title: Phase-matched frequency conversion below 150 nm in KBe2BO3F2.
abstract: Sum frequency mixing has been demonstrated below 150 nm in KBeBO3F2by using the fundamental with its fourth harmonic of a 6 kHz Ti: sapphire laser system. The wavelength of 149.8 nm is the shortest ever obtained to our knowledge by phase matching in nonlinear crystals. The output powers were 3.6 μW at 149.8 nm and 110 μW at 154.0 nm, respectively. The phase matching angles measured from 149.8 to 158.1 nm are larger by 3-4 degrees than those expected from the existing Sellmeier equation. The measured transmission spectra of KBeBO3F2crystals support the generation of coherent radiation below 150 nm.
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Nakazato
authors.forename: Isao
authors.initials: I
authors.lastname: Ito
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Wang
authors.forename: Chuangtian
authors.initials: C
authors.lastname: Chen
authors.forename: Shuntaro
authors.initials: S
authors.lastname: Watanabe