Article
Optics
Peiji Zhou, Ting Li, Yucheng Lin, Lipeng Xia, Li Shen, Xiaochuan Xu, Tao Li, Yi Zou
Summary: By leveraging the artificial gauge field mechanism, a dense waveguide array with a half-wavelength pitch, low-crosstalk, and broadband capability has been demonstrated in silicon. This approach enables flexible routing and significant reduction in on-chip estate, leading to a high-density photonic integrated circuit.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Xiaoyuan Guo, Zi Wang, Yao Zhang, Yingjie Liu, Zimeng Zhang, Jiefeng Xu, Shumin Xiao, Qinghai Song, Ke Xu
Summary: An ultra-broadband multimode waveguide crossing based on subwavelength transmitarray (SWTA) is proposed, which exhibits high transmittance in the propagation direction and excellent confinement in its orthogonal direction. The crossing, designed and fabricated on silicon on insulator, has a compact footprint of only 5.05 μm x 5.05 μm and operates over a large bandwidth from 1.4 to 2.1 μm with an excess loss of less than 0.77 dB. This ultra-broadband and compact multimode crossing enables dense cross connection of waveguides with large data capacity via wavelength and mode division multiplexing.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Lianzhong Jiang, Kin Seng Chiang
Summary: We demonstrate all-optical mode switching using a graphene-buried polymer waveguide asymmetric directional coupler. The device utilizes the photothermal effect of graphene to achieve efficient switching between different modes. The graphene-buried polymer waveguide offers potential for low-power all-optical control devices.
Article
Optics
Mingxiu Yuan, Di Peng, Yuwen Qin, Jianping Li, Meng Xiang, Ou Xu, Songnian Fu
Summary: A broadband multi-frequency microwave photonic up-conversion scheme with a tunable phase shift is proposed and demonstrated. By modulating and superposing the optical signal, multi-frequency microwave signals are obtained and the phase can be continuously adjusted.
OPTICS COMMUNICATIONS
(2022)
Article
Optics
David Gonzalez-Andrade, Irene Olivares, Raquel Fernandez de Cabo, Jaime Vilas, Antonio Dias, Aitor V. Velasco
Summary: In this paper, a novel three-mode architecture based on multimode interference couplers, passive phase shifters, and cascaded symmetric Y-junctions is presented. The architecture can operate up to the third-order mode by including a single switchable phase shifter. Subwavelength grating metamaterials are exploited to overcome bandwidth limitations, resulting in a simulated bandwidth of 161 nm with low insertion loss and crosstalk.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Hao Sun, Bruno Taglietti, Yue Wang, Lawrence R. Chen
Summary: Bragg gratings (BGs) are widely used in microwave photonic signal processing and systems due to their customizable amplitude and phase responses. Waveguide BGs (WBGs) are compact and easily integrated with other components to build MWP systems. Subwavelength grating (SWG) waveguides and passive devices in silicon-on-insulator (SOI) have enabled the development of breakthrough devices based on anisotropic metamaterials.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Li-Yuan Chiang, Chun-Ta Wang, Steve Pappert, Paul K. L. Yu
Summary: We present a passively biased 2 x 2 thermo-optic switch with high power efficiency and fast response time. The switch utilizes the highly concentrated optical field of a slot waveguide mode and the strong thermo-optic effect of a nematic liquid crystal (NLC) cladding. The device demonstrates low power consumption and fast operation speed, providing a new solution for designing thermo-optic actuators.
Article
Engineering, Electrical & Electronic
Heidar Keshavarz, S. Esmail Hosseini, Kambiz Jamshidi, Dirk Plettemeier
Summary: In this paper, an integrated microwave photonic reconfigurable mixer, phase shifter, and frequency doubler based on silicon photonics platform is proposed and theoretically investigated. The structure consists of a novel DDMZM and PM, and can be configured for various functions such as phase tunable mixing, double-balanced mixing, up-converting, down-converting, RF frequency doubling, and phase shifting by adjusting optical wavelength and choosing the proper RF hybrid coupler. The proposed structure is theoretically analyzed and verified through simulations.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Yiming Ma, Yuhua Chang, Bowei Dong, Jingxuan Wei, Weixin Liu, Chengkuo Lee
Summary: Mid-infrared absorption spectroscopy is important for molecule identification and quantification, and integrated photonics technology allows on-chip spectroscopic sensing to minimize device size, cost, and power consumption. The integration of waveguides and photodetectors is essential for on-chip sensing systems, and extending the operating wavelengths to long-wave infrared range faces challenges from both waveguide platforms and photodetection technologies.
Article
Chemistry, Analytical
Muhammad Yasir, Fabio Peinetti, Patrizia Savi
Summary: In this paper, an enhanced tunable microwave phase shifter is proposed, which achieves phase variation by adjusting the conductivity of graphene.
Article
Optics
Jingshu Guo, Chaoyue Liu, Laiwen Yu, Hengtai Xiang, Yuluan Xiang, Daoxin Dai
Summary: Graphene-silicon-graphene waveguide photodetectors operating at wavelengths of 1.55 and 2 μm are demonstrated with potential for large-scale integration. The photodetectors exhibit high bandwidth, ultra-low dark current, high photo-to-dark current ratio, and high linear dynamic range.
LASER & PHOTONICS REVIEWS
(2023)
Article
Physics, Multidisciplinary
Darpan Mishra, Ramesh Kumar Sonkar
Summary: This paper investigates the influence of different process parameters on the performance of a silicon PN optical phase shifter. Process simulation using Silvaco TCAD is conducted to study the effect of dopant implantation dose, implantation energy, annealing temperature and time, wafer temperature, wafer tilt and rotation, and pre-amorphization on the phase and absorption of light. The study shows that ion channeling is a limiting factor on the phase shifter performance, and improvements can be made by tilting the wafer or using a pre-amorphized substrate for implantation. The 3-dB modulation bandwidth is highly dependent on the wafer tilt angle, rotation angle, and the lattice structure of the solid substrate, with significant improvement observed for a pre-amorphized sample.
FRONTIERS IN PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Tao Ma, Shaohui Liu, Yongsheng Tian, Heng Liu, Fang Wang
Summary: A graphene-hBN-silicon hybrid plasmonic rib waveguide is designed for refractive index sensing, achieving a high FOM value by optimizing size parameters and showing remarkable propagation performance peaks. The sensing structure demonstrates good sensitivity for homogeneous and surface sensing, making it suitable for ultra-compact on-chip micro-nano photonic biochemical sensing systems.
IEEE SENSORS JOURNAL
(2021)
Article
Optics
Lianzhong Jiang, Quandong Huang, Kin Seng Chiang
Summary: We propose a low-power all-optical switch based on a graphene-buried balanced Mach-Zehnder interferometer structure. The switch operates by using the heat generated from graphene's absorption of the pump light to switch the signal light. Experimental results show high pump absorption and low signal loss in the fabricated device, allowing for efficient signal switching with minimal sensitivity to temperature variations.
Article
Optics
Hesham A. Okda, Sherif Rabia, Hossam M. H. Shalaby
Summary: An ultrafast, compact, zero-biased, and CMOS-compatible graphene photodetector based on a hybrid plasmonic waveguide is proposed. The photodetector utilizes photonic and plasmonic modes in the waveguide to enhance the detection performance. The results demonstrate high voltage responsivity and photocurrent responsivity at a wavelength of 1550 nm.
Article
Optics
Xiaonan Hu, Marcello Girardi, Zhichao Ye, Pascual Munoz, Anders Larsson, Victor Torres-Company
Article
Optics
Hassan Rahbardar Mojaver, Valery Tolstikhin, Bernardo Gargallo, Rocio Banos, David Domenech, Jessica Lo, Dhiraj Kumar, Kin-Wai Leong, Odile Liboiron-Ladouceur
Article
Optics
Juan Fernandez, Joan Felip, Bernardo Gargallo, Jose David Domenech, Daniel Pastor, Carlos Dominguez-Horna, Pascual Munoz
Article
Optics
Daniel Perez-Lopez, Ana Gutierrez, Jose Capmany
Summary: This research introduces a new unit cell topology design to increase the integration density of photonic processors, achieving the highest integration density for waveguide mesh on a silicon nitride chip. The chip is electrically interfaced to a PCB, demonstrating reconfigurable optical beamsplitters, high peak rejection microwave photonic filters, and dynamic connection and routing of 5G digitally modulated signals within the photonic mesh.
Article
Optics
Yue Wang, Hao Sun, Mostafa Khalil, Wei Dong, Ivana Gasulla, Jose Capmany, Lawrence R. Chen
Summary: We experimentally demonstrate an index-variable OTTDL based on an array of 40 subwavelength grating (SWG) waveguides in silicon-on-insulator, offering potential advantages in terms of compactness and operation versatility for a variety of microwave signal processing applications.
Article
Engineering, Electrical & Electronic
Dong Liang, Jose Capmany, Daniel Perez, Prometheus Dasmahapatra, Qinggui Tan, Xiaojun Li, Li Li, Yong Liu
Summary: This study presents a programmable on-chip photonic processor for various RF receiver configurations, built by interconnecting independent subunits such as Mach-Zehnder interferometers and Ring resonators. The design, fabrication, and characterization of a dedicated chip are described, showing its potential as a reconfigurable filter. Thorough RF receiver related passive processor including out-of-band suppression, carrier-sideband routing, channelization filtering, as well as I-Q mixing is demonstrated, effectively proving the programmable integrated processor's capability for broadband photonic RF receiver.
IEEE PHOTONICS JOURNAL
(2021)
Article
Optics
Erica Sanchez, Daniel Perez-Lopez, Prometheus DasMahapatra, Jose Capmany
Summary: As microwave photonic (MWP) links and systems become more complex, losses will increase, necessitating the incorporation of optical amplification. An analytical model has been developed for amplified arbitrary filtered MWP systems, providing expressions for main figures of merit for intensity modulation direct detection. This model has been applied to a long MWP link and a MWP reconfigurable filter implemented through a programmable waveguide mesh photonic integrated circuit.
Article
Optics
Ling Liu, Xian Jin, Tigang Ning, Lawrence R. Chen, Jose Capmany
Summary: The proposed dual-frequency OEO incorporates a multiband microwave photonic filter, allowing for simultaneous tuning and reconfigurable multi-frequency microwave signals. By adjusting the parameters of optical spectral slicing and sampling, the dual-frequency output can be easily achieved, as well as the switching between single-frequency and dual-frequency output. The multi-passband nature of the MPF opens up possibilities for scaling the scheme for multi-frequency OEO operation in the future.
Article
Optics
Erica Sanchez, Daniel Perez-Lopez, Diego Perez-Galacho, Tan Huy-ho, David Wessel, Jose Capmany
Summary: We present an end-to-end analytic model for calculating the figures of nerit (FOMs) of arbitrarily filtered and amplified heterodyne coherent microwave photonics (MWP) links. This model is applicable to evaluating the performance of complex systems, particularly in the final stage of radio frequency (RF) signal conversion. We apply this model to a specific case in the 5G link, representing the front-haul segment between the central office and the base station. It is expected to serve as a useful and efficient tool for analyzing various cases combining fiber and photonic chip elements during the design stage.
Article
Optics
Ruben Alemany, Pascual Munoz, Daniel Pastor, Carlos Dominguez
Summary: The paper presents a systematic design for manufacturing analysis for thermo-optic phase tuners on a silicon nitride platform, analyzing heat distribution and conducting parametric simulations. Deep air-filled trenches are shown to significantly reduce power consumption and thermal crosstalk, although with a slight decrease in bandwidth.
Editorial Material
Engineering, Electrical & Electronic
Jose Capmany, Christina Lim, Kazutosi Kato, Patrick Runge, Andreas Beling
Summary: The papers in this special section focus on optical detectors and the conversion from photons to electrons, which is a crucial operation in photonic systems. The development in the past five decades, especially based on heterostructures, quantum wells, and uni-carrier operation, has yielded impressive results in terms of bandwidth, noise, and footprint.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
News Item
Optics
Jose Capmany, Daniel Perez-Lopez
Summary: Controlling the refractive index of BaTiO3 thin films through ferroelectric domain switching controlled by electrical pulses is now possible. A device based on this material has been introduced for implementing low-power, high-speed and CMOS-compatible programmable phase shifters in silicon photonic chips.
Article
Engineering, Electrical & Electronic
Pascual Munoz, Daniel Pastor, Luis Alberto Bru, Gloria Mico Cabanes, Jesus Benitez, Dominic Goodwill, Eric Bernier
Summary: In this study, a two-dimensional optical-phased array compatible with FMCW LiDAR is demonstrated using a multiple-input star coupler. Compared to previous single-input designs, the multi-input approach proves to be more efficient in terms of footprint, as it condenses multiple single-input devices into one.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Optics
Xiangzhi Xie, Guchang Chen, Feifei Yin, Kun Xu, Jose Capmany, Yitang Dai
Summary: A time reversal method for broadband microwave signals based on frequency conversion of multiple subbands is proposed and experimentally demonstrated. The input spectrum is divided into narrowband subbands and the center frequency of each subband is reassigned using multiheterodyne measurement. The system achieves both spectral inversion and time reversal of the input waveform. Mathematical derivation and numerical simulation support the equivalence between time reversal and spectral inversion in this system. Experimental results also show successful spectral inversion and time reversal of a broadband signal with instantaneous bandwidth larger than 2 GHz. The proposed solution shows promise for integration without dispersion elements and is competitive for processing broadband microwave signals.
Article
Optics
Xiangzhi Xie, Jilong Li, Kun Xu, Jose Capmany, Yitang Dai
Summary: This paper proposes a method of compressing LFM signals based on the spectral Talbot effect and demonstrates it through experiments. The method can effectively compress broadband LFM signals with long durations and measure the delay difference between signals.
