Recently released in Optics Letters, our article reports on the use of a commercial wavefront sensor to directly monitor and image the Gouy phase shift in photonic nanojets created by micrometer-sized dielectric spheres.
Compared to previous demonstrations, our approach does not require interferometric heterodyne or homodyne detections. Just plug-in the Sid4Bio camera from Phasics on the left/right port of the microscope, run the software, and get the phase image.
Such direct phase imaging using a commercial wavefront sensor should find applications in microscopy, diffractive optics, optical trapping, and point spread function engineering.
Guess who's beyond these lovely bonnets péruviens pour bébé et enfant en coton ?
Metal subwavelength apertures have turned into essential devices to manipulate light at the nanoscale. However, experimentally characterizing the amplification brought by the nanoaperture on the excitation intensity remains a scientific and technical challenge. Such characterization is highly needed to fully understand and optimize the aperture’s design.
Our recent Optics Express manuscript describes a novel experimental method to directly characterize the aperture amplification on the excitation field independently on the emission process. We take advantage of the intrinsic nonlinear dependence of the fluorescence signal on the excitation intensity.
The most funny part is that we report enhanced nonlinear light-matter interaction using only a HeNe laser with less than 1mW CW power.