| 1. |
- Adshead, Mason, et al.
(författare)
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Erbium implantation in thin film Lithium Niobate
- 2023
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Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- Lithium niobate on insulator (LNOI), thanks to its electro-optic properties and second order nonlinearity, is one of the most promising photonic materials for on-chip implementation of a complex photonic integrated circuit (PIC) [1]. Integration of rare earth ion emitters (RIE), characterized by high coherent transitions in both optical and microwave domains, into LNOI is a very attractive perspective to fully exploit the potential of this material in quantum optics applications and for on chip light generation and amplification. By choosing Erbium ions these functionalities can be implemented at telecom wavelengths (~1550 nm). Erbium integration in LNOI can be achieved using the smart cut technique [2]. However, this approach implies heating the material up to ~1100 ºC, approaching the Curie temperature of lithium niobate (~1200 ºC). Ion implantation also permits the incorporation of RIE into the lithium niobate (LN) crystal structure, operating at lower temperature with high spatial precision of the doped region in a complex PIC.
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| 2. |
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| 3. |
- Al-Shammari, Rusul M., et al.
(författare)
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Antibacterial properties of lithium niobate crystal substrates
- 2023
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Ingår i: International Journal of Optomechatronics. - : Informa UK Limited. - 1559-9612 .- 1559-9620. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- The bactericidal properties of chemically patterned lithium niobate substrates under a super-bandgap UV light source is established. UV irradiation of lithium niobate surfaces inoculated with bacteria leads to antimicrobial activity compared to a glass substrate under similar conditions, as determined by surface enhanced Raman spectroscopy and corroborated with a fluorescence-based live/dead assay. This finding may expand the possible biomedical applications of lithium niobate.
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| 4. |
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| 5. |
- Al-Shammari, Rusul M., et al.
(författare)
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Photoinduced Enhanced Raman from Lithium Niobate on Insulator Template
- 2018
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 10:36, s. 30871-30878
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Tidskriftsartikel (refereegranskat)abstract
- Photoinduced enhanced Raman spectroscopy from a lithium niobate on insulator (LNOI)−silver nanoparticle template is demonstrated both by irradiating the template with 254 nm ultraviolet (UV) light before adding an analyte and before placing the substrate in the Raman system (substrate irradiation) and by irradiating the sample in the Raman system after adding the molecule (sample irradiation). The photoinduced enhancement enables up to an ∼sevenfold increase of the surface-enhanced Raman scattering signal strength of an analyte following substrate irradiation, whereas an ∼threefold enhancement above the surface-enhanced signal is obtained for sample irradiation. The photoinduced enhancement relaxes over the course of ∼10 h for a substrate irradiation duration of 150 min before returning to initial signal levels. The increase in Raman scattering intensity following UV irradiation is attributed to photoinduced charge transfer from the LNOI template to the analyte. New Raman bands are observed following UV irradiation, the appearance of which is suggestive of a photocatalytic reaction and highlight the potential of LNOI as a photoactive surface-enhanced Raman spectroscopy substrate.
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| 6. |
- Al-Shammari, Rusul M., et al.
(författare)
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Single-Molecule Nonresonant Wide-Field Surface-Enhanced Raman Scattering from Ferroelectrically Defined Au Nanoparticle Microarrays
- 2018
-
Ingår i: ACS Omega. - : AMER CHEMICAL SOC. - 2470-1343. ; 3:3, s. 3165-3172
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Tidskriftsartikel (refereegranskat)abstract
- Single-molecule detection by surface-enhanced Raman scattering (SERS) is a powerful spectroscopic technique that is of interest for the sensor development field. An important aspect of optimizing the materials used in SERS-based sensors is the ability to have a high density of "hot spots" that enhance the SERS sensitivity to the single-molecule level. Photodeposition of gold (Au) nanoparticles through electric-field-directed self-assembly on a periodically proton-exchanged lithium niobate (PPELN) substrate provides conditions to form well-ordered microscale features consisting of closely packed Au nanoparticles. The resulting Au nanoparticle microstructure arrays (microarrays) are plasmon-active and support nonresonant single-molecule SERS at ultralow concentrations (<10(-9)-10(-13) M) with excitation power densities <1 x 10(-3) W cm(-2) using wide-field imaging. The microarrays offer excellent SERS reproducibility, with an intensity variation of <7.5% across the substrate. As most biomarkers and molecules do not support resonance enhancement, this work demonstrates that PPELN is a suitable template for high-sensitivity, nonresonant sensing applications.
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| 7. |
- Al-Shammari, Rusul M., et al.
(författare)
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Tunable Wettability of Ferroelectric Lithium Niobate Surfaces : The Role of Engineered Microstructure and Tailored Metallic Nanostructures
- 2017
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Ingår i: The Journal of Physical Chemistry C. - : AMER CHEMICAL SOC. - 1932-7447 .- 1932-7455. ; 121:12, s. 6643-6649
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Tidskriftsartikel (refereegranskat)abstract
- An important aspect of optimizing micro- and optofluidic devices for lab on -a-chip systems is the ability to engineer materials properties including surface structure and charge to control wettability. Biocompatible ferroelectric lithium niobate (LN), which is well-known for acoustic and nonlinear optical applications, has recently found potential micro- and optofluidic applications. However, the tunable wettability of such substrates has yet to be explored in detail. Here, we show that the contact angle of LN substrates can be reproducibly tailored between similar to 7 degrees and similar to 421 degrees by controlling the surface topography and chemistry at the nano- and micrometer scale via ferroelectric domain and polarization engineering and polarization-directed photoassisted deposition of metallic nanostructures.
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| 8. |
- Baghban, Mohammad Amin, 1983-
(författare)
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Integrated Nanophotonic Devices in Lithium Niobate
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lithium niobate (LN) is a ferroelectric crystal offering a broad transparency spectrum, together with excellent electro-optic and nonlinear optical properties. Thanks to them, LN is setting the standard for quantum optics and telecommunications in critical applications such as ultrafast modulation and frequency conversion. The development of a reliable nanophotonic platform in LN can be expected to effectively leverage all such appealing functionalities in compact and integrated formats and provide important and complementary functionalities to current silicon-photonics platforms.This thesis encompasses systematic and consistent efforts with the goal to achieve the key building blocks for a comprehensive integrated nanophotonic platform in LN. It involves work on the technology side, sustained and complemented by modelling and experiments, ultimately leading to the demonstration of a few novel devices.Ultrahigh field confinement in nanophotonic waveguides is accompanied by the appearance of non-negligible longitudinal components in the guided optical fields. By fabricating high-quality LN nanopillars and analyzing with theory and experiments their second harmonic generation (SHG) response, we provide evidence for the existence of longitudinal field components and demonstrate the possibility to reshape the SHG polar emission properties of these submicrometric waveguides by fine-tuning the nanopillar size.This thesis also presents a different technological approach, allowing the fabrication of photonic wires as small as 250 nm with lengths up to 1 cm on LN-on-insulator (LNOI), suitable for upscaling to photonic integrated circuit (PIC) architectures. By optimizing the fabrication process, the propagation losses of single-mode waveguides at telecom wavelengths on this platform were brought down from 76 to 1.13 dB/cm. Fine-pitch waveguide structuring was also successfully achieved, enabling LNOI-to-fiber grating couplers and waveguide Bragg gratings, the latter featuring record extinction ratios in LNOI (45 dB), comparable to the state of the art in silicon.The thesis involves also theoretical work on the design of photonic wires where the interplay between LN and waveguide birefringence is used to achieve polarization-insensitive operation for the fundamental guided modes.Finally, two demonstrators are provided for novel and emerging applications of LN to the life sciences, using LNOI surface-patterned templates for enhanced Raman spectroscopy and LN templates for controlled neuron growth and manipulation in microfluidic environments, respectively.
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| 9. |
- Baghban, Mohammad Amin, 1983-, et al.
(författare)
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Phase-Shifted Bragg Grating Resonators in Thin-Film Lithium Niobate Waveguides
- 2019
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Ingår i: 2019 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO).
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Konferensbidrag (refereegranskat)abstract
- We demonstrate narrowband integrated filters with 0.23 mm-long phase-shifted Bragg gratings in corrugated single-mode thin-film LiNbO3 photonic wires, achieving quality factors of 1.24x10(4) and extinction ratios up to 24 dB at telecom wavelengths.
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| 10. |
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| 11. |
- Brambilla, E., et al.
(författare)
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Three and Four-Modes Parametric Processes in Hexagonally Poled Nonlinear Photonic Crystals
- 2018
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Ingår i: OPTICS, PHOTONICS AND LASERS. - : INT FREQUENCY SENSOR ASSOC-IFSA. ; , s. 176-178
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Konferensbidrag (refereegranskat)abstract
- We investigate the properties of the field emitted through parametric down-conversion (PDC) in a nonlinear photonics crystal (NPC) with a hexagonal poling pattern, both from a theoretical point of view and with an experiment performed at the University of Insubria. Considering the high gain regime of PDC, we demonstrate the existence of concurrent PDC processes mediated by two noncollinear poling vectors which are coherently coupled and reciprocally stimulated. We find that these non-standard 3-mode and 4-mode interaction processes undergo a substantial enhancement of the parametric gain with respect to the usual 2-mode PDC, and give rise to hot spots order of magnitudes brighter than standard 2-mode fluorescence which have been observed in the source far field. We performed a complete characterization of the source spectral-angular emission, finding a very good agreement between the experiment and the theoretical predictions.
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| 12. |
- Conforti, Matteo, et al.
(författare)
-
Broadband parametric processes in quadratic nonlinear photonic crystals
- 2014
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Ingår i: Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, BGPP 2014. - Washington, D.C. : The Optical Society.
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Konferensbidrag (refereegranskat)abstract
- We develop a general model, based on a (2+1)D unidirectional pulse propagation equation, for describing broadband noncollinear parametric interactions in two-dimensional quadratic lattices. We apply it to the analysis of twin-beam optical parametric generation in hexagonally poled LiTaO<inf>3</inf>, gaining further insights into experimental observations.
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| 13. |
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| 14. |
- Damm, Signe, et al.
(författare)
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Protein assemblies on ferroelectrically patterned microarrays of Ag nanoparticles
- 2017
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Ingår i: Ferroelectrics (Print). - : TAYLOR & FRANCIS LTD. - 0015-0193 .- 1563-5112. ; 515:1, s. 141-148
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Tidskriftsartikel (refereegranskat)abstract
- Nano-bio interfaces play a significant role in assay device design and performance, here we study the use of a combined plasmonic and ferroelectric active substrate design for protein assemblies on a plasmon active array. We demonstrate that biotinylation and protein assemblies can bemade onmetal nanoparticles patterned on ferroelectric substrates. These results inturndemonstratethat ferroelectric substrates combined with active plasmonics is potentially applicable as substrates for biological assays.
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| 15. |
- El Hassan, Ashraf, et al.
(författare)
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Coherent difference frequency generation in nonlinear photonic crystals
- 2023
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Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- Two-dimensional lattices of the optical nonlinearity implemented by periodic poling in X(2) materials afford additional degrees of freedom for enhanced gains in optical parametric generation [1-2] and the generation of multipartite photon entanglement in compact device formats [3]. So far all investigations have considered single-frequency excitation of the crystals in classical or quantum parametric downconversion regimes. However, the effects underpinned by the coherent coupling of multiple nonlinear resonances unique to 2D lattices, may be expected to further enlarge the spectrum of possibilities also in suitably seeded coherent parametric amplification and difference frequency generation (DFG) processes.
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| 16. |
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| 17. |
- Fergestad, Halvor, et al.
(författare)
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Engineered dispersion measurements in LiNbO3 nanophotonic wires
- 2023
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Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- Dispersion engineering of waveguides in photonic integrated circuits (PIC) is a crucial design tool for tailoring nonlinear functionalities in the rapidly emerging thin film LiNbO3 (TFLN) platform, exemplified by frequency comb generation, soliton formation and broadband frequency conversion [1]. Experimentally, the dispersion of PIC structures is typically measured in terms of free-spectral range (FSR) variation in ring cavity configurations or propagation time delays in long waveguides under short pulse excitation [2], methods with their own limitations when it comes to measurements in straight and relatively short (< cm) waveguides, such as TFLN ones.
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| 18. |
- Fu, Daiheng, et al.
(författare)
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Polarization coupling in thin film lithium niobate waveguide
- 2023
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Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- Polarization control in photonic integrated circuit (PIC) waveguides is receiving broad attention for application in quantum systems and telecommunication [1]. Thin film lithium niobate (TFLN) is an ideal platform for polarization control applications due to its birefringence and electro-optic properties [2]. We observe polarization coupling between fundamental TE and TM modes in TFLN waveguides.
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| 19. |
- Gallo, Katia, 1972-, et al.
(författare)
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Parametric Solitons in Two-Dimensional Lattices of Purely Nonlinear Origin
- 2008
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 100, s. 053901-
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate spatial solitons via twin-beam second-harmonic generation in hexagonal lattices realized by poling lithium niobate planar waveguides. These simultons can be steered by acting on power, direction, and wavelength of the fundamental frequency input.
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| 20. |
- Gallo, Katia, Professor, 1972-, et al.
(författare)
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Spectral engineering of LNOI waveguide : from ultranarrow to broadband
- 2021
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Ingår i: The 11th International Conference on Metamaterials, Photonic Crystals and Plasmonics, META 2021. - : META Conference. ; , s. 784-
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Konferensbidrag (refereegranskat)abstract
- The development of advanced nano-structuring capabilities on LNOI is paving the way towards low-footprint photonic circuits leveraging appealing functionalities of LiNbO3 for ultrafast signal processing and wavelength conversion. In the talk we shall present ultra-narrow bandpass and multiresonance filters, implemented with phase-shifted Bragg gratings in LNOI photonic wires. We shall also discuss designs of dispersion engineered waveguides for broadband second harmonic generation, appealing for wavelength multicasting, ultrashort pulse frequency doubling and enhanced quadratic cascading in the telecom band.
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| 21. |
- Gallo, Katia, Professor, 1972-, et al.
(författare)
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Twin-beam optical parametric generation in nonlinear photonic crystals
- 2011
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Ingår i: Optics InfoBase Conference Papers. - : Optical Society of America (OSA).
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Konferensbidrag (refereegranskat)abstract
- We demonstrate dual-beam optical parametric generation in hexagonally poled LiTaO3. The experimental results indicate a coherent contribution to the parametric gain arising from multiple resonances in the nonlinear lattice.
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| 22. |
- Gatti, Alessandra, et al.
(författare)
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Golden ratio entanglement in hexagonally poled nonlinear crystals
- 2018
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Ingår i: Physical Review A: covering atomic, molecular, and optical physics and quantum information. - : AMER PHYSICAL SOC. - 2469-9926 .- 2469-9934. ; 98:5
-
Tidskriftsartikel (refereegranskat)abstract
- This work analyzes the quantum state of twin photons and twin beams generated by parametric down-conversion in a hexagonally poled photonic crystal, characterized by the simultaneous presence of two nonlinear processes sustained by two vectors of the reciprocal lattice. In those special points of the fluorescence spectrum where the two processes coexist, we show that a tripartite entangled state is realized, equivalent to a single parametric process followed by a beam splitter. By proper angle tuning, a peculiar resonance condition is reached, with a transition to a four-mode entanglement, dominated by the golden ratio of the segment phi = (1 + root 5)/2. A maximal coherence between the two nonlinear processes is established here, as the overall process is shown to be equivalent to two independent parametric processes followed by a beam splitter. We offer an interpretation of the occurrence of the golden ratio in this system based on an analogy between the evolution of the light modes and the Fibonacci sequence.
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| 23. |
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| 24. |
- Jedrkiewicz, Ottavia, et al.
(författare)
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Golden Ratio Gain Enhancement in Coherently Coupled Parametric Processes
- 2018
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Nonlinear optical processes are an essential tool in modern optics, with a broad spectrum of applications, including signal processing, frequency conversion, spectroscopy and quantum optics. Ordinary parametric devices nevertheless still suffer from relatively low gains and wide spectral emission. Here we demonstrate a unique configuration for phase- matching multiple nonlinear processes in a monolithic 2D nonlinear photonic crystal, resulting in the coherent parametric emission of four signal and idler modes, featuring an exponential gain enhancement equal to the Golden Ratio. The results indicate a new route towards compact high- brightness and coherent sources for multi- photon generation, manipulation and entanglement, overcoming limitations of conventional parametric devices.
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| 25. |
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| 26. |
- Levenius, Martin, et al.
(författare)
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Angular degrees of freedom in twin-beam parametric down-conversion
- 2012
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 101:12, s. 121114-
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the effect of angular tuning on coherently coupled optical parametric generation (OPG) in two-dimensional purely nonlinear lattices and demonstrate how it allows accessing both shared signal and shared idler regimes, resulting in twin-beam outputs in the mid- and near infrared, respectively. Furthermore, we present the results of a systematic spectral and angular mapping of the twin-beam OPG response in the near-infrared as a function of the pump incidence angle.
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| 27. |
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| 28. |
- Levenius, Martin, et al.
(författare)
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Spectral and angular mapping of parametric generation in purely nonlinear lattices
- 2012
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Ingår i: CLEO. - Washington, D.C. : Optical Society of America (OSA). ; , s. 6325882-
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Konferensbidrag (refereegranskat)abstract
- We investigate experimentally the spectral and angular degrees of freedom of multi-resonant optical parametric generation in hexagonally poled LiTaO3 and demonstrate access to twin-beam output for either signal or idler waves by pump angle tuning.
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| 29. |
- Li, Tiantong, et al.
(författare)
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Tailoring guided-wave Fano resonances in LiNbO3 nanophotonic wires
- 2023
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Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- Fano resonances in nanophotonic structures are attracting significant attention for the engineering possibilities they may offer in applications such as lasers, sensing and optical signal processing [1]. Most widely explored device architectures in the quest for fully integrated implementation scenarios involve the side-coupling of different waveguide-cavity systems providing the narrowband and broad resonances (discrete and continuum states, respectively) whose interference gives rise to the signature asymmetric Fano lineshapes. Here we present a brand-new approach to achieve Fano resonances in ultracompact 1D waveguide formats through a polarization diversity scheme, exploiting the longitudinal field components of guided modes in high confinement photonic wires in combination with integrated Bragg-resonant structures achieved by sidewall modulation of the same.
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| 30. |
- Liu, S., et al.
(författare)
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OTDM to WDM format conversion based on cascaded SHG/DFG in a single PPLN waveguide
- 2010
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Ingår i: Optics InfoBase Conference Papers. - Washington, D.C. : Optical Society of America (OSA).
-
Konferensbidrag (refereegranskat)abstract
- We propose and experimentally demonstrate error-free OTDM to WDM format conversion based on cSHG/DFG within a 30mm-long PPLN waveguide and a time-to-frequency domain conversion approach, which relies upon switching a linearly chirped pulse.
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| 31. |
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| 32. |
- Manzo, Michele, 1984-, et al.
(författare)
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Two-dimensional domain engineering in LiNbO3 via a hybrid patterning technique
- 2011
-
Ingår i: Optical Materials Express. - 2159-3930 .- 2159-3930. ; 1:3, s. 365-371
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Tidskriftsartikel (refereegranskat)abstract
- We propose a novel electric field poling technique for the fabrication of nonlinear photonic crystals in congruent LiNbO3 substrates, based on a hybrid bi-dimensional mask, which combines periodic proton-exchange and electrode patterns. With it we demonstrate rectangular bulk lattices with a periodicity of 8 µm x 6.78 µm in 500 µm-thick substrates.
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| 33. |
- Neumayer, Sabine, et al.
(författare)
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Interface modulated currents in periodically proton exchanged Mg doped lithium niobate
- 2016
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Ingår i: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 119:11
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Tidskriftsartikel (refereegranskat)abstract
- Conductivity in Mg doped lithium niobate (Mg:LN) plays a key role in the reduction of photorefraction and is therefore widely exploited in optical devices. However, charge transport through Mg:LN and across interfaces such as electrodes also yields potential electronic applications in devices with switchable conductivity states. Furthermore, the introduction of proton exchanged (PE) phases in Mg:LN enhances ionic conductivity, thus providing tailorability of conduction mechanisms and functionality dependent on sample composition. To facilitate the construction and design of such multifunctional electronic devices based on periodically PE Mg:LN or similar ferroelectric semiconductors, fundamental understanding of charge transport in these materials, as well as the impact of internal and external interfaces, is essential. In order to gain insight into polarization and interface dependent conductivity due to band bending, UV illumination, and chemical reactivity, wedge shaped samples consisting of polar oriented Mg:LN and PE phases were investigated using conductive atomic force microscopy. In Mg:LN, three conductivity states (on/off/transient) were observed under UV illumination, controllable by the polarity of the sample and the externally applied electric field. Measurements of currents originating from electrochemical reactions at the metal electrode–PE phase interfaces demonstrate a memresistive and rectifying capability of the PE phase. Furthermore, internal interfaces such as domain walls and Mg:LN–PE phase boundaries were found to play a major role in the accumulation of charge carriers due to polarization gradients, which can lead to increased currents. The insight gained from these findings yield the potential for multifunctional applications such as switchable UV sensitive micro- and nanoelectronic devices and bistable memristors.
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| 34. |
- Neumayer, Sabine M., et al.
(författare)
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Surface Chemistry Controls Anomalous Ferroelectric Behavior in Lithium Niobate
- 2018
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 10:34, s. 29153-29160
-
Tidskriftsartikel (refereegranskat)abstract
- Polarization switching in ferroelectric materials underpins a multitude of applications ranging from nonvolatile memories to data storage to ferroelectric lithography. While traditionally considered to be a functionality of the material only, basic theoretical considerations suggest that switching is expected to be intrinsically linked to changes in the electrochemical state of the surface. Hence, the properties and dynamics of the screening charges can affect or control the switching dynamics. Despite being recognized for over 50 years, analysis of these phenomena remained largely speculative. Here, we explore polarization switching on the prototypical LiNbO3 surface using the combination of contact mode Kelvin probe force microscopy and chemical imaging by time-of-flight mass-spectrometry and demonstrate pronounced chemical differences between the domains. These studies provide a consistent explanation to the anomalous polarization and surface charge behavior observed in LiNbO3 and point to new opportunities in chemical control of polarization dynamics in thin films and crystals via control of surface chemistry, complementing traditional routes via bulk doping, and substrate-induced strain and tilt systems.
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| 35. |
- Ostrovskis, Armands, et al.
(författare)
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170 Gbaud On-Off-Keying SiP Ring Resonator Modulator-based Link for Short-Reach Applications
- 2024
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Ingår i: 2024 IEEE Silicon Photonics Conference, SiPhotonics 2024 - Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- We demonstrate a record 170 Gbaud on-off keying C-band silicon photonics ring resonator modulator-based transmitter with performance below the 6.7% overhead HD-FEC threshold after optical back-to-back and transmission over 100 meters of single mode fiber.
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| 36. |
- Prencipe, Alessandro, et al.
(författare)
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Electro- and Thermo-Optics Response of X-Cut Thin Film LiNbO3Waveguides
- 2023
-
Ingår i: IEEE Journal of Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9197 .- 1558-1713. ; 59:3
-
Tidskriftsartikel (refereegranskat)abstract
- Lithium niobate has been for decades the material of election for integrated nonlinear and electro-optics. Its recent availability in thin films affording subwavelength confinement of light and nanostructuring capabilities has led to ground-breaking results in numerous applications, ranging from ultrafast signal processing to efficient nonlinear optics, where electro-optic (EO) and thermo-optic (TO) functionalities can be further leveraged for enhanced tunability and reconfigurability. This work provides a consistent comparison between these two approaches in the most widely used configuration in LiNbO3 nanophotonics at telecom wavelengths. Using state of the art Bragg grating technology for high precision index measurements, we evaluate the guided-wave EO and TO tunability to be 3\× 10-5 V-1 and 3.6× 10 -3W-1 , respectively, and study further operation and design tradeoffs, cross-talk effects and long-term stability. The results provide useful insights to identify the most appropriate strategies for implementing reconfigurable integrated photonic circuits effectively leveraging the unique features of LiNbO3.
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| 37. |
- Prencipe, Alessandro, et al.
(författare)
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Tunable Ultranarrowband Grating Filters in Thin-Film Lithium Niobate
- 2021
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Ingår i: ACS Photonics. - : American Chemical Society (ACS). - 2330-4022. ; 8:10, s. 2923-2930
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Tidskriftsartikel (refereegranskat)abstract
- Several applications in modern photonics require compact on-chip optical filters with a tailored spectral response. However, achieving subnanometric bandwidths and high extinction ratios is particularly challenging, especially in low-footprint device formats. Phase-shifted Bragg gratings implemented by the sidewall modulation of photonic nanowire waveguides are a good solution for on-chip narrowband operation with reasonable requirements in fabrication and scalability. In this work we report on their implementation and optimization in thin film lithium niobate, a photonic platform that affords reconfigurability by exploiting electrooptic effects. The phase-shifted Bragg grating filters have a footprint smaller than 1 mu m x 1 mm and operate at telecom wavelengths, featuring extinction ratios up to 25 dB. We demonstrate transmission bandwidths as narrow as 14.4 pm (Q = 1.1 x 10(5)) and 8.8 pm (Q = 1.76 x 10(5)) in critically coupled structures and multiwavelength Fabry-Perot configurations, respectively, in full agreement with theoretical predictions. Moreover, by taking advantage of the strong electro-optic effect in lithium niobate, in combination with the tight light confinement of nanophotonic wires and the ultranarrow spectral resonances of optimized grating structures, we demonstrate an electric tunability in peak wavelength and transmission of 25.1 pm/V and 2.1 dB/V, respectively, and a 10.5 dB contrast at CMOS voltages. The results pave the way for reconfigurable narrowband photonic filters with a small footprint and low consumption, to be exploited toward on-chip quantum and nonlinear optics, as well as optical sensing and microwave photonics.
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| 38. |
- Prencipe, Alessandro, et al.
(författare)
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Wavelength meter on thin film lithium niobate based on superconducting single photon detectors
- 2023
-
Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Photonic integrated circuits (PICs) present significant benefits with respect to table-top optical systems regarding footprint, stability, and power consumption. Among the materials used to fabricate PICs, thin film lithium niobate (TFLN) is one of the most attractive ones, as its χ(2) nonlinearity and electro-optic properties allow to implement on-chip light generation and routing [1]. On-chip detection of light has also been demonstrated on TFLN, based on the waveguide integration of superconducting nanowire single photon detectors (SNSPDs) [1]. Combining efficient detectors with TFLN nanophotonic waveguides holds promises for the realization of quantum photonics experiments fully on-chip. On the other hand, the sensitivity of SNSPDs changes with the wavelength of the detected photons [2], setting a boundary to the longest detectable wavelength and limiting the use of the wide transparency window of TFLN. However, this wavelength dependency in the response of SNSPDs can be leveraged to achieve new on-chip functionalities. In this work, by performing a straightforward analysis of the light signal measured at different bias currents [2], we operate hairpin SNSPDs on TFLN as waveguide-integrated wavelength-meters in the telecom bandwidth.
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| 39. |
- Prencipe, Alessandro, et al.
(författare)
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Wavelength-Sensitive Superconducting Single-Photon Detectors on Thin Film Lithium Niobate Waveguides
- 2023
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 23:21, s. 9748-9752
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Tidskriftsartikel (refereegranskat)abstract
- Lithium niobate, because of its nonlinear and electro-optical properties, is one of the materials of choice for photonic applications. The development of nanostructuring capabilities of thin film lithium niobate (TFLN) permits fabrication of small footprint, low-loss optical circuits. With the recent implementation of on-chip single-photon detectors, this architecture is among the most promising for realizing on-chip quantum optics experiments. In this Letter, we report on the implementation of superconducting nanowire single-photon detectors (SNSPDs) based on NbTiN on 300 nm thick TFLN ridge nano-waveguides. We demonstrate a waveguide-integrated wavelength meter based on the photon energy dependence of the superconducting detectors. The device operates at the telecom C- and L-bands and has a footprint smaller than 300 × 180 μm2 and critical currents between ∼12 and ∼14 μA, which ensures operation with minimum heat dissipation. Our results hold promise for future densely packed on-chip wavelength-multiplexed quantum communication systems.
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| 40. |
- Prytz, Nicklas Bjärnhall, et al.
(författare)
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Edge-enhanced optical parametric generation in periodically poled LiNbO3
- 2020
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Ingår i: Optics Express. - : The Optical Society. - 1094-4087. ; 28:14, s. 20879-20887
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate enhanced optical parametric gains occurring at the edge of periodically poled LiNbO3 (PPLN) regions. Experiments performed in MgO-doped PPLN samples, pumped at 532 nm with parametric signal outputs around 800 nm and 1550 nm, exhibit good agreement with numerical simulations of the nonlinear wave dynamics in the system, based on the assumption of an average refractive index increase Delta n = 5.3 x 10(-5) in the PPLN region. Excitation in proximity to the PPLN edge with a pump power of 8.1 mW results in a 3.6-fold output power increase with respect to parametric generation inside the PPLN area.
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| 41. |
- Rowe, W. R., et al.
(författare)
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Gap solitons supported by mode hybridisation in Lithium Niobate nano-waveguides
- 2021
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Ingår i: 2021 Conference On Lasers And Electro-Optics Europe & European Quantum Electronics Conference (Cleo/Europe-Eqec). - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Nano-waveguide platforms have been developed over the past decade providing strong field enhancement and allowing precise control of modal dispersion [1] . Such nano-waveguides produced from materials with strong quadratic (χ (2) ) nonlinearity make excitation of χ (2) temporal solitons feasible [2] . Compared with Kerr solitons, χ (2) solitons have tighter dispersion criteria making nano-waveguides the only practical method for their observation [2] , [3] . As seen in previous work in photonic crystal fibres [4] , mode hybridisation, which occurs generally in waveguides with rectangular (or close to rectangular) cross-section, provides conditions to study novel types of soliton and their dynamics.
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| 42. |
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| 43. |
- Sanaee, Maryam, et al.
(författare)
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Antibody-loading of biological nanocarrier vesicles derived from red-blood-cell membranes
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Antibodies, disruptive potent therapeutic agents against pharmacological targets, face a barrier crossing immune-system and cellular-membranes. To overcome these, various strategies have been explored including shuttling via liposomes or bio-camouflaged nanoparticles.Here, we demonstrate the feasibility to load antibodies into exosome-mimetic nanovesicles derived from human red-blood-cell-membranes. The goat-anti-chicken antibodies are loaded into erythrocyte-membrane derived nanovesicles and their loading yields are characterized and compared with smaller dUTP-cargo. Applying dual-color coincident fluorescence burst methodology, the loading yield of nanocarriers is profiled at single-vesicle level overcoming their size-heterogeneity and achieving a maximum of 38-41% antibody-loading yield at peak radius of 52 nm. The average of 14 % yield and more than two antibodies per vesicle is estimated, comparable to those of dUTP-loaded nanovesicles after additional purification through exosomespin-column. These results suggest a promising route for enhancing biodistribution andintracellular accessibility for therapeutic antibodies using novel, biocompatible, and lowimmunogenicity nanocarriers, suitable for large-scale pharmacological applications.
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| 44. |
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| 45. |
- Sanaee, Maryam, et al.
(författare)
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Dual-Color Confocal Fluorescence Characterizations of Antibody Loading in Bioengineered Nanovesicles
- 2023
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Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- Confocal fluorescence microscopy is powerful for microscopic and nanoscopic analyses with a broad range of applications in biology and medicine, affording high specificity and sensitivites down to single-molecule level [1]. Here we apply a novel dual-color confocal fluorescence microscopy methodology based on coincident burst analysis [2] to quantitative study of the loading yields of bioengineered nanovesicles derived from human red blood cell (RBC) membranes loaded with fluorescently-tagged Antibody (Ab) or dUTP cargo molecules. We prove the successful loading of the RBC nanovesicles with both types of cargo molecules, assess their size statistics and provide quantifications of the loading at single-vesicle level. Fig. 1a shows the tagging scheme adopted for the experiment where Cellvue claret and Alexa488 dyes are respectively used to fluorescently label the outer membrane of the nanovesicles and the cargo molecules. The experimental setup is shown in Fig. 1b, consisting of an inverted microscope with dual excitations at λ1= 640 nm and λ2 = 485 nm. The fluorescence signals centered at λred= 720 nm and λgreen= 535 nm are single-photon-detected and post-selected in separate time gating windows with a delay of 25ns (Fig. 1c). After looking for coincident red-green bursts in the measured time traces (Fig. 1d), size histograms of the loaded vesicles are retrieved (Fig. 1e-f), obtaining average loading yields of 5% and 20% for Ab and dUTP cargos, respectively. Average values of 1.5 and 1.4 loaded Ab (dUTP) cargo molecules per nanovesicle are retrieved from the histograms of Fig. 1g (Fig. 1h). The average size of Ab-loaded nanovesicles is found to be slightly (≈10 nm in radius) larger than the one of dUTP-loaded ones.
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| 46. |
- Sanaee, Maryam, et al.
(författare)
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Size stability and self-agglomeration of erythrocyte-derived membrane nanovesicles versus physiological extracellular vesicles
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Extracellular vesicles (EVs) and plasma membrane-derived exosome-mimetic nanovesicles demonstrate significant potential for drug delivery. Latter synthetic provides higher throughput over physiological EVs. However they face size-stability and self-agglomeration challenges in physiological solutions to be properly characterized and addressed. Here we demonstrate a fast and high-throughput nanovesicle screening methodology relying on dynamic light scattering (DLS) complemented by atomic force microscopy (AFM)measurements, suitable for the evaluation of hydrodynamic size instabilities and aggregation effects in nanovesicle solutions under varying experimental conditions and apply it to the analysis of bio-engineered nanovesicles derived from erythrocytes as well as physiological extracellular vesicles isolated from animal seminal plasma. The synthetic vesicles exhibit a significantly higher degree of agglomeration, with only 8 % of them falling within the typical extracellular vesicle size range (30-200 nm) in their original preparation conditions. Concurrent zeta potential measurements performed on both physiological and syntheticnanovesicles yielded values in the range of -17 to -22 mV, with no apparent correlation to their agglomeration tendencies. However, mild sonication and dilution were found to be effective means to restore the portion of EVs-like nanovesicles in synthetic preparations to values of 54% and 63%, respectively, The results illustrate the capability of this DLS-AFM-based analytical method for real-time, high-throughput and quantitative assessments of agglomeration effects and size instabilities in bioengineered nanovesicle solutions, providing a powerful and easy-to-use tool to gain insights to overcome such deleterious effects and leverage the full potential of this promising biocompatible drug-delivery carriers for a broad range of pharmaceutical applications.
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| 47. |
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| 48. |
- Soubelet, Pedro, et al.
(författare)
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Charged Exciton Kinetics in Monolayer MoSe2 near Ferroelectric Domain Walls in Periodically Poled LiNbO3
- 2021
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 21:2, s. 959-966
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Tidskriftsartikel (refereegranskat)abstract
- Monolayer semiconducting transition metal dichalcogenides are a strongly emergent platform for exploring quantum phenomena in condensed matter, building novel optoelectronic devices with enhanced functionalities. Because of their atomic thickness, their excitonic optical response is highly sensitive to their dielectric environment. In this work, we explore the optical properties of monolayer thick MoSe2 straddling domain wall boundaries in periodically poled LiNbO3. Spatially resolved photoluminescence experiments reveal spatial sorting of charge and photogenerated neutral and charged excitons across the boundary. Our results reveal evidence for extremely large in-plane electric fields of ≃4000 kV/cm at the domain wall whose effect is manifested in exciton dissociation and routing of free charges and trions toward oppositely poled domains and a nonintuitive spatial intensity dependence. By modeling our result using drift-diffusion and continuity equations, we obtain excellent qualitative agreement with our observations and have explained the observed spatial luminescence modulation using realistic material parameters.
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| 49. |
- Stensson, Katarina, et al.
(författare)
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Green-pumped parametric downconversion in hexagonally poled MgO:LiTaO3
- 2014
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Ingår i: Advanced Solid State Lasers, ASSL 2014. - Washington, D.C. : Optical Society of America (OSA). - 9781557528223
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Konferensbidrag (refereegranskat)abstract
- We demonstrate multi-beam optical parametric generation in the 800-1550 nm spectral range sustained by concurrent nonlinear processes in hexagonally poled MgO-doped LiTaO3. Experiments performed with a nanosecond pump at 532 nm yield good agreement with theoretical predictions and hold promise for novel coherent parametric sources based on 2D nonlinear lattices.
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| 50. |
- Zisis, G., et al.
(författare)
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UV laser-induced poling inhibition in proton exchanged LiNbO3 crystals
- 2017
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Ingår i: Applied physics. B, Lasers and optics (Print). - : Springer. - 0946-2171 .- 1432-0649. ; 123:4
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Tidskriftsartikel (refereegranskat)abstract
- The applicability of the UV laser-induced poling inhibition method for ferroelectric domain engineering in proton exchanged lithium niobate planar waveguides is investigated. Our results indicate that intense UV irradiation of proton exchanged lithium niobate samples can, indeed, produce poling inhibited domains in this material under certain irradiation conditions. However, there is strong indication that the temperature gradient that is formed during UV irradiation modifies the local proton concentration leading to changes in the refractive index profile of the original planar waveguide.
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