High order Bessel beams generated by using incoherent LED light source
Abstract
The ideal high order Bessel beams was generated by monochromatic green LED light source for the first time. A novel method using cross-spectral density function and superposition of multi-wavelength was proposed to calculate the intensity distribution of light field emitted from the green LED then through the spiral phase plate and the axicon. And the cross-section intensity distribution along the optical axis based on this method was simulated. An experimental facility was designed to demonstrate the theory. The result showed that the high order Bessel beams could be obtained from the green LED light source by using the aperture to improve the spatial coherence of the light field emitted from the green LED. The cross-section intensity distribution of the experimental result, the size of the center dark spot and the non-diffraction distance were accorded well with the theoretical simulation and calculation. The research result offered the theoretical and experimental basis for the micromanipulation of particles by using incoherent light.
