We report an all-fiberized chirped pulse amplification system without any bulk devices.The stretcher and compressor are chirped fiber Bragg gratings inscribed in a 6/125μm single-mode fiber and a 30/250μm largemode-...We report an all-fiberized chirped pulse amplification system without any bulk devices.The stretcher and compressor are chirped fiber Bragg gratings inscribed in a 6/125μm single-mode fiber and a 30/250μm largemode-area fiber.The fabrication system of chirped fiber Bragg gratings was designed and built by ourselves.The width of the linear exposure spot was controlled according to the different fiber sizes to improve the fabrication quality,and the parameters of chirped fiber Bragg gratings were fine-tuned during the fabrication to achieve the overall system’s spectral matching.Two fiber circulators with the same fiber sizes as the chirped fiber Bragg gratings were employed to auxiliarily achieve the pulse stretching and compression.The dispersion accumulations provided by the stretcher and compressor are 129.8 ps and 90.8 ps.The power amplifiers were composed of the two-stage 10/130μm fiber pre-amplifier and the 30/250μm fiber main amplifier.The proposed chirped pulse amplification system with no spatial light is the true sense of an all-fiberized chirped pulse amplification structure and shows the main trend in development of ultrashort pulse fiber lasers.展开更多
AIM： To assess the effects of small incision lenticule extraction（SMILE） surgery on the corneal endothelium at1 d to 1mo postoperatively.·METHODS： A retrospective, observational study was conducted on 47 pati...AIM： To assess the effects of small incision lenticule extraction（SMILE） surgery on the corneal endothelium at1 d to 1mo postoperatively.·METHODS： A retrospective, observational study was conducted on 47 patients（47 eyes） who received SMILE surgery. Patients were grouped according to contact lens wear condition. The corneal endothelium was examined preoperatively and at 1d, 1wk and 1mo postoperatively.The corneal endothelium was analyzed for endothelial cell density（ECD）, percentage of hexagonal cells, and coefficient of variation（CV） of cell size.·RESULTS： There were no significant decrease in the ECD, percentage of hexagonal cells or increase in CV at1 d, 1wk and 1mo postoperatively（P 〉0.05）. However,there was a small increase of ECD by 2.88% in contact lens wearers（78.26±113.62 cell/mm2, P 〈0.05）.· CONCLUSION： SMILE has no significant adverse effects on the corneal ECD and morphology during 1mo follow-up time.展开更多
基金supported by the Key Program of Beijing Municipal Natural Science Foundation(Grant No.KZ201910005006)the National Natural Science Foundation of China(Grant No.62005004)+1 种基金the Natural Science Foundation of Beijing Municipality(Grant No.4204091)the National Science Foundation for Post-doctor Scientists of China(Grant No.212423)。
文摘We report an all-fiberized chirped pulse amplification system without any bulk devices.The stretcher and compressor are chirped fiber Bragg gratings inscribed in a 6/125μm single-mode fiber and a 30/250μm largemode-area fiber.The fabrication system of chirped fiber Bragg gratings was designed and built by ourselves.The width of the linear exposure spot was controlled according to the different fiber sizes to improve the fabrication quality,and the parameters of chirped fiber Bragg gratings were fine-tuned during the fabrication to achieve the overall system’s spectral matching.Two fiber circulators with the same fiber sizes as the chirped fiber Bragg gratings were employed to auxiliarily achieve the pulse stretching and compression.The dispersion accumulations provided by the stretcher and compressor are 129.8 ps and 90.8 ps.The power amplifiers were composed of the two-stage 10/130μm fiber pre-amplifier and the 30/250μm fiber main amplifier.The proposed chirped pulse amplification system with no spatial light is the true sense of an all-fiberized chirped pulse amplification structure and shows the main trend in development of ultrashort pulse fiber lasers.
基金Supported by the National Natural Science Foundation of China(No.81261130021)Henry G Leong Endowed Professorship fund,PolyU research grant GUA32 for supporting the analysis work in Hong Kong
文摘AIM： To assess the effects of small incision lenticule extraction（SMILE） surgery on the corneal endothelium at1 d to 1mo postoperatively.·METHODS： A retrospective, observational study was conducted on 47 patients（47 eyes） who received SMILE surgery. Patients were grouped according to contact lens wear condition. The corneal endothelium was examined preoperatively and at 1d, 1wk and 1mo postoperatively.The corneal endothelium was analyzed for endothelial cell density（ECD）, percentage of hexagonal cells, and coefficient of variation（CV） of cell size.·RESULTS： There were no significant decrease in the ECD, percentage of hexagonal cells or increase in CV at1 d, 1wk and 1mo postoperatively（P 〉0.05）. However,there was a small increase of ECD by 2.88% in contact lens wearers（78.26±113.62 cell/mm2, P 〈0.05）.· CONCLUSION： SMILE has no significant adverse effects on the corneal ECD and morphology during 1mo follow-up time.
