金刚石自支撑膜的高温红外透过性能

由于金刚石具有低吸收和优异的力学与导热性能使其成为长波(8~12μm)红外光学窗口材料的重要选择。对于许多极端条件的应用,化学气相沉积(CVD)金刚石自支撑膜的高温光学性质至关重要。应用直流电弧等离子喷射法制备光学级金刚石自支撑膜进行变化温度的红外光学透过性能研究,采用光学显微镜、X射线衍射、激光拉曼和傅里叶变换红外-拉曼光谱仪检测CVD金刚石膜的表面形貌、结构特征和红外光学性能。结果表明:在27℃时金刚石膜长波红外8~12μm之间的平均透过率达到65.95%,在500℃时8~12μm处的平均透过率为52.5%。透过率下降可分为3个阶段。对应于透过率随温度的下降,金刚石膜的吸收系数随温度的升高而增加。金刚石自支撑膜表面状态的变化,对金刚石膜光学性能的影响显著大于内部结构的影响。

High-temperature Infrared Transmission of Free-standing Diamond Films

The combination of low absorption and extreme mechanical and thermal properties make dia-mond a compelling choice for some more extreme far infrared (8-12μm) window applications .The op-tical properties of CVD diamond at elevated temperatures are critical to many of these extreme applica-tions .The infrared transmission of free-standing diamond films prepared by DC arc plasma jet were studied at temperature varied conditions .The surface morphology ,structure feature and infrared opti-cal properties of diamond films were tested by optical microscope ,X-ray diffraction ,laser Raman and Fourier-transform infrared spectroscopy .The results show that the average transmittance for 8-12μm is decreased from 65 .95% at 27℃ to 52 .5% at 500℃ ,and the transmittance drop is in three stages . Corresponding to the drop of transmittance with the temperature ,diamond film absorption coefficient increa-ses with the rise of temperature .The influence of the change of surface state of diamond films on the optical properties of diamond films is significantly greater than the influence on the internal structure .