A comparative study on the performance of gas atomized(GA)and rotating-disk atomized(RDA)aluminum alloy powders produced on industrial scale for laser directed energy deposition(L-DED)process was carried out.The powde...A comparative study on the performance of gas atomized(GA)and rotating-disk atomized(RDA)aluminum alloy powders produced on industrial scale for laser directed energy deposition(L-DED)process was carried out.The powder characteristics,the printing process window,and the quality,microstructure,and mechanical properties of printed parts were taken into account for comparison and discussion.The results demonstrate that the RDA powder is superior to the GA powder in terms of sphericity,surface quality,internal defects,flowability,and apparent density,together with a larger printing process window during the L-DED parts fabrication.Besides,the resultant parts from the RDA powder have higher dimensional accuracy,lower internal defects,more uniform and finer microstructure,and more favorable mechanical properties than those from the GA powder.展开更多
We present an experimental demonstration of the rotation measurement using a compact cold atom gyroscope. Atom interference fringes are observed in the stationary frame and the rotating frame, respectively. The phase ...We present an experimental demonstration of the rotation measurement using a compact cold atom gyroscope. Atom interference fringes are observed in the stationary frame and the rotating frame, respectively. The phase shift and contrast of the interference fringe are experimentally investigated. The results show that the contrast of the interference fringe is well held when the platform is rotated, and the phase shift of the interference fringe is linearly proportional to the rotation rate of the platform. The long-term stability, which is evaluated by the overlapped Allan deviation, is 8.5 × 10^-6 rad/s over the integrating time of 1000s.展开更多
A pocket coherent population trapping（CPT） atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated.Using the differential detecting...A pocket coherent population trapping（CPT） atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated.Using the differential detecting magneto–optic rotation effect,a CPT spectrum with the background canceled and a high signal-to-noise ratio is obtained.The experimental results reveal that the sensitivity of the proposed scheme can be improved by half an order,and the ability to detect weak magnetic fields is extended one-fold.Therefore,the proposed scheme is suited to realize a pocket-size CPT magnetometer.展开更多
We report the experimental demonstration of an ultranarrow bandwidth atomic filter by optically induced polarization rotation in multilevel electromagnetically induced transparency systems in hot Rb vapor. With a coup...We report the experimental demonstration of an ultranarrow bandwidth atomic filter by optically induced polarization rotation in multilevel electromagnetically induced transparency systems in hot Rb vapor. With a coupling intensity of 2.3 W/cm^2, the filter shows a peak transmission of 33.2% and a bandwidth of 10 MHz. By altering the coupling frequency, a broad tuning range of several Doppler linewidths of the D1 line transitions of STRb atoms can be obtained. The presented atomic filter has useful features of ultranarrow bandwidth, and the operating frequency can be tuned resonance with the atomic transition. Such narrowband tunable atomic filter can be used as an efficient noise rejection tool in classical and quantum optical applications.展开更多
基金supported by the National Natural Science Foundation of China(No.52074157)Department of Education of Guangdong Province,China(No.2023KTSCX121)Shenzhen Science and Technology Programs,China(Nos.JSGG20210802154210032,JCYJ20210324104608023,JSGG20180508152608855)。
文摘A comparative study on the performance of gas atomized(GA)and rotating-disk atomized(RDA)aluminum alloy powders produced on industrial scale for laser directed energy deposition(L-DED)process was carried out.The powder characteristics,the printing process window,and the quality,microstructure,and mechanical properties of printed parts were taken into account for comparison and discussion.The results demonstrate that the RDA powder is superior to the GA powder in terms of sphericity,surface quality,internal defects,flowability,and apparent density,together with a larger printing process window during the L-DED parts fabrication.Besides,the resultant parts from the RDA powder have higher dimensional accuracy,lower internal defects,more uniform and finer microstructure,and more favorable mechanical properties than those from the GA powder.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11227083 and 91536221
文摘We present an experimental demonstration of the rotation measurement using a compact cold atom gyroscope. Atom interference fringes are observed in the stationary frame and the rotating frame, respectively. The phase shift and contrast of the interference fringe are experimentally investigated. The results show that the contrast of the interference fringe is well held when the platform is rotated, and the phase shift of the interference fringe is linearly proportional to the rotation rate of the platform. The long-term stability, which is evaluated by the overlapped Allan deviation, is 8.5 × 10^-6 rad/s over the integrating time of 1000s.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304362 and 61434005)
文摘A pocket coherent population trapping（CPT） atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated.Using the differential detecting magneto–optic rotation effect,a CPT spectrum with the background canceled and a high signal-to-noise ratio is obtained.The experimental results reveal that the sensitivity of the proposed scheme can be improved by half an order,and the ability to detect weak magnetic fields is extended one-fold.Therefore,the proposed scheme is suited to realize a pocket-size CPT magnetometer.
基金supported by the National Basic Research Program of China(No.2006CB921203)the National Natural Science Foundation of China(No.11174327)+1 种基金the Foundation of Wuhan National Laboratory for Optoelectronics(No.P080002)the support of the Hundred Talent Program by the Chinese Academy of Sciences
文摘We report the experimental demonstration of an ultranarrow bandwidth atomic filter by optically induced polarization rotation in multilevel electromagnetically induced transparency systems in hot Rb vapor. With a coupling intensity of 2.3 W/cm^2, the filter shows a peak transmission of 33.2% and a bandwidth of 10 MHz. By altering the coupling frequency, a broad tuning range of several Doppler linewidths of the D1 line transitions of STRb atoms can be obtained. The presented atomic filter has useful features of ultranarrow bandwidth, and the operating frequency can be tuned resonance with the atomic transition. Such narrowband tunable atomic filter can be used as an efficient noise rejection tool in classical and quantum optical applications.
