VUFF

The group’s research topic is the investigation of ultrashort light and matter interaction processes in different materials with the goal of applying new strategies for practical and innovative micromachining. Nowadays, ultrafast laser micromachining is by far the most advanced laser processing technique. Unlike material processing with longer laser pulses, ultrashort laser pulses have a negligible thermal impact on the material, which in turn reduces or even eliminates the development of heat-affected zones near the processed areas. This matter-light interaction consequence is a key element improving the quality of the micromachining operation and helping to achieve micrometer or even sub-micrometer precision. As the machining process is not dependent on the linear absorption mechanisms, technically all materials: glasses, metals, and mechanically hard materials can be machined using ultrashort laser pulses.

The Ultrafast micromachining group in the LRC was founded in 2002, and began working on topics dealing with volumetric modifications in transparent materials induced by focused femtosecond laser pulses. For example, under certain processing conditions, a smooth change in a material’s refractive index can be locally induced that opens opportunities for the three-dimensional (3D) inscription of photonic devices, such as integrated waveguide networks, various complexity diffractive optics elements (DOE), data bits etc. A second phase of expansion started in 2007, when the group, in collaboration with the Lithuanian laser company Altechna (and later WOP), started to develop new micromachining strategies for semiconductor, metal and other materials. A versatile laser micromachining system was installed in the laboratory with an integrated PHAROS (Light Conversion) laser, capable of implementing a wide spectrum of micromachining techniques.

The group focuses on various micromachining techniques and applications: volumetric modification in transparent materials, waveguide integration, DOE recording, laser-assisted chemical etching of glass, surface patterning, femtosecond ablation etc. Particular attention is given to the development of industry-friendly methods for the rapid cutting and drilling of transparent and opaque materials with femtosecond laser pulses.

The group has participated in several projects funded by the Lithuanian State Science and Studies Foundation (“Femtoapdirbimas”), EU Framework 7 program (“MesMesh”), ESFA (“Development and Utilization of a New Generation Industrial Laser Material Processing Using Ultra- short Pulse Lasers for Industrial Applications”) and others.

  FsMu Apdirbimas grFemtosecond micromachining group in the micro and macro-machining laboratory. From the left: Dr. O. Balachninaitė, Phd stud. A. Alesenkov and A. Baškevičius, Prof. V. Sirutkaitis, Dr. D. Paipulas, Dr. D. Kaškelytė, Dr. E. Gaižauskas, Phd students S. Butkus, Dr. M. Peckus, stud. A. Puišys

FsMu Apdirbimas pvzSamples of Femtosecond micromachining: left - microholes drilled in thermally sensitive ceramics; right – a cogwheel cut from 1-mm thick glass

 

Group members:

  • prof. V. Sirutkaitis,
  • dr. D. Paipulas,
  • dr. O. Balachninaitė,
  • dr. D. Kaškelytė,
  • dr. M. Peckus,
  • Ph.D. students S. Butkus, T. Kudrius,
  • student A. Puišys.

Research topics:

  • The development of novel methods for rapid micro and macro cutting of glass and other materials with Lithuanian-made femtosecond laser systems.
  • Volumetric modification of transparent materials via femtosecond laser pulses. Waveguide and other photonic device integration in glasses.
  • The development of new methods and strategies for laser microprocessing.
  • Femtosecond laser-induced breakdown spectroscopy (LIBS) and its applications for material characterization.

Laboratory equipment:

Two fife-axes submicron positioning micromachining systems with galvanoscanners and integrated Yb:KGW lasers PHAROS (average power – up to 20W, pulse duration – 270 fs, wavelengths - 1030 nm, 515 nm, 343 nm, 257 nm; pulse repetition rate up to 600 kHz).