Polarized GaN-based LED with an integrated multi-layer subwavelength structure.
Polarized GaN-based LED with an integrated multi-layer subwavelength structure.
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DOI：
10.1364/oe.18.007019
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发表时间：
2010-03
期刊：
影响因子：
3.8
通讯作者：
Guiju Zhang;Chinhua Wang;B. Cao;Zengli Huang;Jianfeng Wang;Baoshun Zhang;Ke Xu
中科院分区：
文献类型：
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作者：
Guiju Zhang;Chinhua Wang;B. Cao;Zengli Huang;Jianfeng Wang;Baoshun Zhang;Ke Xu
提出了一种基于集成多层亚波长光栅结构的高偏振输出GaN基LED。研究了三种不同亚波长多层结构的偏振GaN基LED的光传输特性和偏振消光比特性。结果表明，在金属光栅和GaN衬底之间引入一层折射率比GaN衬底低的介质过渡层，可以有效地提高LED的TM透射率（T（TM））和消光比（ER）。与传统的单层金属光栅的灵敏度相比，T（TM）对金属光栅的周期、占空比和宽的工作波长范围的灵敏度已经实现。金属光栅的占空比高达0.75，可以实现> 60 dB的ER，同时T（TM）保持高于~ 90%，这打破了T（TM）和ER总是一对折衷参数的传统限制。分别以MgF（2）和ZnS为过渡层，得到了典型的优化多层膜结构，在材料、厚度、光栅周期和占空比方面都得到了优化。研究结果为设计、优化和制备新型集成GaN基偏振光子器件提供了指导。
A novel type of GaN-based LED with a highly polarized output using an integrated multi-layer subwavelength grating structure is proposed. Characteristics of both optical transmission and polarization extinction ratio of the polarized GaN-based LED with three different multi-layer subwavelength structures are investigated. It is found that both TM transmission (T(TM)) and the extinction ratio(ER) of the LED output can be effectively enhanced by incorporating a dielectric transition layer between the metal grating and GaN substrate with a lower refractive index than that of the GaN substrate. Flat sensitivity of the T(TM) on the period, duty cycle of the metallic grating, and the wide range of operating wavelength have been achieved in contrast to the conventional sensitive behavior in single-layer metallic grating. Up to 0.75 high duty cycle of the metallic grating can be employed to achieve >60dB ER while T(TM) maintains higher than ~90%, which breaks the conventional limit of T(TM) and ER being always a pair of trade-off parameters. Typical optimized multilayer structures in terms of material, thickness, grating periods and duty cycle using MgF(2) and ZnS, respectively, as the transition layers are obtained. The results provide guidance in designing, optimizing and fabricating the novel integrated GaN-based and polarized photonic devices.