Wafer-level substrate-free YIG single crystal film for a broadband tunable terahertz isolator  

作　　者：XILAI ZHANG DAN ZHAO DING ZHANG QIANG XUE FEI FAN YULONG LIAO QINGHUI YANG QIYE WEN 

机构地区：[1]School of Electronic Science and Engineering,State Key Laboratory of Electronic Thin Film and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,China [2]Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology,Institute of Modern Optics,Nankai University,Tianjin 300350,China [3]Shenzhen Institute for Advanced Study,University of Electronic Science and Technology of China,Shenzhen 518110,China

出　　处：《Photonics Research》2024年第3期505-513,共9页光子学研究（英文版）

基　　金：National Key Research and Development Program of China(2023YFB3811300,2023YFB3811305);National Natural Science Foundation of China(62235004,61831012,62371258,62311530115);Sichuan Province Science and Technology Support Program(2021JDTD0026,2023JDGD0012);Shenzhen Science and Technology Program((2021)105)。

摘　　要：Yttrium iron garnet(YIG)is a promising material for various terahertz applications due to its special optical properties.At present,a high-quality YIG wafer is the desire of terahertz communities and it is still challenging to prepare substrate-free YIG single crystal films.In this work,we prepared wafer-level substrate-free La:YIG single crystal films,for the first time,to our knowledge.Terahertz optical and magneto-optical properties of La:YIG films were characterized by terahertz time domain spectroscopy(THz-TDS).Results show that the as-prepared La:YIG film has an insertion loss of less than 3 dB and a low absorption coefficient of less than10 cm-1below 1.6 THz.Benefitting from the thickness of the substrate-free YIG films and low insertion loss,their terahertz properties could be further manipulated by simply using a wafer-stacking technique.When four La:YIG films were stacked,there was an insertion loss of less than 10 dB in the range of 0.1-1.2 THz.The Faraday rotation angle of the four-layer-stacked La:YIG films reached 19°,and the isolation could reach17 dB.By further increasing the stacking number to eight pieces,a remarkable Faraday rotation angle of45°was achieved with an isolation of 23 dB,which is important for practical application in the THz band.This material may provide a milestone opportunity to make various non-reciprocal devices,such as isolators and phase shifters.

关 键 词：YIG FILM INSERTION 

分 类 号：O441.4[理学—电磁学] TB383.2[理学—物理]