In-Situ Optical Temperature Measurement in Micro-Scale during Ultrafast Laser 3D Nanolithography

Direct laser writing (DLW) 3D nanolithography is a mature and well-established precision additive manufacturing technique. However, some effects, such as thermal, acting an important role refashioning the mechanism of the process, are barely studied. The dominant heat sources of the reaction remains under debates, as they are material and excitation regime dependent [1]. The ultimate control of temperature becomes of top priority in case the 3D nano-printing for bio-applications is considered [2] as thermal conditions impact the pathway of polymerization and consequently, affect the morphology of structures fabricated. Unfortunately, no conventional thermometry approaches can be utilized for direct acquizition as the thermal gradients on a μm-scale must be resolved [1].