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Periodically poled second-order nonlinear materials with submicrometer periods are important for the development of quasi-phase matched backward-wave nonlinear optical processes. Interactions involving counter-propagating waves exhibit many unique properties and enable devices such as backward second harmonic generators, mirrorless optical parametric oscillators, and narrow-band quantum entangled photon sources. Fabrication of dense ferroelectric domain gratings in lithium niobate remains challenging, however, due to lateral domain spreading and merging. Here, we report submicrometer periodic poling of ion-sliced x-cut magnesium oxide doped lithium niobate thin films. Electric-field poling is performed using multiple bipolar preconditioning pulses that improve the poling yield and domain uniformity. The internal field is found to decrease with each preconditioning poling cycle. The poled domains are characterized by piezoresponse force microscopy. A fundamental period of 747 nm is achieved.
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Periodic Poling of X-Cut Thin-Film Lithium Niobate: The Route to Submicrometer Periods
Ultra-short poling periods of 1 μm and below in lithium niobate will allow nonlinear optical devices with operation to the UV regime or narrow-band counter-propagating single-photon generation. However, fabrication of such periods in bulk Lithium Niobate penetrating the complete modal areas of waveguides has been challenging. In this work, we demonstrate the fabrication of periodic domain grids with submicrometer periodicity in 300 nm x-cut thin-film lithium niobate. The poling was achieved through application of a single, shaped electrical pulse and electrodes fabricated with a combination of electron-and direct laser-writing lithography. The poling results were investigated with piezo-response force microscopy and second-harmonic microcopy and indicate the poled domains to penetrate fully across the complete film thickness. This will enable the fabrication of novel nonlinear optical devices combining the high efficiency of thin films with ultra-short domain periods.
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- Award ID(s):
- 1640968
- PAR ID:
- 10282995
- Date Published:
- Journal Name:
- 2020 Joint Conference of the IEEE International Frequency Control Symposium and International Symposium on Applications of Ferroelectrics (IFCS-ISAF)
- Page Range / eLocation ID:
- 1 to 2
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/IFCS-ISAF41089.2020.9234870
