1. CPA Laser system

Experiments with a femtosecond laser at microJules energy level and 2KHz repetition rate are done with a CPA system (Clark-MRX 2101). The amplified output beam is at 775 nm wavelength, with 250 fs pulse duration and the max. pulse energy is 0.7 mJ. This system is used in experiments such as laser ablation for micro and nano-structuring experiment on ceramics, semiconductors and metallic film, or two-photon photo-polymerization of photoresists for 3D micro-structuring, development of a multipulses laser for pump-probe experiments. An additional output from the oscillator of the CPA offers femtosecond laser beam at 35 MHz for ultrafast laser spectroscopy.

CPA femtosecond laser

2.Nano-second and pico-second Solid-State Lasers

Our group has a large experience in design and construction of flash and diode pumped solid-state lasers, laser microchip based microlasers, amplified solid-state lasers. A compact Nd:YAG laser with diode pumped microlaser, amplified in a multipass configuration up to 20 mJ pulse energy at 1-10 Hz. The laser can provide output beams at 1064, 532, and 266 nm, with pulse duration of about 500 ps. These laser radiations are suitable to applications such as laser microprocessing, laser induced break-down spectroscopy (LIBS), Near-field nanopatterning

Laser near-field nanolithography on monodispersed colloidal nanoparticles deposited on gold thin film. Laser wavelength l=532 nm. Pulse duration t=450 ps.

3.Microscope for Laser Direct Writing

During the recent research projects we developed a microscope for Laser Direct Writing. Coupled with our femtosecond lasers, the microscope is able to produce by laser ablation any computer designed structures with submicrometer resolution on various materials. Laser induced forward transfer (LIFT) is an other method to direct write microstructures using semiconductors, metallic films, or even biological tissues. We successfully tested the two-photon photopolymerization (TPP) technique on photoresist using two different high repetition rate femtosecond lasers (the attenuated CPA laser at 2 KHz, and a femtosecond oscillator at 80 MHz). The software of our microprocessing microscope is able to create predefined 3D geometries or to import 3D files in STL format, as in the well known rapid prototyping technique.

3D micro-structures on photo-polymers.

4.Nonlinear nanophotonics in UV nano-patterning (UV interferometric lithography)

Nd:YAG nanosecond laser with fundamental Gaussian beam of 150 mJ (1064 nm), SHG (100 mJ, 532 nm) and THG (20 mJ, 355 nm) and coherence length of 0.5 m; highly stable setups).

5. Nonlinear nanophotonics for information technologies at molecular level: ultrafast NLO in quantum dots and in metamaterials with sub-wavelength structures (in visible and IR – telecom bands)

Femtosecond fiber lasers (1030 nm and 1550 nm with SHG and supercontinuum generation in IR), Z-scan setups and wave-mixing setups