非球面碳化硅反射镜的加工与检测

为了获得高精度非球面碳化硅(SiC)反射镜,对非球面碳化硅反射镜基底以及改性后碳化硅反射镜表面的加工与检测技术进行了研究。介绍了非球面计算机控制光学表面成型（CCOS）技术及FSGJ-2非球面数控加工设备。采用轮廓检测法和零位补偿干涉检测法分别对碳化硅反射镜研磨和抛光阶段的面形精度进行了检测,并采用零位补偿干涉检测法及表面粗糙度测量仪对最终加工完毕的碳化硅反射镜的面形精度和表面粗糙度进行检测。测量结果表明：各项技术指标均满足设计要求,其中非球面碳化硅(SiC)反射镜实际使用口径内的面形精度（RMS值）为0.016λ(λ=0.6328μm）,表面粗糙度（RMS值）为0.85nm。     

Manufacturing and testing of a cubic SiC surface

The free surface and unrotational-symmetric surface optical elements have been applied more and more widely along with the development of optical design technology, although they are still difficult for manufacturing. In this letter, a SiC unrotational-symmetric aspheric surface whose surface equation is z =- 3λ（x^a ＋ y^3） （λ= 0.6328μm） has been introduced. The tilt abstraction is adopted to minimize the material removal. The surface figures are peak-to-valley （PV） value of 0.327A and root-mean-square （RMS） value of 0.023A. A non-null testing method based on digital mask is proposed to test this surface. The accuracy of the method is testified by the experiment of standard sphere testing.