Second-order nonlinearities in the domain walls of periodically poled KTiOPO4

The distribution of inverted ferroelectric domains on the surface and within the bulk of a periodically poled KTA (KTiOAsO4) single crystal has been observed using a simple X-ray diffraction imaging setup which takes advantage of the highly coherent beams available at a third-generation synchrotron source, such as the ESRF. This technique allows one to reveal the phase difference between the waves that are Bragg diffracted from adjacent domainsviafree-space propagation (Fresnel diffraction). The phase difference of the diffracted waves is mainly produced by the difference in phases of the structure factors involved, and contains precise structural information about the nature of the domain walls.

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Observation of Periodic Domain Inversion in Periodically Poled LiNbO3 by High-Resolution Topography

Journal of Applied Crystallography ◽

10.1107/s0021889896000283 ◽

1996 ◽

Vol 29 (3) ◽

pp. 279-284 ◽

Cited By ~ 25

Author(s):

Z. W. Hu ◽

P. A. Thomas ◽

J. Webjörn

Keyword(s):

High Resolution ◽

Structural Model ◽

Domain Walls ◽

Periodic Pattern ◽

Periodic Domain ◽

Periodically Poled ◽

Diffraction Mode ◽

Linear Contrast ◽

Domain Inversion ◽

Periodic Domain Inversion

Periodic domain inversion in an electric field poled LiNbO3 crystal has been studied using high-resolution multiple-crystal multiple-reflection X-ray diffraction topography. Fine linear contrast with spacings that correspond to the lateral dimensions of the periodic pattern has been observed by the choice of an appropriate diffraction mode to provide high spatial resolution and is shown to arise essentially from strains at the domain walls. The origin of the strain contrast at the domain walls is suggested primarily to be the result of the domain-inversion processing via the converse piezeoelectric effect. A structural model for the domain inversion that is based on a pseudosymmetry argument is invoked in order to quantify the ionic displacements for twinning. These results are compared with those obtained in a previous study employing a different diffraction mode [Hu, Thomas & Webjörn (1995). J. Phys. D, 28, A189–A194].

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Analyses of All-Optical Ultra-Fast Gate Switches Using Cascaded Second-Order Nonlinear Effect in Periodically Poled Lithium Niobate Waveguides: Methods of Performance Enhancement and Effects of Device Fabrication Errors

2007 9th International Conference on Transparent Optical Networks ◽

10.1109/icton.2007.4296408 ◽

2007 ◽

Author(s):

Yutaka Fukuchi ◽

Takahiro Tanaka ◽

Kenta Watanabe ◽

Masami Akaike

Keyword(s):

Lithium Niobate ◽

Nonlinear Effect ◽

Performance Enhancement ◽

Second Order ◽

Device Fabrication ◽

Periodically Poled ◽

Periodically Poled Lithium Niobate ◽

Fabrication Errors ◽

All Optical

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Generation of Pure State Photon Triplets in the C-Band

Micromachines ◽

10.3390/mi10110775 ◽

2019 ◽

Vol 10 (11) ◽

pp. 775 ◽

Cited By ~ 1

Author(s):

Xi-Rong Su ◽

Yi-Wen Huang ◽

Tong Xiang ◽

Yuan-Hua Li ◽

Xian-Feng Chen

Keyword(s):

Pure State ◽

Schmidt Number ◽

Second Order ◽

Conversion Process ◽

Gaussian Filter ◽

Periodically Poled ◽

Two Photon ◽

Parametric Down Conversion ◽

Photon States ◽

Down Conversion

In this work, the cascaded second-order spontaneous parametric down-conversion (SPDC) is considered to produce pure state photon triplets in periodically poled lithium niobite (PPLN) doped with 5% MgO. A set of parameters are optimized through calculating the Schmidt number of two-photon states generated by each down-conversion process with different pump durations and crystal lengths. We use a Gaussian filter in part and obtain three photons with 100% purity in spectrum. We provide a feasible and unprecedented scheme to manipulate the spectrum purity of photon triplets in the communication band (C-band).

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