Laser material processing with a multi-beam setup based on Excited State AbsorptionWednesday (24.06.2020) 13:46 - 13:49 Room 1
The continued drive towards ever smaller structures requires novel processing techniques that overcome the Abbe limit to open up future applications, e.g., in the fields of photonics and microelectronics [1-3]. Structures with lateral dimensions up to several tens of a nanometer are already realized by means of various photonic processes including multiphoton absorption, intensity threshold processes, and photolithography [4-6]. The present work deals with an alternative, novel technique of sub-diffraction direct laser writing based on a combination of Stimulated Emission Depletion (STED) with the effect of an Excited State Absorption (ESA) that allows the generation of structural sizes in the sub-wavelength range on optically active materials. Analogous to STED-microscopy, this approach creates an excited spatial volume below the diffraction limit. The modified optical properties of this volume compared to the non-excited surrounding regions are used for the subsequent spatially restricted material processing based on an ESA. We present the basic principles of the novel method and show first results of the material modification (e.g., in the form of ablation) solely induced by an ESA, whereby the individual fluences of both the pump- and the ESA-laser pulses are below the respective ablation thresholds. For this purpose, two (ultra-) short laser pulses were spatially superimposed to each other as shown in Figure 1(a). The interaction with an optically active layer deposited on an optically transparent substrate was studied in dependence on the pulse delay (Figure 1(b)). The fabrication of structures (spots and lines) were investigated as a function of versatile parameters including laser wavelength, pulse fluence, pulse delay, substrate material, and laser pulse number.
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|Extended Abstract||Version 1||This is a short manuscript to the abstract||307 KB||Download|
|Poster||Laser material processing with a multi-beam setup based on Excited State Absorption||1 MB||Download|