合肥工业大学电子科学与应用物理学院光学工程系, 安徽 合肥 230601
设计了一种具有偏振滤波特性和保偏特性的空芯负曲率光纤 (HC-NCF), 并对其特性进行了分析。通过引入内包层管破坏常规 HC-NCF 的对称性, 使两个正交方向的基模和内包层玻璃管模式进行耦合, 从而增加两个偏振方向的折射率和损耗差异。进而对光纤双折射特性和损耗的影响因素进行分析, 包括内包层管的壁厚、内包层管的内直径和纤芯直径。结果表明, 当光纤纤芯直径和外包层管环内直径为 30 μm, 外包层和内包层管环壁厚分别为 1.116 μm 和 1.56 μm, 内包层管的内直径为 9 μm 时, 在 1.55 μm 波长处双折射达到 1.33×10-4，基模 x 偏振和 y 偏振方向的偏振消光比达到 4723 (36.7 dB)，并且偏振消光比大于 100 的带宽为 7 nm。 此外, 1.55 μm 波长处的最低损耗约为 0.03 dB/m。这种保偏 HC-NCF 可应用于对偏振敏感的光纤器件。
物理光学 负曲率光纤 双折射 限制损耗 偏振滤波 physical optics negative curvature fibers birefringence confinement loss polarization filter
实验研究了基于光纤布拉格光栅 (FBG) 的直接输出 1570 nm 单波长光纤激光器, 采用光纤耦合器搭建塞格纳克宽带反射器并与部分反射光纤光栅构建直腔激光器, 通过优化光栅反射率和输出方向实现了最高谐振效率为 24.42%、最大输出功率为 2.8 W、边模抑制比为 65 dB 的 1570 nm 光纤激光直接输出。通过增大腔长增加激光器谐振纵模数量, 从而基于纵模间的平均效应实现了 1570 nm 单波长光纤激光器的稳定无拍频输出, 进而利用该激光器作为掺铥光纤的泵浦源实现了 2 μm 波段光纤激光器被动锁模输出。
激光技术 中红外光纤激光器 光纤布拉格光栅 无拍频激光器 被动锁模 laser techniques mid-infrared fiber laser fiber Bragg grating beat-free laser passively mode-locking
Author Affiliations
Abstract
1 Department of Optical Engineering, School of Electronic Science & Applied Physics, Hefei University of Technology, Hefei 230601, China
2 School of Instrument Science and Opto-electronics Engineering, Hefei University of Technology, Hefei 230009, China
3 R&D Center of High Power Laser Components, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
4 Research Center for Advanced Photon Technology, Toyota Technological Institute, Nagoya 468-8511, Japan
Brillouin gain spectra (BGS) in an As2Se3 photonic crystal fiber (PCF) are investigated numerically. The profiles of the BGS are simulated by calculating the characteristics of different-order optical and acoustic waves in the PCFs with different core diameters. For the small-core PCF, there are two peaks in BGS, but there is only one peak for the large-core PCF. We also reveal that in the small-core PCF, the difference of Brillouin frequency shift between the LP01 and LP11 modes is obvious, while it is not obvious in the large-core PCF. The Brillouin threshold increases with the core diameter increasing.
stimulated Brillouin scattering optical mode acoustic mode chalcogenide fiber photonic crystal fiber Chinese Optics Letters
2020, 18(1): 010602
Author Affiliations
Abstract
Department of Optical Engineering, Hefei University of Technology, Hefei 230601, China
We propose a switchable multi-wavelength erbium-doped fiber laser based on a four-mode fiber Bragg grating (FBG). The four-mode FBG is fabricated in a hydrogen pre-loaded fiber by the phase mask method, which can support four linearly polarized modes around 1550 nm. The five operation wavelengths are at 1547.5, 1546.8, 1546.0, 1545.1, and 1544.2 nm, respectively. Through adjusting the polarization state and the lateral offset coupling in cavity, the laser can be switched into the operation state of single, dual, or triple wavelengths. The proposed laser has the advantages of simple configuration, stable operation, and easy adjustment.
060.3510 Lasers, fiber Chinese Optics Letters
2019, 17(1): 010604
Author Affiliations
Abstract
1 Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
4 School of Electronic Science & Applied Physics, Hefei University of Technology, Hefei 230009, China
High flatness, wide bandwidth, and high-coherence properties of supercontinuum (SC) generation in fibers are crucial in many applications. It is challenging to achieve SC spectra in a combination of the properties, since special dispersion profiles are required, especially when pump pulses with duration over 100 fs are employed. We propose an all-solid microstructured fiber composed only of hexagonal glass elements. The optimized fiber possesses an ultraflat all-normal dispersion profile, covering a wide wavelength interval of approximately 1.55 μm. An SC spectrum spanning from approximately 1030 to 2030 nm (corresponding to nearly one octave) with flatness <3 dB is numerically generated in the fiber with 200 fs pump pulses at 1.55 μm. The results indicate that the broadband ultraflat SC sources can be all-fiber and miniaturized due to commercially achievable 200-fs fiber lasers. Moreover, the SC pulses feature high coherence and a single pulse in the time domain, which can be compressed to 13.9-fs pulses with high quality even for simple linear chirp compensation. The Fourier-limited pulse duration of the spectrum is 3.19 fs, corresponding to only 0.62 optical cycles.
Fiber design and fabrication Photonic crystal fibers Nonlinear optics, fibers Pulse compression Femtosecond phenomena Supercontinuum generation Photonics Research
2018, 6(6): 06000601
1 合肥工业大学 电子科学与应用物理学院
2 仪器科学与光电工程学院 合肥 230009
3 合肥工业大学 电子科学与应用物理学院，合肥 230009
4 合肥工业大学 电子科学与应用物理学院，合肥 230009
5 仪器科学与光电工程学院 合肥 230009:
基于有限元算法建立用于刻写中红外光纤布喇格光栅(Fiber Bragg Grating, FBG)的相位模板物理模型，对相位模板的衍射光场进行模拟分析。在模拟过程中，采用平面波和球面波两种不同光源。采用平面波作为入射光时，通过改变平面波的入射角度和相位模板光栅的刻槽深度分析Talbot 衍射图样的变化。采用球面波作为入射光时，通过改变光源与相位模板的距离分析衍射图样的变化。结果表明，当平面波以任意角度斜入射时，沿与入射光相同方向形成Talbot 衍射图样。当改变相位模板刻槽深度时，Talbot 衍射图样的形状和能量分布均发生变化：随着刻槽深度的增加，衍射能量最大值逐渐变大；当刻槽超过一定深度时，能量最大值开始减小，同时Talbot 图像向均匀条纹演变。当球面波入射到相位模板时，Talbot 衍射图样沿球面波传播方向分布。随着球面波波源逐渐靠近相位模板，能量最大值逐渐升高；当超过一定距离时，能量最大值开始下降。
光纤布喇格光栅 相位模板 Talbot 衍射图样 有限元算法 fiber Bragg grating phase mask Talbot diffraction pattern finite element method
合肥工业大学光电技术研究院特种显示技术教育部重点实验室， 安徽 合肥 230009
介绍了固态体积式真三维立体显示的原理及组成部分，主要部分包括高速投影镜头和多平面光学元件。分析了其中高速投影镜头所需达到的参数要求，即过投影镜头中心光线的最大张角不超过14.5°。采用与照相物镜类似的方法设计该镜头，选用具有较大相对孔径的双高斯物镜作为基本类型，确定半部系统的参数，根据对称关系得到全系统。最后采用ZEMAX软件设计出适合项目要求的高速投影镜头。像差分析表明，全视场内最大垂轴像差为63.5 μm，最大横向色差小于2 μm，最大畸变为2.4%。全视场范围内调制传递函数大于0.2的截止频率超过50 lp/mm，能满足1024×768的分辨率要求。
投影镜头 固态体积式真三维 立体显示 像差校正 激光与光电子学进展
2010, 47(1): 011204
1 合肥工业大学光电技术研究院特种显示技术教育部重点实验室, 安徽 合肥 230009
2 中国科学技术大学物理系, 安徽 合肥 230026
对观察到的正色散腔被动锁模掺铒光纤激光器的实验现象进行了理论分析。采用Master方程对被动锁模脉冲的静态特性进行数值模拟, 结果显示正色散腔可以满足稳定性条件, 能够获得稳定的被动锁模脉冲, 并且正色散腔内的脉冲具有很强的啁啾特性。根据耦合非线性薛定谔方程, 对正色散腔内稳定脉冲的动态形成过程进行模拟, 初始的宽时域小信号经过在腔内多次运转后逐渐被放大并压窄, 最终形成稳定的锁模脉冲。对在该腔内观察到的多脉冲共存现象进行分析, 结果表明多脉冲共存是由于脉冲峰值功率的增加受到腔内功率透过率的限制所致, 并对多脉冲在腔内的演变过程进行数值模拟, 其结果与实验相吻合。
激光器 光纤激光器 被动锁模 正色散腔 非线性偏振旋转
