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Abstract This study examines burst laser-induced pitting (BLIP), an understudied surface modification phenomenon driven by ultrafast laser bursts with sub-picosecond to picosecond inter-pulse delays. Through SEM and AFM analysis, we characterize BLIP as sub-micron pits with polarizationdependent oval shapes, alongside high-fluence melting zones and localized ripple-like structures. Unlike conventional LIPSS, BLIP demonstrates exceptional energy coupling efficiency, evidenced by 10× greater damage areas and a steeper fluence-scaling expansion rate than LIPSS, attributed to transient carrier-mediated processes. Pit density decays exponentially with delay (τ ≈ 6.6-8.9 ps), matching the timescale of self-trapped exciton (STE) relaxation, while spatial statistics reveal a delay-driven transition from field-guided ordering (1-5 ps) to randomized distributions (>10 ps). The resonant-like angular distributions and delay-dependent ellipticity reduction indicate competing mechanisms: optical field enhancement dominates at short delays, while energy dissipation and structure disordering prevail at longer delays. Simulation of nanoplasma excitation reveals near-field optical field enhancements responsible for the ellipticity and ripple-like structures. Beyond their fundamental significance, these BLIP nanostructures offer practical functionalities, including use as anti-reflection coatings and hydrophobic surfaces. These findings establish BLIP as a new paradigm in ultrafast laser-material interactions, where burst parameters selectively activate defect-mediated or field-driven modification pathways in dielectrics. 

Helical structures exhibit novel optical and mechanical properties and are commonly used in different fields such as metamaterials and microfluidics. A few methods exist for fabricating helical microstructures, but none of them has the throughput or flexibility required for patterning a large surface area with tunable pitch. In this paper, we report a method for fabricating helical structures with adjustable forms over large areas based on multiphoton polymerization (MPP) using single-exposure, three dimensionally structured, self-accelerating, axially tunable light fields. The light fields are generated as a superposition of high-order Bessel modes and have a closed-form expression relating the design of the phase mask to the rotation rate of the beam. The method is used to fabricate helices with different pitches and handedness in the material SU-8. Compared to point-by-point scanning, the method reported here can be used to reduce fabrication time by two orders of magnitude, paving the way for adopting MPP in many industrial applications.