Superposition of orbital angular momentum of photons by a combined computer-generated hologram fabricated in silica glass with femtosecond laser pulses  

作　　者：郭忠义 曲士良 孙正和 刘树田 

机构地区：[1]Department of Physics, Harbin Institute of Technology [2]Department of Optoelectronic Science, Harbin Institute of Technology at Weihai

出　　处：《Chinese Physics B》2008年第11期4199-4203,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos 10674038 and 10604042);National Basic Research Program of China (Grant No 2006CB302901);the Multidiscipline Scientific Research Foundation of Harbin Institute of Technology, China (Grant No HIT.MD2003.22);the Foundation of Harbin Institute of Technology at Weihai of China (Grant No HIT(WH).2005.20)

摘　　要：This paper introduces a novel method to realize the superposition of orbital angular momentum of photons by combined computer-generated hologram （CCGH） fabricated in silica glass with femtosecond laser pulses. Firstly, the two computer-generated holograms （CGH） of optical vortex were obtained and combined as a CCGH according to the design. Then the CCGH was directly written inside glass by femtosecond laser pulses induced microexplosion without any preor post-treatment of the material. The vortex beams with different vortex topological charges （including new topological charges） have been restructured using a collimated He-Ne laser beam incidence to the CCGH normally. A theoretical and experimental explanation has been presented for the generations of the new topological charges.This paper introduces a novel method to realize the superposition of orbital angular momentum of photons by combined computer-generated hologram （CCGH） fabricated in silica glass with femtosecond laser pulses. Firstly, the two computer-generated holograms （CGH） of optical vortex were obtained and combined as a CCGH according to the design. Then the CCGH was directly written inside glass by femtosecond laser pulses induced microexplosion without any preor post-treatment of the material. The vortex beams with different vortex topological charges （including new topological charges） have been restructured using a collimated He-Ne laser beam incidence to the CCGH normally. A theoretical and experimental explanation has been presented for the generations of the new topological charges.

关 键 词：femtosecond laser MICRO-STRUCTURE optical vortices CGH 

分 类 号：O438.1[机械工程—光学工程]