Ultraprecision grinding of optical materials for high-power lasers
Ultraprecision grinding of optical materials for high-power lasers
复制标题
高功率激光器光学材料的超精密磨削
DOI：
10.1117/12.307042
复制
发表时间：
1998
期刊：
影响因子：
1.9
通讯作者：
S. Nakai
中科院分区：
文献类型：
--
作者：
Y. Namba;K. Yoshida;H. Yoshida;S. Nakai
在光学领域中，磨削被认为是一种粗加工过程，抛光过程必须遵循磨削过程才能获得光学质量的表面。研制了一种超精密平面磨床，采用静压油轴承和热膨胀极低的微晶玻璃主轴，无需任何抛光工艺即可获得光滑的光学表面。各种光学材料，如NbF1、BK7、LHG08熔融二氧化硅、KTP、KDP和CLBO，在经验上确定了实现延性模式磨削所需的条件后，被磨成光学表面。采用超精密磨削工艺在BK7玻璃表面获得了RMS小于0.1 nm的超光滑表面。在波长为1.053微米、脉宽为1 ns的LHG-8激光玻璃上测量了激光损伤阈值。在极化方向平行于磨削方向的磨削表面上，测得损伤阈值为22.2J/cm2。这一数字高于光学抛光获得的数字。在波长为1.053微米、脉宽为30 ns的LHG-8玻璃磨片表面上也获得了293J/cm~2的损伤阈值。
Grinding is considered to be a rough machining process in the field of optics; a polishing process must follow the grinding process for getting optical-quality surfaces. An ultraprecision surface grinder with hydrostatic oil bearings and a glass-ceramic spindle of extremely low thermal expansion was developed to get smooth optical surfaces without any polishing process. Various optical materials such as NbF1, BK7, LHG08 fused silica, KTP, KDP and CLBO were ground into optical surfaces after empirically determining the conditions required to attain ductile-mode grinding. An extremely smooth surface less than 0.1 nm rms was obtained on BK7 glass by the ultraprecision grinding process. The laser-induced damage threshold was measured on variously finished LHG-8 laser glass at (lambda) equals 1.053 micrometers and 1-ns pulse width. The damage threshold was measured at 22.2 J/cm2 on a ground surface with the polarization parallel to the grinding direction. This number is higher than that obtained by optical polish. The damage threshold of 293 J/cm2 was also obtained on a ground LHG-8 glass surface at (lambda) equals 1.053 micrometers and 30-ns pulse width.