RESUMO
To improve the phase-shifting accuracy, this paper presents a novel integrated framework for design, control and experimental validation of the piezoelectric actuated phase shifter with a trade-off between accuracy and cost. The piezoelectric actuators with built-in sensors are adopted to drive the double parallel four-bar linkage flexure hinge-based mechanisms. Three mechanisms form the tripod structure of the assembled phase shifter. Then, a semi-closed loop controller with inner feedback and outer feedforward loops via the external laser interferometer is developed for accurate positioning of the phase shifter. Finally, experiments related with travel range, step response, linearity and repeatability are carried out. The linearity error is 0.21% and the repeatability error of 10 µ m displacement is 3 nm. The results clearly demonstrate the good performance of the developed phase shifter and the feasibility of the proposed integrated framework.
RESUMO
The spectral responsivity is one of the important parameters of detector. With the development of ultraviolet detect technique accurate measure for the spectral responsivity of ultraviolet detector becomes more and more important. A measure principle which is based on the direct comparison measuring method for relative spectral response measurement of the ultraviolet ICCD is introduced. Based on the scientific-grade spectrometer with ultraviolet responsivity, a measurement facility was built. The relative spectral responsivity curve of the ultraviolet ICCD was obtained. The curve indicates that the spectral-response of UV-ICCD is from 220 to 300 nm and the peak response is near 270 nm, which indicates that the UV-ICCD is solar blind. The analysis of the uncertainty shows that the most largest uncertainty of measurement for relative spectral responsivity of the UV-ICCD is 7.79% and meets the requirement.
