In an operation mode of atomic force micro- scopy that uses a higher eigenmode to determine the physical properties of material surface, the ratio between the eigenfrequency of a higher flexural eigenmode and that of ...In an operation mode of atomic force micro- scopy that uses a higher eigenmode to determine the physical properties of material surface, the ratio between the eigenfrequency of a higher flexural eigenmode and that of the first flexural eigenmode was identified as an important parameter that affects the sensitivity and accessibility. Structure features such as cut-out are often used to tune the ratio of eigenfrequencies and to enhance the performance. However, there lacks a systematic and automatic method for tailoring the ratio. In order to deal with this issue, a shape and topology optimization problem is formulated, where the ratio between two eigenfrequen- cies is defined as a constraint and the area of the cantilever is maximized. The optimization problem is solved via the level set based method.展开更多
Transmission properties of tapered fiber including right cone fiber and bend optical fiber are discussed.The transmission efficiency of the tapered fiber is measured.The curve of transmission efficiency versus taper c...Transmission properties of tapered fiber including right cone fiber and bend optical fiber are discussed.The transmission efficiency of the tapered fiber is measured.The curve of transmission efficiency versus taper cone angle is given.By the scalar wave equation and Gaussian approximation,transmission properties of the two kinds of tapered fibers are analyzed,the power losses caused by taper cone angle and by the bending are also calculated.From the experiments and theoretical analysis,it could come to a conclusion that the wider the taper cone angle is,the higher the transmission efficiency will be.展开更多
文摘In an operation mode of atomic force micro- scopy that uses a higher eigenmode to determine the physical properties of material surface, the ratio between the eigenfrequency of a higher flexural eigenmode and that of the first flexural eigenmode was identified as an important parameter that affects the sensitivity and accessibility. Structure features such as cut-out are often used to tune the ratio of eigenfrequencies and to enhance the performance. However, there lacks a systematic and automatic method for tailoring the ratio. In order to deal with this issue, a shape and topology optimization problem is formulated, where the ratio between two eigenfrequen- cies is defined as a constraint and the area of the cantilever is maximized. The optimization problem is solved via the level set based method.
文摘Transmission properties of tapered fiber including right cone fiber and bend optical fiber are discussed.The transmission efficiency of the tapered fiber is measured.The curve of transmission efficiency versus taper cone angle is given.By the scalar wave equation and Gaussian approximation,transmission properties of the two kinds of tapered fibers are analyzed,the power losses caused by taper cone angle and by the bending are also calculated.From the experiments and theoretical analysis,it could come to a conclusion that the wider the taper cone angle is,the higher the transmission efficiency will be.
