Konstantin E Lapshin

Femtosecond laser fabrication of linear graphitized microstructures in a bulk of polycarbonate samples

We have fabricated high aspect ratio straight and curved graphitized lines inside of polycarbonate samples by using a femtosecond laser. Use of a spherical lens with high NA to focusing femtosecond pulse in the bulk of material leads to self-diffraction of laser beam and formation a filamentary structure. We fabricated two kinds of graphitized lines. The first type is a straight line extended in the direction of the laser beam. This type of lines was created by femtosecond laser scanning without pulse overlapping. The second type of graphitized lines is curved lines, which was created by scanning with a significant overlapping of focal spot. We determined conditions of the formation of straight graphitized lines by one femtosecond pulse with diameter about 2 pm and length greater than 1 mm in polycarbonate samples. Mechanism of formation and potential applications of these structures are also discussed.

Managing of spatial characteristics of internal modifications by means of optical delay in cases of femtosecond micromachining of materials

Presents the results of direct managing of spatial characteristics of the modifications in the case of focusing of femtosecond laser pulses in a bulk of material. Managing performed by inserting optical delay into different parts of the focused beam.

Light driven self-ordering in fused quartz

Theoretical and experimental investigation of self-ordering in a fused quartz under strong light pumping is presented. It is shown that uniform radiation drives a self-organization process in a random medium and macroscopic spatially ordered structure is formed.

Excimer laser micromachining

Wavelength, pulse energy, repetition rate of excimer lasers as well as beam profile and beam delivery system are highly important parameters for precision machining. In this paper we report features of our excimer lasers and excimer laser systems that have been designed for micromachining. The examples of treatment of different materials are presented. In particular, we provide some new results of microstructuring of the surface of fused silica and also formation of up to 10 mm long microchannels with extremely high aspect ratio. We discovered some liquid forming under certain circumstances due to drilling of microchannels in PMMA. This liquid remains unchanged in the microchannels after the treatment.