Spectral interference contrast based non-contact photoacoustic microscopy realized by SDOCT

We introduce a method to extract the photoacoustic (PA) signal from a contrast reduction of the interference spectrum acquired by spectral domain optical coherence tomography (SDOCT). This all-optical detection is achieved in a non-contact manner directly on the water surface covered on the sample by using its specular reflection. During SDOCT exposure, the phase of the interference spectrum keeps shaking according to the water surface vibration induced by PA excitation. This results in an interference contrast reduction which is quantified by a fast Fourier transform (FFT) for PA imaging. A tungsten filament, asparagus fern leaf, and mouse auricle are imaged to demonstrate the method. (C) 2022 Optica Publishing Group

Automated summary

This article introduces a method to extract the photoacoustic (PA) signal from the contrast reduction in the interference spectrum obtained from spectral domain optical coherence tomography (SDOCT). The method utilizes the specular reflection on the water surface to achieve all-optical detection in a non-contact manner. By analyzing the phase changes in the interference spectrum induced by water surface vibration, the method enables quantification of the interference contrast reduction for PA imaging.