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

• 来源期刊: 中国物理B（英文版）
• 关键词: femtosecond laser micro-structure optical vortices CGH
• 年，卷（期）: 2008,（11）
• 页码范围: 4199-4203
• 页数: 5页
• 语种: 英文

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 pre-or 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.