Seminar INFLPR, Miercuri, 30.03.2016, ora 10:00, Sectia Laseri, Dr Florin Jipa: “Near-field laser processing method based on transparent photorezist masks”

Sunteti invitati sa participati la seminarului stiintific de miercuri, 30.03.2016, ora 10:00 din Sectia Laseri care va cuprinde prezentarea D-lui Florin Jipa cu titlul: “Near-field laser processing method based on transparent photorezist masks”

In this work a new laser near-field processing method based on photoresist mask is presented. This is an alternative method to the classical laser near-field lithography with colloidal particles. The limitation of the hexagonal symmetry, imposed by the auto-arrangement of the colloidal particles can be overcome if photoresist structures, fabricated by two photon photopolymerization, are used as focusing elements. Controlling the shape and the arrangement of these elements any designed pattern can be produces on materials surface by laser near-field ablation.
Experimentally, the designed masks were used to process a silicon material surface. A single infrared femtosecond laser pulse was used to expose the mask. During the propagation through the mask, the laser pulse is concentrate by the photoresist elements in localized photonic-jets. Depending on the mask configuration, the imprinted pattern on the silicon surface was changed from periodic channels to an array of holes.The AFM and SEM investigations show that these structures have dimensions smaller than laser wavelength and the periodicity is identical with mask configuration.