The investigation of long-period fibre gratings formed by a 3D printer with several grating periods is presented here. The proposed grating device was pressed on to an optical fibre to observe the resonant wavelengths as a function of different groove periods. Results showed that devices with 700 and 800 nm grating period introduced resonant wavelengths of 1,487 and 1,570 nm with refractive index changes of 2.121 × 10⁻³ and 1.963 × 10⁻³, respectively. Once resonant wavelengths were known, an optical time domain reflectometer (OTDR) was employed to determine light behaviour, event positions, and losses. The OTDR trace revealed that the non-reflective event occurred at the grating perturbation position. Consequently, the wavelength-dependent-resonance was caused by the non-contra-directional coupling of light from the fibre core to fibre cladding and its attenuation was a cubic function of an applied force. The proposed approach, therefore, shows a great potential to be used for the sensing applications in the vulnerable environments.

此处介绍了由具有多个光栅周期的 3D 打印机形成的长周期光纤光栅的研究。将所提出的光栅装置压在光纤上，以观察作为不同凹槽周期函数的谐振波长。结果表明，具有 700 和 800 nm 光栅周期的器件引入了 1,487 和 1,570 nm 的谐振波长，折射率变化为 2.121 × 10 ^-3和 1.963 × 10 ^-3， 分别。一旦知道谐振波长，就使用光时域反射计 (OTDR) 来确定光行为、事件位置和损耗。OTDR 轨迹显示非反射事件发生在光栅扰动位置。因此，波长相关共振是由光从纤芯到光纤包层的非反向耦合引起的，其衰减是所施加力的三次函数。因此，所提出的方法显示出用于脆弱环境中的传感应用的巨大潜力。