Second harmonic generation in the near field and far field, a sensitive tool to probe crystalline homogeneity

L. Mahieu-Williame (1) , Samuel Gresillon (1) , Mireille Cuniot-Ponsard (2) , Claude Boccara (1)

1 LOP - Laboratoire d'Optique Physique (UPR0005)
2 Laboratoire Charles Fabry de l'Institut d'Optique / Manolia

In order to probe crystalline orientation of SrxBa1−xNb2O6 _SBN:x_ thin film, we have developed a detection scheme based on a scanning near-field optical microscope _SNOM_. It is used to image simultaneously the fundamental and the second harmonic generation _SHG_ of light by the sample under pulsed laser illumination. We demonstrate on SBN thin films that an apertureless SNOM can dramatically improve the resolution and the sensitivity of SNOM-SHG. Tip direction and focalization are the two crucial parameters in the SNOM-SHG experiments. Moreover, we show the ability of our setup to separate near field from far field contribution to the SHG. This is indeed very helpful in order to measure surface-SHG coefficients.

Domains: Optics [physics.optics]

L. Mahieu-Williame, Samuel Gresillon, Mireille Cuniot-Ponsard, Claude Boccara. Second harmonic generation in the near field and far field, a sensitive tool to probe crystalline homogeneity. Journal of Applied Physics, 2007, 101 (8), pp.083111. ⟨hal-00867590⟩