High speed ultrafast laser anisotropic nanostructuring by energy deposition control via near-field enhancement

Abstract

It is challenging to store the exponentially increasing amount of data in the information age. The multiplexed optical data storage with merits of high data density (hundreds of terabytes/disk), low energy consumption, and long lifetime could open a new era in data storage technology. The recent progress in five-dimensional (5D) optical data storage based on anisotropic nanostructures written by femtosecond (fs) laser pulses in transparent materials reveals its potential for real-world applications, but high writing speed and density remain a major challenge. Here, we propose a method for rapid and energy-efficient writing of highly localized anisotropic nanostructures in silica glass by energy modulated megahertz-rate fs pulses. An isotropic nanovoid is initially generated with pulse energy above the microexplosion threshold and then elongated to an anisotropic nanolamella-like structure via the near-field enhancement effect by lower energy pulses, minimizing the unwanted thermal effects from megahertz-rate fs pulses. The anisotropic nanostructures are exploited for 5D data storage with a rate of 10 6 v o x e l s / s , corresponding to a demonstrated fast information recording of ∼ 225 k B / s and a potentially high-density data storage of ∼ 500 T B / d i s k .

Sub-40nm Nanogratings Self-Organized in PVP-based Polymer Composite Film by Photoexcitation and Two Sequent Splitting under Femtosecond Laser Irradiation

“…The regular nanogratings always appeared in the center of the laser irradiation track in our experiments, indicating that the required energy is higher than that for solidification. The direction of the periods is definitely perpendicular to the polarization [39] as shown in Figure 1c-1f. With a circularly polarized irradiation beam, the U-nanogratings broke into small nanosquares and is in agreement with previous reports (Figure 1g).…”

Femtosecond laser-induced periodic structures: mechanisms, techniques, and applications

“…Birefringent optical components and information storage HSFL nanostructures inside fused silica exhibit birefringence effects comparable to those of quartz crystals 34,36,152,153 and have been used in the storage of multi-dimensional data, as shown in Fig. 12.…”

Polariscopy with optical near-fields

“…nanoscales. 6,7 Linear polarisation probes the orientation of absorption, scattering and reflectance, and their anisotropies, via non-destructive and remote utility. Super-resolution (6 nm) was recently demonstrated within visible wavelengths using a radially polarised beam to map the absorption of carbon nanotubes.…”

“…Polarisation of light in different wavelength ranges has become an essential analytical tool in a diverse range of applications, such as those used for probing material's anisotropy in infrared (IR) wavelengths, 1,2 cataclysmic gravitational astronomical events by the imaging X-ray polarimetry explorer (IXPE), 3 the chirality of matter (or interaction), 4,5 and for multi-dimensional optical memory inscription to control optical retardance at nanoscales. 6,7 Linear polarisation probes the orientation of absorption, scattering and reflectance, and their anisotropies, via non-destructive and remote utility. Super-resolution (6 nm) was recently demonstrated within visible wavelengths using a radially polarised beam to map the absorption of carbon nanotubes.…”