Generation of high peak power, segmented and Bessel beams of tunable range without on-axis intensity modulation

TL;DR

This paper introduces a novel method to generate high peak power, segmented, zero-order Bessel beams with tunable range and no on-axis intensity modulation by illuminating an axicon with hollow Gaussian beams of varying orders.

Contribution

The authors demonstrate a new experimental scheme using hollow Gaussian beams and an axicon to produce Bessel beams with controllable range and peak power, eliminating on-axis intensity modulation.

Findings

Range decreases with higher HGB order

Peak power increases with higher HGB order

Superposing HGBs extends Bessel beam range

Abstract

We propose and experimentally demonstrate a novel experimental scheme to generate high peak power, segmented, smooth, zero-order Bessel beams with tunable range. Illuminating the axicon with hollow Gaussian beams (HGBs) of different orders we have generated Bessel beams of varying range at different positions away from the axicon. The presence of dark core at the center of the HGBs removes the effect of imperfection in the axicon tip. As a result, the entire power of the input beam is transformed into zero-order Bessel beam without any on-axis intensity modulation. We observe the decrease in range and increase in peak power of the zero-order Bessel beam with the order of HGBs. Controlling the superposition of the HGBs of different orders to the axicon we have demonstrated the increase in the range of the Bessel beam. The current technique can also produce Bessel beams of different intensity distribution including single peak or multiple peak Bessel beams. Using single-pass second harmonic generation in nonlinear crystals of different lengths we have further verified the increase of peak power of the Bessel beam with the order of the HGBs and also the increase in the range of the Bessel beam due to the superposed HGBs. The generic experimental scheme can be used at different wavelengths and timescales (continuous-wave to ultrafast).