Author Affiliations
Abstract
1 State Key Laboratory of Energy Photon-Technology in Western China, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Northwest University, Xi’an 710127, China
2 Shaanxi Engineering Technology Research Center for Solid State Lasers and Application, Shaanxi Provincial Key Laboratory of Photo-electronic Technology, Northwest University, Xi’an 710127, China
We demonstrate a stable narrow linewidth single-frequency erbium-doped fiber laser (EDFL) operating at 1.6 µm. A Fabry–Perot fiber Bragg grating and two cascaded subrings are incorporated in the main ring cavity to achieve single-frequency operation. The experimentally measured optical signal-to-noise ratio is greater than 73 dB. Furthermore, the linewidth of the EDFL is measured to be about 480 Hz by the self-built short-delayed self-heterodyne interferometry device. The laser shows superior stability, with no mode-hopping during the 60-min observation period. The proposed EDFL provides a new experimental idea for realizing a single-frequency fiber laser in the L-band.
erbium-doped fiber laser two cascaded subrings single frequency Chinese Optics Letters
2024, 22(4): 041406
Author Affiliations
Abstract
State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon Technology, School of Physics, Northwest University, Xi’an 710069, China
We report a Yb-doped mode-locked fiber laser based on a nonlinear amplifying loop mirror (NALM), which is all-normal-dispersion (ANDi), and allows the output wavelength to be tunable. The laser can generate a stable femtosecond dissipative soliton with a maximum output power of 196 mW. Its repetition rate is 112.4 MHz, and the final pulse duration is 236 fs. By adjusting the angle of the reflective diffraction grating, the mode-locked fiber laser was realized to tune the output with a tuning range of 54 nm from 1011.8 nm to 1065.6 nm. To the best of our knowledge, this is the widest tuning range of an ANDi Yb-doped mode-locked fiber laser based on NALM.
all-normal-dispersion wavelength tuning mode-locked fiber laser Chinese Optics Letters
2023, 21(6): 061402
1 西北大学光子与光子技术研究所,陕西 西安 710127
2 浙江大学光电科学与工程学院,浙江 杭州 310007
Such as, by using the photothermal effect of materials, the surface tension of the lubrication layer on the surface of materials can be changed, thus creating a wetting gradient force to push the droplets to move. Further, the sliding and pinning of the droplet can be controlled by the phase change of the paraffin layer on some functional surfaces. The pyroelectric crystal can generate the dielectric force field on its surface based on the photothermal effect, which could be applied to realize the lossless moving, merging, and splitting of the droplets. In addition, the wettability of the photovoltaic crystals could be changed with the irradiation of light, therefore, can be used to control the behavior of droplets. In this paper, the development of the photo-responsive functional surface in droplet manipulation was briefly reviewed. The mechanisms of the droplet manipulation with the functional surface were expatiated. The categories of functional surfaces were summarized, the characteristics of the structure were analyzed, and the corresponding implementation method was introduced in detail. In addition, the applications of the photo-responsive functional surface in droplet transportation, fusion, and segmentation were introduced. Finally, the future development and potential applications of the photo-responsive functional surface for droplet manipulation were prospected.
光响应 功能表面 液滴操控 润湿性 photo-responsive functional surface droplet manipulation wettability
Author Affiliations
Abstract
1 State Key Laboratory of Energy Photon-Technology in Western China, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Northwest University, Xi’an 710127, China
2 Shaanxi Engineering Technology Research Center for Solid State Lasers and Application, Provincial Key Laboratory of Photo-Electronic Technology, Northwest University, Xi’an 710069, China
3 e-mail: lubaole1123@163.com
4 e-mail: baijt@nwu.edu.cn
Frequency detuning of mode-locked fiber lasers displays many remarkable nonlinear dynamical behaviors. Here we report for the first time the evolution of pulses from mode-locking through period pulsation to -switched mode-locking for three fundamental cases. Our experiments are performed in a hybrid actively and passively amplitude-modulated all-fiber polarization-maintaining mode-locked fiber laser, where the amplitude modulation frequency artificially deviates from the fundamental frequency of the cavity. We design and numerically simulate the laser with coupled Ginzburg–Landau equations. The experimentally observed dynamics of the mode detuning process is discussed with the assistance of the fitted model and numerical simulations, showing the generalizability of the optical mode detuning variation process. Our work provides fundamental insights for understanding perturbations in nonlinear optical resonant cavities and expands the ideas for studying chaotic path theory in hybrid mode-locked fiber lasers.
Photonics Research
2023, 11(3): 383
任丽 1,2,3孙博 1,2,3,*马丽 1,2,3冯晓强 1,2,3白晋涛 1,2,3
1 西北大学 光子学与光子技术研究所,陕西 西安 710127
2 省部共建西部能源光子技术国家重点实验室,陕西 西安 710127
3 西北大学 陕西省光电子技术重点实验室,陕西 西安 710127
对线性啁啾光纤光栅(LCFBG)进行局部点加热时,在不同加热温度、加热宽度和加热位置情况下的输出光谱特性进行了研究。通过数值模拟发现,改变栅区局部加热点的温度和宽度,对透射禁带中窄带透射峰的透射率有较为明显的影响,其透射峰的中心波长也将会发生一定的漂移;透射峰的中心波长与栅区局部加热点的位置存在线性对应关系,且透射峰波长变化范围可覆盖整个透射禁带;LCFBG啁啾系数的大小,决定了改变加热位置导致的透射峰波长的调谐速率。基于理论研究结果,以热敏打印头的加热阵列为加热源,对LCFBG栅区进行局部点加热时的输出光谱特性进行了实验研究,得到了重复性和稳定性都较好、可多波长调谐的窄带透射峰。在实验误差范围内,实验结果与数值模拟得到的结论较为一致。
线性啁啾光纤光栅 局部点加热 相位突变 窄带透射峰 linearly chirped fiber Bragg grating local point heating phase change narrow-band transmission peaks 红外与激光工程
2022, 51(8): 20210708
1 西北大学 光子学与光子技术研究所 省部共建西部能源光子技术国家重点实验室,陕西 西安 710127
2 国家级光电技术与纳米功能材料国际联合研究中心,陕西 西安 710127
3 陕西省光电子技术重点实验室 陕西省全固态激光及应用工程研究中心,陕西 西安 710127
基于光纤环形激光器,设计出由三端口环形器、偏振控制器、未泵浦保偏掺镱光纤和光纤布拉格光栅组成的滤波器件作为高精度滤波器对谐振腔内的模式个数进行抑制,通过调谐偏振控制器,在保偏掺镱光纤内形成的梳状光谱和动态光栅,实现了窄线宽、单、双波长可切换单频掺镱光纤激光器。单波长运行时,在1064.37 nm处测得激光器输出线宽346 Hz,光信噪比大于50 dB,30 min内该激光器波长及功率的不稳定性均在0.01 nm和0.2 dB范围内。通过调节偏振控制器,单波长和双波长可以实现互相切换,双波长分别位于1064.156 nm和1065.236 nm。该技术为超窄线宽激光器的双波长输出提供了新的途径。
光纤激光器 窄线宽 可切换 双波长 fiber laser narrow linewidth switchable double wavelength 红外与激光工程
2022, 51(6): 20220325
1 西北大学 光子学与光子技术研究所,省部共建西部能源光子技术国家重点实验室,西安 710127
2 国家级光电技术与纳米功能材料国际联合研究中心,西安 710127
3 陕西省全固态激光及应用工程技术研究中心,陕西省光电子技术重点实验室,西安 710127
超短脉冲光纤激光器是激光器领域的一个重要分支,由于输出脉冲峰值功率高、脉冲宽度窄,吸引了大量科研工作者的关注。被动锁模技术是产生超短脉冲的常用手段,通过平衡谐振腔内色散与非线性,增益与损耗之间的相互作用来实现超短脉冲输出。深入理解被动锁模机制能够进一步推动超快光源的研究走向成熟。随着输出性能的逐步提升,超短脉冲光纤激光器的适用场景越来越丰富,能在不同领域发挥更加重要的作用。本文综述了目前光纤激光器中常用的几类被动锁模技术,包括:非线性光纤环形镜、非线性偏转旋转、低维纳米材料可饱和吸收体、非线性多模干涉以及最近涌现的Mamyshev振荡器和时空锁模等,阐述了各自的原理以及技术优势,并介绍了其在超短脉冲光纤激光器研究方面的最新进展。
光子学报
2022, 51(10): 1014003
光子学报
2022, 51(10): 1014001
光子学报
2022, 51(10): 1012001
1 西部能源光子技术省部共建国家重点实验室,陕西 西安 710127
2 陕西省全固态激光及应用工程技术研究中心,陕西 西安 710127
3 西北大学光子学与光子技术研究所陕西省光电子技术重点实验室,陕西 西安 710127
4 湖北工业大学理学院,湖北 武汉 430068
拉盖尔-高斯旋转腔系统是获得光力学诱导透明(OMIT)效应的一种特殊装置,进一步提出在该腔中利用非线性耦合和轨道角动量(OAM)交换实现三阶克尔非线性效应的调控。利用系统的哈密顿模型可以得到克尔非线性解析表达式,经过数值模拟研究发现,当系统被调节到OMIT窗口附近时,携带OAM的光场会经历极小的吸收和强烈的色散,从而导致巨克尔非线性效应的产生。与传统的电磁诱导透明(EIT)和OMIT相比,该系统可以通过OAM和其他参数实现巨克尔非线性的调控。不仅如此,轨道角量子数还可以被用于控制光传播的群速度、实现快光和慢光效应。
非线性光学 克尔系数 轨道角动量 快慢光效应 光力学诱导透明 光学学报
2022, 42(22): 2219002