| 1. |
- Gustavsson, Johan, 1974, et al.
(författare)
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Mode and polarization control in VCSELs using shallow surface structures
- 2007
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Ingår i: IET Optoelectronics. ; 1:5, s. 197-205
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Tidskriftsartikel (refereegranskat)abstract
- Monolithic techniques for mode and polarisation control in vertical-cavity surface emitting lasers (VCSELs) using shallow surface structures are summarized and put in the context with other techniques in terms of performance and manufacturability. The method of using circular-symmetric surface structures for mode control and their combination with a sub-wavelength surface grating for simultaneous mode and polarisation control is described in detail, and adherent experimental results for both 850-nm and 1.3-µm oxide-confined VCSELs are presented.
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| 2. |
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| 3. |
- Blomberg, Anders, 1956, et al.
(författare)
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Establishing the barnacle Balanus improvisus as a potent invertebrate monitoring system in marine ecotoxicogenomics
- 2009
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Ingår i: SETAC Europe 19th Annual Meeting Abstract Book, Göteborg 31 May - 4 June, 2009.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- There is a need for potent invertebrate systems for assessing the impacts of environmental contaminants on marine ecosystems. Balanus improvisus, a marine athropod, has a number of promising characteristics that make it a good candidate in such efforts. We have conducted sequencing of a cDNA library from the cyprid larval stage and identified several detoxification systems as well as novel B. improvisus specific genes. To investigate the toxicological gene expression response in this organism, we performed a short-term exposure experiment of the cyprid larvae to two different biofouling substances. From a natural population of B. improvisus, 300 - 1000 cyprids were treated for 23 hours with 390nM CuO or with two different concentrations (10nM or 10μM) of meditomidine. Protein expression changes were studied by 2D-PAGE analysis after DIGE labelling. For gene expression analysis by DNA miroarrays total RNA was extracted and used for cDNA and cRNA/aRNA templates. Roughly 2000 B. improvisus genes were studied represented by 3000 different probes on the arrays (each in duplicates). Candidate genes were confirmed by qPCR. A number of protein expression changes were detected on the 2D gels as a result of the different treatments. Interestingly, the response to the different treatments clearly formed distinct groups in principle component analysis. The DNA microarray analysis revealed several genes as toxicity indicators, e.g. various heat shock proteins, some proteases and factors involved in regulatory processes (transcription factors). Our data indicate that B. improvisus may serve as a tool to evaluate the impacts of marine pollution, and thus to fill the niche as an important invertebrate marine model organism for ecotoxicology and environmental genomics.
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| 4. |
- Grabowski, Alexander, 1993, et al.
(författare)
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Large-Signal Circuit Model for Datacom VCSELs
- 2018
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Ingår i: Conference Digest - IEEE International Semiconductor Laser Conference. - 0899-9406. ; 2018-September, s. 193-194
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Konferensbidrag (refereegranskat)abstract
- We present a physics-based equivalent-circuit model for datacom VCSELs, with ambient temperature and self-heating effects accounted for. This circuit model is unique in accounting for carrier capture dynamics between active region continuum and quantum well bound states. OOK/PAM4 simulations are demonstrated at 25°C and 85°C.
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| 5. |
- Jahed, Mehdi, 1988, et al.
(författare)
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Precise setting of micro-cavity resonance wavelength by dry etching
- 2019
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Ingår i: Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics. - : American Vacuum Society. - 2166-2754 .- 2166-2746. ; 37:3
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Tidskriftsartikel (refereegranskat)abstract
- With an intracavity phase tuning technique, the authors demonstrate <2 nm precision in wavelength setting of vertical-cavity surface-emitting laser (VCSEL) microresonators in the wavelength range 1040-1070 nm using an Ar ion-beam etching process with subnanometer precision in etch depth. This postgrowth fabrication technique for controlling the wavelength of individual VCSELs is promising for the development of monolithic multiwavelength VCSEL arrays with precisely defined wavelengths for wavelength division multiplexed (WDM) optical interconnects and the assembly of compact and high-capacity WDM transmitters.
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| 6. |
- Juodenas, Mindaugas, 1991, et al.
(författare)
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High-angle deflection of metagrating-integrated laser emission for high-contrast microscopy
- 2023
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Ingår i: Light: Science and Applications. - 2047-7538 .- 2095-5545. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Flat metaoptics components are looking to replace classical optics elements and could lead to extremely compact biophotonics devices if integrated with on-chip light sources and detectors. However, using metasurfaces to shape light into wide angular range wavefronts with high efficiency, as is typically required in high-contrast microscopy applications, remains a challenge. Here we demonstrate curved GaAs metagratings integrated on vertical-cavity surface-emitting lasers (VCSELs) that enable on-chip illumination in total internal reflection and dark field microscopy. Based on an unconventional design that circumvents the aspect ratio dependent etching problems in monolithic integration, we demonstrate off-axis emission centred at 60(degrees) in air and 63(degrees) in glass with > 90% and > 70% relative deflection efficiency, respectively. The resulting laser beam is collimated out-of-plane but maintains Gaussian divergence in-plane, resulting in a long and narrow illumination area. We show that metagrating-integrated VCSELs of different kinds can be combined to enable rapid switching between dark-field and total internal reflection illumination. Our approach provides a versatile illumination solution for high-contrast imaging that is compatible with conventional microscopy setups and can be integrated with biophotonics devices, such as portable microscopy, NIR-II range bioimaging, and lab-on-a-chip devices.
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| 7. |
- Kong, D., et al.
(författare)
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Single Dark-Pulse Kerr Comb Supporting 1.84 Pbit/s Transmission over 37-Core Fiber
- 2020
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Ingår i: Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS. - 1092-8081. ; 2020-May
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Konferensbidrag (refereegranskat)abstract
- We show that a single dark-pulse Kerr comb can generate high enough OSNR to carry 1.84 Pbit/s data, achieved by 223 WDM spectral lines modulated with 32-Gbaud, SNR-adapted probabilistically shaped DP-QAM, over a 37-core fiber.
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| 8. |
- Lavrencik, Justin, et al.
(författare)
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Optimum VCSEL Apertures for High-Speed Multimode Fiber Links
- 2018
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Ingår i: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings. - 9781943580385
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Konferensbidrag (refereegranskat)abstract
- Cross-correlations of VCSEL transverse mode groups with different apertures are used to predict dispersion dependent RIN. Experiments with wideband multimode fiber confirm the noise enhancement dependence on aperture, which increases with fewer mode VCSELs.
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| 9. |
- Lengyel, Tamas, 1986, et al.
(författare)
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Pre-emphasis enabled 50 Gbit/s transmission over 1000 m SMF using a 1060 nm single-mode VCSEL
- 2018
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 54:20, s. 1186-1187
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Tidskriftsartikel (refereegranskat)abstract
- A single-mode 1060 nm vertical-cavity surface-emitting laser (VCSEL) and single-mode fibre (SMF) based link with two-tap active pre-emphasis enabling error-free transmission of 50 Gbit/s NRZ-OOK over 1000 m is presented.
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| 10. |
- Tibaldi, Alberto, et al.
(författare)
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Analysis of Carrier Transport in Tunnel-Junction Vertical-Cavity Surface-Emitting Lasers by a Coupled Nonequilibrium Green's Function-Drift-Diffusion Approach
- 2020
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Ingår i: Physical Review Applied. - 2331-7019. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- This work investigates carrier transport in tunnel junctions for vertical-cavity surface-emitting lasers (VCSELs). The study is performed with a quantum-corrected semiclassical approach, where tunneling is described rigorously with a nonequilibrium Green's function formalism based on a multiband description of the electronic structure. Validated with experimental results, the proposed approach provides a quantum -kinetic perspective of the tunneling process and paves the way toward a comprehensive theory of VCSELs, bridging the gap between semiclassical and quantum simulations.
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