塑料太赫兹纤维/波导管制造技术研究

Researchs on Terahertz technology has experienced dramatic growth recently in both technical achievement and commercial implementation. The growth is application driven, with interest from various fields such as chemical and astronomical spectroscopy and sensing, medical and biological imaging and analysis, defense and security screening, communication networks and radars, etc. Many of these applications, however, utilize free-space propagation, resulting in weak beam confinement and vulnerability to environmental fluctuations. Focal spot size is diffraction limited and relatively large for the wavelengths of interest, which inconveniently requires large sample areas in material characterization applications and makes system miniaturization challenging. THz waveguides, provide a promising approach to overcome these drawbacks, and may lead to compact and low-cost integrated THz systems.However,up to now，there is a current lack of options for low-loss broadband transmission fibers and for functional fiber-based devices.. The polymer Topas COC has both low loss and low dispersion in the THz regime and is therefore an ideal candidate for the base material of the future THz fiber/pipe.This project aims at designing, drawing, and characterizing resultant topas COC fibers /pipe for THz waveguide.The Topas COC THz fiber features a subwavelength-size core suspended in the middle of a large porous outer cladding. This design allows convenient handling of the subwavelength fibers without distorting their modal profile. Additionally, the air-tight porous cladding serves as a natural enclosure for the fiber core, thus avoiding the need for a bulky external enclosure for humidity-purged atmosphere.the another of the proposed THz waveguide is consisting of a topas COC pipe with ringlike small air-holes array cladding..The fabrication is implemented via our-self invented preform-extrusion-drawing technique.We characterize transmission losses of the fabricated fibers in terahertz using a home-made non-destructive THz-TDS.We will demonstrate experimentally that introduction of small air-holes array into core of subwaveguide Topas COC fiber,or cladding of topas THz pipe, further reduces its transmission loss. .We believe that Topas-based waveguide technology is well suited to tackle the challenges of THz wave guiding. Towards that end, Topas COC possess several key incentives: it has relatively low-loss THz materials with very good thermo-mechanical properties, are cost-effective and easy to process, and thus amenable to an industrial-scale deployment of plastic-based THz waveguides and devices.

太赫兹系统的紧凑化、轻量化、柔性化以及低成本化的实现有待类似于光波导技术的太赫兹波导系统的问世。太赫兹波导系统的关键技术之一是低损耗的波导元件制造技术。本申请拟开展用于太赫兹波传输的聚合物太赫兹波导管（THZ pipe）、聚合物太赫兹纤维（THz fiber）的设计与制造技术研究。拟以在可见光区、太赫兹区透明的新型聚合物材料TopasCOC为基质，设计满足不同太赫兹系统需求的THz pipe \THz fiber。在完成两种THz waveguide结构设计的基础上，研究制造过程的各个关键技术：预制棒尺寸与高精度模具设计制造、预制棒制造技术、预制棒拉伸技术中的关键科学问题，寻求所设计光纤的几何尺寸、有序度、周期性得到有效控制的条件。在攻克制造技术难点的基础上，制造出两种不同结构的低损耗太赫兹波导，为构筑新一代轻量、紧凑、柔性、低价格太赫兹系统提供技术支撑。

太赫兹波导系统的关键技术之一是低损耗的波导元件的制造技术。本项目开展了用于太赫兹波传输的聚合物太赫兹波导管、聚合物太赫兹纤维的设计与制造技术的研究。我们以在太赫兹区透明性最好聚合物材料TopasCOp为基质，设计了能够满足不同太赫兹系统需求的多模微结构包层THz pipe，带隙型单模太赫兹光纤，悬浮芯太赫兹光纤，微结构梯度折射率太赫兹光纤。在完成四种THz waveguide结构设计的基础上，开展了规模化制造太赫兹光纤技术的研究。掌握了制备过程的各个关键技术：预制棒尺寸与高精度模具设计制造、预制棒制造技术、预制棒拉伸技术中的关键科学问题，制造4种不同结构的低损耗太赫兹纤维，损耗达到国际最先进水平，为我国的相关高校，研究机构提供了试用样品。我们制造太赫兹光纤及波导管的技术是国际国内独创，具有完全的自主知识产权。为开拓太赫兹光纤的应用，我们与中国工程物理研究院太赫兹技术研究中心合作开展了太赫兹光纤系统的研发。联合研制了太赫兹光纤耦合器，建立了聚合物微结构太赫兹光纤的表征系统，聚合物太赫兹光纤为波导的演示系统。为我国研制新一代轻量、紧凑、柔性、低价格太赫兹系统奠定了坚实可靠的技术基础。