Optical limiting and speckle of low power continuous wave laser beams using nonlinear scattering in photorefractive Zr: LiNbO3 crystals

The optical limiting caused by nonlinear scattering in the photorefractive Zr-doped LiNbO3 crystals was studied for lower-power laser beams with wavelengths of 514.5 and 532 nm. The measurements of speckle evolution indicate that the samples with 0.625 <= [Zr] <= 1.25 mol% exhibit the very large gain factor for holographic amplification of noise gratings. Based on the direct measurements of the output power depending on the input one, we conclude that these samples behaved as hard optical limiters for the laser beams with a low incident power. Thus, these crystals find their potential application in the optical limiting devices.

Automated summary

The study found that photorefractive Zr-doped LiNbO3 crystals exhibit optical limiting effects on lower-power laser beams with wavelengths of 514.5 and 532 nm, with samples of specific doping concentrations showing a large gain factor. Based on the relationship between output power and input power, these crystals behaved as hard optical limiters and have potential applications in optical limiting devices.