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| 2. |
- Eismann, U., et al.
(författare)
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An all-solid-state laser source at 671 nm for cold-atom experiments with lithium
- 2012
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Ingår i: Applied physics. B, Lasers and optics (Print). - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 106:1, s. 25-36
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Tidskriftsartikel (refereegranskat)abstract
- We present an all-solid-state narrow-linewidth laser source emitting 670 mW output power at 671 nm delivered in a diffraction-limited beam. The source is based on a frequency-doubled diode-end-pumped ring laser operating on the 4F 3/2 → 4I 13/2 transition in Nd:YVO 4. By using periodically poled potassium titanyl phosphate (ppKTP) in an external buildup cavity, doubling efficiencies of up to 86% are obtained. Tunability of the source over 100 GHz is accomplished. We demonstrate the suitability of this robust frequency-stabilized light source for laser cooling of lithium atoms. Finally, a simplified design based on intracavity doubling is described and first results are presented.
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| 3. |
- Femenia, M., et al.
(författare)
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Scanning Kelvin probe force microscopy and magnetic force microscopy for characterization of duplex stainless steels
- 2003
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 150:6, s. B274-B281
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Journal article (peer-reviewed)abstract
- In this study, the Volta potential distribution over the surface of duplex stainless steels (DSSs) has been mapped for the first time with submicrometer resolution by scanning Kelvin probe force microscopy (SKPFM). The different magnetic properties of ferrite and austenite enable the utilization of magnetic force microscopy (MFM) for visualizing their surface distribution without the need of surface etching. The combined MFM and SKPFM mapping of the same area makes it possible to associate the variation in the Volta potential to the phase distribution and phase boundaries. The difference in potential between the two phases is measurable and significant. Generally, the ferrite phase was associated to regions of lower potential, and the austenite phase to regions of more noble potential. This can be regarded as direct evidence of galvanic interactions between the two phases. The phase boundary regions often exhibited a lower potential in the ferrite phase, indicating a higher tendency to corrosion. The high lateral resolution of SKPFM provides the possibility of comparing these results with those obtained from other localized techniques, a necessary step for a deeper understanding of the local corrosion processes in DSSs.
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| 4. |
- Hart, James L., et al.
(author)
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Electron-beam-induced ferroelectric domain behavior in the transmission electron microscope : Toward deterministic domain patterning
- 2016
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In: Physical Review B. - 2469-9950 .- 2469-9969. ; 94:17
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Journal article (peer-reviewed)abstract
- We report on transmission electron microscope beam-induced ferroelectric domain nucleation and motion. While previous observations of this phenomenon have been reported, a consistent theory explaining induced domain response is lacking, and little control over domain behavior has been demonstrated. We identify positive sample charging, a result of Auger and secondary electron emission, as the underlying mechanism driving domain behavior. By converging the electron beam to a focused probe, we demonstrate controlled nucleation of nanoscale domains. Molecular dynamics simulations performed are consistent with experimental results, confirming positive sample charging and reproducing the result of controlled domain nucleation. Furthermore, we discuss the effects of sample geometry and electron irradiation conditions on induced domain response. These findings elucidate past reports of electron beam-induced domain behavior in the transmission electron microscope and provide a path towards more predictive, deterministic domain patterning through electron irradiation.
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| 6. |
- Kores, Cristine C., et al.
(author)
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Quasi-phase matched second harmonic generation in periodically poled Rb-doped KTiOPO4 ridge waveguide
- 2018
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In: Optics Express. - : Optical Society of America. - 1094-4087. ; 26:25, s. 33142-33147
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Journal article (peer-reviewed)abstract
- A 10.8 mu m wide ridge waveguide was fabricated by diamond-blade dicing in an ion-exchanged periodically poled Rb-doped KTiOPO4 sample. The waveguide was used to generate blue second harmonic light at 468.8 nm in the TM(00 )mode through first order Type I quasi-phase matching, exploiting the large d(33) coefficient of the crystal. It was evaluated using a cw Ti:Sapphire laser, and 6.7 mu W of blue light was generated with 5.8 mW of fundamental radiation at 933.8 nm coupled through the waveguide. The results presented here pave the way for efficient nonlinear processes in a waveguide format. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
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| 7. |
- Kores, Cristine C., et al.
(author)
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Quasi-phase matching waveguides on lithium niobate and KTP for nonlinear frequency conversion : A comparison
- 2021
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In: APL PHOTONICS. - : AIP Publishing. - 2378-0967. ; 6:9, s. 091102-
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Journal article (peer-reviewed)abstract
- Established waveguide fabrication technologies on lithium niobate (LN) and potassium titanyl phosphate (KTP) were revisited, and a comparative analysis of their performance for type-0 quasi-phase matched second-harmonic generation at 1.55 mu m was provided based on literature data and our simulations. This analysis aided identifying gaps where the waveguide performance is below the theoretical predictions, and the possible reasons are discussed. It provides the reader with a roadmap for choosing the most appropriate waveguide type and material choice between LN and KTP for desired performance of targeted applications.
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| 8. |
- Kores, Cristine C., et al.
(author)
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Type I quasi-phase matching in a periodically poled Rb-doped KTiOPO4 ridge waveguide
- 2019
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In: Optics InfoBase Conference Papers. - : OSA - The Optical Society.
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Conference paper (peer-reviewed)abstract
- Nonlinear optics in waveguides provide means for efficient nonlinear interactions as this platform permits high confinement over long interaction lengths, and it has been a field of intense research since the early days of nonlinear optics [1]. With the development of electric field poling [2] and novel waveguide fabrication methods, waveguide devices have become of interest again and exploited in several contemporary applications like spectroscopy, metrology, sensing and quantum optics. The challenge that drives the field in the present days is the development of waveguides with small modal cross section, high transverse overlap between interacting modes, and low propagation loss. Rubidium-doped KTP (RKTP) is an attractive material as it has high nonlinear coefficients, strong resistance to optical damage, and a wide transparency range. Furthermore, it presents lower ionic conductivity, compared with its isomorph KTP, allowing fabrication of high quality ferroelectric domain gratings [3]. Waveguide fabrication techniques combined with periodically poled structures allows to obtain quasi-phase matching (QPM) of Type I for RKTP so the strong d33 coefficient can be exploited [4].
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| 9. |
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| 10. |
- Lagatsky, A. A., et al.
(author)
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Efficient Doubling of Femtosecond Pulses in Aperiodically and Periodically Poled KTP Crystals
- 2007
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In: Optics express. - 1094-4087. ; 15:3, s. 1155-1160
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Journal article (peer-reviewed)abstract
- Efficient doubling of femtosecond pulses in periodically and aperiodically poled KTP crystals is demonstrated by employing the quasi-phasematched frequency conversion technique. Conversion efficiencies as high as 60% were achieved using either aperiodically or periodically poled KTP nonlinear crystals in an extracavity, single-pass configuration using a diode-pumped femtosecond Yb:KYW laser as the pump source. The temporal characteristics of the frequency-doubled pulses as a function of focusing conditions in a "thick" nonlinear crystal regime have been investigated experimentally and pulses as short as 177 fs have been generated at around 520 nm under strong focusing conditions using a KTP crystal with aperiodic poling.
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