A new industrial method has been developed to produce polydisperse spherical colloidal silica particles with a very broad particle size,ranging from 20-95 nm.The process uses a reactor in which the original seed solut...A new industrial method has been developed to produce polydisperse spherical colloidal silica particles with a very broad particle size,ranging from 20-95 nm.The process uses a reactor in which the original seed solution is heated to 100 ℃,and then active silicic acid and the seed solution are titrated to the reactor continuously with a constant rate.The original seeds and the titrated seeds in the reactor will go through different particle growth cycles to form different particle sizes.Both the particles＇ size distribution and morphology have been characterized by dynamic light scattering（DLS）and the focus ion beam（FIB） system.In addition,the as-prepared polydisperse colloidal silica particle in the application of sapphire wafer＇s chemical mechanical polishing（CMP） process has been tested.The material removal rate（MRR） of this kind of abrasive has been tested and verified to be much faster than traditional monodisperse silica particles.Finally,the mechanism of sapphire CMP process by this kind of polydisperse silica particles has been investigated to explore the reasons for the high polishing rate.展开更多
In this paper,we introduce a horizontal slot in the reversed-rib chalcogenide glass waveguide to tailor its dispersion characteristics.The waveguide exhibits a flat and low dispersion over a wavelength range of 1080 n...In this paper,we introduce a horizontal slot in the reversed-rib chalcogenide glass waveguide to tailor its dispersion characteristics.The waveguide exhibits a flat and low dispersion over a wavelength range of 1080 nm,in which the dispersion fluctuates between-10.6 ps·nm-1·km-1 and ＋11.14 ps·nm-1·km-1.The dispersion tailoring effect is due to the mode field transfer from the reversed-rib waveguide to the slot with the increase of wavelength,which results in the extension of the low dispersion band.Moreover,the nonlinear coefficient and the phase-matching condition of the fourwave mixing process in this waveguide are studied,showing that the waveguide has great potential in nonlinear optical applications over a wide wavelength range.展开更多
基金Project supported by the National Major Scientific and Technological Special Project during the Twelfth Five-year Plan Period of China(Grant No.2009ZX02030-1)the National Natural Science Foundation of China(Grant No.51205387)the Science and Technology Commission of Shanghai,China(Grant No. 11nm0500300),and the Science and Technology Commission of Shanghai,China(Grant No. 14XD1425300)
文摘A new industrial method has been developed to produce polydisperse spherical colloidal silica particles with a very broad particle size,ranging from 20-95 nm.The process uses a reactor in which the original seed solution is heated to 100 ℃,and then active silicic acid and the seed solution are titrated to the reactor continuously with a constant rate.The original seeds and the titrated seeds in the reactor will go through different particle growth cycles to form different particle sizes.Both the particles＇ size distribution and morphology have been characterized by dynamic light scattering（DLS）and the focus ion beam（FIB） system.In addition,the as-prepared polydisperse colloidal silica particle in the application of sapphire wafer＇s chemical mechanical polishing（CMP） process has been tested.The material removal rate（MRR） of this kind of abrasive has been tested and verified to be much faster than traditional monodisperse silica particles.Finally,the mechanism of sapphire CMP process by this kind of polydisperse silica particles has been investigated to explore the reasons for the high polishing rate.
基金Project supported by the National Basic Research Program of China(Grant Nos.2013CB328700 and 2011CBA00303)the National Natural Science Foundation of China(Grant Nos.61575102 and 61321004)
文摘In this paper,we introduce a horizontal slot in the reversed-rib chalcogenide glass waveguide to tailor its dispersion characteristics.The waveguide exhibits a flat and low dispersion over a wavelength range of 1080 nm,in which the dispersion fluctuates between-10.6 ps·nm-1·km-1 and ＋11.14 ps·nm-1·km-1.The dispersion tailoring effect is due to the mode field transfer from the reversed-rib waveguide to the slot with the increase of wavelength,which results in the extension of the low dispersion band.Moreover,the nonlinear coefficient and the phase-matching condition of the fourwave mixing process in this waveguide are studied,showing that the waveguide has great potential in nonlinear optical applications over a wide wavelength range.
