Hessler Steffen, Knopf Stefan, Rommel Mathias, Girschikofsky Maiko, Schmauss Bernhard, Hellmann Ralf
Opt Lett. 2020 Oct 1;45(19):5510-5513. doi: 10.1364/OL.402768.
In this Letter, we report on significantly improved surrounding RI sensitivity of epoxy polymer waveguide Bragg grating sensors. Uniform Bragg gratings were generated inside flat rectangular epoxy waveguides near the cutoff regime using standard phase mask excimer laser writing. Thickness controlled nanolayers of high-index titanium dioxide were deposited homogeneously on the waveguide sensor's surface area by repeated reactive sputter processing. Maximum Bragg wavelength shifts as high as 74.22 nm, as well as maximum sensitivities around 523 nm/RI unit corresponding to a minimum RI resolution of 1.9⋅10, could be obtained by employing a ∼75 thick titanium dioxide coating.
在本信函中，我们报告了环氧聚合物波导布拉格光栅传感器的周围折射率（RI）灵敏度得到显著提高。使用标准相位掩膜准分子激光写入技术，在接近截止状态的扁平矩形环氧波导内部生成了均匀的布拉格光栅。通过重复反应溅射工艺，在波导传感器的表面积上均匀沉积了厚度可控的高折射率二氧化钛纳米层。通过采用约75纳米厚的二氧化钛涂层，可获得高达74.22纳米的最大布拉格波长偏移，以及对应于最低RI分辨率为1.9×10⁻⁵的约523纳米/RI单位的最大灵敏度。
