The steady-state gain distribution in cladding pumped thulium-doped fiber laser（TDFL） is analytically and numerically solved based on the rate equations including loss coefficients and cross relaxation effect. With ...The steady-state gain distribution in cladding pumped thulium-doped fiber laser（TDFL） is analytically and numerically solved based on the rate equations including loss coefficients and cross relaxation effect. With the gain curve, a problem, which is named optical feedback inhibition（OFI） and always occurs in tandem TDFL-Ho：YAG laser system, is analyzed quantitatively. The actual characteristics of output spectra and power basically prove the conclusion of theoretical analysis. Then a simple mirror-deflected L-shaped cavity is employed to restrain the external feedback and simplify the structure of fiber-bulk Ho：YAG laser. Finally, 25 W of 2097-nm laser power and 51.2% of optical-to-optical conversion efficiency are obtained, and the beam quality factor is less than 1.43 obtained by knife-edge method.展开更多
Limited by the tiny structure of axons,the effects of these axonal hyperpolarizing inputs on neuronal activity have not been directly elucidated.Here,we imitated these processes by simultaneously recording the activit...Limited by the tiny structure of axons,the effects of these axonal hyperpolarizing inputs on neuronal activity have not been directly elucidated.Here,we imitated these processes by simultaneously recording the activities of the somas and proximal axons of cortical pyramidal neurons.We found that spikes and subthreshold potentials propagate between somas and axons with high fidelity.Furthermore,inhibitory inputs on axons have opposite effects on neuronal activity according to their temporal integration with upstream signals.Concurrent with somatic depolarization,inhibitory inputs on axons decrease neuronal excitability and impede spike generation.In addition,following action potentials,inhibitory inputs on an axon increase neuronal spike capacity and improve spike precision.These results indicate that inhibitory inputs on proximal axons have dual regulatory functions in neuronal activity（suppression or facilitation）according to neuronal network patterns.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61275146)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120002110066)the Special Program of the Co-construction with Beijing Municipal Government of China(Grant No.20121000302)
文摘The steady-state gain distribution in cladding pumped thulium-doped fiber laser（TDFL） is analytically and numerically solved based on the rate equations including loss coefficients and cross relaxation effect. With the gain curve, a problem, which is named optical feedback inhibition（OFI） and always occurs in tandem TDFL-Ho：YAG laser system, is analyzed quantitatively. The actual characteristics of output spectra and power basically prove the conclusion of theoretical analysis. Then a simple mirror-deflected L-shaped cavity is employed to restrain the external feedback and simplify the structure of fiber-bulk Ho：YAG laser. Finally, 25 W of 2097-nm laser power and 51.2% of optical-to-optical conversion efficiency are obtained, and the beam quality factor is less than 1.43 obtained by knife-edge method.
基金supported by the National Natural Science Foundation of China,No.31500836,81671288the Natural Science Foundation of Anhui Province of China,No.1608085QH176
文摘Limited by the tiny structure of axons,the effects of these axonal hyperpolarizing inputs on neuronal activity have not been directly elucidated.Here,we imitated these processes by simultaneously recording the activities of the somas and proximal axons of cortical pyramidal neurons.We found that spikes and subthreshold potentials propagate between somas and axons with high fidelity.Furthermore,inhibitory inputs on axons have opposite effects on neuronal activity according to their temporal integration with upstream signals.Concurrent with somatic depolarization,inhibitory inputs on axons decrease neuronal excitability and impede spike generation.In addition,following action potentials,inhibitory inputs on an axon increase neuronal spike capacity and improve spike precision.These results indicate that inhibitory inputs on proximal axons have dual regulatory functions in neuronal activity（suppression or facilitation）according to neuronal network patterns.
