Fabrication Technology of a Subwavelength Metal Grating Polarizer
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摘要: 亚波长周期结构光栅具有传统光栅所不具有的特殊特性,采用严格耦合波法设计并制作了一种柔性双层金属光栅偏振器,通过纳米压印技术在方形的PC(Polycarbonate,聚碳酸酯)上制备了周期为278 nm,深度为110 nm,占空比为0.5的亚波长光栅,通过磁控溅射技术在制作的介质光栅上沉积了70 nm的金属铝层,制作了具有双层金属结构的柔性双层金属光栅偏振器,并用光谱测试系统进行了简单的性能测试。实验结果表明,当入射光波长范围在350~800 nm时,制作的柔性双层光栅偏振器偏振特性优良,且具有非常高的透过率和消光比,分别高达48%和100000。该制作工艺只由纳米压印和金属蒸镀完成,省去了复杂的涂胶、剥离及刻蚀,因此在大批量生产偏振器方面具有很明显的优势,可普遍用于光探测器件、光电开光等半导体光电子器件的制作过程。Abstract: Sub-wavelength periodic grating has special characteristics that are lacking in traditional grating. In this study, a flexible double-layer metal grating polarizer is designed and fabricated using a strict coupled wave method. Through nanoimprinting technology, sub-wavelength grating with a period of 278 nm, depth of 110 nm, and duty cycle of 0.5 is prepared on a square polycarbonate (PC). A 70 nm metal aluminum layer is deposited on the fabricated dielectric grating by magnetron sputtering, and a double-layer metal structure is fabricated. A flexible double-layer metal grating polarizer is developed, and the performance of the polarizer is tested using a spectrum measurement system. Experimental results showed that when the wavelength range of the incident light was 350-800 nm, the flexible double-layer grating polarizer had good polarization characteristics. The polarized light transmission efficiency and extinction ratio were as high as high as 48% and 100000, respectively. The manufacturing process involves only nanoimprinting and metal evaporation processes and thus excludes coating, stripping, and etching of the imprint adhesive. Therefore, our method exhibits evident advantages in terms of low-cost and batch production of large-area polarizers and thus can be widely used in the manufacturing process of semiconductor optoelectronic devices such as optical-detection and optoelectronic devices.
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Key words:
- flexible /
- wire-grid polarizer /
- TM transmission efficiency /
- extinction ratio
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表 1 柔性双层金属光栅偏振器的参数
Table 1. Parameters of subwavelength metal grating polarizer
Materials and structures Materials and parameters Substrate materials PC Metallic materials Al Period/nm 278 Duty cycle 0.5 Aluminum thickness/nm 70 Distance between two metal grating layers/nm 50 PC grating height/nm 100 -
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