key points: tg in optical range has been used to study coherent phonons and thermal transport
DESCRIPTION
X-ray four-wave mixing: Transient grating measurements of nano-scale thermo-elastic responses. F. Hofmann , K.A . Nelson. Key points: TG in optical range has been used to study coherent phonons and thermal transport To move to nano-scale need to reduce grating period and hence the wavelength - PowerPoint PPT PresentationTRANSCRIPT
Key points:• TG in optical range has been used to study
coherent phonons and thermal transport• To move to nano-scale need to reduce
grating period and hence the wavelength• LCLS provides unique opportunity
–> coherence and time resolution• Experimental requirements
–> split and delay of pump and probe
–> generation of overlapping beams• Generalized non-linear X-ray spectroscopy
X-ray four-wave mixing: Transient grating measurements of nano-scale thermo-elastic responses
F. Hofmann, K.A. Nelson
Roseker et al. Optics Letters 34 (12) 2009
X-ray pump-probe splittingTransient grating
Johnson et al. J. Appl. Phys. 110, 113513 (2011)
samplex-ray gratings
signal
Transient grating generation
Heilmann et al. Optics Express 16, 8658 (2008)
Ti film on Si substrate, 0.76μm grating period
Rogers et al. Annu. Rev. Mater. Sci. 30:117–57 (2000)
Decane with alumina nanoparticles
Schmidt et al. J. App. Phys. 103, 083529 2008
Coherent phonons & thermal grating decay