In:
Optics Letters, Optica Publishing Group, Vol. 46, No. 3 ( 2021-02-01), p. 536-
Abstract:
We systematically studied femtosecond laser-inscribed self-organized nanogratings and geometric phase elements such as a polarization diffraction focusing lens and Q-plate in sapphire crystal. Besides the void structures observed in the focus, nanogratings with periods of 150~300 nm were observed, depending on a nanoslit that took the role of a seeding effect by localized light field enhancement. The non-polarized refractive index change and birefringence were measured with values around 1 ∼ 2 × 10 − 3 and 6 × 10 − 4 , respectively. Based on the laser-inscribed form birefringence, a geometric phase lens and Q-plate were successfully demonstrated in sapphire with high imaging and a focusing effect. We expect that our findings may promote the understanding of laser-induced nanogratings in bulk and potential applications in geometric phase elements.
Type of Medium:
Online Resource
ISSN:
0146-9592
,
1539-4794
Language:
English
Publisher:
Optica Publishing Group
Publication Date:
2021
detail.hit.zdb_id:
243290-0
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