A low-cost and high-efficiency method for fabricating variable line-space gratings is reported. Specifically, oxygen plasma was used to process the stretched wedge polydimethylsiloxane substrate. After slowly releasing the stress, a gradient grating with a continuous change in line spacing was formed via self-assembly. The period of the self-assembly grating was 2.96 to 3.25 μm, from thick to thin, when the sample was stretched transversely. In longitudinal stretching, the period was 3.71 to 5.20 μm from thick to thin. The period variation range of the gratings obtained by the two types of stretching was 15% and 45%, respectively. Diffraction tests of the two samples showed that the diffraction spots were evident. The diffraction angles varied in the range of 11.31 deg to 12.41 deg and 7.12 deg to 9.93 deg. The gratings prepared using this method can compensate for the shortcomings of the traditional process and have a wide range of application prospects.

中文翻译：

---

用于制造可变线距光栅的楔形 PDMS 衬底的自组装

报道了一种低成本、高效率的可变线距光栅制造方法。具体而言，氧等离子体用于处理拉伸​​的楔形聚二甲基硅氧烷基材。在缓慢释放应力后，通过自组装形成线间距连续变化的梯度光栅。当样品横向拉伸时，自组装光栅的周期为2.96～3.25 μm，由厚到薄。纵向拉伸时，从厚到薄的周期为3.71～5.20μm。两种拉伸方式得到的光栅周期变化范围分别为15%和45%。两个样品的衍射测试表明衍射斑点明显。衍射角在11.31度到12.41度和7.12度到9.93度的范围内变化。