High refractive index immersion liquid for super-resolution 3D imaging using sapphire-based aNAIL optics
Abstract
Optically-transparent immersion liquids with refractive index (n ~ 1.77) to match sapphire-based aplanatic numerical aperture increasing lens (aNAIL) are necessary for achieving deep 3D imaging with high spatial resolution. We report that antimony tribromide (SbBr) salt dissolved in liquid diiodomethane (CHI) provides a new high refractive index immersion liquid for optics applications. The refractive index is tunable from n = 1.74 (pure) to n = 1.873 (saturated), by adjusting either salt concentration or temperature; this allows it to match (or even exceed) the refractive index of sapphire. Importantly, the solution gives excellent light transmittance in the ultraviolet to near-infrared range, an improvement over commercially-available immersion liquids. This refractive index matched immersion liquid formulation has enabled us to develop a sapphire-based aNAIL objective that has both high numerical aperture (NA = 1.17) and long working distance (WD = 12 mm). This opens up new possibilities for deep 3D imaging with high spatial resolution.
Cite
@article{arxiv.1512.08208,
title = {High refractive index immersion liquid for super-resolution 3D imaging using sapphire-based aNAIL optics},
author = {Junaid M. Laskar and P. Shravan Kumar and Stephan Herminghaus and Karen E. Daniels and Matthias Schröter},
journal= {arXiv preprint arXiv:1512.08208},
year = {2016}
}