Article
Engineering, Electrical & Electronic
Saket Kaushal, Jose Azana
Summary: This paper provides a detailed analysis of using ultra-compact on-chip discrete spectral phase filters based on waveguide Bragg gratings for managing group-velocity dispersion in broadband waveforms. The study demonstrates the potential for achieving target GVD profiles on high-rate periodic pulsed waveforms and highlights the application possibilities on non-periodic signals.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Rui Cheng, Lukas Chrostowski
Summary: This tutorial discusses the development of Integrated Bragg gratings (IBGs) on the silicon-on-insulator (SOI) platform and their potential applications in optical telecommunications and signal processing. The design methodology for SOI-based IBGs is described, along with examples of advanced optical devices.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
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
Clemens Singer, Alexander Goetz, Adarsh S. Prasad, Martin Becker, Manfred Rothhardt, Sarah M. Skoff
Summary: This study demonstrates the thermal tuning capability of an alignment-free, fiber-integrated Fabry-Perot cavity, which can function as a narrowband filter with wavelength tuning and high suppression performance. Additionally, in the field of quantum optics, quantum emitters can be coupled to the cavity for reversible manipulation of cavity effects.
Article
Materials Science, Multidisciplinary
Stefan Kefer, Dominik Pape, Gian-Luca Roth, Steffen Hessler, Bernhard Schmauss, Ralf Hellmann
Summary: This study demonstrates a novel approach for the fabrication and rapid prototyping of monolithic photonic platforms with integrated sensing structures. By utilizing injection-molded substrates and UV radiation to modify the refractive index, the platform is equipped with high-sensitivity temperature and refractive index measurement capabilities. The integration of Bragg grating and Fabry-Perot cavity during micromilling process opens up new possibilities for optical sensing applications.
OPTICAL MATERIALS EXPRESS
(2021)
Article
Nanoscience & Nanotechnology
Ju Won Choi, Byoung-Uk Sohn, Ezgi Sahin, George F. R. Chen, Doris K. T. Ng, Benjamin J. Eggleton, Carel Martijn de Sterke, Dawn T. H. Tan
Summary: In this manuscript, a new approach for generating picosecond pulse trains from low power, continuous-wave light is introduced. This is achieved by utilizing cross-phase modulation technology in an ultra-silicon-rich nitride grating. The significance of this technique lies in its ability to generate high repetition rate ultrashort pulses from weak continuous-wave light.
Article
Engineering, Electrical & Electronic
Jonathan Cauchon, Jean-Michel Vallee, Jonathan St-Yves, Wei Shi
Summary: The study introduces a deep learning model for reconstructing physical designs of complex coupled photonic systems from their spectral responses, enabling inverse design and fabrication diagnosis. The model demonstrates high efficiency and accuracy in device reconstruction and fabricated device evaluation, showcasing great potential for data-driven processes required by Industry 4.0.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Alexander Chen, Amir Begovic, Stephen Anderson, Zhaoran Rena Huang
Summary: Si photonic foundry fabricated cascaded and continuous spiral shaped silicon nitride waveguides with Bragg grating structures to achieve on-chip true-time delay line. Time-domain measurement method was used to characterize the delay time, and the highest group index extracted from cascaded SiN grating waveguides is 19.7, while the continuous spiral SiN grating waveguide produces a delay time of 3.78 ns.
IEEE PHOTONICS JOURNAL
(2022)
Article
Optics
Carlos Perez-Armenta, Alejandro Ortega-Monux, Jose Manuel Luque-Gonzalez, Robert Halir, Jens Schmid, Pavel Cheben, Inigo Molina-Fernandez, J. Gonzalo Wanguemert-Perez
Summary: A polarization-independent 2 x 2 multimode interference coupler in a 220 nm silicon-on-insulator platform is designed and experimentally demonstrated for the first time using subwavelength grating metamaterial topology to control electromagnetic properties. The coupler operates for both TE and TM polarization states with polarization dependent loss, insertion loss, imbalance all less than 1 dB, and phase errors below 5 degrees in the wavelength range from 1500 nm to 1560 nm. The device has a small footprint of 3.5 µm x 47.25 µm and is fabricated using a single etch-step process compatible with immersion deep-UV lithography with a minimum feature size of 100 nm.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Mathias J. Weisen, James C. Gates, Corin B. E. Gawith, Peter G. R. Smith, Peter Horak
Summary: The study proposes the use of bi-directional propagation of light in silica integrated coupled waveguide structures for linear optical processing, implementing linear operations using symmetric and unitary matrices. It demonstrates the realization of an arbitrary 4x4 coupler through a linear sequence of more fundamental 2x2 couplers, and discusses the implementation in a silica integrated platform utilizing direct UV-written waveguides and grating couplers for optimized coupling efficiency.
IEEE PHOTONICS JOURNAL
(2021)
Article
Nanoscience & Nanotechnology
Ju Won Choi, Byoung-Uk Sohn, Ezgi Sahin, George F. R. Chen, Peng Xing, Doris K. T. Ng, Benjamin J. J. Eggleton, Dawn T. H. Tan
Summary: This manuscript investigates nonlinear pulse propagation in a chip-based nonlinear Bragg grating and observes clear signatures of gap soliton propagation, including slow light, intensity-dependent transmission, intensity-dependent temporal delay, and gap soliton compression.
Article
Chemistry, Analytical
Siim Heinsalu, Katsuyuki Utaka
Summary: We present two methods to improve wavelength sensitivity for multi-slot sub-wavelength Bragg grating refractive index sensors, achieving significant improvements compared to previous results.
Article
Optics
Lichao Zhang, Jiamin Chen, Weichao Ma, Guangyuan Chen, Ruoming Li, Wangzhe Li, Junming An, Jiashun Zhang, Yue Wang, Guangyang Gou, Chunxiu Liu, Zhimei Qi, Ning Xue
Summary: This paper introduces four basic bending methods and proposes an n-adjustable (NA) bend that can achieve lower losses compared to other basic bends by adjusting n values. The circular bend and Euler bend are special cases of the proposed NA bend. The proposed bend shows promise as a candidate for low-loss compact photonic integrated circuits.
Article
Engineering, Electrical & Electronic
Claudio Porzi, Manuel Reza, Paolo Ghelfi, Marc Sorel, Antonella Bogoni
Summary: We report a silicon photonics flat-top bandpass microwave photonic filter with large out-of-band power rejection of over 40 dB and tunability of central frequency up to 70 GHz. The RF bandpass transfer function can be widely configured without sacrificing filter performance. The filter integrates a phase modulator and a tunable optical splitter to achieve a high level of functional integration.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Xudong Gao, Zhenzhu Xu, Yupeng Zhu, Chengkun Yang, Shoubao Han, Zongming Duan, Fan Zhang, Jianji Dong
Summary: Due to its advantages such as low propagation loss, wide operation bandwidth, continuous delay tuning, fast tuning speed, and compact footprints, chirped Bragg grating waveguide has great potential in wideband phased array beamforming systems. However, the large group delay error has hindered its practical applications. One of the main factors causing large group delay errors is the nonlinear group delay spectrum. In this study, waveguides with nonlinear gradient widths are adopted to compensate for the nonlinear effect of the grating apodization on the mode effective index, resulting in a linear group delay spectrum and a halved group delay error.
FRONTIERS OF OPTOELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Charles Matte-Breton, Rene-Jean Essiambre, Colin Kelly, Younes Messaddeq, Sophie LaRochelle
Summary: We report the characterization of a cladding-pumped multicore fiber with annular erbium doping for low gain compression over the C-band. The experimental results show that significant reduction in gain compression of multicore cladding-pump amplifiers can be achieved with the proposed annular doping design in the cladding.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Rodolfo Martinez-Manuel, Jonathan Esquivel-Hernandez, Sophie LaRochelle
Summary: A novel method is presented to reduce the nonlinearity effect of a wavelength scanning diode laser in a low-reflectivity Fabry-Perot interferometer. The proposed method improves system resolution and achieves a temperature insensitive sensing system. It is demonstrated by measuring the thermo-optic coefficient of liquid samples and presenting long-term performance experimental results.
IEEE SENSORS JOURNAL
(2022)
Article
Optics
Hanlin Feng, Saber Jalilpiran, Frederic Maes, Lixian Wang, Sophie LaRochelle
Summary: In this study, theoretical and experimental uncertainty analysis is conducted to improve the performance prediction of erbium-doped fiber amplifiers in the extended L-band. The optimal EDF lengths and uncertainties in the measured clustering ratio are determined. The accuracy of the Giles parameters is verified through comparison of simulation results and experimental measurements.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Rodolfo Martinez-Manuel, Jonathan Esquivel-Hernandez, Luis M. Valentin-Coronado, Sophie LaRochelle
Summary: A fiber sensor for directional bending monitoring is proposed, which is made of a single piece of multimode elliptical-core fiber and works in a reflection regime. The interference spectrum generated by the system has nonuniform amplitude and nonperiodic shape, making it suitable for pattern recognition algorithms. The flexible rod fixed with the sensor generates specific optical spectra for each bending position, which can be identified by the pattern recognition algorithm. Experimental results of directional bending monitoring based on pattern recognition and trajectory estimation are presented.
IEEE SENSORS JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Jack A. Smith, Henry Francis, Gabriele Navickaite, Michael J. Strain
Summary: This article presents a high-performance silicon nitride photonic integrated circuit platform that operates at visible wavelengths and is accessible through the commercial foundry, LIGENTEC. The article measures propagation losses across the visible spectrum from 450 nm to 850 nm. For wavelengths above 630 nm, the losses are <1 dB/cm in TE and <0.5 dB/cm in TM. In addition, sets of single mode waveguide-coupled ring resonators across three separate chips were tested and analyzed. The article provides an analysis of the loss and coupling, considering the bus-ring coupling gap and waveguide width. High confinement, low loss devices based on chip-scale silicon nitride are becoming increasingly important for the next generation of integrated optical devices operating at visible wavelengths.
OPTICAL MATERIALS EXPRESS
(2023)
Review
Physics, Applied
J. A. Smith, D. Jevtics, B. Guilhabert, M. D. Dawson, M. J. Strain
Summary: This review provides an overview of transfer printing for integrated photonics applications, including considerations of materials and fabrication processes, efficient optical coupling methods, and high-accuracy inter-layer alignment. State-of-the-art integration demonstrations are presented, covering optical sources and detectors, quantum emitters, sensors, and opto-mechanical devices. Future developments in the technology for dense multi-materials integration at wafer scales are discussed.
APPLIED PHYSICS REVIEWS
(2022)
Article
Optics
Graeme E. Johnstone, Johannes Herrnsdorf, Martin D. Dawson, Michael J. Strain
Summary: Challenging imaging applications that require ultra-short exposure times or imaging in photon-starved environments often have extremely low numbers of photons per pixel (<1 photon per pixel). To improve the image quality in such photon-sparse images, post-processing techniques, such as Bayesian retrodiction and bilateral filtering, can be used to estimate the number of photons detected and improve the spatial distributions in single-photon imaging applications. In this study, we demonstrate that at high frame rates (>1 MHz) and low incident photon flux (<1 photon per pixel), image post-processing techniques can provide better grayscale information and spatial fidelity of reconstructed images compared to simple frame averaging, with up to a 3-fold improvement in SSIM.
Article
Engineering, Electrical & Electronic
Mai Banawan, Satyendra K. Mishra, Ariane Gouin, Nathalie Bacon, Xun Guan, Lixian Wang, Sophie LaRochelle, Leslie A. Rusch
Summary: Modal multiplexing can increase fiber capacity, but often requires high digital processing with MIMO algorithms. The use of OAM for multiplexing can support MIMO-free reception, but operates in an interference limited regime. In this study, we compare the performance of MIMO-free and standard electronic 2 x 2 MIMO systems and show that the receiver complexity is similar. We explore the use of commercial coherent receivers with 2 x 2 MIMO, making OAM demultiplexing effective with current technology and enhancing the total bit rate.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Pierre-olivier Janvier, Charles Matte-Breton, Kaboko Jean-Jacques Monga, Lixian Wang, Leslie Rusch, Sophie LaRochelle
Summary: We propose a novel optimization method to reduce the differential modal gain (DMG) in few-mode cladding-pumped erbium-doped fiber amplifiers (FM-EDFAs). By combining two design criteria and defining a figure-of-merit (FOM), we achieve low DMG designs without high computational cost. We illustrate this method with the design of six-mode erbium-doped fibers (EDFs) for amplification over the C-Band targeting designs that are compatible with standard fabrication processes.
Article
Engineering, Electrical & Electronic
Saber Jalilpiran, Victor Fuertes, Jacques Lefebvre, Nicolas Gregoire, Firat Ertac Durak, Nelson Landry, Lixian Wang, Victor Anthony Garcia Rivera, Younes Messaddeq, Sophie LaRochelle
Summary: We have developed baria-silica erbium-doped fibers (Ba-EDF) using modified chemical vapor deposition (MCVD) process and solution-doping technique to extend the bandwidth of L-band EDFAs beyond 1620 nm. The low loss (<10 dB/km at 1200 nm) fiber cores with BaO concentration of 1-3 mol% and Er3+ concentration of 8x10(24) m(-3) were successfully achieved. Increasing the BaO content positively affected the optical properties and EDFA performance, showing a reduction in pair-induced quenching and a bi-exponential luminescence decay with a dominant 15.5 ms lifetime component. The absorption/emission coefficients also revealed a red-shift in the signal excited state absorption, leading to a moderate extension of the L-band gain to longer wavelengths (1622 nm).
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Eleni Margariti, Gemma Quinn, Dimitars Jevtics, Benoit Guilhabert, Martin D. Dawson, Michael J. Strain
Summary: A continuous, single shot roller transfer printing process is introduced for large-scale hybrid integration of semiconductor devices. It demonstrates transfer of a 320 x 240 pixel micro-LED array, with sub-micron relative position accuracy, representing over 75,000 individual devices in one shot. The transfer printing process maintains array geometry, with pixel spatial location error less than 1 & mu;m deviation from the as-designed layout. An automated sub-micron precision metrology system using simple optical microscopy is developed to assess device populations and yield.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Engineering, Electrical & Electronic
Mohammad Ahmadi, Jacques Lefebvre, Wei Shi, Sophie LaRochelle
Summary: This work optimizes silicon Raman amplifiers for fabrication with open-access foundry sub-micron silicon platform, and experimentally validates the importance of considering non-reciprocal Raman gain. The results demonstrate loss-less Raman-assisted optical circuits and stimulated Raman scattering amplification with net-gain using low pump powers.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Benoit Guilhabert, Sean P. Bommer, Nils K. Wessling, Dimitars Jevtics, Jack A. Smith, Zhongyi Xia, Saptarsi Ghosh, Menno Kappers, Ian M. Watson, Rachel A. Oliver, Martin D. Dawson, Michael J. Strain
Summary: Transfer printing technology has been widely used for integrating planar membrane devices on photonic and electronic circuits. This work introduces an advanced transfer print system that allows printing of optical devices in non-planar geometries and enables in-situ optical monitoring. The system demonstrates the printing of micro-resonators coupled to on-chip waveguides, inverted device printing, and the assembly of micro-cavities with semiconductor micro-lenses and nanowire lasers. Non-standard substrates such as optical chip facets and single-mode fibre ends are also successfully printed. The in-situ optical coupling through the transfer printing system enables real-time active alignment of the printed devices.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2023)
Proceedings Paper
Nanoscience & Nanotechnology
Jack A. Smith, Zhibo Li, Saprtarsi Ghosh, Henry Francis, Gabriele Navickaite, Loyd J. McKnight, Rachel A. Oliver, Martin D. Dawson, Michael J. Strain
Summary: Silicon nitride (Si3N4) is a high-performance material platform for visible wavelength photonic integrated circuits, especially for heterogeneous/hybrid integration of complementary materials. This work characterizes the performance of Si3N4 from LIGENTEC as a base for hybrid integration.
2023 IEEE PHOTONICS SOCIETY SUMMER TOPICALS MEETING SERIES, SUM
(2023)
Article
Engineering, Electrical & Electronic
Mai Banawan, Satyendra K. Mishra, Younes Messaddeq, Sophie LaRochelle, Leslie A. Rusch
Summary: Ring core fibers (RCF) are high-performance modal multiplexing techniques with low crosstalk and support for orbital angular momentum (OAM) modes. However, characterizing RCFs is challenging due to the lack of commercial multiplexers. We have successfully used perfect vortex beams to accurately measure mode-dependent loss (MDL) in RCFs.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
