Ultrafast Laser Direct Writing in Glass: Thermal Accumulation Engineering and Applications

Abstract

Ultrafast laser direct writing (ULDW) is explored as a facile technique to induce unprecedented physical phenomena and functional structures three dimensionally in glass. The rapid prototyping and compatibility with a diversity of materials offer solutions to requirements for various applications and new emerging platforms in photonic circuits and networks, quantum platform, optical storage, nonlinear optics, and integrated multifunctional photonic chips. In this review, tuning the local thermal accumulation in the ULDW is demonstrated to provide a unique opportunity to induce a series of physical phenomena and produce structure modifications in glass beyond ULDW with negligible thermal accumulation. The device performance and fabrication efficiency are also improvable with adjusting local thermal accumulation. The principles of thermal ULDW, the generated structures and their applications are reviewed. This paper also gives an outlook to the basic challenges of thermal ULDW, and the important and promising directions for the future research.

Three-dimensional direct lithography of stable perovskite nanocrystals in glass

“…During ultrafast-laser direct lithography, the temperature of the laser-impacted domains increased rapidly with the number of pulses and remained stable at the maximum after several tens of pulses (typically less than 100 pulses that correspond to a t i of 1 ms for a 100-kHz ultrafast laser). A quenching process occurred after shutting off the ultrafast-laser irradiation ( 23 ). The ultrafast laser–induced temperature (>1000°C; fig.…”

Femtosecond laser-inscribed optical waveguides in dielectric crystals: a concise review and recent advances

“…The femtosecond laser modification may bring out some effects in dielectrics, such as refractive index changes, 33 stress, 63 birefringence, 64 nanogratings, 65,66 voids, 67,68 and thermal melting. 69 To promote permanent refractive index changes in the focal volumes, which are the base for waveguides, the pulse intensity has to be carefully controlled to avoid breakdown. 70,71 Nevertheless, the processes of femtosecond laser modification are generally very complex and strongly rely on the nature of materials and parameters of laser pulses.…”

Curved lattices of crystals formed in glass

“…Furthermore, beyond the formation of crystalline dots within a static temperature profile, the laser can be scanned, creating a dynamic temperature profile with the ability to pattern the crystals into full 3D architectures [14][15][16][17][18][19][20] that can even subsequently be erased or corrected. 21 Laser processing of glass has already been heavily discussed for modification, [22][23][24] space-selective crystallization, 14,16,25 and designing the orientation of these laser-fabricated crystals. 16,19,26 A precise control of the temperature profile is a unique and crucial benefit of laser heating.…”