About Us

    Welcome to the Song Group website (currently under construction). We are interested in nanophotonics, passive-cooling, topological materials, metamaterials, and quantum photonics. We engage in both theoretical and experimental studies. Our research finds applications in sustainable energy, information processing, directed energy, and integrated devices.

    Dr. Song joined the University of Sydney in 2021 as a senior lecturer. Before, he was a postdoctoral fellow working with Prof. Shanhui Fan at Stanford University, where he focused on nanophotonics, topological materials, thermal photonics, and renewable energy. He developed the passive cooling textiles together with his collaborators. He also discovered several new effects in fundamental photonics such as the topological edge-gain effect and $\mathcal{PT}$-symmetric optical non-reciprocity. His thesis work was carried out in Prof. Claire Gmachl's group at Princeton University. There, he theoretically studied semiconductor quantum structures using techniques such as the non-equilibrium Green's functions. Experimentally, he developed several novel quantum-cascade light sources and detectors.

    Openings:
    We have one open Ph.D. position in theoretical nanophotonics. If you are interested, please feel free to contact us at alex.song (at) sydney.edu.au.

Journal Publications

  1. Mansi Goyal, Changrong Shi, Morteza Hassanpour, Jingsan Xu, Xinshu Zhuang, Xueping Song, Alex Y. Song, and Zhanying Zhang, "Exploring chiral photonic cellulose nanocrystal composites: From self-assembly to advanced applications", Advances in Colloid and Interface Science 347, 103688 (2026)
  2. Zhewen Ma, Yuanhao Feng, Alex Y. Song, Toan Dinh, Min Hong, John Bell, Boyou Hou, Pingan Song, and Wei Zheng, "A Scalable, Durable, Fire-Safe All-Day Passive Radiative Cooling Coating for Sustainable Buildings", Advanced Functional Materials, e17278 (2025)
  3. Zhuoyuan Lu, Jiri Janousek, Syed M. Assad, Shuyao Qiu, Mayank Joshi, Yecheng Hu, Alex Y. Song, Chuanyu Wang, Manuka Suriyage, Jie Zhao, Ping Koy Lam, and Yuerui Lu, "Counter-propagating entangled photon pairs from monolayer GaSe", Nature Communications 16(1), 9616 (2025)
  4. Jadon Y. Lin, C. Martijn de Sterke, Michael S. Wheatland, Alex Y. Song, and Boris T. Kuhlmey, "All-optical damping forces enhanced by metasurfaces for stable relativistic lightsail propulsion", Physical Review Applied 22(6), 064028 (2024)
  5. Alessandro Tuniz, Alex Y. Song, Giuseppe Della Valle, and C. Martijn de Sterke, "Coupled mode theory for plasmonic couplers", Applied Physics Reviews 11(2), 021309 (2024)
  6. Akhil Kalapala, Alex Y. Song, Mingsen Pan, Chhabindra Gautam, Luke Overman, Kevin Reilly, Thomas J. Rotter, Ganesh Balakrishnan, Ricky Gibson, Robert Bedford, James J. Coleman, Shanhui Fan, and Weidong Zhou, "Scaling Challenges in High Power Photonic Crystal Surface-Emitting Lasers", IEEE Journal of Quantum Electronics 58(4), 2400409 (2022)
  7. Alessandro Tuniz, Alex Y. Song, Giuseppe Della Valle, and C. Martijn de Sterke, "Plasmonic Sensors beyond the Phase Matching Condition: A Simplified Approach", Sensors 22(24), 9994 (2022)
  8. Alex Y. Song, Akhil Raj Kumar Kalapala, Ricky Gibson, Kevin James Reilly, Thomas Rotter, Sadhvikas Addamane, Haiwen Wang, Cheng Guo, Ganesh Balakrishnan, Robert Bedford, Weidong Zhou, and Shanhui Fan, "Controllable finite ultra-narrow quality-factor peak in a perturbed Dirac-cone band structure of a photonic-crystal slab", Applied Physics Letters 119(3), 031105 (2021) (Editor's Pick)
  9. Haiwen Wang, Cheng Guo, Weiliang Jin, Alex Y. Song, and Shanhui Fan, "Engineering arbitrarily oriented spatiotemporal optical vortices using transmission nodal lines", Optica 8(7), 966 (2021)
  10. Siddharth Buddhiraju, Alex Song, Georgia T. Papadakis, and Shanhui Fan, "Nonreciprocal Metamaterial Obeying Time-Reversal Symmetry", Physical Review Letters 124(25), 257403 (2020)
  11. Momchil Minkov, Ian A. D. Williamson, Lucio C. Andreani, Dario Gerace, Beicheng Lou, Alex Y. Song, Tyler W. Hughes, and Shanhui Fan, "Inverse Design of Photonic Crystals through Automatic Differentiation", ACS Photonics 7(7), 1729–1741 (2020)
  12. Alex Y. Song, Xiao-Qi Sun, Avik Dutt, Momchil Minkov, Casey Wojcik, Haiwen Wang, Ian A. D. Williamson, Meir Orenstein, and Shanhui Fan, "\(\mathcal{PT}\)-symmetric topological edge-gain effect", Physical Review Letters 125(3), 033603 (2020)
  13. Ian A. D. Williamson, Momchil Minkov, Avik Dutt, Jiahui Wang, Alex Y. Song, and Shanhui Fan, "Integrated Nonreciprocal Photonic Devices With Dynamic Modulation", Proceedings of the IEEE 108(10), 1759–1784 (2020)
  14. Siddharth Buddhiraju, Yu Shi, Alex Song, Casey Wojcik, Momchil Minkov, Ian A. D. Williamson, Avik Dutt, and Shanhui Fan, "Absence of unidirectionally propagating surface plasmon-polaritons at nonreciprocal metal-dielectric interfaces", Nature Communications 11(1), 674 (2020)
  15. Alex Y. Song, Yu Shi, Qian Lin, and Shanhui Fan, "Direction-dependent parity-time phase transition and nonreciprocal amplification with dynamic gain-loss modulation", Physical Review A 99(1), 013824 (2019)
  16. Lili Cai, Alex Y. Song, Wei Li, Po-Chun Hsu, Dingchang Lin, Peter B. Catrysse, Yayuan Liu, Yucan Peng, Jun Chen, Hongxia Wang, Jinwei Xu, Ankun Yang, Shanhui Fan, and Yi Cui, "Spectrally Selective Nanocomposite Textile for Outdoor Personal Cooling", Advanced Materials 30(35), 1–7 (2018)
  17. Alex Y. Song, Peter B. Catrysse, and Shanhui Fan, "Broadband Control of Topological Nodes in Electromagnetic Fields", Physical Review Letters 120(19), 193903 (2018)
  18. Yucan Peng, Jun Chen, Alex Y. Song, Peter B. Catrysse, Po-Chun Hsu, Lili Cai, Bofei Liu, Yangying Zhu, Guangmin Zhou, David S. Wu, Hye Ryoung Lee, Shanhui Fan, and Yi Cui, "Nanoporous polyethylene microfibres for large-scale radiative cooling fabric", Nature Sustainability 1(2), 105–112 (2018)
  19. Alex Y. Song, Akhil Raj Kumar Kalapala, Weidong Zhou, and Shanhui Fan, "First-principles simulation of photonic crystal surface-emitting lasers using rigorous coupled wave analysis", Applied Physics Letters 113(4), 041106 (2018)
  20. Lili Cai, Alex Y. Song, Peilin Wu, Po-Chun Hsu, Yucan Peng, Jun Chen, Chong Liu, Peter B. Catrysse, Yayuan Liu, Ankun Yang, Chenxing Zhou, Chenyu Zhou, Shanhui Fan, and Yi Cui, "Warming up human body by nanoporous metallized polyethylene textile", Nature Communications 8(1), 496 (2017)
  21. Po-chun Hsu, Chong Liu, Alex Y Song, Ze Zhang, Yucan Peng, Jin Xie, Kai Liu, Chun-lan Wu, Peter B Catrysse, Lili Cai, Shang Zhai, Arun Majumdar, Shanhui Fan, and Yi Cui, "A dual-mode textile for human body radiative heating and cooling", Science Advances 3(11), e1700895 (2017)
  22. Alex Y. Song, Rajaram Bhat, Pierre Bouzi, Chung-En Zah, and Claire F. Gmachl, "Three-dimensional interface roughness in layered semiconductor structures and its effect on intersubband transitions", Physical Review B 94(16), 165307 (2016)
  23. Po-Chun Hsu, Alex Y. Song, Peter B. Catrysse, Chong Liu, Yucan Peng, Jin Xie, Shanhui Fan, and Yi Cui, "Radiative human body cooling by nanoporous polyethylene textile", Science 353(6303), 1019–1023 (2016)
  24. Peter B. Catrysse, Alex Y. Song, and Shanhui Fan, "Photonic Structure Textile Design for Localized Thermal Cooling Based on a Fiber Blending Scheme", ACS Photonics 3(12), 2420–2426 (2016)
  25. Alex Y. Song, Rajaram Bhat, Andrew A. Allerman, Jie Wang, Tzu-Yung Huang, Chung-En Zah, and Claire F. Gmachl, "Quantum cascade emission in the III-nitride material system designed with effective interface grading", Applied Physics Letters 107(13), 132104 (2015)
  26. Omri Wolf, Andrew A. Allerman, Xuedan Ma, Joel R. Wendt, Alex Y. Song, Eric A. Shaner, and Igal Brener, "Enhanced optical nonlinearities in the near-infrared using III-nitride heterostructures coupled to metamaterials", Applied Physics Letters 107(15) (2015)
  27. Yu Song, Rajaram Bhat, Tzu-Yung Huang, Pranav Badami, Chung-En Zah, and Claire Gmachl, "III-nitride quantum cascade detector grown by metal organic chemical vapor deposition", Applied Physics Letters 105(18), 182104 (2014)
  28. Yu Song, Jens Sonntag, Sergey B. Mirov, Claire F. Gmachl, and Jacob B. Khurgin, "Mid-infrared light emission from a Fe\(^{2+}\):ZnSe polycrystal using quantum cascade laser pumping", Applied Physics Letters 105(14), 141108 (2014)
  29. Pierre M. Bouzi, YenTing Chiu, Christoph Deutsch, Yamac Dikmelik, Yu Song, Vadim Tokranov, Serge Oktyabrsky, and Claire Gmachl, "Importance of growth direction in mid-infrared quantum cascade lasers", Journal of Applied Physics 116(3) (2014)
  30. Chao Wang, Qi Zhang, Yu Song, and Stephen Y. Chou, "Plasmonic Bar-Coupled Dots-on-Pillar Cavity Antenna with Dual Resonances for Infrared Absorption and Sensing: Performance and Nanoimprint Fabrication", ACS Nano 8(3), 2618–2624 (2014)
  31. Yu Song, Dong Chen, Lai Wang, Hongtao Li, Guangyi Xi, and Yang Jiang, "Splitting of valance subbands in the wurtzite c-plane InGaN/GaN quantum well structure", Applied Physics Letters 93(16) (2008)
  32. Huang Jin, Sun Chang-Zheng, Song Yu, Xiong Bing, and Luo Yi, "Phase Noise of Optically Generated Microwave Using Sideband Injection Locking", Chinese Physics Letters 25(11), 3980–3983 (2008)
  33. Ming Gao, Liheng Rong, Yinxiang Xiong, Wei Xie, Mansi Goyal, Xiyuan Wang, Preethi Shanmugam, Yecheng Hu, Sid Assawaworrarit, Simon C. Fleming, C Martijn de Sterke, Judith M. Dawes, Zhanying Zhang, Shanhui Fan, Boris T. Kuhlmey, and Alex Y. Song, "Passive cooling cotton", under review in Nature
These authors contributed equally.

Conference Presentations

  1. Alex Y. Song, "To see light from just one angle", The 30th International Conference on Optical MEMS and Nanophotonics (OMN), 2025
  2. Ming Gao, Yinxiang Xiong, Boris T. Kuhlmey, C. Martijn de Sterke, Simon Fleming, and Alex Y. Song, "Enhanced solar reflection in zinc oxide nanoparticle attached cotton", The Australian and New Zealand Conference on Optics and Photonics (ANZCOP), 2024
  3. Liam P. van Ravenstein, Jadon Y. Lin, C. Martijn de Sterke, Alex Y. Song, Michael S. Wheatland, and Boris T. Kuhlmey, "Rotational relativistic damping and linear stability analysis of lightsails", The Australian and New Zealand Conference on Optics and Photonics (ANZCOP), 2024
  4. Ming Gao, Yinxiang Xiong, and Alex Y. Song, "", 2024 International Symposium on Advanced Materials & Sustainable Technology, 2024
  5. Yecheng Hu and Alex Y. Song, "Fragility of edge states in topological photonic structures", The International Conference on Nanomaterials & Atomaterials Science and Applications (INCASA), 2024
  6. Wei Wen Wong, Tuomas Haggren, Dragomir Neshev, Hark Hoe Tan, Andrey Sukhorukov, Chennupati Jagadish, and Alex Y. Song, "Scaling of Single-Mode Surface-Emitting Lasers with a Perturbed Dirac-Cone", IEEE 29th International Semiconductor Laser Conference (ISLC), ME1, 2024
  7. Yecheng Hu and Alex Y. Song, "Fragility of edge states in topological photonic structures", The Australian and New Zealand Conference on Optics and Photonics (ANZCOP), 2023
  8. Jadon. Y. Lin, C. Martijn de Sterke, Michael S. Wheatland, Alex Y. Song, and Boris T. Kuhlmey, "Generalized Poynting-Robertson damping of relativistic lightsails: orders of magnitude improvements of stability through optical design", The Australian and New Zealand Conference on Optics and Photonics (ANZCOP), 2023
  9. Alex Y. Song, "Rigorous coupled-wave analysis for the bound states in the continuum and the guided modes below the light cone", CLEO: Fundamental Science, FW4C.2, 2023
  10. Haiwen Wang, Cheng Guo, Weiliang Jin, Alex Y. Song, and Shanhui Fan, "", CLEO: QELS Fundamental Science, JTh4Q.4, 2022
  11. Alex Y. Song, Xiao-Qi Sun, Avik Dutt, Momchil Minkov, Casey Wojcik, Haiwen Wang, Ian Williamson, Meir Orenstein, and Shanhui Fan, "$\mathcalPT$-symmetric topological edge-gain effect", CLEO: Science and Innovations, FM2A.2, 2020
  12. Alex Y. Song, Akhil Raj Kumar Kalapala, Weidong Zhou, and Shanhui Fan, "First-principles simulation of photonic-crystal surface-emitting lasers using rigorous coupled wave analysis", SPIE Photonics West, Proceedings of SPIE, Novel In-Plane Semiconductor Lasers XVIII, 1093908, 2019
  13. Akhil R. K. Kalapala, Weidong Zhou, Seungwon Yeom, Sadhvikas J. Addamane, Kevin J. Reilly, Alex Song, Ricky Gibson, Ganesh Balakrishnan, Robert Bedford, and Shanhui Fan, "Optically Pumped 1 $\mu$m Low Threshold Photonic Crystal Surface Emitting Lasers Grown on GaAs Substrate", 2019 IEEE Photonics Conference (IPC), 1–2, 2019
  14. Alex Y. Song, Peter B. Catrysse, and Shanhui Fan, "Broadband Control of Topological Nodes in Electromagnetic Fields", CLEO: Science and Innovations, FTu3E.7, 2018
  15. Yu Song, Rajaram Bhat, Andrew Allerman, Tzu-Yung Huang, Chung-En Zah, and Claire Gmachl, "Light emission from III-nitride quantum cascade structures designed with effective interface grading", SPIE Photonics West, 2015
  16. Yu Song, Rajaram Bhat, Andrew Allerman, Tzu-Yung Huang, Chung-En Zah, and Claire Gmachl, "", International Quantum Cascade Lasers School & Workshop, 2014
  17. Yu Song, Rajaram Bhat, Andrew Allerman, Tzu-Yung Huang, Pranav Badami, Chung-En Zah, and Claire Gmachl, "Effect of Interface Roughness in Ultra-Thin Semiconductor Quantum Wells", CLEO: Science and Innovations, STh4I.2, 2014
  18. Yu Song, Rajaram Bhat, Pierre Bouzi, Chung-En Zah, and Claire Gmachl, "Effect of Interface Roughness in Ultra-Thin Semiconductor Quantum Wells", APS March Meeting, L45.00011, 2014
  19. Yu Song, Rajaram Bhat, Chung-En Zah, Pranav Badami, Tzu-Yung Huang, and Claire Gmachl, "", International Conference on Intersubband Transitions in Quantum Wells, 2013
  20. Yu Song, Sergey B. Mirov, Claire F. Gmachl, and Jacob B. Khurgin, "Photoluminescence Characteristics of Fe\textsuperscript2+ Doped ZnSe Polycrystal with Quantum Cascade Laser Pumping", CLEO: Science and Innovations, CF1I.1, 2013
  21. Yu Song, Rajaram Bhat, Chung-En Zah, and Claire Gmachl, "", International Quantum Cascade Lasers School & Workshop, 2012
  22. Yu Song, Sergey B. Mirov, Claire F. Gmachl, and Jacob B. Khurgin, "Photoluminescence in a Fe\textsuperscript2+ Doped ZnSe crystal using near absorption edge Quantum Cascade Laser pumping", CLEO: Science and Innovations, CTu2D.3, 2012
  23. Yu Song, Yamac Dikmelik, Claire F. Gmachl, and Jacob B. Khurgin, "Analytical modeling of Quantum Cascade lasers: A study of the transport and lasing characteristics", CLEO: Quantum Electronics and Laser Science, JW2A.93, 2012
  24. Yu Song, Yamac Dikmelik, and Jacob B. Khurgin, "", International Conference on Intersubband Transitions in Quantum Wells, 2011
  25. Yu Song, Jacob B. Khurgin, and Yamac Dikmelik, "", SPIE Photonics West, 2011
  26. Yu Song, Matthew Escarra, Colin Montemarano, William Charles, and Claire Gmachl, "", MIRTHE Summer Workshop, 2010
  27. Jin Huang, Changzheng Sun, Bing Xiong, Yu Song, and Yi Luo, "Phase noise characteristics of optically generated microwave by sideband injection locking", International Nano-Optoelectronic Workshop (iNOW), 301, 2008
  28. Yu Song, Bing Xiong, Changzhen Sun, and Yi Luo, "Low Residual Stress and High Repeatability of SiN\textsubscriptX Thin Films for InP-based Optoelectronic Device Fabrication by Dual Radio Frequency Plasma Enhanced Chemical Vapor Deposition", IEEE 19th International Conference on Indium Phosphide and Related Materials (IPRM), 233, 2007

Patents

  1. Yi Cui, Shanhui Fan, Cai Lili, Wei Li, Po-Chun Hsu, and Alex Y. Song, "Spectrally selective textile for passive radiative outdoor personal cooling", Patent WO/2019/152952, US Patent App. 16/267,242, (2019)
  2. Yi Cui, Shanhui Fan, Po-Chun Hsu, Alex Yu Song, Peter B Catrysse, and Yucan Peng, "Infrared-transparent porous polymer textile for human body cooling and heating", Patent WO/2017/143222, US Patent App. 16/066,247, (2019)
  3. Yi Cui, Peter B Catrysse, Jun Chen, Shanhui Fan, Po-Chun Hsu, Yucan Peng, and Alex Yu Song, "Infrared-transparent, polymer fiber-based woven textiles for human body cooling", Patent WO/2018/058062, US Patent App. 16/333,874, (2019)

Software

  • Inkstone
    Efficient solver based on rigorous coupled-wave analysis to simulate electromagnetic responses of 3D and 2D multi-layered structures with in-plane periodicity, such as gratings, photonic-crystal slabs, metasurfaces, surface-emitting lasers, nano-antennas, and more.
  • T-Dyno
    A finite-difference time-domain (FDTD) package equipped with dynamic modulations in the refractive index and gain/loss.

Professional Preparation

Postdoc

Electrical Engineering, Stanford University

2015 ~ now

Postdoc

Electrical Engineering, Princeton University

2014 ~ 2015

Ph.D.

Electrical Engineering, Princeton University

2014

 

Minor 1: Applied Mathematics, Minor 2: Physics

 

M.S.

Electronic Engineering, Tsinghua University

2009

B.S. (with Honor)

Mathematics and Physics, Tsinghua University

2006

Services & Other Activities

  • Teaching assistant, ELE-208, “Electronic and Photonic Devices”, 2014 spring & 2013 spring
  • Teaching assistant, IC & Optics Fabrication Course, ELE, 2013 fall
  • Mentor to more than ten undergraduate students in their summer research programs, independent works and/or junior and senior theses at Princeton University
  • I am a reviewer for American Physical Society (APS), American Institute of Physics (AIP), Optical Society of America (OSA) and Institute of Electrical and Electronics Engineers (IEEE)
  • I've volunteered in various programs for introducing science and engineering to pre-college students and the general public (YSAP, annual Science and Engineering Expo, engineering school / ELE departmental open houses, MIRTHE exhibition at various conferences and events, etc.) I enjoy teaching science to the next generation!