High flux coherent supercontinuum soft X-ray source driven by a single-stage 10 mJ, kHz, Ti:sapphire laser amplifier

摘要

We demonstrate the highest flux tabletop source of coherent soft X-rays todate, driven by a single-stage 10 mJ Ti:sapphire regenerative amplifier at 1kHz. We first down-convert the laser to 1.3 um using a parametric amplifier,before up-converting it to soft X-rays using high harmonic generation in ahigh-pressure, phase matched, hollow waveguide geometry. The resultingoptimally phase matched broadband spectrum extends to 200 eV, with a soft X-rayphoton flux of > 10^6 photons/pulse/1% bandwidth at 1 kHz, corresponding to >10^9 photons/s/1% bandwidth, or approximately a three order-of-magnitudeincrease compared with past work. Finally, using this broad bandwidth X-raysource, we demonstrate X-ray absorption spectroscopy of multiple elements andtransitions in molecules in a single spectrum, with a spectral resolution of0.25 eV, and with the ability to resolve the near edge fine structure.