In petawatt laser system, the gratings.used to compose pulse compressor are very large in size which can be only acquired currently by arraying small aperture gratings to form a large one instead, an approach referred...In petawatt laser system, the gratings.used to compose pulse compressor are very large in size which can be only acquired currently by arraying small aperture gratings to form a large one instead, an approach referred to as grating tiling. Theory and experiments have demonstrated that the coherent addition of multiple small gratings to form a larger grating is viable, the key technology of which is to control the relative position and orientation of each grating with high precision. According to the turin factors that affect the performance of the grating tiling, a 5-DOF ultraprecision stage is developed for the grating tiling experiment. The mechanism is formed by serial structures. The motion of the mechanism is guided by flexure hinges and driven by piezoelectric actuators and the movement resolution of which can achieve nanometer level. To keep the stability of the mechanism, capacitive position sensors with nanometer accuracy are fixed on it to provide feedback signlas with which to realize closed-loop control, thus the positioning.precision of the mechanism is within several nanometers range through voltage control and digital PID algorithm. Results of experiments indicate that the performance of the mechanism can meet the requirement of precision for grating tiling.展开更多
The first issue of Chinese Forestry Science and Technology, which is the only academic Journal in English issued by Chinese Academy of Forestry (CAF), is now formally published and presented to our readers. Chinese Ac...The first issue of Chinese Forestry Science and Technology, which is the only academic Journal in English issued by Chinese Academy of Forestry (CAF), is now formally published and presented to our readers. Chinese Academy of Forestry is China's tiptop research organization in forestry, and was founded in 1912. Now it consists of 19 research institutes and centres that are distributed in major provinces and autonomous regions in China, and has a total of展开更多
基金This project is supported by Nanotechnology Promotion Center, Science and Technology Commission of Shanghai Municipality, China (No. 0359nm004)
文摘In petawatt laser system, the gratings.used to compose pulse compressor are very large in size which can be only acquired currently by arraying small aperture gratings to form a large one instead, an approach referred to as grating tiling. Theory and experiments have demonstrated that the coherent addition of multiple small gratings to form a larger grating is viable, the key technology of which is to control the relative position and orientation of each grating with high precision. According to the turin factors that affect the performance of the grating tiling, a 5-DOF ultraprecision stage is developed for the grating tiling experiment. The mechanism is formed by serial structures. The motion of the mechanism is guided by flexure hinges and driven by piezoelectric actuators and the movement resolution of which can achieve nanometer level. To keep the stability of the mechanism, capacitive position sensors with nanometer accuracy are fixed on it to provide feedback signlas with which to realize closed-loop control, thus the positioning.precision of the mechanism is within several nanometers range through voltage control and digital PID algorithm. Results of experiments indicate that the performance of the mechanism can meet the requirement of precision for grating tiling.
文摘The first issue of Chinese Forestry Science and Technology, which is the only academic Journal in English issued by Chinese Academy of Forestry (CAF), is now formally published and presented to our readers. Chinese Academy of Forestry is China's tiptop research organization in forestry, and was founded in 1912. Now it consists of 19 research institutes and centres that are distributed in major provinces and autonomous regions in China, and has a total of
