Multiple-spot parallel processing for laser micronanofabrication

Optical storage arrays: a perspective for future big data storage

“…Various optical parallelism methods for generating multifocal arrays in single laser shots have been proposed and experimentally demonstrated, including microlens arrays, 51 diffractive optical elements, 52 Debye-based Fourier transformation 53 and dynamic computer-generated holograms. 54 Among these methods, Debye-based Fourier transformation enables the formation of diffraction-limited multifocal spots using a high-NA objective wherein each focal spot can be dynamically programmable, which is a necessity for ultrahigh-density optical recording.…”

A tutorial on optics for ultrafast laser materials processing: basic microprocessing system to beam shaping and advanced focusing methods

“…To obtain a uniform intensity distribution in the focal spot array, the incident femtosecond laser was expanded before entering the microlens array. Amazingly, a subdiffraction-limited resolution of ~ 250 nm has been achieved with this system [25] . Previously, a major drawback of the multifocus parallel laser fabrication was that it could be used only for fabricating the microstructures arranged in periodic arrays.…”

“…Figure 4 A -C schematically shows the three typical systems for parallel femtosecond microprocessing. Among them, the technique based on a microlens array shown in Figure 4A is a straightforward extension of the concept of the direct writing system described in Section 3.1 by spatially splitting the single focal spot into multiple foci uniformly distributed in the focal plane [24,25] . The microlens array converts the collimated femtosecond laser beam into an array of focal spots in plane A.…”

Dynamic optics for ultrafast laser processing

“…This can be done through the use of a microlens array [6], space-time focusing [7] or holography [8]. The approach used here is to display phase-only holograms on a liquid crystal spatial light modulator.…”