A kind of periodically polarized film substrate and its preparation method

Abstract

The present application provides a periodically polarized thin film substrate and a preparation method thereof. The periodically polarized thin film substrate includes a substrate (1), a buffer layer (2) and a piezoelectric single crystal layer (3) laminated in sequence, wherein , the piezoelectric single crystal layer (3) includes at least two piezoelectric single crystal sublayers (31), the polarization directions of adjacent piezoelectric single crystal sublayers (31) are opposite, obtained by bonding, the application provides The preparation method forms a periodically polarized thin film substrate by directly bonding multiple piezoelectric single crystal sublayers on the buffer layer. This method can be carried out at room temperature, and the process difficulty is low. The chemical cycle and the number of cycles can be flexibly controlled; effectively avoid the risk of breakdown caused by high voltage and the deterioration of surface quality caused by surface plating electrodes, and prevent light leakage into the substrate by setting a buffer layer, thereby reducing signal loss. The PPLN fabricated based on this substrate has completely through vertical domain walls.

Description

Technical field [0001] The present application belongs to the field of functional semiconductor materials, and more particularly to a periodic polarized thin film substrate and a preparation method thereof. Background technique [0002] Periodic Poled Ln, PPLN by quasi-phase matching technique (PPLN) is widely used in multiplier / decreasing, optical varieties oscillation, etc. In addition, in the field of optical communications, especially wavelength conversion, all-optical switching, in particular, in particular wavelength conversion, all-optical switching, also has broad application prospects. [0003] In lithium niobate, relative to oxygen ions (negative electrical), due to the position of lithium ion (positive electricity) and niobium ion (positive electricity), a special direction from positive electrodes to negative electricity is formed, along this direction along biotic acid The z-axis of the lithium crystal, that is, the + z-axis direction or the -z direction. If a volt...

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Problems solved by technology

[0008] In order to solve at least one of the aforementioned problems, for example, it is very difficult to prepare PPLN in the prior art method, the electric domain wall of the prepared PPLN has bending deformation, it is difficult to be close to vertical, the period length is difficult to reach the nanometer level, and the total period length of the PPLN is limited by In view of the limitations and the large signal loss of PPLN in the optical transmission process, this application provides a periodically polarized thin film substrate and its preparation method. The thickness of the electron layer is as low as nanometers, and the period length and number of periods of the periodically polarized thin film can be prepared on demand by controlling the thickness of each single crystal piezoelectric layer and the number of layers of the single crystal piezoelectric layer. Therefore, based on this The periodically poled film substrate provided by the application can obtain a periodically poled film with completely penetrating vertical domain walls, the period length is at the nanometer level, and the total period length can be specifically set according to needs

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