Investigation of Focusing Properties on Astigmatic Gaussian Beams in Nonlinear Medium

Abstract

Ultra-short laser filamentation has been intensively studied due to its unique optical properties for applications in the field of remote sensing and detection. Although significant progress has been made, the quality of the laser beam still suffers from various optical aberrations during long-range transmission. Astigmatism is a typical off-axis aberration that is often encountered in the off-axis optical systems. An effective method needs to be proposed to suppress the astigmatism of the beam during filamentation. Herein, we numerically investigated the impact of the nonlinear effects on the focusing properties of the astigmatic Gaussian beams in air and obtained similar results in the experiment. As the single pulse energy increases, the maximum on-axis intensity gradually shifted from the sagittal focus to the tangential focus and the foci moved forward simultaneously. Moreover, the astigmatism could be suppressed effectively with the enhancement of the nonlinear effects, that is, the astigmatic difference and the degree of beam distortion were both reduced. Through this approach, the acoustic intensity of the filament (located at the tangential focal point) increased by a factor of 22.8. Our work paves a solid step toward the practical applications of the astigmatism beam as the nonlinear lidar.

Conditions for the efficiency of optical limiting based on experiment and quantum chemical calculations

“…For this reason, the development of high-tech laser components is required. It is well known, that optical limiters are capable of operating at high speeds and providing rapid adjustment of radiation parameters, which is important, in particular, for remote sensing to measure distances, 2 using nanosecond 3 and femtosecond 4–6 laser pulses.…”

Young's formula for Gaussian beams: theoretical derivation and experimental verification

“…In the field of modern optics, Gaussian beams have garnered significant attention due to their unique propagation characteristics and wide range of applications. [1][2][3] While the theory of on-axis transmission of traditional laser beams is relatively mature, research on the off-axis transmission of Gaussian beams is comparatively scarce, especially in the analysis of optical transformations involving off-axis beams and optical surfaces. [4][5][6] Over the years, researchers have continuously delved into the study of how aberrations affect the transmission properties of Gaussian beams.…”