Hollow-core antiresonant terahertz fiber-based TOPAS extruded from a 3D printer using a metal 3D printed nozzle

Abstract

We report the use of a terahertz (THz) transparent material, cyclic olefin copolymer (COC or TOPAS), for fabricating a hollow-core antiresonant fiber that provides an electromagnetic wave guidance in the THz regime. A novel fabrication technique to realize a hollow-core antiresonant polymer optical fiber (HC-ARPF) for THz guidance is proposed and demonstrated. The fiber is directly extruded in a single-step procedure using a conventional fused deposition modeling 3D printer. The fiber geometry is defined by a structured nozzle manufactured with a metal 3D printer, which allows tailoring of the nozzle design to the various geometries of microstructured optical fibers. The possibility to use the HC-ARPF made from TOPAS for guiding in the THz region is theoretically and experimentally assessed through the profile of mode simulation and time-frequency diagram (spectrogram) analysis.

Ultra-High Sensitivity Terahertz Microstructured Fiber Biosensor for Diabetes Mellitus and Coronary Heart Disease Marker Detection

“…For the length of terahertz MSF, 50 mm~100 mm is usually set as appropriate. If the fiber length is too low, the number of terahertz wave oscillations inside the fiber is too few to form a stable mode field distribution, and at the same time, it will enhance the difficulty of experimental operation; if the MSF length is too long, the MSF biosensor may face problems such as output signal attenuation, sensitivity to bending loss, and more likelihood of fiber defects during the manufacturing process [ 20 , 34 , 35 ].…”

“…The combination of 3D printing and extrusion technologies enables rapid and precise fabrication of MSFs, which typically involves extruding a molten cyclic olefin polymer through a 3D printing nozzle and stretching it directly to the size required for THz sensing [ 20 , 35 ]. Compared with other traditional techniques for fiber preparation, this technique simplifies the fiber prefabrication and enables precise manufacturing of MSF structures with large duty cycles [ 35 ].…”

“…For example, use of MSFs has been reported for temperature measurement [ 11 , 12 ], gas monitoring [ 13 ], cancer cell detection [ 14 , 15 ], chemical identification [ 9 , 16 , 17 ], and blood composition detection [ 18 , 19 ]. Compared with other types of MSFs, hollow-core MSFs are often preferred, as they provide larger contact areas between the THz wave and the analytes, and are also convenient to manufacture [ 9 , 20 ]. By adjusting geometric parameters, such as core diameters and pore shapes/arrangements, important optical properties including the relative sensitivity can be effectively changed.…”

A Novel High-Sensitivity Terahertz Microstructure Fiber Biosensor for Detecting Cancer Cells

“…Recently, the development of 3D printing techniques has enabled versatile implementations of MSF structures [42]. The 3D printing method relies on the principle of molten deposition and the thermoplastic extrusion and stretching of TOPAS material to produce thin fiber structures.…”

Single-Mode Hollow-Core Anti-Resonant Waveguides for Low-Loss THz Wave Propagation

“…However, the development of HC-PBG THz waveguides has been restricted by their narrow bandwidth, complex structure, low design flexibility, and manufacturing difficulty. Fortunately, these drawbacks plaguing HC-PBG THz waveguides can be overcome by another type of hollow-core THz waveguides, i.e., the hollow-core anti-resonant (HC-AR) THz waveguides, also known as inhibited-coupling hollow-core THz waveguides [18], [19]. The HC-AR THz waveguides have several distinct advantages such as a wider transmission window, lower loss, and manufacturing simplicity.…”