摘要
基于ZnO纳米柱制备及发光实验,建立了ZnO纳米柱的位置和大小都是无序的二维介质结构模型.通过构建增益模型,用时域有限差分法数值模拟了无序介质中频谱特性以及ZnO增益频谱范围内的某一个共振峰对应的波源在无序介质中的光场分布情况,发现了局域模的存在.分四种情况讨论了此局域模的受激辐射与泵浦面积的关系:改变泵浦功率,从左到右依次增加两层ZnO纳米柱泵浦和单独泵浦一个局域区域;泵浦功率一定时,增加泵浦局域区域和非局域区域中ZnO纳米柱个数.结果表明:存在一个临界泵浦功率,当泵浦功率小于临界泵浦功率时,无论泵浦面积多大都不能激发局域模;当泵浦功率大于临界泵浦功率时,对于不同的泵浦功率,局域模被激发所需的临界泵浦面积不同;随着泵浦功率的增加,当泵浦面积一定时,光场相对强度呈递增趋势,当泵浦功率超过临界功率时,光场相对强度急剧上升.
Based on the growth and photoluminescences experiment of Zinc Oxide（ZnO） nanorods,the structrue model of two-dimensional random media,in which the location and radius of ZnO nanorods are all disordered,was constructed.Using ZnO gain model,the spectrum characteristics and spatial distribution of optical field at some resonant peak in ZnO nanorods random media were simulated numerically by means of the finite difference time domain method,and the localized mode was found.The effect of pump area on stimulated radiation of the local mode in ZnO nanorods random media was studied from four aspects： changing the pump intensity,increasing the pump size every two columns from left to right,only pumping a zone of localized mode,and increasing the excitation area（the number of the ZnO nanorods） in localized area and nonlocal area respectively when the pump intensity is fixed.The results show： there exists a critical pump power;when the pump intensity is smaller than pump intensity at the lasing threshold,no localized mode can be excited with the size of the pump area;when the pump power reaches above the critical pump power,in the case of different pump powers,localized modes can be excited with different critical pump sizes;when the power size is fixed,the relative light intensity increases with the increasing of the pump intensity and the relative light intensity increases rapidly when the pump intensity exceeds the lasing threshold.
出处
《光子学报》
EI
CAS
CSCD
北大核心
2011年第11期1738-1743,共6页
Acta Photonica Sinica
基金
The National Natural Science Foundation of China(No.61067002)
Jiangxi Province Natural Science Foundation(No.2009GZW0002)
Jiangxi Province Educational Committee Special Fund for Graduate Innovation(No.YC10A127)
关键词
无序介质
局域模
泵浦面积
受激辐射
Random media
Localized mode
Pump sizes
Stimulated emission
