Journal Articles

2024

  • Vivswan Shah, Nathan Youngblood, “Leveraging Continuously Differentiable Activation Functions for Learning in Quantized Noisy Environments,” Under Review (2024) Link

  • Sadra Rahimi Kari, Nicholas A. Nobile, Dominique Pantin, Vivswan Shah, Nathan Youngblood, “Realization of an integrated coherent photonic platform for scalable matrix operations,” Optica 11(4), 542-551 (2024) Link

2023

  • Nicholas Nobile, John Erickson, Carlos Ríos, Yifei Zhang, Juejun Hu, Steven Vitale, Feng Xiong, Nathan Youngblood, “Time-resolved temperature mapping leveraging the strong thermo-optic effect in phase-change materials,” ACS Photonics 10(10), 3576–3585 (2023) Link

  • Nicholas A. Nobile, Chuanyu Lian, Hongyi Sun, Yi-Siou Huang, Brian Mills, Cosmin Constantin Popescu, Dennis Callahan, Juejun Hu, Carlos A. Ríos Ocampo, Nathan Youngblood, “Nonvolatile Tuning of Bragg Structures Using Transparent Phase-Change Materials,” Optical Materials Express 13(10), 2700-2710 (2023) Link

  • Vivswan Shah, Nathan Youngblood, “AnalogVNN: A Fully Modular Framework for Modeling and Optimizing Photonic Neural Networks,” APL Machine Learning 1, 026116 (2023) Link
        - Software documentation

  • Wen Zhou, Bowei Dong, Nikolaos Farmakidis, Xuan Li, Nathan Youngblood, Kairan Huang, Yuhan He, C David Wright, Wolfram HP Pernice, Harish Bhaskaran, “In-memory photonic dot-product engine with electrically programmable weight banks,” Nature Communications 14, 2887 (2023) Link

  • John Erickson, Nicholas Nobile, Daniel Vaz, Gouri Vinod, Carlos Ríos, Yifei Zhang, Juejun Hu, Steven Vitale, Feng Xiong, Nathan Youngblood, “Comparing the thermal performance and endurance of resistive and PIN silicon microheaters for phase-change photonic applications,” Optics Materials Express 13 (6), 1677-1688 (2023) Link

  • Nathan Youngblood, Carlos Ríos, Wolfram Pernice, Harish Bhaskaran, “Integrated Optical Memristors,” Nature Photonics 17, 561–572 (2023) Link

  • Sadra Rahimi Kari, Carlos Ríos, Lei Jiang, Jiawei Meng, Nicola Peserico, Volker J. Sorger, Juejun Hu, Nathan Youngblood, “Optical and electrical memories for analog optical computing,” IEEE JSTQE 29(2), 16100812 (2023) Link

  • Nathan Youngblood, “Coherent photonic crossbar arrays for large-scale matrix-matrix multiplication,” IEEE JSTQE 29(2), 1–11 (2023) Link

2022

  • James Y. S. Tan* / Zengguang Cheng*, Johannes Feldmann, Xuan Li, Nathan Youngblood, Utku E. Ali, C. David Wright, Wolfram H. P. Pernice, Harish Bhaskaran, “Monadic Pavlovian associative learning in a backpropagation-free photonic network” Optica 9(7), 792–802 (2022) Link

  • Chuanyu Lian, Christos Vagionas, Theonitsa Alexoudi, Nikos Pleros, Nathan Youngblood, Carlos Ríos, “Photonic (computational) memories: tunable nanophotonics for data storage and computing,” Nanophotonics 11(17), 3823-3854 (2022) Link

  • Nikolaos Farmakidis* / Nathan Youngblood*, June Sang Lee, Johannes Feldmann, Alessandro Lodi, Xuan Li, Samarth Agarwal, Wen Zhou, Lapo Bogani, Wolfram HP Pernice, C David Wright, Harish Bhaskaran, “Electronically reconfigurable photonic switches incorporating phase change plasmonics,” Advanced Science 2200383 (2022) Link

  • John R. Erickson, Vivswan Shah, Qingzhou Wan, Nathan Youngblood, Feng Xiong, “Designing fast and efficient electrically-driven phase change photonics using foundry compatible waveguide-integrated microheaters,” Optics Express 30, 13673-13689 (2022) Link

  • Nathan Youngblood, Clement Talagrand, Benjamin Porter, Carmelo Guido Galante, Steven Kneepkens, Dmitry Yarmolich, Ruy S. Bonilla, Peiman Hosseini, Robert Taylor, Harish Bhaskaran, “Broadly-tunable smart glazing using an ultra-thin phase-change material,” ACS Photonics 9(1), 90–100 (2022) Link
        - Featured on The Times, London and The Daily Mail

2021

  • Nikolaos Farmakidis* / Jacob L. Swett*, Nathan Youngblood, Xuan Li, Charalambos Evangeli, Samarth Aggarwal, Jan A. Mol, Harish Bhaskaran, “Exploiting rotational asymmetry for sub-50 nm mechanical nanocalligraphy,” Microsystems & Nanoengineering 7, 84 (2021) Link

  • Johannes Feldmann* / Nathan Youngblood* / Maxim Karpov*, Helge Gehring, Xuan Li, Maik Stappers, Manuel Le Gallo, Xin Fu, Anton Lukashchuk, Arslan Raja, Junqiu Liu, C. David Wright, Abu Sebastian, Tobias Kippenberg, Wolfram Pernice, Harish Bhaskaran, “Parallel convolution processing using an integrated photonic tensor core,” Nature 589, 52–58 (2021) Link
        - Featured on Nature News and Views

2020

  • Xuan Li, Nathan Youngblood, Wen Zhou, Johannes Feldmann, Jacob Swett, Samarth Aggarwal, Abu Sebastian, C. David Wright, Wolfram Pernice, Harish Bhaskaran, “On-chip Phase Change Optical Matrix Multiplication Core,” 2020 IEEE International Electron Devices Meeting (IEDM), San Francisco, CA, 7.5.1–7.5.4 (2020) Link

  • Xuezhi Ma, Nathan Youngblood, Xiaoze Liu, Yan Cheng, Preston Cunha, Kaushik Kudtarkar, Xiaomu Wang, Shoufeng Lan, “Engineering photonic environments for two-dimensional materials,” Nanophotonics 10(3), 1031–1058 (2020) Link

  • Qiang He, Nathan Youngblood, Zengguang Cheng, Xiangshui Miao, Harish Bhaskaran, “Dynamically tunable transmissive color filters using ultra-thin phase change materials,” Optics Express 28, 39841–39849 (2020) Link

  • Xuan Li, Nathan Youngblood, Zengguang Cheng, Santiago Garcia-Cuevas Carrillo, Emanuele Gemo, Wen Zhou, Wolfram Pernice, C. David Wright, Harish Bhaskaran, “Experimental investigation of silicon and silicon nitride platforms for phase change photonic in-memory computing,” Optica 7(3), 218–225 (2020) Link

  • Johannes Feldmann, Nathan Youngblood, Xuan Li, David Wright, Harish Bhaskaran, Wolfram Pernice, “Integrated 256 cell photonic phase change memory with 512-bit capacity,” IEEE JSTQE 26(2), 1–7 (2020) Link

  • Farzaneh Zokaee, Qian Lou, Nathan Youngblood, Weichen Liu, Yiyuan Xie, Lei Jiang, “LightBulb: a photonic-nonvolatile-memory-based accelerator for binarized convolutional neural networks,” DATE 2020 1438–1443 (2020) Link

2019

  • Nikolaos Farmakidis* / Nathan Youngblood*, Xuan Li, James Tan, Jacob L. Swett, Zengguang Cheng, Wolfram H. P. Pernice, C. David Wright, Harish Bhaskaran, “Plasmonic nanogap enhanced phase change devices with dual electrical-optical functionality,” Science Advances 5(11), eaaw2687 (2019) Link
        - Featured on Nature Research Highlights

  • Santiago G-C Carrillo, Emanuele Gemo, Xuan Li, Nathan Youngblood, Andrew Katumba, Peter Bienstman, Wolfram Pernice, Harish Bhaskaran, C. David Wright, “Behavioral modeling of integrated phase-change photonic devices for neuromorphic computing applications,” APL Materials 7, 091113 (2019) Link

  • Syed Ghazi Sarwat, Zengguang Cheng, Nathan Youngblood, Mohd Sharizal Alias, Sapna Sinha, Jamie H. Warner, Harish Bhaskaran, “Strong Opto-structural coupling in low dimensional GeSe3 films,” Nano Letters 19 (10), 7377–7384 (2019) Link

  • Emanuele Gemo, Santiago Garcia-Cuevas Carrillo, Carlota Ruiz De Galarreta, Anna Baldycheva, Hasan Hayat, Nathan Youngblood, Harish Bhaskaran, Wolfram H. P. Pernice, C. David Wright, “Plasmonically-enhanced all-optical integrated phase-change memory,” Optics Express 27(17), 24724–24737 (2019) Link

  • Johannes Feldmann, Nathan Youngblood, C. David Wright, Harish Bhaskaran, Wolfram H. P. Pernice, “All-optical spiking neurosynaptic networks with self-learning capabilities” Nature 569, 208–214 (2019) Link
        - Featured on Nature News and Views

  • Nathan Youngblood, Carlos A. Rios, Emanuele Gemo, Johannes Feldmann, Zengguang Cheng, Anna Baldycheva, Wolfram H. P. Pernice, C. David Wright, Harish Bhaskaran, “Tunable volatility of Ge2Sb2Te5 in integrated photonics,” Advanced Functional Materials 29, 1807571 (2019) Link

  • Xuan Li, Nathan Youngblood, Carlos A. Rios, Zengguang Cheng, Wolfram H. P. Pernice, C. David Wright, Harish Bhaskaran, “Fast and reliable storage using a 5-bit, non-volatile photonic memory cell,” Optica 6(1), 1–6 (2019) Link
        - Featured on the cover of Optica

  • Carlos A. Rios* / Nathan Youngblood*, Zengguang Cheng, Manuel Le Gallo, Wolfram H. P. Pernice, C. David Wright, Abu Sebastian, Harish Bhaskaran, “In-memory computing on a photonic platform,” Science Advances 5(2), eaau5759 (2019) Link
        - Featured on IBM’s research blog and Nature Electronics

2018

  • Syed Ghazi Sarwat, Nathan Youngblood, Yat-Yin Au, Jan A. Mol, C. David Wright, Harish Bhaskaran, “Engineering interface-dependent photoconductivity in Ge2Sb2Te5 nanoscale devices,” ACS Applied Materials and Interfaces 10(51), 44906–44914 (2018) Link

  • Carlos A. Rios, Stegmaier, M., Zengguang Cheng, Nathan Youngblood, C. David Wright, Wolfram H. P. Pernice, Harish Bhaskaran, “Controlled switching of phase-change materials by evanescent-field coupling in integrated photonics [Invited],” Optical Materials Express 8(9), 2455–2470 (2018) Link

  • Zengguang Cheng, Carlos A. Rios, Nathan Youngblood, C. David Wright, Wolfram H. P. Pernice, Harish Bhaskaran, “Device-level photonic memories and logic applications using phase-change materials,” Advanced Materials 30, 1802435 (2018) Link

2017

  • Zengguang Cheng, Carlos A. Rios, Nathan Youngblood, C. David Wright, Wolfram H. P. Pernice, Harish Bhaskaran, “On-chip phase-change photonic memory and computing,” SPIE Proceedings, 10345:1034519 (2017) Link

  • Rouming Peng, Khaliji, K., Nathan Youngblood, Grassi, R., Tony Low, Mo Li, “Mid-infrared electro-optic modulation in few-layer black phosphorus,” Nano Letters, 17, 6315–6320 (2017) Link

  • Mei Xu, Yuqian Gu, Rouming Peng, Nathan Youngblood, Mo Li, “Black phosphorus mid-infrared photodetectors,” Applied Physics B, 123:130 (2017) Link

  • Nathan Youngblood, Mo Li, “Ultrafast photocurrent measurements of a black phosphorus photodetector,” Applied Physics Letters, 110, 051102 (2017) Link

  • Che Chen, Nathan Youngblood, Rouming Peng, Daehan Yoo, Daniel A. Mohr, Timothy W. Johnson, Sang-Hyun Oh, Mo Li, “Three-dimensional integration of black phosphorus photodetector with silicon photonics and nanoplasmonics,” Nano Letters, 17, 6315–6320 (2017) Link

  • Nathan Youngblood, Rouming Peng, Andrei Nemilentsau, Tony Low, Mo Li, “Layer tunable third-harmonic generation in multilayer black phosphorus,” ACS Photonics, 4(1), 8–14 (2017) Link

2016 to 2014

  • Nathan Youngblood, Mo Li, “Integration of 2D materials on a silicon photonics platform for optoelectronics applications,” Invited Review Article for Nanophotonics, 6(6), 1205–1218 (2016) Link

  • Nathan Youngblood, Che Chen, Steven J. Koester, Mo Li, “Waveguide-integrated black phosphorus photodetector with high responsivity and low dark current,” Nature Photonics, 9, 249–252 (2015) Link

  • S. C. Lee, Nathan Youngblood, Y. B. Jiang, E. J. Peterson, C. J. M. Stark, T. Detchprohm, C. Wetzel, Steven R. J. Brueck, “Incorporation of indium on cubic GaN epitaxially induced on a nanofaceted Si(001) substrate by phase transition,” Applied Physics Letters, 107(23), 231905 (2015) Link

  • Nathan Youngblood, Yoska Anugrah, Rui Ma, Steven J. Koester, Mo Li, “Multifunctional graphene optical modulator and photodetector integrated on silicon waveguides,” Nano Letters, 14(5), 2741–2746 (2014) Link

Conference Proceedings

  • S. Rahimi Kari, A. Hastings, N. Nobile, D. Pantin, V. Shah, N. Youngblood, “Integrated Coherent Photonic Crossbar Arrays for Efficient Optical Computing,” Conference on Lasers and Electro-Optics (CLEO), Charlotte, NC (2024)

  • N. Nobile, C. Lian, H. Sun, Y.-S. Huang, B. Mills, C. Constantin Popescu, D. Callahan, J. Hu, C.A. Ríos Ocampo, N. Youngblood, “Nonvolatile Tuning of Bragg Structures Using Transparent Phase-Change Materials,” Conference on Lasers and Electro-Optics (CLEO), Charlotte, NC (2024)

  • F. Vasquez-Aza, H. Sun, C. Lian, Y.S. Huang, S. A. Vitale, I. Takeuchi, J. Hu, N. Youngblood, C. Rios, G. Pavlidis, “Maximizing the Thermal Performance of Microheaters for Non-Volatile Phase Change Photonics: A Comparative Study of Pulse Width Parameter Effects,” IEEE ITherm 2024, Denver, CO (May 2024)

  • S. Rahimi Kari, D. Pantin, N. Youngblood, “Scalable and efficient coherent photonic unit cell for time-multiplexed multiplication and correlation detection,” SPIE Photonics West, San Francisco, CA (Jan 2023)

  • V. Shah, N. Youngblood, “AnalogVNN: A Fully Modular Framework for Photonic Analog Neural Networks,” IEEE IPC 2022, Vancouver, Canada (Nov 2022)

  • N. Nobile, J. Erickson, C. Rios, Y. Zhang, JJ Hu, F. Xiong, N. Youngblood, “Dynamic Mapping of Temperature Using Phase-Change Materials,” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2022)

  • N. Farmakidis, N. Youngblood, J. S. Lee, J. Feldmann, W. H. P. Pernice, C. D. Wright, H. Bhaskaran, “Plasmonically Enhanced Electronically Addressable Photonic Switches Incorporating Phase-Change Materials,” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2022)

  • W. Zhou, X. Li, N. Youngblood, W. H. P. Pernice, C. D. Wright, H. Bhaskaran, “Electrical switching of Ge2Sb2Te5 memory cells based on silicon photonic waveguide microheaters,” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2022)

  • J. Erickson, V. Shah, Q. Wan, N. Youngblood, F. Xiong, “Designing fast and efficient electrically driven phase change photonics using foundry compatible waveguide-integrated microheaters,” Photonics and Electronics Research Symposium (PIERS), Hangzhou, China (2022)

  • J. Tan, Z. Cheng, J. Feldmann, X. Li, N. Youngblood, U. E. Ali, C. D. Wright, W. H. P. Pernice, H. Bhaskaran, “Associative learning on phase change photonics,” SPIE Nanoscience + Engineering, San Diego, CA (2021)

  • E. Gemo, S. G. C. Carrillo, J. Faneca, C. Ruíz de Galarreta, H. Hayat, N. Youngblood, A. Baldycheva, W. H. P. Pernice, H. Bhaskaran, C. D. Wright, “Sub-wavelength plasmonic-enhanced phase-change memory,” SPIE OPTO, San Francisco, CA (2020)

  • X. Li, N. Youngblood, W. Zhou, J. Feldmann, J. L. Swett, S. Aggarwal, A. Sebastian, C. D. Wright, W. H. P. Pernice, H. Bhaskaran, “On-chip Phase Change Optical Matrix Multiplication Core,” 2020 IEEE International Electron Devices Meeting (IEDM), San Francisco, CA, 7.5.1–7.5.4 (2020)

  • N. Youngblood, N. Farmakidis, X. Li, H. Bhaskaran, “Nanoscale Optoelectronic Memory with Nonvolatile Phase-Change Photonics [Highlighted Talk],” Conference on Lasers and Electro-Optics (CLEO), San Jose, California USA (2020)

  • E. Gemo, S. G. C. Carrillo, J. Faneca, N. Youngblood, W. H. P. Pernice, H. Bhaskaran, C. D. Wright, “A plasmonic route towards the energy scaling of on-chip integrated all-photonic phase-change memories,” European Phase-Change and Ovonic Symposium (E\PCOS), Grenoble, France (2019)

  • N. Youngblood, Z. Cheng, N. Farmakidis, X. Li, J. Tan, H. Bhaskaran, “Phase change photonics for brain-inspired computing,” SPIE Defense + Commercial Sensing, Baltimore, MD (2019)

  • C. Ríos, N. Youngblood, Z. Cheng, M. Le Gallo, W. H. P. Pernice, C. D. Wright, A. Sebastian, and H. Bhaskaran, “All-photonic in-memory computing based on phase-change materials,” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2019)

  • C. D. Wright, H. Bhaskaran, W. H. P. Pernice, S. G. Carrillo, E. Gemo, A. Baldycheva, Z. Cheng, X. Li, C. Rios, N. Youngblood, J. Feldmann, N. Gruhler, and M. Stegmaier, “Integrated Phase-change Photonics: A Strategy for Merging Communication and Computing,” Optical Fiber Communication Conference (OFC), San Diego, CA (2019)

  • E. Gemo, N. Youngblood, Z. Cheng, C. Ríos, M. Stegmaier, A. Baldycheva, W. H. P. Pernice, H. Bhaskaran, C. D. Wright, “Modelling phase-change integrated photonic devices,” European Phase-Change and Ovonic Symposium (E\PCOS), Catania, Italy (2018)

  • N. Youngblood, X. Li, H. Bhaskaran, “Phase-change materials for non-volatile, integrated photonic memory and computation [Invited Talk],” LIMIS, Changsha, China (2018)

  • N. Youngblood, C. Talagrand, P. Hosseini, H. Bhaskaran, “Dynamic Smart Windows Using Phase Change Materials [Late Breaking Paper],” MRS Spring Meeting, Phoenix, Arizona USA (2018)

  • N. Youngblood, C. Rios, E. Gemo, Z. Cheng, W. H. P. Pernice, C. D. Wright, H. Bhaskaran, “Phase change materials exhibit tunable volatility in integrated photonics,” SPIE Photonics West, San Francisco, California USA (2018)

  • R. Peng, K. Khaliji, N. Youngblood, R. Grassi , T. Low, M. Li, “Mid-infrared electro-optic modulation in few-layer black phosphorus,” SPIE OPTO, San Francisco, CA (2018)

  • Z. Cheng, C. Ríos, N. Youngblood, C. D. Wright, W. H. P. Pernice, H. Bhaskaran, “On-chip phase-change photonic memory and computing,” SPIE Nanoscience + Engineering, San Diego, CA (2017)

  • S. G. C. Carrillo, E. Gemo, N. Youngblood, X. Li, A. Katumba, P. Bienstman, W. H. P. Pernice, H. Bhaskaran, C. D. Wright, “A behavioural model for integrated phase-change photonics,” European Phase-Change and Ovonic Symposium (E\PCOS), Aachen, Germany (2017)

  • R. Peng, N. Youngblood, M. Li, “Mid-infrared electro-optic modulation in black phosphorus,” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2017)

  • C. Chen, D. Yoo, N. Youngblood, S. Oh, M. Li, “Mid-infrared plasmonic coaxial nanorings for surface enhanced infrared absorption (SEIRA) spectroscopy,” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2017)

  • N. Youngblood, M. Li, “Ultrafast photocurrent spectroscopy in a black phosphorus van der waals heterostructure [Invited Talk],” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2016)

  • C. Chen, N. Youngblood, D. Mohr, D. Yoo, T. Johnson, R. Peng, S. Oh, and M. Li, “Black Phosphorus Photodetector on Silicon Photonic and Plasmonic Hybrid Platform,” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2016)

  • N. Youngblood, R. Peng, A. Nemilentsau, T. Low, M. Li, “Thickness dependent third-harmonic generation in few-layer black phosphorus [Post-Deadline Talk],” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2016)

  • C. Chen, N. Youngblood, M. Li, “Study of black phosphorus anisotropy on silicon photonic waveguide,” IEEE Optoelectronics Global Conference (OGC), Shenzhen, China (2015)

  • N. Youngblood, C. Chen, S. J. Koester, M. Li, “A black phosphorus FET integrated on a silicon waveguide for high speed, low dark current photodetection,” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2015)

  • N. Youngblood, Y. Anugrah, R. Ma, S. J. Koester, M. Li, “Simultaneous optical modulation and detection using graphene integrated on a silicon waveguide,” Conference on Lasers and Electro-Optics (CLEO), San Jose, CA (2014)

Invited Talks

  • N. Youngblood, “Integrated photonics circuits for fast and efficient (classical) computing” PQI 2022 Conference, Pittsburgh, PA (Sept 2022)

  • N. Nobile, J. Erickson, C. Ríos, Y. Zhang, JJ Hu, F Xiong, N. Youngblood, “Design and characterization of electrically programmable phase change photonic devices,” 12th International Conference on Metamaterials, Photonic Crystals and Plasmonics (META 2022), Torremolinos, Spain (July 2022)

  • N. Youngblood, “Controlling and characterizing phase change devices for photonic computing applications [Advanced Nanoscale Engineering Group Seminar],” University of Oxford, Oxford, UK (July 2022)

  • N. Youngblood, “Phase change materials for photonic memory and neuromorphic computing [Guest Lecture],” CMC Active Silicon Photonics Fabrication Course, Virtual Event (June 2022)

  • N. Youngblood, “Reconfigurable photonic systems for optical memory, computation, and beyond [ECE Graduate Seminar],” Tufts University, Medford, MA (March 2022)

  • N. Youngblood, “Reconfigurable photonic processors for ultrafast and efficient computation,” Accipiter Systems, Wexford, PA (March 2022)

  • N. Youngblood, “Nanoscale Optoelectronic Memory with Nonvolatile Phase-Change Photonics,” Pittsburgh Quantum Institute, Pittsburgh, PA (July 2020)

  • N. Youngblood, “Phase-change materials for photonic memory, computing, and beyond [ECE Graduate Seminar],” University of Minnesota, Minneapolis, MN (2020)

  • N. Youngblood, “Phase-change photonic computing and beyond [ECE Graduate Seminar],” University of Pittsburgh, Pittsburgh, PA (2019)

  • N. Youngblood, X. Li, H. Bhaskaran, “Phase-change materials for non-volatile, integrated photonic memory and computation [Invited],” LIMIS, Changsha, China (2018)

  • N. Youngblood, M. Li, “Ultrafast photocurrent spectroscopy in a black phosphorus van der waals heterostructure [Invited],” Conference on Lasers and Electro-Optics (CLEO), San Jose, California USA (2016)