Chiamenti Ismael, Elsmann Tino, Reupert Aaron, Kara Oguzhan, Becker Martin, Wondraczek Lothar, Chernysheva Maria
Opt Lett. 2021 Apr 15;46(8):1816-1819. doi: 10.1364/OL.420264.
Fiber gratings are among key components in fiber-based photonics systems and, particularly, laser cavities. In the latter, they can play multiple roles, such as those of mirrors, polarizers, filters, or dispersion compensators. In this Letter, we present the inscription of highly reflective first-order fiber Bragg gratings (FBGs) in soft indium fluoride-based () fibers using a two-beam phase-mask interferometer and a femtosecond laser. We demonstrate an enhanced response of -based fiber to a visible (400 nm) inscription wavelength compared to ultraviolet irradiation at 266 nm. In this way, FBGs with a reflectivity >99.7 were inscribed at around 1.9 µm with the bandwidth of 2.68 nm. After thermal annealing at 393K, the Bragg wavelength demonstrates stable thermal shift of 20 pm/K in the temperature range 293-373K. These observations suggest a potential extension of fiber-based laser components to an operational range of up to 5 µm.
光纤光栅是基于光纤的光子学系统中的关键组件之一，尤其是在激光腔中。在激光腔中，它们可以发挥多种作用，例如充当镜子、偏振器、滤波器或色散补偿器。在本信函中，我们展示了使用双光束相位掩模干涉仪和飞秒激光在基于氟化铟（）的软光纤中写入高反射率一阶光纤布拉格光栅（FBG）。与266nm的紫外线照射相比，我们证明了基于的光纤对可见（400nm）写入波长具有增强的响应。通过这种方式，在1.9μm左右写入了反射率>99.7且带宽为2.68nm的FBG。在393K进行热退火后，布拉格波长在293 - 373K的温度范围内表现出20pm/K的稳定热漂移。这些观察结果表明基于光纤的激光组件有可能扩展到高达5μm的工作范围。
