Mizeikis Vygantas（ミゼイキス ビガンタス）

Femtosecond laser lithography uses tightly focused powerful femtosecond laser pulses to draw various micro- and nano-structures in materials. The outcome of such drawing can be of fundamental and applied interest to various fields of science and technology, especially electronics. My research over the last two decades has been focused on its application in two fields: photonics and materials science. In photonics, I have been using two-photon polymerization induced by the femtosecond laser pulses in photoresists to realize 3D periodic micro- and nano-structures that allow control over emission, absorption and propagation of light by exploiting sub-wavelength scale interaction between optical waves and finely-patterned structures. 3D photonic crystals exhibiting the structural color phenomenon were realized. Photonic crystals having spatially varied (chirped) lattice periods and capable of spatially focusing light along its propagation direction were demonstrated. Anisotropic photonic crystals exhibiting strong optical birefringence were realized. Metalo-dielectric optical metasurfaces exhibiting perfect absorption of radiation at infrared wavelengths were achieved. These applications are potentially important to the development of novel optical and environmental sensors, information processing, optical energy conversion, and security applications. In materials science I took part in the studies of modification induced in solid crystals using micro-explosions ignited by tightly focused femtosecond laser pulses. Due to extremely high temperature and pressure created by micro-explosions, dissociation of sapphire (Al2O3) into hot electron-ion plasma followed by formation of a new ultra-dense phase aluminum not existing in normal conditions, was confirmed. The fact that all these results were achieved in simple desktop experiments that do not require cleanroom environment, vacuum conditions, use of aggressive chemicals, etc., illustrates the benefits of femtosecond laser lithography for applied and fundamental science.