title: Enhanced intermodal four-wave mixing for visible and near-infrared wavelength generation in a photonic crystal fiber.
abstract: We demonstrate experimentally an enhanced intermodal four-wave mixing (FWM) process through coupling positively chirped femtosecond pulses into the deeply normal dispersion region of the fundamental mode of an in-house fabricated photonic crystal fiber (PCF). In the intermodal phase-matching scheme, the energy of the pump waves at 800 nm in the fundamental mode is efficiently converted into the anti-Stokes waves around 553 nm and the Stokes waves within the wavelength range of 1445-1586 nm in the second-order mode. The maximum conversion efficiency of η(as) and η(s) of anti-Stokes and Stokes waves can be up to 21% and 16%, respectively. The Stokes frequency shift Ω is 5580  cm(-1). The fiber bending and intermodal walk-off effect of pulses do not have significant influence on the nonlinear optical process.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Yuan
authors.forename: Xinzhu
authors.initials: X
authors.lastname: Sang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wu
authors.forename: Guiyao
authors.initials: G
authors.lastname: Zhou
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Xian
authors.initials: X
authors.lastname: Zhou
authors.forename: Chongxiu
authors.initials: C
authors.lastname: Yu
authors.forename: Kuiru
authors.initials: K
authors.lastname: Wang
authors.forename: Binbin
authors.initials: B
authors.lastname: Yan
authors.forename: Ying
authors.initials: Y
authors.lastname: Han
authors.forename: Hwa Yaw
authors.initials: HY
authors.lastname: Tam
authors.forename: P K A
authors.initials: PK
authors.lastname: Wai