Absolute calibration of the refractive index in photo-induced photonic lattices

Abstract

We demonstrate a method to experimentally calibrate the refractive index modulation in photorefractive lattices, a task rarely addressed that is crucial for quantitative comparisons of theories with experiments. We consider the linear propagation of a normally incident plane wave through simple lattices and its modulation amplitude at crystal output face. Finding no evidence of longitudinal (Talbot-like) oscillations, we discard an ideal propagation theory and construct a simple effective model that includes longitudinal relaxation. We obtain calibrations of 1D and 2D lattices consistent with standard theory in a high saturation regime. For 2D lattices, we find anisotropies $\chi =1.5-2.5$, stronger for smaller lattice period, and refractive indexes larger than for 1D lattices, also with more noise.

14 pages, 8 figures. To appear in Optics Express (substantial changes, final version)

References in corpus (2)

• Structure analysis of two-dimensional nonlinear self-trapped photonic lattices in anisotropic photorefractive media
• Analysis of transverse Anderson localization in refractive index structures with customized random potential

Cited by in corpus (5)

• Anisotropic nonlinear refractive index measurement of a photorefractive crystal via spatial self-phase modulation
• Photorefractive writing and probing of anisotropic linear and non-linear lattices
• Fractional discrete vortex solitons
• Localized vortex beams in anisotropic Lieb lattices
• Mobility of localized beams in non-homogeneous photonic lattices