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- Aad, G., et al.
(author)
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- 2012
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In: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368 .- 1550-7998. ; 86:7
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Journal article (peer-reviewed)
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3. |
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4. |
- Canalias, Carlota, et al.
(author)
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In situ visualization of domain kinetics in flux grown KTiOPO4 by digital holography
- 2007
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 102:6, s. 064105-
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Journal article (peer-reviewed)abstract
- The fast dynamic evolution of ferroelectric domains during electric field poling in flux grown KTiOPO4 crystals was investigated online by a digital holography based technique. The dependence of the ferroelectric domain kinetics on the electric field temporal wave form and poling history was studied. High-speed imaging by means of a complementary metal-oxide-semiconductor image sensor camera allowed in situ measurement of the domain wall propagation speed under different poling conditions. The results also give evidence of the strong influence of the dielectric surface layer in this material.
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5. |
- Grilli, Simonetta, et al.
(author)
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A Mach-Zehnder interferometric system for measuring the refractive indices of uniaxial crystals
- 2002
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In: Optics communications. - 0030-4018. ; 202, s. 9-15
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Journal article (peer-reviewed)abstract
- We report a new interferometric technique for measuring the ordinary and extraordinary refractive indices of uniaxial crystals. The technique is based on the measurement of the rotation-dependent phase changes of the optical path length in crystal plates. Accurate measurement of the phase shift as a function of the rotation of the sample is achieved by using a fast-Fourier-transform based fringe analysis method for phase retrieval. The principle of the method is discussed and measurements of the ordinary and extraordinary refractive indices of a lithium niobate crystal are reported.
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7. |
- Grilli, Simonetta, et al.
(author)
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Control of lateral domain spreading in congruent lithium niobate by selective proton exchange
- 2006
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In: Applied physics letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 89:3, s. 032902-
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Journal article (peer-reviewed)abstract
- Proton exchange was observed to increase the poling voltage for congruent lithium niobate. Patterned proton exchange was then used to control domain nucleation and inhibit broadening of reversed domains. Periodically proton exchanged samples were used to form domain gratings by electric field poling just using planar electrodes and without need for poling current control. The reversed domain gratings had a duty cycle faithfully reproducing that of the proton exchanged pattern with straight domain walls parallel to the x face, thus demonstrating that high-fidelity reversed domain patterning is possible to obtain by a relatively simple process.
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8. |
- Grilli, Simonetta, et al.
(author)
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Double-face and submicron two-dimensional domain patterning in congruent lithium niobate
- 2006
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In: IEEE photonics technology letters. - 1041-1135. ; 18, s. 541-
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Journal article (peer-reviewed)abstract
- We report on the simultaneous fabrication of two-dimensional submicron engineered domain patterns on both crystal faces, in congruent lithium niobate. The fabrication technique is based on interference photolithography, which allows short pitch over large areas, followed by electric field poling performed in overpoling regime. Experimental results for different domain pattern geometries, on the two crystal faces, are reported. These structures could be useful for short-wavelength frequency conversion and Bragg gratings applications. The moire effect is used in the lithographic process to fabricate more complex structures which could find application in photonic bandgap devices.
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9. |
- Grilli, Simonettta, et al.
(author)
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In-situ visualization, monitoring and analysis of electric field domain reversal process in ferroelectric crystals by digital holography
- 2004
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In: Optics express. - 1094-4087. ; 12:9, s. 1832-1842
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Journal article (peer-reviewed)abstract
- In-situ monitoring of domain reversal in congruent lithium niobate by a digital holographic technique is described. While the ferroelectric polarization is reversed by electric field poling, the two-dimensional distribution of the phase shift, due mainly to the linear electro-optic and piezoelectric effects, is measured and visualized. Digital holography is used to reconstruct both amplitude and phase of the wavefield transmitted by the sample to reveal the phase shift induced by adjacent reversed domains during the poling. The resulting movies of both amplitude and phase maps, for in-situ visualization of domain pattern formation, are shown. The possibility of using the technique as tool for monitoring in real-time the periodic poling of patterned samples is discussed.
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10. |
- Grilli, Simonetta, et al.
(author)
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Investigation on reversed domain structures in lithium niobate crystals patterned by interference lithography
- 2003
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In: Optics express. - 1094-4087. ; 11, s. 392-
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Journal article (peer-reviewed)abstract
- We demonstrate fabrication of periodically poled lithium niobate samples by electric field poling, after patterning by interference lithography. Furthermore we investigate the poling process at an overpoling regime which caused the appearance of submicron dot domains very similar to those induced by backswitch but different in nature. We show the possibility for realizing submicron-scaled three-dimensional domain patterns that could be applied to the construction of photonic crystals and in nonlinear optics. We show that high etch-rate applied to such structures allows to obtain pyramidal-like submicron relief structures which in principle could find application for waveguide construction in photonic bandgap devices
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