Supercontinuum Airy beams

Airy beams are of great interest as a result of their unusual characteristics, they are non-diffracting and also propagate along a parabolic path due to the presence of a transversal acceleration component. In this paper the generation of a white light Airy beam is presented, an investigation is also carried out to determine how the properties of an Airy beam change with the wavelength and spatial coherence of the source. A supercontinuum source is used in conjunction with a spatial light modulator to produce the Airy beams. The wavelength dependence study of the Airy beam parameters was carried out by inserting interference filters into the supercontinuum beam path to select each wavelength. The parameters investigated are the deflection coefficient of the Airy beam, b₀, this quantifies the parabolic path traveled by the beam; the characteristic length, x₀, which is related to the lobe spacing, and lastly the aperture coefficient, a₀. The deflection coefficient and the characteristic length were both found to be wavelength dependent. The aperture coefficient did not alter as a result of wavelength, however it was found to be dependent on the spatial coherence, and therefore on the M² value, of the beam. The other parameters, b₀ and x₀, are unaffected by the spatial coherence of the source.