A new conception of nano-laser is proposed in which depending on the size of nano-clusters (silicon quantum dots (QD)), the pumping level of laser can be tuned by the quantum confinement (QC) effect, and the populatio...A new conception of nano-laser is proposed in which depending on the size of nano-clusters (silicon quantum dots (QD)), the pumping level of laser can be tuned by the quantum confinement (QC) effect, and the population inversion can be formed between the valence band and the localized states produced from the surface bonds. The nano-laser belongs to the emission of type Ⅱ. The peaks of stimulated emission are observed at 605 nm and 693 nm. Through the micro-cavity of nano-laser, a full width at half maximum of the peak at 693 nm can reach to 0.5 nm. The theoretical model and the experimental results indicate that it is a necessary condition for setting up nano-laser that the smaller size of nano-clusters (d<3 nm) can make the localized states into band gap below the conduction band opened and the states of conduction band become the pumping level of nano-laser. The emission energy of nano-laser will be limited in the range of 1.7～2.3 eV generally due to the position of the localized states in gap, which is good in agreement between the experiments and the theory.展开更多
The reflection Talbot effect under the illumination of Gaussian spherical wave and plane wave is observed on 1D and 2D photonic crystal of silicon prepared by nanosecond laser. It is found that the distance between tw...The reflection Talbot effect under the illumination of Gaussian spherical wave and plane wave is observed on 1D and 2D photonic crystal of silicon prepared by nanosecond laser. It is found that the distance between two adjacent Talbot images increases lineally with increasing of image distance as well as amplification of Talbot images under the illumination of Gaussian spherical wave. The result of theory is coincident with that of experiment, which shows that selecting suitable wavefront shape of input field can enlarge the amplification rate and improve the resolution of Talbot imaging. The reflection Talbot effect will have a lot of good application in microscopy of micro-fabrication on silicon, such as detecting period structures of plasma on line of PLD fabricating.展开更多
基金Support from the National Natural Science Foundation of China ( Grant No.10764002,60966002,11264007)the National Key Laboratory of Surface Physics in Fudan University
文摘A new conception of nano-laser is proposed in which depending on the size of nano-clusters (silicon quantum dots (QD)), the pumping level of laser can be tuned by the quantum confinement (QC) effect, and the population inversion can be formed between the valence band and the localized states produced from the surface bonds. The nano-laser belongs to the emission of type Ⅱ. The peaks of stimulated emission are observed at 605 nm and 693 nm. Through the micro-cavity of nano-laser, a full width at half maximum of the peak at 693 nm can reach to 0.5 nm. The theoretical model and the experimental results indicate that it is a necessary condition for setting up nano-laser that the smaller size of nano-clusters (d<3 nm) can make the localized states into band gap below the conduction band opened and the states of conduction band become the pumping level of nano-laser. The emission energy of nano-laser will be limited in the range of 1.7～2.3 eV generally due to the position of the localized states in gap, which is good in agreement between the experiments and the theory.
基金Support from the National Natural Science Foundation of China ( Grant No. 11264007 )from the National Key Laboratory of Surface Physics in Fudan University
文摘The reflection Talbot effect under the illumination of Gaussian spherical wave and plane wave is observed on 1D and 2D photonic crystal of silicon prepared by nanosecond laser. It is found that the distance between two adjacent Talbot images increases lineally with increasing of image distance as well as amplification of Talbot images under the illumination of Gaussian spherical wave. The result of theory is coincident with that of experiment, which shows that selecting suitable wavefront shape of input field can enlarge the amplification rate and improve the resolution of Talbot imaging. The reflection Talbot effect will have a lot of good application in microscopy of micro-fabrication on silicon, such as detecting period structures of plasma on line of PLD fabricating.
