Domain Engineering Enabled Giant Linear Electro‐Optic Effect and High Transparency in Ferroelectric KTa1−xNbxO3 Single Crystals. Issue 6 (18th March 2022)

• Record Type: Journal Article
• Authors: Shang, Annan; Liu, Ruijia; Chen, Chang-Jiang; Lee, Yun‐Goo; Chao, Ju-Hung; Zhang, Wei; Wetherington, Maxwell; Yin, Shizhuo
• Is Part Of: Physica status solidi. Volume 16:Issue 6(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-18
• Subjects: ferroelectric crystal -- linear electro-optic coefficient -- Pockels electro-optic effect -- polar nano-region (PNR) -- potassium tantalate niobate (KTN) crystal; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.202200005
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : A giant linear electro‐optic (EO) effect and high transparency in ferroelectric potassium tantalate niobate [( K T a 1 − x N b x O 3 ), KTN] crystal is achieved via a thermally controlled domain engineering method. It involves a two‐step thermal annealing process: 1) a rapid cooling process that forms polar nano‐regions (PNRs), i.e., a cooling rate of 1 . 67 ° C s − 1 from T c + 58 ° C to T c + 8 ° C where T c is the Curie temperature; and 2) a slow cooling process that facilitates abnormal domain growth (AGG) i.e., a cooling rate of 0 . 0115 ° C s − 1 from T c + 8 ° C to T c − 15 ° C . Since PNR can have a faceted boundary and high anisotropy, it can promote AGG within single crystals to realize solid‐state domain conversion macroscopically from a multi‐domain to single‐domain crystal within a slow cooling process. The resultant KTN crystal offers high transparency that is equivalent to its paraelectric phase; and a linear EO coefficient ( γ 51 ) as large as γ 51 ≈ 51200 p m V − 1, which is five times the value of conventional KTN crystals with similar composition. This giant linear EO coefficient represents a major technical advance in EO materials and significantly reduces the driving voltage, power, and footprint of many types of EO devices. Abstract : A giant linear electro‐optic (EO) effect as large as γ 51 ≈ 51 200 p m V − 1 and high transparency in ferroelectric potassium tantalate niobate [( K T a 1 − x N b x O 3 ), KTN] crystal is achieved via a thermally controlled domain engineering method due to the abnormal domain growth‐like process produced by polar nanoregions. This significantly reduces the driving voltage, power, and footprint of many types of EO devices.