Research On Fabrication Of Metamaterials Based Teraherz Devices By Laser Decal Transfer

Metamaterial is a kind of artificial material which based on the micro-nanostructure of orderly surface, and by reasonable design of metal structures, metamaterials can achieve intriguing and unique electromagnetic propagation characteristics which are not available in natural materials, such as negative refraction, superlens, electromagnetic cloaking, high frequency magnetic response and so on. At present, most terahertz metamaterial is fabricated by conventional lithography technique with high cost, long period, and complex procedure. Therefore, to seek a kind of microstructure devices fabrication method with low cost, high efficiency, simple steps and superior performance is urgently necessary and has caused widely attention.Laser decal transfer is a novel direct-write technique which based on the laser induced forward transfer of the nano metal suspension liquid. With loading different computer graphics on digital micromirror device and single laser pulse it can fabricate microstructure devices on a variety of materials. Laser decal transfer has great potential in the development, customization, modification and repair of microelectronic circuits, and fabrication of metamaterials. In this paper, we have firstly fabricated terahertz metamaterials on the surface of the quartz crystal by using laser decal transfer in China. Our research work of this paper include as follow:(1) We systematically studied laser decal transfer, including establishing and optimizing the optical path, designing the software of microstructure devices fabrication, the research of sample fabrication processes and technological factors influence. The minimum of the line width fabricated by laser decal transfer is 4 μm for now and the thickness of the nano silver layer is adjustable from 100 nm to 500 nm. This technique has the advantage of low cost, high efficiency, environmentally friendly and changing the structure and shape of the transfer structure dynamically. It is an effective technique to fabricate terahertz metamaterials.(2) We successfully fabricated terahertz double split ring resonators bridge structure and its complementary structure on thickness of 200 um quartz crystal with laser decal transfer, and also measured their performances with step profiler and THz-TDS system. The measured results show that the simple have good repeatability, thickness uniformity and well agree with CST simulation. Laser decal transfer can be used to fabricate terahertz metamaterial devices.(3) We have researched a complementary double split ring(CDSRR) terahertz filter which have three resonance peaks range from 0.2 THz to 1.4 THz, and the range of resonant frequency can be flexibility chosen by adjusting the size of inner ring and outer ring. We also analyzed the electromagnetic characteristics change of the filter under the influence of electromagnetic wave with CST simulation software. The outer ring impact the three transmission bands, and the inner ring mainly impact the second transmission band. We have fabricated the sample structure on the surface of quartz crystal by laser decal transfer, and there are three resonance peaks around 0.40 THz、0.82 THz、1.15 THz from the experiment result which is consistent with the results of simulation.In this paper, we use low viscosity nano silver paste to fabricate metamaterials on silver deposition substrate. In the future, it’s possible to fabricate metamaterials on receive substrate with high viscosity nano silver paste.