The neutral surface of a concave thin mirror is too close to the mirror surface,which makes it difficult to effectively mount the flexible structure and increases the mirror surface shape error.To address this problem...The neutral surface of a concave thin mirror is too close to the mirror surface,which makes it difficult to effectively mount the flexible structure and increases the mirror surface shape error.To address this problem,we design a flexible support structure including connectors,a support plate,and flexible structures,and construct an equivalent mirror by installing connectors and a support plate on the back of the mirror.While ensuring that the neutral surface of the equivalent mirror is moved away from the mirror surface,we optimize the support structure so that the rotary center of the flexible structure is located on the neutral surface of the equivalent mirror,avoiding the tilting moment.Following design and modeling of the structure,we analyze the static and dynamic characteristics using a finite element simulation,finding a root-mean-square(RMS)value for the surface shape error of 9.28 nm under the coupled effects of 1g gravity load,4℃ temperature rise,and 0.005 mm unevenness assembly error,with a fundamental frequency of 170.75 Hz,which all meet the design requirements.Finally,we carry out a surface shape error test of the mirror assembly,confirming it to meet the design index requirement of the mirror assembly.Simulation and test results verify the reliability and effectiveness of our proposed support structure.展开更多
This paper deals with vacuum UV optical coatings for micro mirror applications. High reflecting low-stress optical coatings have been developed for the next-generation of micro mechanical mirrors. The optimized metal ...This paper deals with vacuum UV optical coatings for micro mirror applications. High reflecting low-stress optical coatings have been developed for the next-generation of micro mechanical mirrors. The optimized metal systems are applicable in the VUV spectral region and can be integrated in the technology of MOEMS, such as spatial light modulators (SLM) and micro scanning mirrors.展开更多
Pumped by a 940 nm fiber-coupled diode laser, a passively mode-locked Yb：YAG thin disk oscillator was demonstrated with a semiconductor saturable absorber mirror（SESAM）. 12.1 W mode-locked pulses were obtained with...Pumped by a 940 nm fiber-coupled diode laser, a passively mode-locked Yb：YAG thin disk oscillator was demonstrated with a semiconductor saturable absorber mirror（SESAM）. 12.1 W mode-locked pulses were obtained with pulse duration of 698 fs at the repetition rate of 57.43 MHz. Measurement showed that the beam quality was close to the diffraction limit.展开更多
拓扑优化方法和陶瓷增材制造技术的结合为开发轻质高性能的大口径碳化硅反射镜提供了一种有效的方法.以反射镜背部支撑结构构型为设计对象,以最大刚度为目标、反射镜质量为约束,采用板筋布局与高度协同优化(Heaviside-function based di...拓扑优化方法和陶瓷增材制造技术的结合为开发轻质高性能的大口径碳化硅反射镜提供了一种有效的方法.以反射镜背部支撑结构构型为设计对象,以最大刚度为目标、反射镜质量为约束,采用板筋布局与高度协同优化(Heaviside-function based directional growth topology parameterization,H-DGTP)方法建立了具备陶瓷可制造性约束的轻薄化设计方法.该方法针对典型大口径碳化硅空间反射镜的实际需求,设计了具有陶瓷可制造性的反射镜镜体轻薄化构型;进一步采用尺寸优化方法对拓扑优化的反射镜镜体结构进行了重构和精细化设计;利用DLP陶瓷增材制造技术成功制备了反射镜陶瓷样件,验证了所设计的反射镜镜体轻薄化构型满足陶瓷增材制造的可制造性要求.对轻薄化设计方案进行了数值仿真,反射镜法向轴沿x,y和z向自重载荷的均方根RMS值分别为3.27,3.27和7.55 nm,反射镜面密度为13.21 kg/m2.分析结果表明,优化后的大口径碳化硅空间反射镜在满足面形精度设计要求的同时大幅减轻了反射镜重量,验证了该方法在增材制造碳化硅反射镜轻薄化设计方面的有效性.展开更多
基金supported by the National Natural Science Foundation of China(12473085).
文摘The neutral surface of a concave thin mirror is too close to the mirror surface,which makes it difficult to effectively mount the flexible structure and increases the mirror surface shape error.To address this problem,we design a flexible support structure including connectors,a support plate,and flexible structures,and construct an equivalent mirror by installing connectors and a support plate on the back of the mirror.While ensuring that the neutral surface of the equivalent mirror is moved away from the mirror surface,we optimize the support structure so that the rotary center of the flexible structure is located on the neutral surface of the equivalent mirror,avoiding the tilting moment.Following design and modeling of the structure,we analyze the static and dynamic characteristics using a finite element simulation,finding a root-mean-square(RMS)value for the surface shape error of 9.28 nm under the coupled effects of 1g gravity load,4℃ temperature rise,and 0.005 mm unevenness assembly error,with a fundamental frequency of 170.75 Hz,which all meet the design requirements.Finally,we carry out a surface shape error test of the mirror assembly,confirming it to meet the design index requirement of the mirror assembly.Simulation and test results verify the reliability and effectiveness of our proposed support structure.
文摘This paper deals with vacuum UV optical coatings for micro mirror applications. High reflecting low-stress optical coatings have been developed for the next-generation of micro mechanical mirrors. The optimized metal systems are applicable in the VUV spectral region and can be integrated in the technology of MOEMS, such as spatial light modulators (SLM) and micro scanning mirrors.
基金Project supported by the National Key Basic Research Program of China(Grant No.2013CB922402)the National Major Instrument Program of China(Grant No.2012YQ120047)the National Natural Science Foundation of China(Grant No.61210017)
文摘Pumped by a 940 nm fiber-coupled diode laser, a passively mode-locked Yb：YAG thin disk oscillator was demonstrated with a semiconductor saturable absorber mirror（SESAM）. 12.1 W mode-locked pulses were obtained with pulse duration of 698 fs at the repetition rate of 57.43 MHz. Measurement showed that the beam quality was close to the diffraction limit.
