Vacuum-ultraviolet to infrared supercontinuum in hydrogen-filled photonic crystal fiber

• DOI: 10.1364/optica.2.000292
• Publication Date: 2015-03-27T13:28:45Z
• Authors: Federico Belli; Amir Abdolvand; Wonkeun Chang; John C. Travers; Philip St.J. Russell
• Keywords: Supercontinuum; Ultraviolet

Although supercontinuum sources are readily available for the visible and near infrared (IR), recently also mid-IR, many areas of biology, chemistry, physics would benefit greatly from availability compact, stable, spectrally bright deep-ultraviolet vacuum-ultraviolet (VUV) sources. Such have, however, not yet been developed. Here we report generation a supercontinuum, spanning more than three octaves 124 nm to beyond 1200 nm, in hydrogen-filled kagome-style hollow-core photonic crystal fiber (kagome-PCF). Few-microjoule, 30 fs pump pulses at wavelength 805 nm launched into fiber, where they undergo self-compression via Raman-enhanced Kerr effect. Modeling indicates that before reaching minimum subcycle pulse duration ∼1 fs, much less one period molecular vibration (8 fs), nonlinear reshaping envelope, accentuated by self-steepening shock formation, creates an ultrashort feature causes impulsive excitation long-lived coherent vibrations. These phase modulate strong VUV dispersive wave (at 182 nm or 6.8 eV) on trailing edge pulse, further broadening spectrum VUV. The results show first time kagome-PCF guides well