"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, and Markus Gühr; Photonics, 04/15/15.

Additional Authors: Emily Sistrunk, Jaewoo Jeong, Mahesh G. Samant, Alexander X. Gray , Hermann A. Dürr, Stuart S. P. Parkin, and Markus Gühr

Abstract:

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.