Laser Doppler holographic microscopy in transmission: application to fish embryo imaging

TL;DR

This paper extends Laser Doppler holographic microscopy to transmission mode, enabling detailed, multimodal imaging of blood flow in living fish embryos with quantitative capabilities.

Contribution

The authors developed a transmission geometry for Laser Doppler holographic microscopy, allowing multimodal, quantitative imaging of blood flow in live fish embryos.

Findings

Successfully imaged blood vessels and flow in fish embryos

Produced Doppler images with flow direction in RGB colors

Captured movies of individual blood cell motion

Abstract

We have extended Laser Doppler holographic microscopy to transmission geometry. The technique is validated with living fish embryos imaged by a modified upright bio-microcope. By varying the frequency of the holographic reference beam, and the combination of frames used to calculate the hologram, multimodal imaging has been performed. Doppler images of the blood vessels for different Doppler shifts, images where the flow direction is coded in RGB colors or movies showing blood cells individual motion have been obtained as well. The ability to select the Fourier space zone that is used to calculate the signal, makes the method quantitative.