Volume Modification

Highly focused ultrashort pulses enable volume modification of transparent materials, such as glass, sapphire, and other crystals. The robust control of laser parameters and precise intra-volume positioning of laser focal spot allows inscription of complex structures like Bragg gratings and waveguides.

The process is typically driven by multiphoton absorption, which requires high intensities so that the material is modified only at the focal spot. The laser-induced material volume modification impacts the density of the material and, subsequently, the refractive index. This is a key principle utilized in the creation of fiber Bragg gratings (FBGs) as alternating structures are written into the transparent material by inducing refractive index change rather than optically damaging the fiber. FBGs have been demonstrated in both single-mode and dual-cladding fibers.

Furthermore, the modified material can be chemically etched away. This two-step process is called selective laser etching. After volume modification, the glass or sapphire gains different etching properties. Thus, using material-dependent etching solutions, various mechanically stable and durable structures, like curved waveguides or even 3D forms, are obtained.

PHAROS and CARBIDE femtosecond lasers are widely used for all of the aforementioned volume modification applications, making a strong impact in the development of future technologies.

  • 100 fs – 20 ps tunable pulse duration
  • 4 mJ maximum pulse energy
  • 20 W maximum output power
  • Single-shot – 1 MHz repetition rate
  • BiBurst
  • Automated harmonic generators (up to 5th harmonic)
  • 190 fs – 20 ps tunable pulse duration
  • 2 mJ maximum pulse energy
  • 80 W maximum output power
  • Single-shot – 2 MHz repetition rate
  • BiBurst
  • Air-cooled version
  • 515 nm, 343 nm, 257 nm, or 206 nm output
  • Automated harmonic selection
  • Mounted directly on the laser head
  • Industrial-grade design
  • 515 nm, 343 nm, or 257 nm output
  • Automated harmonic selection
  • Mounted directly on the laser head
  • Industrial-grade design
  • 30 W UV model option

Circular cross section waveguides processed by multi-foci-shaped femtosecond pulses

Z. Li, X. Li, F. Yu, Q. Chen, Z. Tian, and H. Sun, Optics Letters 3 (46), 520 (2021).

Highly Emissive Deep-Red Perovskite Quantum Dots in Glass: Photoinduced Thermal Engineering and Applications

K. Sun, D. Tan, J. Song, W. Xiang, B. Xu, and J. Qiu, Advanced Optical Materials, 2100094 (2021).

Photoluminescence of Point Defects in Silicon Dioxide by Femtosecond Laser Exposure

V. D. Michele, E. Marin, A. Boukenter, M. Cannas, S. Girard, and Y. Ouerdane, physica status solidi (a), 2000802 (2021).

Self-organized phase-transition lithography for all-inorganic photonic textures

B. Zhang, D. Tan, Z. Wang, X. Liu, B. Xu, M. Gu, L. Tong, and J. Qiu, Light: Science & Applications 1 (10) (2021).

Control of Laser Induced Cumulative Stress for Efficient Processing of Fused Silica

Q. Sun, T. Lee, M. Beresna, and G. Brambilla, 1 (10) (2020).

Direct Laser Written Waveguide in Tellurite Glass for Supercontinuum Generation in 2 µm Spectral Range

A. G. Okhrimchuk, A. D. Pryamikov, A. V. Gladyshev, G. K. Alagashev, M. P. Smayev, V. V. Likhov, V. V. Dorofeev, S. E. Motorin, and Y. P. Yatsenko, Journal of Lightwave Technology 6 (38), 1492-1500 (2020).

Femtosecond laser inscription of waveguides and Bragg gratings in transparent cyclic olefin copolymers

G. Roth, S. Hessler, S. Kefer, M. Girschikofsky, C. Esen, and R. Hellmann, Optics Express 12 (28), 18077 (2020).


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