目的 通过等离子体喷射制备不同质量CVD金刚石膜并研究其光学及热学性能，试图建立起两种性能的相互关联性。方法 采用光学显微镜、X射线衍射仪、激光拉曼光谱仪、傅里叶变换红外光谱仪和NETZSCH LFA467导热仪检测CVD金刚石膜的表面形貌、晶粒尺寸、结构特征和红外光学性能、热学性能。结果 金刚石自支撑膜的光学性能及热学性能密切相关，本质上取决于氮和非金刚石相的含量。当金刚石膜内氮质量分数大于0.009%时，氮含量是决定光学性能及热学性能的关键因素，且两者随着氮含量的增加呈线性衰减趋势；当氮质量分数小于0.009%时，氮的影响相对较小，晶粒尺寸成为影响金刚石膜热导率的主要因素，此时晶粒尺寸对金刚石膜红外透过率影响较小。此外，金刚石中C—H吸收与非金刚石相含量正相关，其对金刚石光学及热学性能影响规律与N杂质基本一致。结论 CVD金刚石膜的热导率和红外透过率随着金刚石膜的氮杂质含量和C—H吸收系数的降低而逐渐提高，当达到一定程度，红外透过率相对热导率的增加表现出滞后性。

The work aims to establish interconnectedness between optical property and thermal property by studying the two properties of CVD diamond films of different weight prepared by DC arc plasma jet. Surface morphology, grain size, structure feature, infrared optical property and thermal property of CVD diamond films were examined with optical microscope, X-ray diffractometer, Raman spectrometer, Fourier-transform infrared spectroscope and NETZSCH LFA467. The optical property was closely related to thermal property of free-standing diamond films. The two properties mainly depended on content of N and non-diamond phase. As N content of the films exceeded 0.009%, N content was the key factor affecting both properties, and both exhibited linear attenuation trend. As N content was below 0.009%, N content had slight effects, grain size became the main factor affecting thermal conductivity of the diamond films, and grain size had slight effects on IR transmittance of the diamond films. In addition, C—H absorption was positively correlated with content of non-diamond phase, its law of influence on thermal conductivity and IR transmittance of the diamond films was basically consistent with that of N impurity. Thermal conductivity and IR transmittance of diamond films gradually increase with the decrease of N impurity content and C—H absorption coefficient, and the thermal conductivity is more sensitive than thermal transmittance when the N impurity content and C—H absorption coefficient decrease to certain level.