杨四刚 副研究员
中国北京市海淀区清华大学电子工程系 100084
电话： 86-
办公室位置：罗姆楼3-101
电子邮箱：ysg@tsinghua.edu.cn
个人简介: 杨四刚，湖北仙桃人。2008年于清华大学电子工程系毕业获工学博士学位。其间研究工作两次被光电子领域介绍研究进展的杂志Photonics Spectra予以专题报道。2008年8月至2010年7月在香港大学电机电子工程系从事博士后研究，从事光纤参量放大以及光纤参量振荡器的研究。现在清华大学电子工程系工作，任副研究员。过去及现在的主要研究方向有：光纤方向计算电磁学，光子晶体光纤，光纤非线性，光纤参量放大、参量振荡，硅基频率梳以及太赫兹波等。曾获2004年亚太光通信会议“ Best Student Paper Award”；清华大学2008年“优秀博士学位论文二等奖”等奖项。他是美国光学学会（OSA）的刊物Optics Letters, Optics Express, Journal of the Optical Society of America B, Applied Optics以及IEEE相关刊物的审稿人。

教育背景1996.9～2000.7 东北大学 学士
2000.9～2003.7 华中科技大学 硕士
2003.9～2008.2 清华大学 博士

工作履历2008.8～2010.7 香港大学电机与电子工程学系 博士后
2010.8至今 清华大学电子工程系 助理研究员、副研究员

学术兼职国际电子电气工程师协会（IEEE）会员
美国光学学会（OSA）会员
知名期刊审稿人：OSA OL/OE/JOSAB/AO/COL ；IEEE PTL/JLT

研究领域光子晶体光纤：是继基于传统掺杂工艺的单模光纤和高非线性光纤之后出现的一种新型光纤。其包层由折射率周期性分布的透光材料形成，纤芯由周期性被破坏的缺陷形成。按导光机理的不同，主要分为折射率引导型光子晶体光纤和光子带隙型光子晶体光纤。由于其独特的结构，其双折射、有效模式面积、色散、非线性等参数具有高度可调节性。使之在光谱学、生物医学、光纤传感、光纤激光器、非线性光学、光通信等领域具有广泛的应用前景。
光纤参量放大器和光纤参量振荡器：激光的出现，对人类的生活产生了革命性的影响。在一些新的应用领域，如生物、医疗、海洋开发以及大气探测等领域，需要在传统激光器不能覆盖的新波段工作的光源。光纤参量放大器具有带宽大、增益高、噪声低等特点。其突出的一个优点是其增益带宽由泵浦波长和增益介质共同决定。通过选择合适的泵浦波长和增益介质，几乎在可任意波段辐射。光子晶体光纤具有非常灵活的色散特性。基于光子晶体光纤的参量振荡器，可在传统激光器不能工作的波段提供可调谐的光辐射，是一种非常具有应用前景的新波长光源。
波长变换：全光波长变换，是通过非线性媒质，将已有波长变换到新的波长。 变换后的波长可以覆盖从紫外到中红外的大跨度波段。因此波长变换提供了一种产生特殊波长辐射的有效手段。光子晶体光纤由于其折射率调制大，具有高非线性，色散特性非常灵活，是进行波长变换的理想介质。因此，基于光子晶体光纤的波长变换，是目前研究的热点问题。
太赫兹波：太赫兹波是频率介于微波和红外之间的一种电磁辐射。作为连接传统电磁波和光波的桥梁, 太赫兹波兼具光波和微波的优点，被看作是电磁频谱研究中最后一个前沿领域。太赫兹波因在诸多领域具有重要的应用前景日益受到学术界和工业界的重视，是当前研究的难点和热点课题。主要研究太赫兹波的产生、传播以及应用等。

研究概况主要从事光纤及波导非线性研究。过去及现在的主要研究工作包括光纤方向计算电磁学、光子晶体光纤理论仿真、光纤非线性、光纤参量放大和参量振荡、太赫兹波、硅基频率梳等。实际指导的博士生2014年入选第19届清华大学“学术新秀”，并被评为2014年清华大学优秀博士毕业生。实际指导的博士论文“基于光子晶体光纤非线性效应的超宽带可调谐光源”入选”Springer Theses” (the best of best)以英文版出版。负责指导的硕士生一人被评为2014年北京市优秀毕业生。所发表论文中一篇被期刊Journal of Optics评为”Highlights of 2014”；一篇被期刊Electronics Letters予以专题报道；先后两次被Photonics Spectra予以专题报道。

学术成果Journal Papers
[1] Sigang Yang, Xiaojian Wang, Zhaohui Wu, Chen Jin, Minghua Chen, Shizhong Xie, Narrow linewidth terahertz generation engined by all-fiber parametric optical source, IEEE Photonics Journal, 7(6), **, 2015.
[2] Lei Zhang&, Sigang Yang*,Xiaojian Wang, Doudou Gou, Hongwei Chen, Minghua Chen, and Shizhong Xie, Demonstration of optical parametric gain generation at 1 μm regime based on a photonic crystal fiber pumped by picosecond mode-locked ytterbium- doped fiber laser, Journal of Optics, 16(1), 015202, 2014.
[3] Lei Zhang&, Sigang Yang*, Xiaojian Wang, Doudou Gou,Wei Chen, Wenyong Luo, Hongwei Chen, Minghua Chen, and Shizhong Xie, Photonic Crystal Fiber Based Wavelength- Tunable Optical Parametric Amplifier and Picosecond Pulse Generation，IEEE Photonics Journal, 6(5),**, 2014.
[4] Lei Zhang&, Sigang Yang*, Xiaojian Wang, Doudou Gou, Hongwei Chen, Minghua Chen, and Shizhong Xie, High-efficiency all-fiber optical parametric oscillator based on photonic crystal fibers pumped by ytterbium-doped fiber laser, Electronics Letters, 50(8), 624-626,2014.
[5] Lei Zhang&, Sigang Yang*, Xiaojian Wang, Doudou Gou, Hongwei Chen, Minghua Chen, and Shizhong Xie, Picosecond photonic crystal fiber-based doubly resonant optical parametric oscillator, IEEE Photonics Technology Letters, 26(7), 682-685, 2014.
[6] Gou Dou-Dou&, Yang Si-Gang*, Zhang Lei,Wang Xiao-Jian, Chen Hong-Wei, Chen Ming-Hua,Xie Shi-Zhong, Chen Wei, and Luo Wen-Yong, Fiber optical parametric oscillator based on photonic crystal fiber pumped with all-normal-dispersion mode-locked Yb:fiber laser, Chinese Physics B, 23(11), 114204,2014.
[7] Lei Zhang, Sigang Yang, Ying Han, Hongwei Chen, Minghua Chen, and Shizhong Xie, Optical parametric generation with two pairs of gain bands based on a photonic crystal fiber, Optics Communications, 300, 22-26, 2013.
[8] Lei Zhang&, Sigang Yang*, Xiaojian Wang, Doudou Gou, Xiangliang Li, Hongwei Chen, Minghua Chen, and Shizhong Xie, Widely tunable all-fiber optical parametric oscillator based on a photonic crystal fiber pumped by a picosecond ytterbium-doped fiber laser, Optics Letters, 38(22), 4534-4537, 2013.
[9] Lei Zhang&, Sigang Yang*, Pengxiao Li, Xiaojian Wang, Doudou Gou, Wei Chen, Wenyong Luo, Hongwei Chen, Minghua Chen, and Shizhong Xie, An all-fiber continuously time-dispersion- tuned picosecond optical parametric oscillator at 1 μm region, Optics Express, 21(21), 25167-25173,2013.
[10] Lei Zhang&, Sigang Yang*, Ying Han, Hongwei Chen, Minghua Chen, and Shizhong Xie, Simultaneous generation of tunable giant dispersive waves in the visible and mid-infrared regions based on photonic crystal fibers, Journal of Optics, 15(7), 075201,2013.
[11] Sigang Yang, Kenneth K. Y. Wong, Minghua Chen, Shizhong Xie，Fiber Optical Parametric Oscillator Based on Highly Nonlinear Dispersion-Shifted Fiber，Frontiers of Optoelectronics，6(1):25-29, 2013. Invited.
[12] Feifei Yin, Sigang Yang, Hongwei Chen, Minghua Chen, and Shizhong Xie, Tunable single-longitudinal-mode Ytterbium all fiber laser with saturable-absorber-based auto-tracking filter. Optics Communications. 285:2702-2706, 2012.
[13] Feifei Yin, Sigang Yang, Hongwei Chen, Minghua Chen, and Shizhong Xie, 60-nm-wide Tunable Single-longitudinal-mode Ytterbium Fiber Laser with Passive Multiple Ring Cavity, IEEE Photonics Technology Letters. 23(22):1658-1660, 2011.
[14] Sigang Yang, Chi Zhang, Yue Zhou, and Kenneth Kin-Yip Wong, “Two-Wavelength Square-Waveform Generation Based on Fiber Optical Parametric Oscillator,” IEEE Transactions on Microwave Theory and Techniques, 58(11): 3381-3386,2010.
[15] Sigang Yang, Kim K. Y. Cheung, Yue Zhou, and Kenneth K. Y. Wong, “Tunable Single-Longitudinal-Mode Fiber Optical Parametric Oscillator,” Optics Letters, 35(4):481-483, 2010.
[16] Sigang Yang, Kim K. Y. Cheung, Yue Zhou, and Kenneth K. Y. Wong, “Dispersion-Tuned Harmonically Mode-Locked Fiber-Optical Parametric Oscillator,” IEEE Photonics Technology Letters,22(8):580-582,2010.
[17] Sigang Yang, Yue Zhou, Jia Li, and Kenneth K.-Y. Wong, “Actively Mode-Locked Fiber Optical Parametric Oscillator,” IEEE Journal of Selected Topics in Quantum Electronics, 15(2):393-398, 2009.
[18] Sigang Yang, Xing Xu, Yue Zhou, Kim K. Y. Cheung, and Kenneth K. Y. Wong, “Continuous-Wave Single-Longitudinal-Mode Fiber Optical Parametric Oscillator with Reduced Pump Threshold,” IEEE Photonics Technology Letters,21(24):1870-1872, 2009.
[19]Sigang Yang, Hongwei Chen, Ciyuan Qiu,Ming Chen,Minghua Chen,Shizhong Xie,Jinyan Li and Wei Chen. “Slow-light delay enhancement in small-core pure silica photonic crystal fiber based on Brillouin scattering,” Optics Letters, 33(2),95-97,2008.
[20] Sigang Yang, Yejin Zhang, Jinyan Li, Wei Chen, Lina He, and Shizhong Xie. “Experimental Study of Mode Field Evolution of Dual-Core Photonic Crystal Fiber,” IEEE Photonics Technology Letters, 19(19):1523- 1525,2007.
[21] Sigang Yang, Yejin Zhang, Lina He, and Shizhong Xie. “Broadband dispersion-compensating photonic crystal fiber,” Optics Letters, 31(19):2830-2832,2006.
[22] Sigang Yang, Yejin Zhang, Xiaozhou Peng, Yang Lu, Shizhong Xie. “Theoretical study and experimental fabrication of high negative dispersion photonic crystal fiber with large area mode field,” Optics Express, 14(7):3015-3023, 2006.
Conference Papers
[1] Sigang Yang, Xiaojian Wang, Chen Jin, Donghui Jin, Hongwei Chen, Minghua Chen, Shizhong Xie，Optical generation of Terahertz based on all fiber highly coherent optical parametric light source， 40th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2015), H3A3.
[2] Zhaohui Wu,Sigang Yang, Xiaojian Wang, Minghua Chen,Hongwei Chen, Shizhong Xie, Widely Tunable Narrowband Terahertz Source Based on Difference Frequency Generation from Parameter Light Source, Asia Communications and Photonics Conference (ACP) 2015, ASu3C.2.
[3] Chen Jin,Sigang Yang, Xiaojian Wang, Minghua Chen,Hongwei Chen, Shizhong Xie, Stable Nanosecond Chirp-free Pulse Generation with Ultra-narrow Bandwidth from a Passively CW Mode-locked Fiber Laser, Asia Communications and Photonics Conference (ACP) 2015, AM3B.5.
[4] Lei Zhang&, Sigang Yang*, Hongwei Chen, Minghua Chen, and Shizhong Xie, Broadly time-dispersion-tuned narrow linewidth all-fiber-integrated optical parametric oscillator, Optical Fiber Communication Conference, OFC: 2014, W4E.2.
[5] Lei Zhang&, Sigang Yang*, Hongwei Chen, Minghua Chen, and Shizhong Xie, Ultraviolet-shift supercontinuum generation by cross-phase modulation in photonic crystal fiber，2013 Conference on Lasers and Electro-Optics: Laser Science to Photonic Applications, CLEO: 2013, JW2A.13.
[6] Lei Zhang&, Sigang Yang*, Hongwei Chen, Minghua Chen, and Shizhong Xie, Wavelength-tunable red-shift Cherenkov radiation in photonic crystal fibers for mid-infrared wavelength generation, 18th Opto-Electronics and Communications Conference, OECC: 2013, WS4-4.
[7] Doudou Gou&, Sigang Yang*, Lei Zhang, Xiaojian Wang, Hongwei Chen, Shizhong Xie, Theoretical design and experimental demonstration of photonic crystal fibers operating for parametric generation near 1.06 um, Asia Communications and Photonics Conference. ACP, 2013.
[8] Doudou Gou&, Sigang Yang*,Feifei Yin, Lei Zhang, Xiaojian Wang, Hongwei Chen, Shizhong Xie, SESAM-based ring-cavity all-normal-dispersion tunable ytterbium mode-locked fiber laser, 18th Opto-Electronics and Communications Conference, OECC: 2013.
[9] Xiaojian Wang&, Sigang Yang*, Lei Zhang, Hongwei Chen, Minghua Chen, Shizhong Xie, Theoretical modeling and experimental verification of optical parametric amplifier based on photonic crystal fiber at 1 um band, Asia Communications and Photonics Conference. ACP, 2013.
[10] Sigang Yang, Qin Li, K.S. Lui, and Kenneth K. Y. Wong, FM Mode-Locked Fiber Optical Parametric Oscillator, 37th European Conference on Optical Communication (ECOC). 2011. We.10.P1.04.
[11]Sigang Yang, Chi Zhang, Yue Zhou, and Kenneth K. Y. Wong, “Photonic Generation of Square Waveform Based on Fiber Optical Parametric Oscillator,” paper JTuD82, 2010 Conference on Lasers and Electro Optics/ Quantum Electronics and Laser Science Conference (CLEO/QELC), San Jose, California, USA (May 2010).
[12] Sigang Yang, Kim K. Y. Cheung, Xing Xu, Yue Zhou, and Kenneth K. Y. Wong, “Tunable Single-Longitudinal-Mode Fiber Optical Parametric Oscillator with Saturable-Absorber-Based Auto-Tracking Filter,” paper JWA16, 2010 Optical Fiber Communication Conference (OFC), San Diego, California, USA (March 2010).
[13] Sigang Yang; Jia Li; Yue Zhou; Wong, K.K.Y, “Actively mode-locked fiber optical parametric oscillator,” paper JWA12, 2009 Optical Fiber Communication Conference (OFC), San Diego, California, USA (March 2009).
[14]Sigang Yang, Yu Liang, Xing Xu, Kenneth K. Y. Wong, “Single-Longitudinal-Mode Continuous-Wave Fiber Optical Parametric Oscillator,” paper 7.1.3, 35nd European Conf. on Optical Communications (ECOC), Vienna, Austria(Sept. 2009).
[15]Sigang Yang, Xing Xu, and Kenneth K. Y. Wong, “Low threshold, dual-cavity continuous-wave fiber optical parametric oscillator,” paper TuA7, 14th OptoElectronics and Communications Conference (OECC), Hong Kong, China (2009).
[16] Sigang Yang, Yejin Zhang, Lina He, Shizhong Xie. “Experimental demonstration of very high negative chromatic dispersion dual-core photonic crystal fiber,” paper OThA6, 2007 Optical Fiber Communication Conference (OFC), Anaheim, California, USA (March 2007).
[17] Sigang Yang, Yejin Zhang, Shizhong Xie. “Transformation of a single mode photonic crystal fiber into a tunable dispersion compensator,” paper We3.P.1, 32nd European Conference on Optical Communication(ECOC), Cannes, France (Sept.2006).
[18] Sigang Yang, Yejin Zhang, Shizhong Xie. “Tunable Optical Filter Employing a Novel Quartz Cavity Etalon by Precise Angle Tuning,” 2006 Asia-Pacific Optical Communication Conference (APOC), Gwangju, South Jeolla, South Korea (2006).
[19] Sigang Yang,Yejin Zhang,Xiaozhou Peng,Xiangfei Chen,Shizhong Xie. “Analysis and evaluation of the effect of fabrication-related structure fluctuations on the loss of photonic crystal fibers,” 2004 Asia-Pacific Optical Communication Conference (APOC), Beijing, China (Nov. 2004).