A micro-Gai absolute gravimeter based on high-precision and high-stability heterodyne interferometer is presented. The distance measuring technology of the gravimeter is studied in detail. The experimental results of ...A micro-Gai absolute gravimeter based on high-precision and high-stability heterodyne interferometer is presented. The distance measuring technology of the gravimeter is studied in detail. The experimental results of distance measuring for a free-falling motion show that the high-precision heterodyne interferometer described in this paper can meet the demand of a micro-Gal absolute gravimeter with relative uncertainty of 6.4 × 10^-9. Moreover, the heterodyne interferometer is more stable than the Mach-Zehnder interferometer （MZI） which is widely used in present absolute gravimeters.展开更多
We investigate femtosecond laser direct writing （FLDW） in the fabrication of magneto-optical （MO） microstructures. The experimental results show that FDLW can introduce positive refractive index change in the MO m...We investigate femtosecond laser direct writing （FLDW） in the fabrication of magneto-optical （MO） microstructures. The experimental results show that FDLW can introduce positive refractive index change in the MO materials. With the increase of the writing intensity of femtosecond laser pulses, refractive index change increases, whereas Verdet constant of the damaged area decreases nonlinearly. With suitable writing intensity, we obtain a single-mode waveguide in which Verdet constant is 80% of the bulk MO glass.展开更多
In conventional pulsed laser deposition （PLD） technique, plume deflection and composition distribution change with the laser incident direction and pulse energy, then causing uneven film thickness and composition di...In conventional pulsed laser deposition （PLD） technique, plume deflection and composition distribution change with the laser incident direction and pulse energy, then causing uneven film thickness and composition distribution for a multicomponent film and eventually leading to low device quality and low rate of final products. We present a novel method based on PLD for depositing large CIGS films with uni- form thickness and stoichiometry. By oscillating a mirror placed coaxially with the incident laser beam, the laser＇s focus is scanned across the rotating target surface. This arrangement maintains a constant re- flectance and optical distance, ensuring that a consistent energy density is delivered to the target surface by each laser pulse. Scanning the laser spot across the target suppresses the formation of micro-columns, and thus the plume deflection effect that reduces film uniformity in conventional PLD technique is eliminated. This coaxial scanning PLD method is used to deposit a CIGS film, 500 nm thick, with thickness uniformity exceeding ±3% within a 5 cm diameter, and exhibiting a highly homogeneous elemental distribution.展开更多
Certainly, when Richard Feynman outlined his vision of the prospects of nanotechnology in 1959 with his legendary speech“There is Plenty of Room at the Bottom”, no one would have thought of where we are today, only ...Certainly, when Richard Feynman outlined his vision of the prospects of nanotechnology in 1959 with his legendary speech“There is Plenty of Room at the Bottom”, no one would have thought of where we are today, only 60 years later. In the 21 st century, nanoparticles(NPs) are found almost everywhere and are pervasive in science, technology, and our everyday lives.展开更多
文摘A micro-Gai absolute gravimeter based on high-precision and high-stability heterodyne interferometer is presented. The distance measuring technology of the gravimeter is studied in detail. The experimental results of distance measuring for a free-falling motion show that the high-precision heterodyne interferometer described in this paper can meet the demand of a micro-Gal absolute gravimeter with relative uncertainty of 6.4 × 10^-9. Moreover, the heterodyne interferometer is more stable than the Mach-Zehnder interferometer （MZI） which is widely used in present absolute gravimeters.
基金supported by the National Natural Science Foundation of China (Nos. 60978020 and61178004)the National "973" Program of China (Nos. 2011CB922003 and 2007CB307003)
文摘We investigate femtosecond laser direct writing （FLDW） in the fabrication of magneto-optical （MO） microstructures. The experimental results show that FDLW can introduce positive refractive index change in the MO materials. With the increase of the writing intensity of femtosecond laser pulses, refractive index change increases, whereas Verdet constant of the damaged area decreases nonlinearly. With suitable writing intensity, we obtain a single-mode waveguide in which Verdet constant is 80% of the bulk MO glass.
基金supported by the Shenzhen Basic Research Project of Science and Technology under Grant No.JCYJ20120613112423982
文摘In conventional pulsed laser deposition （PLD） technique, plume deflection and composition distribution change with the laser incident direction and pulse energy, then causing uneven film thickness and composition distribution for a multicomponent film and eventually leading to low device quality and low rate of final products. We present a novel method based on PLD for depositing large CIGS films with uni- form thickness and stoichiometry. By oscillating a mirror placed coaxially with the incident laser beam, the laser＇s focus is scanned across the rotating target surface. This arrangement maintains a constant re- flectance and optical distance, ensuring that a consistent energy density is delivered to the target surface by each laser pulse. Scanning the laser spot across the target suppresses the formation of micro-columns, and thus the plume deflection effect that reduces film uniformity in conventional PLD technique is eliminated. This coaxial scanning PLD method is used to deposit a CIGS film, 500 nm thick, with thickness uniformity exceeding ±3% within a 5 cm diameter, and exhibiting a highly homogeneous elemental distribution.
文摘Certainly, when Richard Feynman outlined his vision of the prospects of nanotechnology in 1959 with his legendary speech“There is Plenty of Room at the Bottom”, no one would have thought of where we are today, only 60 years later. In the 21 st century, nanoparticles(NPs) are found almost everywhere and are pervasive in science, technology, and our everyday lives.
