基于光子晶体光纤的可调谐光源产生及OPCPA相关技术研究
文献类型：学位论文
| 作者 | 王河林 |
| 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 | 徐至展 ; 冷雨欣 |
| 关键词 | 光子晶体光纤 超连续谱 调制不稳定性 光学参量啁啾脉冲放大 |
| 其他题名 | Tunable light source generation based on photonic crystal fiber and research on related techniques for OPCPA |
| 中文摘要 | 超强超短激光脉冲由于具有高的峰值功率和窄的脉冲宽度，可为众多学科领域研究提供前所未有的实验手段和极端物理条件。因此，超强超短激光技术的发展已成为了当今科学研究的重要领域之一。 光子晶体光纤(Photonic Crystal Fiber，PCF)由于具有色散可控，高非线性系数和单模传输等特性，使得它在可调谐光源产生、载波包络相位控制、光学相干层析成像、超连续谱产生、激光脉冲压缩和光学参量放大等领域具有广阔的应用前景。近年来，基于光子晶体光纤的可调谐光源的产生不仅为新波段、可调谐超短激光产生与应用开拓了新的研究方向，而且为超短激光脉冲放大技术的发展起了重要的推动作用。本论文主要研究光子晶体光纤在可调谐激光光源产生和控制，以及在光学参量啁啾脉冲放大(Optical Parametric Chirped Pulse Amplification, OPCPA)中的应用。本论文的主要结论和创新点概括如下： 1. 利用可调谐飞秒激光脉冲泵浦双零色散波长分别为1022 nm和1075 nm的光子晶体光纤，研究了高非线性光子晶体光纤中超连续谱的产生。将钛宝石振荡器输出中心波长在1064 nm附近可调的飞秒激光脉冲注入到光子晶体光纤后，由于泵浦脉冲波长靠近PCF的第二个零色散波长1075 nm且位于它的反常色散区，各种非线性效应的联合作用导致在泵浦脉冲两侧产生了双频段超连续谱，泵浦脉冲能量倒空现象发生。通过优化泵浦脉冲的功率和波长，最终获得了带宽为600 nm的超连续谱输出。 2. 理论和实验研究了高非线性保偏光子晶体光纤中的反斯托克斯频移现象。基于双折射光子晶体光纤中的四波混频，推导了不同相位匹配条件下的反斯托克斯频移量，详细分析了泵浦光能量，偏振方向和泵浦波长对反斯托克斯频移的影响。研究表明，反斯托克斯频移取决于功率相关和偏振相关的相位匹配条件。实验中，用钛宝石振荡器输出的1064 nm飞秒激光脉冲泵浦保偏光子晶体光纤， 在600 nm附近得到了反斯托克斯频移峰，且沿光纤两正交轴输出的光谱频移量约为189 THz。该实验结果和理论分析结果相吻合，说明通过控制泵浦光参数可以有效获得需要的可调谐光源。 3. 根据高双折射光子晶体光纤的结构参数，研究了泵浦光的偏振态对双色色散波产生的影响，首次提出了偏振相关的双色色散波产生的相位匹配理论。实验和理论结果表明，泵浦光的偏振方向决定了色散波的产生位置，这主要由于沿光纤快慢轴的色散不同，而不同的色散决定了不同的相位匹配，进而影响到色散波产生。实验中，当入射光偏振方向从光纤慢轴旋转到光纤快轴时，观察到明显的双色色散波产生现象，两色散波之间的频移量为18 nm，这与所提出的理论分析结果一致。 4. 通过理论分析和数值计算，得到了光纤中通用调制不稳定性增益公式。基于用全矢量有效折射率法和频域有限差分法设计的三种不同结构双零色散波长PCF，理论上研究了光纤结构，泵浦波长和泵浦功率对它们的调制不稳定性增益的影响。通过优化这些参数发现，当光纤参数为d/=0.676, =1.4，最优化泵浦功率、波长分别为250 W和1530 nm时，最优化调制不稳定性增益带宽可达到260 nm。 5. 利用光子晶体光纤产生的新波段可调谐光源，发展了基于光子晶体光纤的全光同步OPCPA激光放大器。将钛宝石振荡器输出的中心波长为850 nm的飞秒脉冲一部分注入到高双折射光子晶体光纤中，利用光纤的孤子自频移特性得到了1064 nm的孤子脉冲，该脉冲接着经过再生放大器和倍频晶体后，得到的中心波长为532 nm， 能量为2 mJ和脉冲宽度为235 ps的激光脉冲用来泵浦波长为850 nm的另一部分啁啾信号光脉冲，实现了1.8106倍的放大增益。 |
| 英文摘要 | Ultraintense and ultrashort laser pulse with high peak power and short pulse duration makes it possible to offer novel experimental methods and extreme physical conditions. Therefore the development of ultraintense and ultrashort laser technology has become one of the important research fields. Due to the advantages of photonic crystal fibers (PCFs), including controllable dispersion, high nonlinear coefficient and single mode etc., PCFs can be applied in many research fields, such as tunable light source generation, carrier-envelop phase control, optical coherence tomography, supercontinuum generation, laser pulse compression, optical parametric amplification etc.. In recent years, the tunable light source based on PCFs not only creats a new field for the generation and applification of new working wavelength and tunable ultrashort laser, but also promotes the development of ultrashort laser pulse amplification technology. Therefore, it is significant to study the applification of PCFs in the generation and control of tunable light source, and optical parametric chirped pulse amplification (OPCPA). The main results in this dissertation have been summarized as follows: 1. The supercontinuum generation in PCF with high nonlinear coeffiecient is investigated when the pulse from the tunable Ti: sapphire oscillator is injected into PCF with two zero-dispersion wavelengthes (ZDWs), 1022 nm and 1075 nm. The reseach results show that, when the tunable femtosecond pulse around 1064 nm is in the anomalous dispersion regime of the PCF and is close to its second ZDW 1075 nm, the corporate operation of different nonlinear effects results in two-band superconntinuum generation, and the energy depletion of pump pulse is observed. Further, the supercontinuum with about 600 nm bandwidth is obtained by optimizing the working wavelength and power of the pump pulse. 2. The anti-Stokes frequency shift characteristic in high nonlinearity polarization-maintaining PCF is investigated experimentally and theoretically. Based on phase-matching four-wave mixing (FWM) in PCF, the mount of anti-Stokes frequency shift is obtained in different phase-matching conditions, and the effect of pump pulse power, pump pulse wavelength, polarization direction on anti-Stokes frequency shift is analyzed in detail. The results show that, the anti-Stokes frequency shift depends on the power- , polarization-dependent phase matching conditions. In the experiment, the anti-Stokes peak at about 600 nm is observed with the 1064 nm femtosecond pulse pumping the NL-PM-780 PCF, and the frequency shift between the output spectra along the two-orthogonal axes of PCF is 189 THz, which is in good agreement with the theoretical simulations. It indicates that the tunable light source can be obtained by changing the pumping pulse parameters. 3. According to the structure parameters of high birefringent PCFs, the effect of pump-pulse polarization on two-color dispersion waves generations is studied, and phase matching theory on polarization-dependent two-color dispersion waves generation is firstly brought up. The theoritical and experimental results show that, the position of dispersion wave generation depends on the polarization direction of pump pulse, and the main reason is that the different dispersion values along the fiber fast/slow axis decide the different phase matching processes. In experiment, the two-color dispersion wave generation is observed in PCF when the polarization direction of the incident pulse is changed from the fiber slow axis to the fiber fast axis, and the frequency shift between them is 18 nm, which is in good agreement with the theoretical simulations. 4. By theoretical analysis and numerical simulation, the general expression of modulation instability (MI) gain in PCFs is obtained. Based on three kinds of designed PCFs with two ZDWs by using the improved full vector index method (IFVIM) and finite-difference frequency domain (FDFD) way, the effect of fiber structure, pump power and wavelength on MI gain is studied theoretically. By optimization, when the fiber parameters are d/=0.676, =1.4, pumping power and wavelength are 250 W and 1530 nm respectively, the optimal MI gain bandwidth can be increased to 260 nm. 5. The all-optical synchronization optical parametric chirped pulse amplification (OPCPA) system is developed with PCF-based tunable light pulses. The 850 nm femtosecond laser pulse from a Ti:sapphire oscillator is partly injected into a high-birefringnce PCF. Subsequently, a 1064 nm soliton pulse is generated due to soliton self-frequency shift effect in PCF, which is amplified in following Nd:YAG regenerative amplifier. Its double frequency light (532 nm) with the energy of 2 mJ and the duration of 235 ps is suitable for being used as a pump source in the OPCPA system, and the total 1.8106 amplifier gain is demonstrated for the 850 nm chirped pulse. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15632]  |
| 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 | 王河林. 基于光子晶体光纤的可调谐光源产生及OPCPA相关技术研究[D]. 中国科学院上海光学精密机械研究所. 2010. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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