Photonics (Apr 2015)

Self Referencing Heterodyne Transient Grating Spectroscopy with Short Wavelength

  • Jakob Grilj,
  • Emily Sistrunk,
  • Jaewoo Jeong,
  • Mahesh G. Samant,
  • Alexander X. Gray,
  • Hermann A. Dürr,
  • Stuart S. P. Parkin,
  • Markus Gühr

DOI
https://doi.org/10.3390/photonics2020392
Journal volume & issue
Vol. 2, no. 2
pp. 392 – 401

Abstract

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Heterodyning by a phase stable reference electric field is a well known technique to amplify weak nonlinear signals. For short wavelength, the generation of a reference field in front of the sample is challenging because of a lack of suitable beamsplitters. Here, we use a permanent grating which matches the line spacing of the transient grating for the creation of a phase stable reference field. The relative phase among the two can be changed by a relative translation of the permanent and transient gratings in direction orthogonal to the grating lines. We demonstrate the technique for a transient grating on a VO2 thin film and observe constructive as well as destructive interference signals.

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