用于应力测量的可调谐光栅

为了更简单地制备出可用于应力测量的光栅褶皱结构,采用基于刚性薄膜/柔性衬底的自组装工艺制备了可调谐光栅。首先在聚乙烯对苯二酸脂(PET)薄膜上旋涂一层聚二甲基硅氧烷(PDMS)薄膜,将双层薄膜弯曲并用氧气等离子体处理,在其表面生成一层刚性氧化层,借助柔性PET对刚性层施加均匀应力,当应力超过临界值时,在PDMS基底上自组装形成光栅褶皱结构。然后根据光栅分光原理,将这种可调谐的光栅结构应用于应力测试。实验结果表明:当光栅的曲率半径为1.4mm时,制备的可调谐光栅褶皱在0%~10%的应变范围得到的波长变化为452~507nm;当光栅的曲率半径为5.6mm时,制备的可调谐光栅褶皱在0%~15%的应变范围得到的波长变化为498~572nm。本文提出的可调谐光栅制备方法是一种成本低、工艺简单、可批量化生产的工艺方法,也是一种制备变间距光栅的潜在方法,未来有望应用于光谱仪、光通讯等领域。

Tunable grating for stress measurement

In order to prepare well-ordered micron and submicron grating fold structures for simpler stress measurement, tunable grating was prepared by a self-assembly process based on a rigid film/flexible substrate. A polydimethylsiloxane (PDMS) substrate was prepared on polyethylene (PET) by the spin-coating method; then, the curved PDMS-PET substrates were processed in oxygen plasma. After appropriate surface treatment time in plasma, the curved substrates were flattened, and well-ordered wrinkling shape gratings were obtained due to mechanical buckling instability. Then, according to the principle of grating spectral, proper stress measurement can be achieved when a tunable grating structure was used for stress testing. The experimental results show that:When the curvature radius of the grating is 1.4 mm, the wavelength of the tunable grating folds prepared from 0 to 10% of the strain ranges from 452 to 507 nm;when the radius of curvature of the grating is 5.6 mm, the wavelength of the tunable grating folds prepared from 0 to 15% of the strain ranges from 498 to 572 nm. The proposed method of tunable grating fabrication is a low cost, simple process and enables mass production technology. It is a potential method to prepare variable spacing grating. Its expected applications in future include spectrometry, optical communication, and other related fields.