An x-ray probe of laser-aligned molecules

We demonstrate a hard x-ray probe of laser-aligned small molecules. To align small molecules with optical lasers, high intensities at nonresonant wavelengths are necessary. We use 95 ps pulses focused to 40 mu m from an 800 nm Ti:sapphire laser at a peak intensity of 10(12) W/cm(2) to create an ensemble of aligned bromotrifluoromethane (CF(3)Br) molecules. Linearly polarized, 120 ps x-ray pulses, focused to 10 mu m, tuned to the Br 1s-->sigma* preedge resonance at 13.476 keV, probe the ensemble of laser-aligned molecules. The demonstrated methodology has a variety of applications and can enable ultrafast imaging of laser-controlled molecular motions with Angstrom-level resolution. (C) 2008 American Institute of Physics.