聚酰亚胺/银红外空芯波导的研制

Fabrication of Polyimide-coated Silver Infrared Hollow Waveguides for Medical CO_2 Laser Transmission

设计并制备了一种新型的聚酰亚胺／银空芯波导，其实验工作的重点是聚酰亚胺薄膜的制备。采用改进的液相工艺，我们在石英毛细管内制备了表面光滑均一的银膜，然后，再将折射率非常接近理论最佳值（ ）的聚酞亚胺膜涂覆在银管内。通过控制聚酰亚胺膜的厚度，可以对银空芯波导在特定的波长处有降低损耗的作用。除了 ６～９μｍ处的基团吸收外，这种空芯波导在整个中红外区域的损耗都很小。在 １０．６μｍ波长处的损耗为０．４ ｄＢ／ｍ，传输能量为 １０ Ｗ时，可以稳定传输 ２０ ｍｉｎ以上，基本上可以满足 ＣＯ２激光在医疗中的应用。

The design and fabrication of a new style polyimide- coated silver hollow glass waveguide for medical CO2 laser transmission are described. The emphasis of the experiment is the fabrication of polyimide layer. Based on improved liquid- phase techniques, we fabricate smooth and uniform silver film inside a fused silica capillary. Then, the polyimide layer whose refractive index is very close to the optimum refractive index of a coated dielectric () is coated inside the silver tube. By controlling the thickness of coated polyimide, the loss of the hollow waveguide can be reduced at different wavelength. The losses of the fabricated hollow glass waveguides are very small over the wide mid-infrared wavelength region except for the wavelengths of large absorption of polyimide, 6~9 μm. This new style hollow waveguides can transmit 10 W CO2 laser energy stably for more than 20 minutes with loss less than 0.4 dB/m, which is suitable for the application of medical C02 laser.