Search

Your search keyword '"Ting CHEN"' showing total 21 results
Start Over Author "Ting CHEN" Publication Type Reports
21 results on '"Ting CHEN"'

1. Unveiling the origins of quasi-phase matching spectral imperfections in thin-film lithium niobate frequency doublers

Author

Zhao, Jie, Li, Xiaoting, Hu, Ting-Chen, Sayem, Ayed Al, Li, Haochuan, Tate, Al, Kim, Kwangwoong, Kopf, Rose, Sanjari, Pouria, Earnshaw, Mark, Fontaine, Nicolas K., Wang, Cheng, and Blanco-Redondo, Andrea

Subjects
Physics - Optics, Physics - Applied Physics
Abstract

Thin-film lithium niobate (TFLN) based frequency doublers have been widely recognized as essential components for both classical and quantum optical communications. Nonetheless, the efficiency of these devices is hindered by imperfections present in the quasi-phase matching (QPM) spectrum. In this study, we present a thorough analysis of the spectral imperfections in TFLN frequency doublers with varying lengths, ranging from 5 mm to 15 mm. Employing a non-destructive diagnostic method based on scattered light imaging, we identify the sources and waveguide sections that contribute to the imperfections in the QPM spectrum. Furthermore, by mapping the TFLN film thickness across the entire waveguiding regions, we successfully reproduce the QPM spectra numerically, thus confirming the prominent influence of film thickness variations on the observed spectral imperfections. This comprehensive investigation provides valuable insights into the identification and mitigation of spectral imperfections in TFLN-based frequency doublers, paving the way toward the realization of nonlinear optical devices with enhanced efficiency and improved spectral fidelity.

Published
2023

2. A surface-normal photodetector as nonlinear activation function in diffractive optical neural networks

Author

Ashtiani, Farshid, Idjadi, Mohamad Hossein, Hu, Ting-Chen, Grillanda, Stefano, Neilson, David, Earnshaw, Mark, Cappuzzo, Mark, Kopf, Rose, Tate, Alaric, and Blanco-Redondo, Andrea

Subjects
Physics - Optics, Computer Science - Emerging Technologies
Abstract

Optical neural networks (ONNs) enable high speed parallel and energy efficient processing compared to conventional digital electronic counterparts. However, realizing large scale systems is an open problem. Among various integrated and non-integrated ONNs, free-space diffractive ONNs benefit from a large number of pixels of spatial light modulators to realize millions of neurons. However, a significant fraction of computation time and energy is consumed by the nonlinear activation function that is typically implemented using a camera sensor. Here, we propose a novel surface-normal photodetector (SNPD) with a nonlinear response to replace the camera sensor that enables about three orders of magnitude faster (5.7 us response time) and more energy efficient (less than 10 nW/pixel) response. Direct efficient vertical optical coupling, polarization insensitivity, inherent nonlinearity with no control electronics, low optical power requirements, and the possibility of implementing large scale arrays make the SNPD a promising nonlinear activation function for diffractive ONNs. To show the applicability, successful classification simulation of MNIST and Fashion MNIST datasets using the measured response of SNPD with accuracy comparable to that of an ideal ReLU function are demonstrated.

Published
2023

3. Education Arms Race: Obama-Era Discourses, New York City School Reform, and the Future of Critical Media Literacy

Author

Wendy Yuen Ting Chen

Abstract

From the Cold War to the neoliberal era, state-sanctioned education reforms have been less concerned with responsible citizenship or social justice than matters of national security and economic supremacy. Meanwhile, the United States struggles to climb international education rankings or even close its own national achievement gap. While it continues to lead the world's information economies and dominate the global media industry, the perceived threat to its preeminent status is intensified in a multipolar world. In President Obama's speeches declaring the "educational arms race" and the new "Sputnik moment," he warned that the United States is at a greater risk than ever of being surpassed by rival nations if its students fail to keep pace with developments in technology. Accordingly, there has been a significant investment by prominent politicians, tech leaders, and educational policymakers to increase technical skills under this rationale. Learning technical skills such as coding can be advantageous in the new media landscape. However, communication scholars argue that technical skills must be taught within the critical framework of civics-based media education that is vital for a democratic society. This dissertation examines how students, teachers, and administrators during Obama's presidency responded to official discourses that defined the national agenda for digital learning in a global economy. In the national context, it provides a Critical Discourse Analysis of private-sector campaigns, political messages, and visual texts pertaining to the challenges and opportunities facing American schools in the digital age. In the local context of the New York City education system, it draws on a multi-site case study conducted between 2014-2015 across four public high schools where media and technology are the focus of an academic theme. Critical Discourse Analysis of interviews and observations reveal the extent to which the official discourse of worldwide competition -- reinforced by corporate interests and an ideology of national defense -- has infiltrated these learning environments. This dissertation considers the social and cultural implications of the most familiar refrains available to us on the role of technology in American schools, in the lives of young people, and in the future of the United States as superpower. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Published
2023

5. The First X-Ray Polarization Observation of the Black Hole X-Ray Binary 4U 1630–47 in the Steep Power-law State

Author

Nicole Rodriguez Cavero, Lorenzo Marra, Henric Krawczynski, Michal Dovčiak, Stefano Bianchi, James F. Steiner, Jiri Svoboda, Fiamma Capitanio, Giorgio Matt, Michela Negro, Adam Ingram, Alexandra Veledina, Roberto Taverna, Vladimir Karas, Francesco Ursini, Jakub Podgorný, Ajay Ratheesh, Valery Suleimanov, Romana Mikušincová, Silvia Zane, Philip Kaaret, Fabio Muleri, Juri Poutanen, Christian Malacaria, Pierre-Olivier Petrucci, Ephraim Gau, Kun Hu, Sohee Chun, Iván Agudo, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolò Bucciantini, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolò Di Lalla, Alessandro Di Marco, Immacolata Donnarumma, Victor Doroshenko, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Javier A. García, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl, Wataru Iwakiri, Svetlana G. Jorstad, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Frédéric Marin, Andrea Marinucci, Alan P. Marscher, Herman L. Marshall, Francesco Massaro, Ikuyuki Mitsuishi, Tsunefumi Mizuno, Chi-Yung Ng, Stephen L. O’Dell, Nicola Omodei, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Melissa Pesce-Rollins, Maura Pilia, Andrea Possenti, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Oliver J. Roberts, Roger W. Romani, Carmelo Sgrò, Patrick Slane, Gloria Spandre, Paolo Soffitta, Douglas A. Swartz, Toru Tamagawa, Fabrizio Tavecchio, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey S. Tsygankov, Roberto Turolla, Jacco Vink, Martin C. Weisskopf, Kinwah Wu, and Fei Xie

Published
2023
Full Text
View/download PDF

6. Controlled Electrode Magnetization Alignment in Planar Elliptical Ferromagnetic Break Junction Devices

Author

Scott, Gavin D. and Hu, Ting-Chen

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Controlling the magnetization reversal process of magnetic elements is important for a wide range of applications that make use of magnetoresistive effects, but is difficult to achieve for devices that require adjacent thin film structures capable of contacting an individual molecule or quantum dot. We report on the fabrication and measurement of ferromagnetic break junction devices with planar, elliptical leads to address the particular challenge of controlling the relative magnetization alignment between neighboring electrodes. Low temperature transport measurements, supported by finite-element micromagnetic simulations, are used to characterize the magnetoresistance response across a range of conductance levels. We demonstrate that an in-plane external field applied parallel to the hard axis of the ellipses may be used to controllably switch the magnetization of the source and drain electrodes between monodomain-like parallel and antiparallel configurations for devices in the tunneling regime., Comment: 6 pages, 6 figures

Published
2016
Full Text
View/download PDF

7. IXPE and XMM-Newton Observations of the Soft Gamma Repeater SGR 1806–20

Author

Roberto Turolla, Roberto Taverna, Gian Luca Israel, Fabio Muleri, Silvia Zane, Matteo Bachetti, Jeremy Heyl, Alessandro Di Marco, Ephraim Gau, Henric Krawczynski, Mason Ng, Andrea Possenti, Juri Poutanen, Luca Baldini, Giorgio Matt, Michela Negro, Iván Agudo, Lucio A. Antonelli, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolò Bucciantini, Fiamma Capitanio, Simone Castellano, Elisabetta Cavazzuti, Chieng-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolò Di Lalla, Immacolata Donnarumma, Victor Doroshenko, Michal Dovčiak, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Wataru Iwakiri, Svetlana G. Jorstad, Philip Kaaret, Vladimir Karas, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Frédéric Marin, Andrea Marinucci, Alan P. Marscher, Herman L. Marshall, Francesco Massaro, Ikuyuki Mitsuishi, Tsunefumi Mizuno, C.-Y. Ng, Stephen L. O’Dell, Nicola Omodei, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Melissa Pesce-Rollins, Pierre-Olivier Petrucci, Maura Pilia, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Oliver J. Roberts, Roger W. Romani, Carmelo Sgró, Patrick Slane, Paolo Soffitta, Gloria Spandre, Douglas A. Swartz, Toru Tamagawa, Fabrizio Tavecchio, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey S. Tsygankov, Jacco Vink, Martin C. Weisskopf, Kinwah Wu, and Fei Xie

Published
2023
Full Text
View/download PDF

8. X-Ray Polarimetry Reveals the Magnetic-field Topology on Sub-parsec Scales in Tycho’s Supernova Remnant

Author

Riccardo Ferrazzoli, Patrick Slane, Dmitry Prokhorov, Ping Zhou, Jacco Vink, Niccolò Bucciantini, Enrico Costa, Niccolò Di Lalla, Alessandro Di Marco, Paolo Soffitta, Martin C. Weisskopf, Kazunori Asakura, Luca Baldini, Jeremy Heyl, Philip E. Kaaret, Frédéric Marin, Tsunefumi Mizuno, C.-Y. Ng, Melissa Pesce-Rollins, Stefano Silvestri, Carmelo Sgrò, Douglas A. Swartz, Toru Tamagawa, Yi-Jung Yang, Iván Agudo, Lucio A. Antonelli, Matteo Bachetti, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Fiamma Capitanio, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Immacolata Donnarumma, Victor Doroshenko, Michal Dovčiak, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Wataru Iwakiri, Svetlana G. Jorstad, Fabian Kislat, Vladimir Karas, Takao Kitaguchi, Jeffery J. Kolodziejczak, Henric Krawczynski, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Andrea Marinucci, Alan P. Marscher, Herman L. Marshall, Giorgio Matt, Ikuyuki Mitsuishi, Fabio Muleri, Michela Negro, Stephen L. O’Dell, Nicola Omodei, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Pierre-Olivier Petrucci, Maura Pilia, Andrea Possenti, Juri Poutanen, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Oliver Roberts, Roger W. Romani, Gloria Spandre, Fabrizio Tavecchio, Roberto Taverna, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey S. Tsygankov, Roberto Turolla, Kinwah Wu, Fei Xie, and Silvia Zane

Published
2023
Full Text
View/download PDF

9. Momentum-space entanglement for interacting fermions at finite density

Author

Hsu, Ting-Chen Leo, McDermott, Michael B., and Van Raamsdonk, Mark

Subjects
High Energy Physics - Theory, Condensed Matter - Strongly Correlated Electrons, Quantum Physics
Abstract

We investigate the entanglement between individual field theory modes in finite-density systems of interacting relativistic and non-relativistic fermions in one spatial dimension. We calculate the entanglement entropy for a single field theory mode and the mutual information between any two modes. The calculation is perturbative in the four-fermion (two-body) coupling, with the leading contribution at order lambda^2 log(lambda^2). At this leading order, the perturbative expression for the entanglement entropy of a mode diverges logarithmically as the momentum of the mode approaches the Fermi surface from above or below. The mutual information between modes is largest for pairs of modes just above and below the Fermi momentum. The entanglement properties of modes near the Fermi surface are qualitatively the same if the field theory is cut off to eliminate modes away from the Fermi surface., Comment: 19 pages, LaTeX, 7 figures

Published
2012
Full Text
View/download PDF

12. A Simulation Framework for Precision Landing and Hazard Avoidance Technology Assessments

Author

Alicia Dwyer Cianciolo, Soumyo Dutta, Rafael Lugo, Anthony Williams, and Po-Ting Chen

Subjects
Spacecraft Design, Testing And Performance
Abstract

To meet NASA’s challenge to return humans to the Moon in 2024 and establish a sustainable presence in 2028 requires advances in autonomous spacecraft navigation. The Safe and Precise Landing Integrated Capabilities Evolution (SPLICE) project, which leverages previous work at NASA to develop multi-mission precision landing and hazard avoidance technologies, is using a multi-faceted approach to achieve the advanced landing requirements. In addition to increasing the technology readiness level of key sensors and developing high performance space computing, SPLICE uses simulations to determine navigation requirements and evaluate sensor performance. The effort evaluates various precision landing concepts of operations, not only for the lunar human and robotic missions, but also for potential missions to other solar system destinations. This paper summarizes the six degree-of-freedom high fidelity simulation framework, trajectory design methodology, and sensor models being considered for a variety of precision lander missions. Initial results of the navigation sensor performance for a human Mars mission are presented. Finally, trade and sensitivity studies are outlined for future work to fully characterize sensor performance assumptions and modifications required to achieve precision landing and hazard avoidance.

Published
2020
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results