Imaging of latent three-dimensional exposure patterns created by direct laser writing in photoresists

摘要

A technique to visualize latent three-dimensional photoexposure patterns recorded in photoresist using direct laser writing technique is described. Owing to photoluminescence quenching in the regions of photoresist previously exposed to intense laser radiation, spatial mapping of two-photon excited photoluminescence intensity across the laser-processed region was found to reveal size, shape, and geometric parameters of the exposed patterns prior to their development. Fast, non-destructive preliminary diagnostics of the laser-written structures may improve the versatility and applicability of direct laser writing technique for fast prototyping of micro- and nano-structures.