Han, MolongSmith, DanielKahro, TaunoStonytė, DominykaKasikov, AarneGailevičius, DariusTiwari, VipinXavier, Agnes Pristy IgnatiusGopinath, ShivasubramanianNg, Soon HockRajeswary, Aravind Simon John FrancisTamm, AileKukli, Kaupo2024-09-202024-09-202024https://doi.org/10.3390/mi15040537https://hdl.handle.net/10062/104852Axial resolution is one of the most important characteristics of a microscope. In all microscopes, a high axial resolution is desired in order to discriminate information efficiently along the longitudinal direction. However, when studying thick samples that do not contain laterally overlapping information, a low axial resolution is desirable, as information from multiple planes can be recorded simultaneously from a single camera shot instead of plane-by-plane mechanical refocusing. In this study, we increased the focal depth of an infrared microscope non-invasively by introducing a binary axicon fabricated on a barium fluoride substrate close to the sample. Preliminary results of imaging the thick and sparse silk fibers showed an improved focal depth with a slight decrease in lateral resolution and an increase in background noise.enAttribution-NonCommercial-NoDerivs 3.0 Estoniainfrared microscopyaxial resolutionbinary axiconphotolithographyfemtosecond ablationchemical imaginginfo:eu-repo/semantics/article