title: Stressed waveguides with tubular depressed-cladding inscribed in phosphate glasses by femtosecond hollow laser beams.
abstract: We report on the single-step fabrication of stressed optical waveguides with tubular depressed-refractive-index cladding in phosphate glasses by the use of focused femtosecond hollow laser beams. Tubelike low index regions appear under direct exposure due to material rarefaction following expansion. Strained compacted zones emerged in domains neighboring the tubular track of lower refractive index, and waveguiding occurs mainly within the tube core fabricated by the engineered femtosecond laser beam. The refractive index profile of the optical waveguide was reconstructed from the measured transmitted near-field intensity.
authors.affiliation: State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China.
authors.forename: Xuewen
authors.initials: X
authors.lastname: Long
authors.forename: Jing
authors.initials: J
authors.lastname: Bai
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Razvan
authors.initials: R
authors.lastname: Stoian
authors.forename: Rongqing
authors.initials: R
authors.lastname: Hui
authors.forename: Guanghua
authors.initials: G
authors.lastname: Cheng