Effects of primary aberration on the spatiotemporal optical vortex focus

A spatiotemporal optical vortex (STOV) with transverse orbital angular momentum has several potential applications. However, refractive index mismatch, beam tilt and optical path misalignment are often inevitable during the application of an optical system. To investigate the focusing field of light pulse, the effects of primary aberrations such as the spherical aberration, coma, and astigmatism were analyzed. The simulation results indicate that three-dimension spatiotemporal distributions of the focusing light pulse are affected by primary aberration. On the principal coordinate planes, coma can distort the intensity structure and shift the STOV focus perpendicular to the propagation direction, while spherical aberration and astigmatism induce the actual STOV focus to shift along the propagation direction. Astigmatism do not affect the intensity structure of spatiotemporal plane without spiral phase, but stretch the 3D STOV focus along one spatial axis. Coma and astigmatism are necessary to be avoided to obtain a perfect STOV focus. It is helpful to improve the applications of STOV focus, such as optical tweezers, microscopy, and communications.