Coherence switching of a degenerate VECSEL for multimodality imaging

TL;DR

This paper presents a compact, electrically pumped VECSEL that can switch between high and low spatial coherence modes, enabling multimodality imaging such as high-speed microscopy and flow dynamics analysis.

Contribution

It introduces a novel degenerate VECSEL source with adjustable spatial coherence for multimodal imaging applications.

Findings

Successfully demonstrated coherence switching in a compact VECSEL

Enabled multimodal imaging of embryo heart function

Achieved low power loss during mode switching

Abstract

We demonstrate a VECSEL (vertical external cavity surface emitting laser) based degenerate source with an adjustable degree of spatial coherence that is electrically pumped, mechanically compact and supports continuous-wave emission. The laser operation can be switched between a large number of mutually incoherent spatial modes and few-mode operation at little power loss. This technology allows multimodality imaging, where low spatial coherence illumination is used for traditional high-speed video-microscopy and high spatial coherence illumination is used to extract dynamic information of flow processes. The initial demonstration is performed on imaging embryo heart function in Xenopus, which is an important animal model for human heart disease.