Article
Chemistry, Physical
Xiong Deng, Shen Shen, Yanli Xu, Jiangtao Liu, Jun Li, Zhenhua Wu
Summary: This study investigates photonic-crystal-like devices and microcavities in graphene. The results show that these graphene-based devices can be significantly smaller in size compared to conventional photonic crystals, thanks to the shorter optical transport wavelength in graphene. By changing the applied voltage, the functionality of the devices can be altered, making them highly programmable and adjustable. Furthermore, these devices can be integrated with traditional microelectronic circuits, leading to potential applications in photonic integrated circuits and computing.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Xiong Deng, Shen Shen, Yanli Xu, Jiangtao Liu, Jun Li, Zhenhua Wu
Summary: This theoretical study investigates photonic-crystal-like devices and microcavities in graphene. The results show that graphene-based devices can be scaled down significantly compared to conventional photonic crystals due to the shorter optical transport wavelength in graphene. The devices have high programmability and can be integrated with traditional microelectronic circuits, offering potential applications in photonic integrated circuits and computing.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Inge Nys, Peter Ropac, Brecht Berteloot, Miha Ravnik, Kristiaan Neyts
Summary: Novel electro-optic components with enhanced functionality can be designed by using well-designed anchoring patterns in a liquid crystal (LC) device. Two types of nematic LC diffraction gratings with varying periodicity are presented, manufactured with patterned photoalignment at the confining substrates. The surface anchoring periodicity can redirect the incident light into different diffraction orders, resulting in a scattering appearance of the grating. The structural and optical properties of the gratings can be tuned by applying an external voltage.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Chemistry, Multidisciplinary
Anik Kumar Ghosh, Swagato Sarkar, Takuya Tsuda, Soosang Chae, Andre Knapp, Mirko Nitschke, Amit Das, Sven Wiessner, Tobias A. F. Koenig, Andreas Fery
Summary: Metal-semiconductor nanostructures are widely used in photodetection, photocatalysis, and photovoltaics. In photodetection, the resistance typically decreases with the generation of charge carriers upon illumination, but an opposite response, an increase in resistance, is observed in interconnected metal-semiconductor gratings. This study presents a fabrication method using wrinkle structuring and oblique angle material deposition to create photoresistors with large-area periodic structures and cracks that serve as connections for two-point contact measurements. It is also found that an additional deposition of an amorphous titania layer further enhances the current reduction on photoexcitation.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Line Jelver, Joel D. Cox
Summary: Phosphorene, an atomically thin material, has garnered significant attention in the fields of optoelectronics and nanophotonics due to its exceptional optical properties and the ability to actively control light-matter interactions through electrical doping. Researchers have discovered that localized plasmons supported by phosphorene nanoribbons exhibit high tunability in relation to edge termination and doping charge polarity, leading to intense nonlinear optical responses at moderate doping levels. The tunability of plasmons in doped phosphorene nanoribbons at near-infrared frequencies can facilitate efficient high-harmonic generation by combining the electronic band structure and plasmonic field confinement.
Article
Engineering, Electrical & Electronic
Daniele Melati, Mohsen Kamandar Dezfouli, Yuri Grinberg, Jens H. Schmid, Ross Cheriton, Siegfried Janz, Pavel Cheben, Dan-Xia Xu
Summary: Compact and efficient optical antennas are designed using grating-based micro-antennas with perfectly vertical emission. Through optimization and machine learning, high performance designs are discovered, achieving high diffraction and coupling efficiency with a one-step apodized grating.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2021)
Article
Multidisciplinary Sciences
Alex Dikopoltsev, Yonatan Sharabi, Mark Lyubarov, Yaakov Lumer, Shai Tsesses, Eran Lustig, Ido Kaminer, Mordechai Segev
Summary: Photonic time-crystals are spatially homogeneous media that exhibit periodic variations in their electromagnetic susceptibility, leading to temporal reflections and refractions of propagating waves. Free electrons in these crystals spontaneously emit radiation, with a significantly amplified emission process when associated with momentum-gap modes. Quantum interference between spontaneous emission and electron emission into the band modes suppresses the interdependent emission. Therefore, the study of free-electron physics in photonic time-crystals offers a platform to explore various exciting phenomena.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Engineering, Electrical & Electronic
Xuetong Zhou, Hon Ki Tsang
Summary: Using an optimized shift-pattern overlay method, a new high-efficiency silicon waveguide grating coupler operating at 1550 nm center wavelength was developed. The simulation predicted a coupling loss of 0.68 dB, and the experimentally measured loss was 0.89 dB. This achievement was obtained without the need for substrate bottom mirrors or electron beam lithography, using standard processes from a commercial foundry's multi-project wafer fabrication service.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Xin Tu, Wansheng Xie, Zhenmin Chen, Ming-Feng Ge, Tianye Huang, Chaolong Song, H. Y. Fu
Summary: By utilizing deep neural networks and finite-difference time-domain solver, efficient design of silicon photonic devices can be achieved; the study shows that both forward and inverse design methods can result in high prediction accuracy for the coupler, reaching up to 91.7%.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Shweta Mehta, Suchitra Vankalkunti, Pawan Kumar Kachhap, Prakash Ratan Gautam, Mandeep Singh
Summary: This study proposes a photonic crystal refractive-index sensor for the detection of volatile organic compounds (VOC). Two sensor designs using Y-splitter photonic crystal waveguide are analyzed using the finite-difference time-domain (FDTD) method. Simultaneous monitoring of two different analytes is possible across the arms of the Y-splitter. The use of porous silicon (p-Si) rods with a porosity of 25% creates a variable refractive index sensing region, resulting in a relative shift in the resonant wavelength of the traveling mode. The numerical simulations confirm a sensitivity of -195.83 nm/RIU and a figure-of-merit of -24.482 RIU-1 in the presence of hazardous alcohols.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Chemistry, Multidisciplinary
Jae S. Hwang, Jin Xu, Aaswath P. Raman
Summary: Researchers have designed and experimentally demonstrated an approach using doped III-V semiconductors to simultaneously control the spectral peak, bandwidth, and directionality of infrared emissivity. InAs-based gradient epsilon-near-zero (ENZ) photonic structures exhibit broadband directional emission with different spectral bandwidths and ranges depending on doping concentration profile and thickness. This approach provides a versatile photonic platform for dynamically controlling broadband spectral and directional emissivity in applications such as heat transfer and infrared sensing.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Fu-Li Hsiao, Chia-Ying Ni, Ying-Pin Tsai, Ting-Wei Chiang, Yen-Tung Yang, Cheng-Jui Fan, Hsuan-Ming Chang, Chien-Chung Chen, Hsin-Feng Lee, Bor-Shyh Lin, Kai-Chun Chan, Chii-Chang Chen
Summary: Photonic crystals with unique dispersion relation can be used to design miniaturized optical components for quantum computing. A half-waveplate element with a photonic crystal is designed to rotate the polarization direction of incident light on a waveguide. The polarization rotation length and the optical axis's angle can be effectively calculated using the dispersion relation of photonic crystals. Polarization rotators designed based on photonic crystal structures exhibit low insertion loss and favorable polarization rotation performance.
Article
Chemistry, Multidisciplinary
Ines Margarida Pinheiro Caetano, Joao Paulo N. Torres, Ricardo A. Marques Lameirinhas
Summary: Simulation of coupling nanoantennas with solar cells demonstrates an enhancement in capturing and absorbing radiation, which could have significant implications for future photovoltaic technology applications.
Article
Nanoscience & Nanotechnology
Israr Ahmed, Mohamed Elsherif, Seongjun Park, Ali K. Yetisen, Haider Butt
Summary: This study developed rapid, reliable, and reusable alcohol sensors based on hydrogel-based fiber optic probes. The sensors were fabricated using a simple, rapid, and facile process by imprinting Aztec microstructures onto alcohol-sensitive hydrogels. The sensors showed real-time sensing capability towards various concentrations of ethanol, isopropanol, methanol, and dimethyl sulfoxide. The developed optical fiber sensors exhibited fast response time, high sensitivity, and low limit of detection, making them suitable for remote and real-time alcohol sensing in multiple industries.
ACS APPLIED NANO MATERIALS
(2022)
Review
Physics, Multidisciplinary
Alessandro Tuniz
Summary: Nonlinear plasmonics plays a key role in enhancing photonics integrated circuits, improving efficiency of light-matter interactions, and enabling high-performance optical signal processing and terahertz signal generation and detection.
RIVISTA DEL NUOVO CIMENTO
(2021)
Article
Neurosciences
Yijun Bao, Emily Redington, Agnim Agarwal, Yiyang Gong
Summary: Fluorescence microscopy and genetically encoded calcium indicators allow us to understand brain function by recording in vivo videos. However, analyzing these videos can be challenging due to false transients caused by non-specific calcium sources and neighboring neurons. We developed a novel method (TUnCaT) that can quickly and accurately unmix the calcium signals, outperforming existing algorithms in terms of accuracy and speed.
FRONTIERS IN NEUROSCIENCE
(2022)
Article
Optics
C. Shirpurkar, J. Zang, K. Y. Yang, D. Carlson, S. P. Yu, E. Lucas, S. Pericherla, J. Yang, M. Guidry, D. Lukin, G. H. Ahn, J. Lu, L. Trask, F. Aflatouni, J. Vuckovic, S. B. Papp, P. J. Delfyett
Summary: The experimental demonstration presents a 400 Gbit/s optical communication link utilizing wavelength-division multiplexing and mode-division multiplexing, with a novel 400 GHz frequency comb source and 4x4 mode-division multiplexer structures for increased data capacity.
Article
Nanoscience & Nanotechnology
Alexander D. White, Logan Su, Daniel I. Shahar, Ki Youl Yang, Geun Ho Ahn, Jinhie L. Skarda, Siddharth Ramachandran, Jelena Vuckovic
Summary: Vortex beams are stable solutions of Maxwell's equations that have phase singularities and orbital angular momentum. They have unique properties and find applications in various fields. This study presents a general framework for generating integrated vortex beam emitters using photonic inverse design. Experimental demonstrations and the design of a vortex beam multiplexer are shown. The foundry-fabricated beam emitters with wide bandwidths and high efficiencies are also described.
Article
Optics
Alexander D. White, Geun Ho Ahn, Kasper Van Gasse, Ki Youl Yang, Lin Chang, John E. Bowers, Jelena Vuckovic
Summary: This article demonstrates an integrated approach for passively isolating a continuous-wave laser using the non-reciprocal Kerr nonlinearity in ring resonators. By using silicon nitride as the model platform, the authors achieve single ring isolation of 17-23 dB with 1.8-5.5 dB insertion loss, and cascaded ring isolation of 35 dB with 5 dB insertion loss. They also demonstrate hybrid integration and isolation with a semiconductor laser chip using these devices.
Article
Physics, Multidisciplinary
Daniil M. Lukin, Melissa A. Guidry, Joshua Yang, Misagh Ghezellou, Sattwik Deb Mishra, Hiroshi Abe, Takeshi Ohshima, Jawad Ul-Hassan, Jelena Vuckovic
Summary: This study reports on the integration of near-transform-limited silicon vacancy (VSi) defects into microdisk resonators fabricated in a CMOS-compatible 4H-silicon carbide-on-insulator platform. It demonstrates a single-emitter cooperativity of up to 0.8 and optical superradiance from a pair of color centers coupled to the same cavity mode. The effect of multimode interference on the photon scattering dynamics from this multiemitter cavity quantum electrodynamics system is investigated. These results are crucial for the development of quantum networks in silicon carbide and bridge the classical-quantum photonics gap by uniting optically coherent spin defects with wafer-scalable, state-of-the-art photonics.
Article
Optics
Geun Ho Ahn, Alexander D. White, Hyungjin Kim, Naoki Higashitarumizu, Felix M. Mayor, Jason F. Herrmann, Wentao Jiang, Kevin K. S. Multani, Amir H. Safavi-Naeini, Ali Javey, Jelena Vuckovic
Summary: Many attractive photonics platforms lack integrated photodetectors due to material incompatibilities and lack of process scalability. This research shows that tellurium can be evaporated onto photonic chips using a thermal evaporation and deposition technique, resulting in air-stable, high-speed, ultrawide-band photodetectors. These photodetectors demonstrate detection from visible to short-wave infrared, a bandwidth of over 40 GHz, and platform-independent scalable integration with various photonic structures.
Article
Biochemical Research Methods
Casey M. Baker, Yiyang Gong
Summary: Neural ensembles are widely distributed in the brain and are essential for cognitive functions such as memory and perception. Previous research has shown that ensembles in the visual cortex exhibit pattern completion properties, with just two neurons able to activate ensembles containing tens of neurons. However, methods for identifying pattern completion neurons are not well-developed. In this study, a computational model of the visual cortex was used to optimize the selection of pattern completion neurons. The study identified ensembles of excitatory neurons using clustering techniques and found that the power of a neuron pair to activate an ensemble was correlated with various graph theory parameters. Additionally, a novel latency metric was developed to identify pattern completion neurons in vivo. These findings improve our understanding of pattern completion properties and have practical applications in controlling ensemble activation during behavioral studies.
PLOS COMPUTATIONAL BIOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Henry Carfagno, Melissa A. . Guidry, Joshua Yang, Lauren McCabe, Joshua M. O. Zide, Jelena Vuckovic, Matthew F. Doty
Summary: Highly efficient photonic couplers for quantum emitters in fiber networks were designed and tested. The inverse-designed structures outperformed traditional grating outcouplers. A novel fabrication method with smaller feature size constraint improved the device transmission efficiency. Employing broadband optimization criteria resulted in a more robust design.
Article
Optics
G. Spektor, D. Carlson, Z. Newman, J. L. Skarda, N. Sapra, L. Su, S. Jammi, A. R. Ferdinand, A. Agrawal, J. Vuckovic, S. B. Papp
Summary: Visible light wavelengths are crucial for controlling quantum matter and advancing quantum technologies. The development of visible integrated photonics allows for scalable circuits with complex functionalities, pushing the boundaries of science and technology. Our experimental approach demonstrates the generation and control of free-space radiation within a single Ta2O5 layer, enabling the production of circularly polarized beams at challenging wavelengths and paving the way for atomic-physics-based quantum technologies.
Article
Optics
Melissa A. Guidry, Daniil M. Lukin, Ki Youl Yang, Jelena Vuckovic
Summary: In this work, we theoretically study the collective dynamics of the quantum fluctuations of soliton microcombs, which are self-organized pulses of light sustained in driven Kerr microresonators. We find that a dissipative Kerr soliton crystal is accompanied by pulses of squeezed multimode vacuum and derives its operational stability from the strong detuning of the below-threshold parametric process. We present a photonic architecture that enables independent control of the above-and below-threshold states and achieves a high degree of squeezing (>15 dB) in the output waveguide with realistic losses.
Article
Chemistry, Multidisciplinary
Ryan J. Gelly, Alexander D. White, Giovanni Scuri, Xing Liao, Geun Ho Ahn, Bingchen Deng, Kenji Watanabe, Takashi Taniguchi, Jelena Vuckovic, Hongkun Park
Summary: Efficient nanophotonic devices are crucial in applications such as quantum networking, optical information processing, sensing, and nonlinear optics. However, integrating two-dimensional materials into photonic structures is often limited by size and material quality. This study uses hexagonal boron nitride as a waveguiding layer to improve the optical quality of embedded films. By combining it with photonic inverse design, it provides a complete platform for interfacing with optically active 2D materials and enables various functionalities. This work opens up possibilities for advanced 2D-material nanophotonic structures in classical and quantum nonlinear optics.
Article
Chemistry, Multidisciplinary
Kinfung Ngan, Yuan Zhan, Constantin Dory, Jelena Vuckovic, Shuo Sun
Summary: This study presents a new technique that allows for the deterministic assembly of diamond color centers in a silicon nitride photonic circuit, enabling maximum light-matter interaction strength and paving the way for scalable manufacturing of large-scale quantum photonic circuits.
Article
Optics
Joshua Yang, Melissa A. Guidry, Daniil M. Lukin, Kiyoul Yang, Jelena Vuckovic
Summary: Inverse design has brought revolutionary changes to the field of photonics by automating the development of complex structures with unique functionalities. However, its application in nonlinear photonics has been limited. In this study, we demonstrate quantum and classical nonlinear light generation in silicon carbide nanophotonic inverse-designed Fabry-Perot cavities, showcasing the power of inverse design for nonlinear optics.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Guillermo Angeris, Theo Diamandis, Jelena Vuckovic, Stephen P. Boyd
Summary: In this paper, a method for computing bounds for various efficiency metrics in photonics is presented, with a focus on the case where the objective function can be expressed as the ratio of two quadratic functions of the field. A simple semidefinite programming relaxation for this problem is demonstrated. A numerical example of bounding the maximal mode conversion purity for a given device size is provided. The paper is accompanied by an open source Julia package for basic simulations and bounds.
Article
Chemistry, Multidisciplinary
Amani A. Hariri, Alyssa P. Cartwright, Constantin Dory, Yasser Gidi, Steven Yee, Ian A. P. Thompson, Kaiyu X. Fu, Kiyoul Yang, Diana Wu, Nicolo Maganzini, Trevor Feagin, Brian E. Young, Behrad Habib Afshar, Michael Eisenstein, Michel J. F. Digonnet, Jelena Vuckovic, H. Tom Soh
Summary: This study presents a design architecture that can convert existing aptamers into reversible aptamer switches, allowing for tuning of their kinetic and thermodynamic properties without prior knowledge of the ligand binding domain. By combining these switches with evanescent-field-based optical detection hardware, the study demonstrates a biosensor system that can continuously measure multiple biomarkers in complex samples with rapid time responses.
ADVANCED MATERIALS
(2023)
