Bi-modal photothermal/optical microscopy for complementary bio-imaging with high resolution and contrast

TL;DR

This paper introduces a bimodal microscopy technique combining reflection-mode optical and photoacoustic imaging for high-resolution, contrast-rich visualization of biological samples, enhancing feature detection and heat localization.

Contribution

The study presents a novel bimodal microscopy method integrating optical and photoacoustic imaging with precise laser positioning, providing complementary visualization and adjustable image quality.

Findings

Photoacoustic imaging enhances visualization of micro-hairs in Drosophila.

Modulation frequency controls photoacoustic image quality.

Combined modality offers high resolution and contrast in bio-imaging.

Abstract

In the paper, combined bimodal microscopic visualization of biological objects based on reflection-mode optical and photoacoustic measurements was presented. Gasmicrophone configuration was chosen for the registration of photothermal response. Precise positioning of the scanning laser beam with modulated intensity was performed employing acousto-optic deflectors. Photoacoustic images are shown to give complementary details to the optical images obtained in the reflected light. Specifically, the photoacoustic imaging mode allows much better visualization of the features with enhanced heat localization due to the reduced heat outflow. For example, the application of the photoacoustic imaging mode was especially successful to visualize Drosophila fly's micro-hairs. Furthermore, the photoacoustic image quality was shown to be adjusted through modulation frequency.