Generating autofocused aberration laser beams with different spectral performance

Abstract

We present a flexible approach for generating autofocused aberration laser beams (ALBs) of different wavelengths based on the diffractive optical element (DOE) design with distinct phase transmittance that has radial power q and periodic angular dependence sin(mφ). The diffraction pattern of ALBs strongly depends on the periodic angular power controlled phase of the DOE. During free-space propagation, the ALBs with different wavelengths convert into different light distributions that have mth-order symmetry (for odd m) and 2mth-order symmetry (for even m). The ALBs exhibit autofocusing properties that significantly differ at longer wavelengths relatively with smaller wavelengths. The formation of light intensity distributions in free-space propagation has a sharp focusing feature that strongly depends on the radial power q. The numerically simulated results are presented for wavelengths in the infrared, visible, and ultra-violet regimes. The experimental findings measured at a wavelength of λ = 1064 nm, show good agreement with the numerically simulated results and thus verifying our approach.