Photonic Integrated Circuits Research Papers (original) (raw)
2025
Within the scope of our EU FP7 C3PO project, we are developing novel, energy-efficient, colourless photonic technologies for low-cost, next-generation dense wavelengthdivision-multiplexed metro transport and access networks. The... more
Within the scope of our EU FP7 C3PO project, we are developing novel, energy-efficient, colourless photonic technologies for low-cost, next-generation dense wavelengthdivision-multiplexed metro transport and access networks. The colourless transmitters use reflective arrayed photonic integrated circuits, particularly hybrid reflective electroabsorption modulators, and multi-wavelength laser sources, with custom power-efficient driver circuitry. A lowloss piezoelectric beam-steering optical matrix switch allows for dynamic wavelength reconfigurability. Simplifying the required optical and electronic hardware, as well as avoiding the need for expensive, thermally-stabilised tuneable lasers, will yield cost and energy savings for data switching applications in future metro, access, and datacentre interconnection networks. We report on recent advancement towards these low-power optical networks, providing the latest systems results achieved with key enabling hybrid photonic integrated devices and electronic driver/receiver arrays for our targeted applications.
2025, IEEE access
We present the design performance validation of an energy-efficient silicon Mach-Zehnder modulator (MZM) with a forward-biased PIN junction by simulation and experiment. With a length of 50 µm, the presented MZM exhibits at least four... more
We present the design performance validation of an energy-efficient silicon Mach-Zehnder modulator (MZM) with a forward-biased PIN junction by simulation and experiment. With a length of 50 µm, the presented MZM exhibits at least four times smaller form factor for the active phase-shifter than the state-of-the-art. Furthermore, we recorded a remarkably low VπL of only 0.0025 V×cm. By thermal tuning of an additional heater, segmented with the phase shifter, the measured DC extinction ratio of the MZM was 30 dB. Non-return-to-zero data transmission up to 5 Gb/s and the generation of sinc-shaped Nyquist pulse sequences with a bandwidth of 12 GHz is demonstrated. The very small footprint and power consumption make the presented MZM an ideal choice for various applications like Nyquist pulse generation, parallel analog signal processing, arbitrary waveform generation, etc.
2025, IEEE Photonics Journal
Sampling is the primary functional step of an analogue to digital conversion, required for sensing, measurement, signal processing, metrology, and various data communication applications. Here we present, for the first time, to the best... more
Sampling is the primary functional step of an analogue to digital conversion, required for sensing, measurement, signal processing, metrology, and various data communication applications. Here we present, for the first time, to the best of our knowledge, the optical sampling of different microwave signals with sinc-pulse sequences with a very compact integrated silicon photonics ring modulator. By a simple time interleaving with three branches, the employed ring modulator enables ultra-compact photonic integrated analog to digital converters with a sampling rate of three times the RF bandwidth of itself and of the used photodetector and electronic devices. Therefore, its analogue bandwidth is 50% higher than the RF bandwidth of the incorporated electronics and photonics. Thus, the method might enable high-bandwidth analogue to digital converters with ultra-compact footprint and lower power consumption for future communication systems, sensors, and measurement devices.
2025, Optical and Quantum Electronics
For any photonic device simulation, the accuracy of the numerical solution not only depends on the methods being used but also on the discretization parameters used in that numerical method. In this work, Finite Element Method and Finite... more
For any photonic device simulation, the accuracy of the numerical solution not only depends on the methods being used but also on the discretization parameters used in that numerical method. In this work, Finite Element Method and Finite Difference Time Domain Method based on Maxwell's equations were used to simulate optical waveguides and directional couplers. As the solution accuracy may also depend on the index contrast used in such photonic devices, the characteristics of low-index contrast Germanium doped Silica and high-index contrast Silicon Nanowire Waveguides were analyzed, evaluated and benchmarked. Numerical results to benchmark Directional Couplers are also reported in this paper.
2025, OSA Continuum
In the past, multimode transmission through fibers has not been considered a preferred means of signal propagation due to the intermodal dispersion, which limits the data rate. However, recently, there has been an interest in using... more
In the past, multimode transmission through fibers has not been considered a preferred means of signal propagation due to the intermodal dispersion, which limits the data rate. However, recently, there has been an interest in using different modes as individual channels to increase the overall data rate. However, the challenging task in implementing such a system is that each individual mode has to be excited separately without mixing, and these should remain separated even at the bents and splices, and finally, they need to be collected separately. In this paper, design and optimization of a compact optical mode splitter by introducing a small slot in a silicon nanowire waveguide is demonstrated by employing a full-vectorial finite element method. The authors report here that by creating a slot within a waveguide, the desired coupling length ratio of 1:2 between the fundamental and the second modes can be obtained. The waveguide junctions have also been analyzed by using a rigorous least squares boundary residual method to study power transfer efficiency and effect of fabrication tolerances.
2025, Scientific reports
When silicon photonic integrated circuits (PICs), defined for transmitting and receiving optical data, are successfully monolithic-integrated into major silicon electronic chips as chip-level optical I/Os (inputs/outputs), it will bring... more
When silicon photonic integrated circuits (PICs), defined for transmitting and receiving optical data, are successfully monolithic-integrated into major silicon electronic chips as chip-level optical I/Os (inputs/outputs), it will bring innovative changes in data computing and communications. Here, we propose new photonic integration scheme, a single-chip optical transceiver based on a monolithic-integrated vertical photonic I/O device set including light source on bulk-silicon. This scheme can solve the major issues which impede practical implementation of silicon-based chip-level optical interconnects. We demonstrated a prototype of a single-chip photonic transceiver with monolithic-integrated vertical-illumination type Ge-on-Si photodetectors and VCSELs-on-Si on the same bulk-silicon substrate operating up to 50 Gb/s and 20 Gb/s, respectively. The prototype realized 20 Gb/s low-power chip-level optical interconnects for λ ~ 850 nm between fabricated chips. This approach can have ...
2025, STEAM-AI Magazine
Photonic Integrated Circuits (PICs) are vital for AI's future due to their ability to process and transmit data at light speed with low energy consumption. They enable faster, parallel computation and reduce heat generation, making them... more
Photonic Integrated Circuits (PICs) are vital for AI's future due to their ability to process and transmit data at light speed with low energy consumption. They enable faster, parallel computation and reduce heat generation, making them ideal for data-intensive AI tasks in edge devices, data centers, and neuromorphic computing systems.
2025
Brain-chip technology represents a groundbreaking advancement at the intersection of neuroscience, artificial intelligence, and human augmentation. This paper explores the potential of brain chips to enhance cognitive capabilities,... more
Brain-chip technology represents a groundbreaking advancement at the intersection of neuroscience, artificial intelligence, and human augmentation. This paper explores the potential of brain chips to enhance cognitive capabilities, integrate humans with machines, and augment physical abilities. Through neural implants and brain-machine interfaces (BMIs), brain chips could enable memory restoration, accelerated learning, and improved decision-making, as well as foster deeper human-machine collaboration. Additionally, they present the possibility of revolutionizing prosthetics and sensory augmentation, offering unprecedented control over physical capabilities and sensory experiences. However, these advancements raise significant ethical concerns, including privacy issues, social inequality, and questions surrounding autonomy and identity. This paper examines both the transformative potential and the societal implications of brain-chip technology, highlighting the need for careful regulatory frameworks as these technologies evolve. The future of human enhancement via brain chips could redefine cognitive and physical limits, but also challenges our understanding of humanity's relationship with technology.
2025, 2007 IEEE/SEMI Advanced Semiconductor Manufacturing Conference (ASMC)
The availability of a precise physical description of the imaging system that was used to expose an OPC calibration tests pattern is now possible. This data is available from scanner manufacturers of the tool as built and also by scanner... more
The availability of a precise physical description of the imaging system that was used to expose an OPC calibration tests pattern is now possible. This data is available from scanner manufacturers of the tool as built and also by scanner self-metrology in the Fab at any time. This information reduces significant uncertainty when regressing a model used for OPC and allows the creation of more accurate models with better predictability. This paper explores the considerations necessary for best leveraging this data into the OPC model creation flow.
2025, COMSNETS
In a mobile network, it is important to identify energy inefficient RRUs (Remote Radio Units) to improve the overall energy efficiency of the network and achieve significant energy and cost savings. Existing solutions can identify... more
In a mobile network, it is important to identify energy inefficient RRUs (Remote Radio Units) to improve the overall energy efficiency of the network and achieve significant energy and cost savings. Existing solutions can identify inefficient RRUs based on hardware alarms or faults, but not energy consumption in real time for a given region. In this paper, we propose a network energy consumption model and method to identify inefficient RRUs with respect to power consumption in real time. Our method involves ML models trained on the historical data of performance management (PM) counters to predict the RRU energy consumption, on the basis of which the RRUs having a higher divergence between predicted and actual energy consumption are identified. The system is trained and tested with simulated data based on a major network operator.
2025, Optics Express
We present an analysis of Fourier-transform arrayed waveguide gratings in the Fresnel diffraction regime. We report a distinct spatial modulation of the interference pattern referred to as the Moiré-Talbot effect. The effect and its... more
We present an analysis of Fourier-transform arrayed waveguide gratings in the Fresnel diffraction regime. We report a distinct spatial modulation of the interference pattern referred to as the Moiré-Talbot effect. The effect and its influence in a FT AWG device is explained by deriving an original analytical expression for the modulated field, and is also confirmed by numerical simulations using the angular spectrum method to solve the Fresnel diffraction integral. We illustrate the retrieval of spectral information in a waveguide Fourier-transform spectrometer in the presence of the Moiré-Talbot effect. The simulated device comprises two interleaved waveguide arrays each with 180 waveguides and the interference order of 40. It is designed with a Rayleigh spectral resolution of 0.1 nm and 8 nm bandwidth at wavelength λ ∼ 1.5 μm. We also demonstrate by numerical simulations that the spectrometer crosstalk is reduced from -20 dB to -40 dB by Gaussian apodization.
2025, Conference on Lasers and Electro-Optics
We report on the experimental demonstration of a chip-scale microresonator comb enabled optical frequency synthesizer using an agile and highly-integrated heterodyne optical phase-locked loop with InP-based photonic integrated circuit and... more
We report on the experimental demonstration of a chip-scale microresonator comb enabled optical frequency synthesizer using an agile and highly-integrated heterodyne optical phase-locked loop with InP-based photonic integrated circuit and commercial-off-the-shelf electronic components.
2025, 2009 IEEE International Conference on Indium Phosphide & Related Materials
Within the past couple of years InP-based Photonic Integrated Circuits (PICs) have become the subject of aggressive development for commercial applications primarily for the telecommunications industry. Chips with hundreds of photonic... more
Within the past couple of years InP-based Photonic Integrated Circuits (PICs) have become the subject of aggressive development for commercial applications primarily for the telecommunications industry. Chips with hundreds of photonic components carry live traffic in the field, but questions remain about cost/volume/performance tradeoffs, as well as the need for common integration platforms and/or foundry services. Research efforts have been influenced by these issues.
2025, IEEE Photonics Technology Letters
Photocurrent spectroscopy is used to characterize band edges in quantum-well intermixed InGaAsP material lattice matched to InP. The band edge absorption data is used as a design tool to predict the dc performance of electroabsorption... more
Photocurrent spectroscopy is used to characterize band edges in quantum-well intermixed InGaAsP material lattice matched to InP. The band edge absorption data is used as a design tool to predict the dc performance of electroabsorption modulators, and is shown to agree well with data obtained from actual devices. In addition, we demonstrate the presence of an exciton peak in InGaAsP quantum wells, and present its evolution as a function of quantum-well intermixing and reverse bias voltage.
2025, Journal of Lightwave Technology
The paper provides detailed guidelines for the optimal design of ContactLess Integrated Photonic Probes suitable to track and control the local optical power in photonic circuits. With reference to current technology platforms, the paper... more
The paper provides detailed guidelines for the optimal design of ContactLess Integrated Photonic Probes suitable to track and control the local optical power in photonic circuits. With reference to current technology platforms, the paper provides a guide to extract the electrical parameters of the probe and to highlight their role in defining the achievable resolution. Crucial technological and geometrical choices are discussed, together with layout and interconnection solutions oriented to a highly dense integration of the probes. Finally, the criteria for the optimal coupling of the probes to the most suitable readout electronics providing the maximization of the SNR are presented. With these guidelines in mind, transparent in-line local power monitors featuring -35 dBm sensitivity, 40 dB of dynamic range, broadband response from 1.3 to 1.6 µm, a speed down to tens of µs and a minimum size of tens of µm can be effectively designed for high performance reconfiguration and closed-loop control of complex photonic circuits.
2025, Journal of Lightwave Technology
2025
In this paper a new design for a 16×1 arrayed waveguide grating (AWG) with a flat spectral response is presented which is suitable for wavelength division multiplexing (WDM) networks. We designed a 16 channel silicon-based device with... more
In this paper a new design for a 16×1 arrayed waveguide grating (AWG) with a flat spectral response is presented which is suitable for wavelength division multiplexing (WDM) networks. We designed a 16 channel silicon-based device with center wavelength of 1550 nm and 1.6 nm channel spacing. In our new design the insertion loss for the side channels decreases drastically up to 6 dB. Also, the maximum insertion loss difference between channels decreases from 8 to 2 dB and the spectral response of the device is flattened.
2025, Journal of Lightwave Technology
This paper describes the advantages that the introduction of photonic integration technologies can bring to the development of photonic-enabled wireless communications systems operating in the millimeter wave frequency range. We present... more
This paper describes the advantages that the introduction of photonic integration technologies can bring to the development of photonic-enabled wireless communications systems operating in the millimeter wave frequency range. We present two approaches for the development of dual wavelength sources for heterodyne-based millimeter wave generation realized using active/passive photonic integration technology. One approach integrates monolithically two distributed feedback semiconductor lasers along with semiconductor optical amplifiers, wavelength combiners, electro-optic modulators and broad bandwidth photodiodes. The other uses a generic photonic integration platform, developing narrow linewidth dual wavelength lasers based on arrayed waveguide gratings. Moreover, data transmission over a wireless link at a carrier wave frequency above 100 GHz is presented, in which the two lasers are free-running, and the modulation is directly applied to the single photonic chip without the requirement of any additional component.
2025, 2014 16th International Telecommunications Network Strategy and Planning Symposium (Networks)
Ferreira e Simão Brandão as minha desculpas por todas as vezes que vos interrompi o raciocínio para vos por as minhas dúvidas, sem o vosso know-how isto não tinha a mesma piada. À Associação Juvenil de Ciência o espaço a que dediquei mais... more
Ferreira e Simão Brandão as minha desculpas por todas as vezes que vos interrompi o raciocínio para vos por as minhas dúvidas, sem o vosso know-how isto não tinha a mesma piada. À Associação Juvenil de Ciência o espaço a que dediquei mais tempo da minha juventude, tempo esse muito bem empregue. A todas as pessoas que lá conheci, que me orientaram e que eu orientei. Em especial ao Gonçalo Pimentel, o meu melhor amigo que eu ainda hoje não consegui perceber completamente e que por isso mantém a mesma piada desde o momento que o conheci. Podia-te agradecer por muita coisa, mas principalmente pelas decisões que tomaste para me proteger e eu não percebi. Para chegar a esta tese, cinco anos de curso ficaram para trás e é sem dúvida que de pessoas se fazem as recordações. Começo por agradecer primeiro a quem me deixou no final da licenciatura Maria Beatriz Ferreira. Escusado será dizer que te agradeço pela ajuda ao longo deste percurso. Quero sim deixar público aqui que muito do que sou hoje academica, pessoal e profissionalmente o devo a ti. Foi um orgulho poder partilhar três anos de estudo e diversão contigo, muitas estórias e muitos sorriso ainda estarão para se desenlaçar.
2024, Optik
We present the design of a 4-port photonic crystal-based optical circulator employing ring resonator cross connect filters, suitable for photonic integrated circuits schemes. This unique design allows the operation in both clockwise as... more
We present the design of a 4-port photonic crystal-based optical circulator employing ring resonator cross connect filters, suitable for photonic integrated circuits schemes. This unique design allows the operation in both clockwise as well as counterclockwise directions and shows a calculated normalized transmission of over 80%. Since the spectra ranges cover the whole third communication window, any wavelength in these ranges can be circulated through the proposed photonic crystal-based optical circulator even different wavelengths at the same time.
2024, Radioengineering
The paper describes theoretical and experimental results that enabled the authors to proof optical bistability behavior of a specially modified bistable semiconductor laser diode (BLD) created on a structure with a saturable absorption... more
The paper describes theoretical and experimental results that enabled the authors to proof optical bistability behavior of a specially modified bistable semiconductor laser diode (BLD) created on a structure with a saturable absorption section. A mathematical model of the light-current characteristic, condition for bistability and the basic parameters of the hysteresis loop were derived by solving a system of three rate equations. That system was used for simulation of the light-current characteristic and conditions of bistability of the realized BLDs. For selected operating points of the simulated lightcurrent characteristic the parameters of hysteresis loop and element values of the BLD electrical equivalent circuit for small signal variations were calculated. The bistability was experimentally measured by the new time method devised for impulse bistability verification (IBV). The basic measured and calculated parameters of the hysteresis loop of the BLD light-current characteristic were compared.
2024, 33rd European Conference and Exhibition on Optical Communication - ECOC 2007
By exploiting the symmetry of bidirectional wavelength-connections in WDM networks, we propose an N×N bidirectional OXC using one N/2×N/2 reversible optical switch to reduce the complexity of the OXCs. The feasibility is demonstrated at... more
By exploiting the symmetry of bidirectional wavelength-connections in WDM networks, we propose an N×N bidirectional OXC using one N/2×N/2 reversible optical switch to reduce the complexity of the OXCs. The feasibility is demonstrated at 10 Gb/s.
2024
The effort is divided into specific topics applicable to data processing. Those topics include the Dember effect, alignment of a ring laser gyro, measurement of the Fresnel drag coefficient, integrated optical switches, aluminum gallium... more
The effort is divided into specific topics applicable to data processing. Those topics include the Dember effect, alignment of a ring laser gyro, measurement of the Fresnel drag coefficient, integrated optical switches, aluminum gallium arsenide waveguides, Fredkin gates, optically reconfigurable superconductive circuits, and an initial investigation into the application of an acoustooptical tunable filter to the interrogation of fiber optic Bragg sensors.
2024, Optics and Photonics Society of Iran
In this paper a new design for a 16×1 arrayed waveguide grating (AWG) with a flat spectral response is presented which is suitable for wavelength division multiplexing (WDM) networks. We designed a 16 channel silicon-based device with... more
In this paper a new design for a 16×1 arrayed waveguide grating (AWG) with a flat spectral response is presented which is suitable for wavelength division multiplexing (WDM) networks. We designed a 16 channel silicon-based device with center wavelength of 1550 nm and 1.6 nm channel spacing. In our new design the insertion loss for the side channels decreases drastically up to 6 dB. Also, the maximum insertion loss difference between channels decreases from 8 to 2 dB and the spectral response of the device is flattened.
2024
We report on optical properties of Fabry-Pérot (FP) resonator based on Si-air one-dimensional photonic crystal (1D PC) with coupled triple-cavity modes (or defects). These defects obtained by infiltration of the air-cavity with the filler... more
We report on optical properties of Fabry-Pérot (FP) resonator based on Si-air one-dimensional photonic crystal (1D PC) with coupled triple-cavity modes (or defects). These defects obtained by infiltration of the air-cavity with the filler of tunable refractive index. The coupled FP resonators design is CMOS compatible and has potential for application in tuning an individual transmission bands in wave-division multiplexing (WDM) systems.
2024
The proposed encoder in two dimensional photonic crystals is analyzed interms of flow of light inside waveguides. Waveguides have been created by removing silicon rods in the structure and defects with smaller radii have been created to... more
The proposed encoder in two dimensional photonic crystals is analyzed interms of flow of light inside waveguides. Waveguides have been created by removing silicon rods in the structure and defects with smaller radii have been created to achieve the proper couplers operations. The photonic band gap of the proposed encoder is determined and their performance is evaluated using finite difference time domain method. The proposed design has an optical output power threshold range between 76-94% for ON state and threshold level of OFF state is below 20%. The proposed encoder is operated in the wavelength of 1550 nm. Hence, it is applicable for high speed optical integrated circuit. The response time and contrast ratio calculated from the proposed encoder are 0.24 ps and 8.59 dB which are comparatively better than the literature reported with compare to footprint area of the proposed encoder.
2024, Bulletin of the American Physical Society
On-chip optical isolators are indispensible components of integrated optics, and can be modified to enable four-port and multi-port circulators and modulators. We have implemented an on-chip optical isolator by placing a racetrack... more
On-chip optical isolators are indispensible components of integrated optics, and can be modified to enable four-port and multi-port circulators and modulators. We have implemented an on-chip optical isolator by placing a racetrack resonator next to a single mode waveguide and coating half of the resonator with a uniformly magnetized magneto-optical film, which breaks the time-reversal symmetry of light propagation and provides different refractive indices and phase shifts for forward and backward propagating waves. At every pass, the optical mode inside the resonator accumulates Faraday rotation in addition to phase shift due to propagation. The transmission from the output port of the waveguide has a Lorentzian dip due to the resonance peak of the resonator. Light can only propagate in the clockwise direction inside the resonator. Here we model how cascading multiple ring resonators can increase the overall quality factor of the isolator and narrow the resonance linewidth, due to the longer photon lifetime inside the cavity. As a result of better control of Faraday rotation, the isolation ratio is enhanced and the device footprint is reduced with respect to Mach-Zehnder waveguide isolators.
2024
To create photonic multi-chip modules, integrated photonic chips need to be connected internally and to external glass fibers. A novel approach to address this task is the concept of photonic wire bonding, where free-standing polymer... more
To create photonic multi-chip modules, integrated photonic chips need to be connected internally and to external glass fibers. A novel approach to address this task is the concept of photonic wire bonding, where free-standing polymer waveguides are printed in-situ by two-photon polymerization. This book contains a detailed description of the methodology of photonic wire bonding together with a number of key experiments.
2024, Nature Reviews Materials
The integration of functional nanomaterials and heterostructures with photonic architectures has laid the foundation for important photonic and optoelectronic applications. The advent of epitaxy and layer lift-off techniques has enabled a... more
The integration of functional nanomaterials and heterostructures with photonic architectures has laid the foundation for important photonic and optoelectronic applications. The advent of epitaxy and layer lift-off techniques has enabled a wide spectrum of two-dimensional materials and three-dimensional single-crystalline freestanding thin films with diverse optical functionalities, featuring van der Waals (vdW) interfaces suitable for photonic vdW integration. Physical assembly leveraging vdW interactions eliminates the constraints of epitaxial lattice-matching, introducing unprecedented freedom to combine dissimilar materials with appealing optoelectronic properties but radically distinct crystal structures. Various prefabricated vdW building blocks can be combined in novel hetero-integrated photonic architectures and hybrid vdW heterostructures to prototype new devices and explore exotic nanophotonic phenomena at mixed-dimensional vdW interfaces. The ultrathin nature of these freestanding nanomembranes also enables flexible and lightweight photonic devices for low-cost wearable and multifunctional health-care applications. In this Review, we survey the recent progress in photonic nanomembranes with vdW interfaces, discussing a broad range of delaminated freestanding nanomembranes from film preparation to device implementation. We also analyse the remaining challenges and highlight emerging opportunities for advanced vdW hetero-integration.
2024
Several strategies have been adopted and are still being developed for providing Si-Photonic Integrated Circuits with lasers. "Hybrid integration" architectures (integration of processed and finished III-V chips, e.g. SOAs and Lasers) and... more
Several strategies have been adopted and are still being developed for providing Si-Photonic Integrated Circuits with lasers. "Hybrid integration" architectures (integration of processed and finished III-V chips, e.g. SOAs and Lasers) and "Heterogeneous integration" schemes (integration of unprocessed III-V material on Silicon, followed by wafer level processing) will be reviewed and compared.
2024, Arxiv preprint arXiv:1004.4481
AbstractThe main issue in the optical transmission is switching speed. The optical packet switching faces many significant challenges in processing and buffering. The generalized multilevel protocol switching seeks to eliminate the... more
AbstractThe main issue in the optical transmission is switching speed. The optical packet switching faces many significant challenges in processing and buffering. The generalized multilevel protocol switching seeks to eliminate the asynchronous transfer mode and synchronous optical ...
2024
DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page... more
DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
2024, Karbala International Journal of Modern Science
A phase shift electro-optic semiconductor structure that features a Mach-Zehnder Interferometer (MZI) is numerically analyzed. The interferometer structure considers a highly-doped Si-based waveguide that can control the phase shift by... more
A phase shift electro-optic semiconductor structure that features a Mach-Zehnder Interferometer (MZI) is numerically analyzed. The interferometer structure considers a highly-doped Si-based waveguide that can control the phase shift by varying the refractive index through the carrier concentration while applying a control voltage. To analyze the structure, Kramers-Kronig dispersion relations, the effective index method and the Drude model are implemented within a finite element software. As a result, for an optical waveguide structure with a 9 mm length and 10 V, it is possible to obtain a phase shift by that allows, at the output of the MZI, total interference that is required to modulate an optical communication link.
2024, 2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference
DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page... more
DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
2024, Optics Express
The design, fabrication, characterization, and modeling of basic building blocks of plasmonic circuitry based on dielectric-loaded surface polariton waveguides, such as bends, splitters, and Mach-Zehnder interferometers are presented. The... more
The design, fabrication, characterization, and modeling of basic building blocks of plasmonic circuitry based on dielectric-loaded surface polariton waveguides, such as bends, splitters, and Mach-Zehnder interferometers are presented. The plasmonic components are realized by depositing subwavelength dielectric ridges on a smooth gold film using mass-production-compatible UV-photolithography. The near-field characterization at telecommunication wavelengths shows the strong mode confinement and low radiation and bend losses. The performance of the devices is found in good agreement with results obtained by full vectorial three-dimensional finite element simulations.
2024, SPIE Proceedings
In this paper, we review our work on efficient, broadband and polarization independent interfaces between a silicon-oninsulator photonic IC and a single-mode optical fiber based on grating structures. The high alignment tolerance and the... more
In this paper, we review our work on efficient, broadband and polarization independent interfaces between a silicon-oninsulator photonic IC and a single-mode optical fiber based on grating structures. The high alignment tolerance and the fact that the optical fiber interface is out-of-plane provide opportunities for easy packaging and wafer-scale testing of the photonic IC. Next to fiber-chip interfaces we will discuss the use of silicon grating structures in III-V on silicon optoelectronic components such as integrated photodetectors and microlasers.
2024, 2013 IEEE Photonics Conference
In this paper we describe Ge-on-Si waveguides and Mach-Zehnder interferometers operating in the 5.2-5.4 µm wavelength range. 3dB/cm waveguide losses and Mach-Zehnder interferometers with 20dB extinction ratio are presented. Index... more
In this paper we describe Ge-on-Si waveguides and Mach-Zehnder interferometers operating in the 5.2-5.4 µm wavelength range. 3dB/cm waveguide losses and Mach-Zehnder interferometers with 20dB extinction ratio are presented. Index Terms-mid-infrared, photonic integrated circuits, germanium on silicon
2024, Optics Letters
By integrating soft-lithography-based nanofluidics with silicon nanophotonics, we demonstrate dynamic, liquid-based addressing and high ⌬n / n͑ϳ0.1͒ refractive index modulation of individual features within photonic structures at... more
By integrating soft-lithography-based nanofluidics with silicon nanophotonics, we demonstrate dynamic, liquid-based addressing and high ⌬n / n͑ϳ0.1͒ refractive index modulation of individual features within photonic structures at subwavelength length scales. We show ultracompact tunable spectral filtering through nanofluidic targeting of a single row of holes within a planar photonic crystal. We accomplished this with an optofluidic integration architecture comprising a nanophotonic layer, a nanofluidic delivery structure, and a microfluidic control engine. Variants of this technique could enable dynamic reconfiguration of photonic circuits, selective introduction of optical nonlinearities, or delivery of single molecules into resonant cavities for biodetection.
2024, Optics Communications
We propose a set of photonic crystals that realize a nonlinear quantum Rabi model equivalent to a two-level system driven by the phase of a quantized electromagnetic field. The crystals are exactly solvable in the weak-coupling regime;... more
We propose a set of photonic crystals that realize a nonlinear quantum Rabi model equivalent to a two-level system driven by the phase of a quantized electromagnetic field. The crystals are exactly solvable in the weak-coupling regime; their dispersion relation is discrete and the system is diagonalized by normal modes similar to a dressed state basis. In the strong-coupling regime, we use perturbation theory and find that the dispersion relation is continuous. We give the normal modes of the crystal in terms of continued fractions that are valid for any given parameter set. We show that these photonic crystals allow state reconstruction in the form of coherent oscillations in the weak-coupling regime. In the strong-coupling regime, the general case allows at most partial reconstruction of single waveguide input states, and non-symmetric coherent oscillations that show partial state reconstruction of particular phase-controlled states.
2024, Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications VII
In the paper, we present numerical results on characterization of transmitting properties of wideband filters based on linear and nonlinear photonic crystals confined with the waveguide. Novel characteristics of the PhC filters such as... more
In the paper, we present numerical results on characterization of transmitting properties of wideband filters based on linear and nonlinear photonic crystals confined with the waveguide. Novel characteristics of the PhC filters such as density of modes maps and transmission maps are computed, and their efficiency is analyzed. Presented characteristics can be used as an auxiliary optimization tools to reduce optical losses when designing high-efficient optical interconnects.
2024, Electronics Letters
Two-photon absorption (TPA) generated by unpolarised band-limited amplified spontaneous emission (BL-ASE) noise is found to be within 5% of that generated by circularly polarised BL-ASE noise for silicon-based devices. A simple formula... more
Two-photon absorption (TPA) generated by unpolarised band-limited amplified spontaneous emission (BL-ASE) noise is found to be within 5% of that generated by circularly polarised BL-ASE noise for silicon-based devices. A simple formula that describes the TPA generated by partially polarised BL-ASE noise as a function of material dichroism is given and verified experimentally.
2024, IEEE Photonics Journal
A multipurpose and ultra-compact nanoplasmonic wavelength filter based on stub structure in a metal-insulator-metal (MIM) waveguide is suggested and numerically investigated. A novel approach of connecting two stepped-like apertures to... more
A multipurpose and ultra-compact nanoplasmonic wavelength filter based on stub structure in a metal-insulator-metal (MIM) waveguide is suggested and numerically investigated. A novel approach of connecting two stepped-like apertures to both input and output ports is applied to form Fabry-Perot (FP) cavities, which enabled the structure to act as a dual band-pass filter at wavelengths 1310 nm and 1550 nm. It is shown that the variation in cavities' length allows to realize a long-wavelength cutoff filter, and cutoff wavelength can be easily tuned by adjusting the length of the cavities. Furthermore, it is revealed that increasing the gap between the stepped-like apertures and the cavities provides a triple band-pass at telecom wavelengths, e.g., 1267.5 nm, 1414.19 nm, and 1644.7 nm. The tunable broadband high-pass wavelength filter is then achieved while the lengths of stepped-like apertures and stub resonators are set to be identical. Finally, a tunable nearly perfect absorber can be obtained by varying the width of stub resonators. Therefore, because of functionality, size, as well as efficiency the proposed plasmonic filter may greatly contribute to miniaturization of next generation of photonic integrated circuits (PICs), and find applications in on-chip integration and wavelength-division multiplexing (WDM) in optical communication systems.
2024, IEEE Photonics Technology Letters
A novel approach to reduce the coupling length and to increase the coupling coefficient in waveguide directional couplers implemented on two-dimensional (2-D) photonic crystals (PhC) is proposed. To increase the coupling coefficient of a... more
A novel approach to reduce the coupling length and to increase the coupling coefficient in waveguide directional couplers implemented on two-dimensional (2-D) photonic crystals (PhC) is proposed. To increase the coupling coefficient of a 2-D PhC directional coupler, which is composed of two parallel PhC waveguides separated by one or several rows of rods, the radius of the rods between both waveguides is reduced. The application of this feature to ultrasmall channel interleavers and wavelength demultiplexers is addressed.
2024
In the past four years, I have grown tremendously in mental and conceptual thinking to be able to complete my PhD research project. This is due to my PhD supervisor, Associate Prof Liu Ai Qun, whom has given me many guidance and teachings... more
In the past four years, I have grown tremendously in mental and conceptual thinking to be able to complete my PhD research project. This is due to my PhD supervisor, Associate Prof Liu Ai Qun, whom has given me many guidance and teachings in research and has motivated me to continue to move forward. I would also like to express my thanks to my co-supervisor Dr Li Jing, and senior fellow Dr Zhang Xuming for their valuable advices and sharing research experiences in the last four years. I would also like to thank two important colleagues, Miss Sun Yi and Mr Muhammad Faeyz Karim for sharing the joy and sadness on my path to completing my PhD project. Special thanks to Assistant Prof Chia Wai Mun and Miss Yap Lee Jong for their support and encouragement in the hardest moment of my PhD period. My
2024
In this study, we have theoretically investigated transmission properties of transverse electric fields at visible region frequencies in one dimensional defect Metallic-Dielectric photonic crystals. We examined the effect of photonic... more
In this study, we have theoretically investigated transmission properties of transverse electric fields at visible region frequencies in one dimensional defect Metallic-Dielectric photonic crystals. We examined the effect of photonic crystals thickness, layer numbers, layer refractive indexes and defects on transparency. We use OptiFDTD software for simulations. OptiFDTD software uses finite-different time-domain method.
2024, Optics Letters
We fabricated and measured the optical loss of polysilicon waveguides deposited using hot-wire chemical vapor deposition at a temperature of 240°C. A polysilicon film 220 nm thick was deposited on top of a 2000 nm thick plasma-enhanced... more
We fabricated and measured the optical loss of polysilicon waveguides deposited using hot-wire chemical vapor deposition at a temperature of 240°C. A polysilicon film 220 nm thick was deposited on top of a 2000 nm thick plasma-enhanced chemical vapor deposition silicon dioxide layer. The crystalline volume fraction of the polysilicon film was measured by Raman spectroscopy to be 91%. The optical propagation losses of 400, 500, and 600 nm waveguides were measured to be 16.9, 15.9, and 13.5 dB∕cm, respectively, for transverse electric mode at the wavelength of 1550 nm. Scattering loss is expected to be the major contributor to the propagation loss.
2024, Optics Communications
Exploring hybrid plasmonic waveguide is a major breakthrough for achieving low-loss lightwave propagation at subwavelength size. Various types of passive hybrid plasmonic waveguides have been reported, but research on active hybrid... more
Exploring hybrid plasmonic waveguide is a major breakthrough for achieving low-loss lightwave propagation at subwavelength size. Various types of passive hybrid plasmonic waveguides have been reported, but research on active hybrid plasmonic waveguides is very limited. In this study, we propose a tunable hybrid plasmonic waveguide in which its modal characteristics could be dynamically tuned by manipulating the evanescent field of a dielectric waveguide using a closely suspended tuning waveguide. The device can obtain a long-distance lightwave propagation at centimeter scale while maintaining the propagation mode at deep-subwavelength size (2.44 2 /10 5). Using the proposed tuning method, the propagation length can be tuned more than 100% at the same propagation mode area. The proposed device with a propagation length that can be tuned in a wide range is a promising candidate for building active photonic components.
2024, Optics Communications
Multi-degree implementations of the reconfigurable optical add-drop multiplexer (ROADM) are analyzed in terms of in-band crosstalk performance with an emphasis on the reduction in the number of wavelength selective switches used in the... more
Multi-degree implementations of the reconfigurable optical add-drop multiplexer (ROADM) are analyzed in terms of in-band crosstalk performance with an emphasis on the reduction in the number of wavelength selective switches used in the module. It is shown experimentally that an 8-degree ROADM using the wavelength selective switches for channel adding and optical splitters for channel dropping performs closely to one that uses switches for both operations. A new modular architecture based on the wavelength selective switches is proposed for implementations applicable to large degree nodes. Performance analysis of this architecture indicates node scalability to 256 degree with crosstalk-induced power penalties below 0.5 dB.