A novel asymmetric optothermal microactuator was developed. A microactuator of 750μm length was machined by an excimer laser micmmachining system using single layer material. It had an asymmetric structure consisting...A novel asymmetric optothermal microactuator was developed. A microactuator of 750μm length was machined by an excimer laser micmmachining system using single layer material. It had an asymmetric structure consisting of two thin expansion arms with different widths. A laser diode （660nm） was employed as the external power source to activate the microactuator. We introduced a charge coupled device （CCD）-combined optical microscope and a computer system to observe and capture the microactuator＇ s deflection and vibration. Experiments have been carried out to check the feasibility of deflection, and the data of deflection have been measured under different laser power as well as under different pulse frequency. The results show that the actuator can practically generate an obvious lateral deflection or vibration, the maximum could be larger than 20μm. Moreover, the deflection status of the microactuator could be controlled wirelessly or remotely by changing the laser power and its pulse frequency.展开更多
Orthorhombic HoMnO3(HMO) thin films were grown epitaxially on LaAlO3(001) substrates by using pulsed laser deposition technique. The films showed perfect orthorhombic crystallization and were well-aligned with the sub...Orthorhombic HoMnO3(HMO) thin films were grown epitaxially on LaAlO3(001) substrates by using pulsed laser deposition technique. The films showed perfect orthorhombic crystallization and were well-aligned with the substrates. The in-plane dielectric constant and loss of HMO films were measured as functions of temperature(80–300 K) and frequency(120 Hz–100 kHz) by using coplanar interdigital electrodes. Two thermally activated dielectric relaxations were found, and the respective peaks shifted to higher temperatures as the measuring frequency increased. The in-plane dielectric properties of epitaxial orthorhombic HMO films were considered as universal dielectric response behavior, and the dipolar effects and the hopping conductivity induced by the charge carriers were used to explain the results.展开更多
In this paper, a self-mode-locked Nd:YVO_4 picosecond vortex laser is demonstrated, which can operate on the different Laguerre-Gaussian(LG) modes at 1 064 nm. A π/2 mode converter is utilized to realize the picoseco...In this paper, a self-mode-locked Nd:YVO_4 picosecond vortex laser is demonstrated, which can operate on the different Laguerre-Gaussian(LG) modes at 1 064 nm. A π/2 mode converter is utilized to realize the picosecond vortex laser with LG mode transformed from the high-order Hermite-Gaussian(HG) mode. For the proposed laser, the mode-locked pulse repetition rate is 1.81 GHz. The average output powers of LG_(12) mode and LG_(02) mode are 1.241 W and 1.27 W, respectively, and their slope efficiencies are 23.2% and 24%, respectively.展开更多
基金Supported by the National High Technology Research and Development Program of China (No. 2006AA04Z237)the National Natural Science Foundation of China (No. 50775205)
文摘A novel asymmetric optothermal microactuator was developed. A microactuator of 750μm length was machined by an excimer laser micmmachining system using single layer material. It had an asymmetric structure consisting of two thin expansion arms with different widths. A laser diode （660nm） was employed as the external power source to activate the microactuator. We introduced a charge coupled device （CCD）-combined optical microscope and a computer system to observe and capture the microactuator＇ s deflection and vibration. Experiments have been carried out to check the feasibility of deflection, and the data of deflection have been measured under different laser power as well as under different pulse frequency. The results show that the actuator can practically generate an obvious lateral deflection or vibration, the maximum could be larger than 20μm. Moreover, the deflection status of the microactuator could be controlled wirelessly or remotely by changing the laser power and its pulse frequency.
基金supported by Shandong Province Natural Science Foundation of China(Grant No.ZR2011AM014)
文摘Orthorhombic HoMnO3(HMO) thin films were grown epitaxially on LaAlO3(001) substrates by using pulsed laser deposition technique. The films showed perfect orthorhombic crystallization and were well-aligned with the substrates. The in-plane dielectric constant and loss of HMO films were measured as functions of temperature(80–300 K) and frequency(120 Hz–100 kHz) by using coplanar interdigital electrodes. Two thermally activated dielectric relaxations were found, and the respective peaks shifted to higher temperatures as the measuring frequency increased. The in-plane dielectric properties of epitaxial orthorhombic HMO films were considered as universal dielectric response behavior, and the dipolar effects and the hopping conductivity induced by the charge carriers were used to explain the results.
基金supported by the National Natural Science Foundation of China(No.61108021)the Fundamental Research Funds for the Central Universities(Nos.2013JBM091 and S16JB00010)
文摘In this paper, a self-mode-locked Nd:YVO_4 picosecond vortex laser is demonstrated, which can operate on the different Laguerre-Gaussian(LG) modes at 1 064 nm. A π/2 mode converter is utilized to realize the picosecond vortex laser with LG mode transformed from the high-order Hermite-Gaussian(HG) mode. For the proposed laser, the mode-locked pulse repetition rate is 1.81 GHz. The average output powers of LG_(12) mode and LG_(02) mode are 1.241 W and 1.27 W, respectively, and their slope efficiencies are 23.2% and 24%, respectively.
