Preliminary results of the application of optical coherence tomography (OCT), in particular in its spectral mode (SOCT) to the control of a varnish ablation process, are presented. Examination of the ablation craters made with an Er:YAG laser allows optimization of the laser emission parameters controlling fluence with respect to efficiency and safety of the ablation process. Results of measurements of ablation crater depth as a function of the number of pulses for a given fluence are presented for selected resins. This validates the applicability of SOCT to calibration of ablation conditions for the particular laser-varnish-paint layer combinations, and of its usage in planning the varnish ablation procedure. These results also imply that a review of conventional ablation thresholds is called for. Applicability of the SOCT technique to contemporaneous in situ monitoring of the range of varnish ablation is discussed.
Doppler optical coherence tomography imaging of local fluid flow and shear stress within microporous scaffolds