[20a-P1-1~11] 3.7 Laser processing

▲ [20a-P1-8] Characterization of two-photon exposure patterns in photoresist using photoluminescence quenching

〇(D)Edy Yulianto¹, Subhashri Chatterjee¹, Vygantas Mizeikis¹ (1.Shizuoka University)

Keywords:Direct Laser Writing

Direct Laser Writing (DLW) technique allows fabrication of three-dimensional (3D) objects and structures with high spatial resolution [1]. Ultrashort pulse laser beam is focused tightly in the bulk of photoresist, where optical exposure is induced in tiny 3D regions via two-photon (TPA) or multi-photon (MPA) absorption and writing of extended features is realized by linear scan of the beam focus. Here, we describe a technique to characterize the recorded latent 3D features in photoresist using quenching of photoluminescence excited by scanning a low-intensity probe beam over the previous recordings. Figure 1(a) shows schematic image of the experiment, which involves writing of x-oriented of thick lines at elevated laser power (5-15 mW) and their scanning along y-axis using low power (0.5 mW) probe beam, while recording the PL intensity. The experimental data in Fig. 1(b) demonstrate spatial variation of PL intensity representing spatial width of the recorded lines. Determination of useful parameters of the photoexposure patterns, such as threshold exposure dose and approximate size and shape of the recorded features using this method will be demonstrated.
[1] M.Malinauskas, M. Farsari, A. Piskarskas, S. Juodkazis, Phys. Reports 533, pp.02, (2013)