，实验验证了光纤自相关仪的可行性和优越性。 利用悬臂梁的应力动态可调谐原理，分析了带宽1nm和色散量900ps/nm~1200ps/nm的线性啁啾光纤光栅和中心波长相匹配的0.15nm左右窄带滤波光纤光栅对超短脉冲波形和谱形的变换，实现了将超短脉冲从fs量级变换到百ps量级，并且波形在一定范围内具有动态可调谐的功能。通过实验验证了脉冲宽度调谐的合理性。此外，啁啾脉冲在放大过程中不可避免地存在增益窄化、增益饱和以及自相位调制等因素的影响，提出了利用光纤光栅进行光谱预整形的技术方案，并给出了初步实验验证。 利用超结构光纤光栅的脉冲波形变换技术和啁啾光纤光栅的时域泰伯效应，实现将一个超短脉冲变换为高重复频脉冲序列，然后通过光电转化获得了60GHz高频信号的产生。文中对系统中超结构光纤光栅和啁啾光纤光栅的设计参数作了理论数值分析，给出了相应理论验证，为以后实际系统的各种应用提供了理论指导。 提出采用级联GT干涉仪产生高频毫米波的系统方案，与单个GT干涉仪相比，级联GT干涉仪可以通过改变相对位置来控制脉冲在级联GT干涉仪之间的反射次数，最终达到调谐产生的脉冲包络和优化毫米波性能。文中对级联GT干涉仪的系统方案进行较为系统的理论分析，并构建了相应的实验测量装置，产生重复频率为23.6GHz超短脉冲序列，实验的结果与理论分析较好的吻合，验证了系统方案的合理性。 |
| 英文摘要 | Laser pulse shaping technology have a widespread application foreground for high-speed optical telecommunication, extremely high intensity laser-matter interactions, quantum dynamics control, High power pulse amplification source, biological medicine, all-optical switch, ultra-fast laser spectroscopy, nonlinear fiber optics and laser inertial Confinement Fusion experiment, which is now a very important research area in laser technology. With the fast development of fiber technology, some novel ultrashort pulse generation and pulse shaping technology based on fiber photonic components were put forward. The advantages of fiber photonic components over other pulse shaping technologies include the inherent all-fiber approach, compactness, low insertion loss, high stabilization and the potential for low cost. Ultrashort pulse fiber laser and pulse shaping devices are designed in such background. The main contents of the thesis are as follows: Nonlinear polarizer rotation (NPR) fiber laser and ultra-short pulse fiber laser based on semiconductor saturable absorber mirror (SESAM) are developed. NPR fiber laser can generate ps-width pulse with tunable central wavelength and 30nm tunable range can be achieved. Dual-wavelength operation and more in an erbium-doped fiber ring laser mode-locked through nonlinear polarization rotation technique can be obtained and the location of the dual wavelengths and the separation between them closely depend on the cavity birefringence and the profile of the gain medium.Fiber laser based on SESAM can generates pulse width with 400-700fs and higher stabilization. By using a SESAM in the EDFL cavity, stable Q-switching,Q-switched mode-locking, continuous-wave mode-locking, harmonic mode-locking,dual-pulse,triple-pulse operations and so on can be manipulated simply by tuning a polarization controller while keeping the pump power at the same level and the corresponding analysis were discussed. Autocorrelator based on fiber devices with measurement range from fs to hundred ps is developed. Experimentally, we measured the output pulse width of nonlinear polarization rotation mode-locked fiber laser which showed that the auto-correlator was feasible. Compared with bulk optical autocorrelator, the fiber auto-correlator and the fiber laser system possessed the characteristics of convenient connecting, easy structure and legerity, and so on. The tunable chirped FBG with 3dB bandwidth of 1nm and narrowband FBG with 3dB bandwidth of 0.15nm are designed and analyzed by cantilever beam dynamic tuning. Dispersion parameters of LCFBG can be tuned from 900ps/nm to 1200ps/nm and implement the tunable ultrashort pulse from fs to hundred ps range and verified the rationality in the experimental system. Moreover, gain narrowing, gain saturation and self-phase modulation have an important impact on chirped pulse amplification system and the output pulse spectrum has a great aberration. Therefore, the beforehand spectral shaping is proposed by superstructure FBG and the primary experiment demonstrate the rational scheme. A simple optical approach is proposed to generate high repetition rate pulse signal from single ultrashort pulse based on the pulse reshaping of superstructure fiber Bragg grating (SSFBG) and temporal Tablot effect of chirped FBG and achieve the 60GHz high frequency signal by photoelectric conversion. In our scheme, the relative parameters of the SSFBG and the linear chirped fiber Bragg grating (LCFBG) are analyzed and verfied theoretically, which can provide the theoretical guidance in the application system. A novel optical approach is proposed to generate millimeter-wave (MMW) pulse signal by high repetition-rate multiplication in two cascaded Gires-Tournois Interferometers (GTIs). Compared with single GTI, the cascaded GTIs can optimize the MMW pulse envelope and radio frequency (RF) signal performance by adjusting the space of cascaded GTIs to change the reflection times of optical propagating signal. The primary schemes on the cascaded GTIs are analyzed theoretically and measured experimentally.The 23.6GHz pulse sequence was acquired. It is shown that the good agreement between experimental results and theoretical simulations, which verified the feasibility in the Radio over Fiber (RoF) system. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15640]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 徐钦峰. 基于光纤器件的超短脉冲波形变换技术研究[D]. 中国科学院上海光学精密机械研究所. 2010. |
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