Improvement of the photorefractive response of Fe-doped KNbO₃ crystals by MeV proton irradiation

详细信息    查看全文

• 作者：Fluck ; D. ; Brü ; lisauer ; S. ; Gü ; nter ; P. ; Buchal ; Ch. ; Beckers ; L.
• 关键词：Photorefractive ; Waveguide ; Proton implantation ; Potassium niobate ; Reduction process
• 刊名：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
• 出版年：1999
• 出版时间：January 2, 1999
• 年：1999
• 卷：148
• 期：1-4
• 页码：678-682
• 全文大小：129 K

文摘

We demonstrate that the photorefractive properties such as gain and response time in Fe-doped KNbO₃ crystals can be greatly improved by MeV proton irradiation. The observed reduction of the crystals from p-type to n-type is caused by a change in the ratio of the densities of donors to acceptors, denoted by the reduction ratio R=[Fe²⁺]/[Fe³⁺]. We have been able to change the reduction ratio R over orders of magnitude by proton implantation. The creation of oxygen vacancies is proposed to be responsible for the observed reduction. Based on our model, we determine key parameters of photorefractive Fe-doped KNbO₃ crystals, such as dopant concentration, segregation coefficient, and optical absorption cross section.