We demonstrate subwavelength sectioning on biological samples with a conventional confocal microscope. This optical sectioning is achieved by the phenomenon of supercritical angle fluorescence, wherein only a fluorophore next to the interface of a refractive index discontinuity can emit propagating components of radiation into the so-called forbidden angles. The simplicity of this technique allows it to be integrated with a high numerical aperture confocal scanning microscope by only a simple modification on the detection channel. Confocal-supercritical angular fluorescence microscopy would be a powerful tool to achieve high-resolution surface imaging, especially for membrane imaging in biological samples.
© 2014 Optical Society of America
Original Manuscript: November 11, 2013
Revised Manuscript: December 19, 2013
Manuscript Accepted: December 19, 2013
Published: January 24, 2014
Vol. 9, Iss. 4 Virtual Journal for Biomedical Optics
Siddharth Sivankutty, Thomas Barroca, Céline Mayet, Guillaume Dupuis, Emmanuel Fort, and Sandrine Lévêque-Fort, "Confocal supercritical angle microscopy for cell membrane imaging," Opt. Lett. 39, 555-558 (2014)