Photonic nanojet assisted enhancement in transmission of light through hollow pyramid shaped near field probes

Abstract

We report the use of sub-wavelength confinement of light using dielectric microspheres for enhancing transmission through the cantilever-based hollow probes used in a near-field scanning optical microscope. With an appropriate choice of the dielectric microsphere, an order of magnitude enhancement was achieved in transmission through the probe. In addition, transmission through such a tip was also found to be less sensitive to the axial and lateral offset between the beam waist and symmetry axis of the probe tip.

All-dielectric concentration of electromagnetic fields at the nanoscale: the role of photonic nanojets

“…They attached a dielectric microsphere to the tip of a cantilever-based hollow probe used in a near-field scanning optical microscope and observed an order of magnitude enhancement in the measured images. 282 We should mention that the application of microscale or nanoscale structures to enhance transmission and absorption is not exclusively engineered; Mother Nature has provided several examples. For example, leaves have adapted themselves to meet the essential prerequisite of funneling light energy efficiently and channeling it to the reaction centers to promote photosynthesis through hierarchical morphologies with optimized structures of various shapes and sizes.…”

Wavelength encoded polarization measurements for simultaneous spectral and polarimetric characterization in near field

“…Near field scanning optical microscopy (NSOM) that makes use of nano-scale aperture for illumination or collection and scanning probe technology is widely used for nanoscale optical microscopy and spectroscopy [1][2][3][4]. Among the commonly used near field probes namely the pulled fiber probes and the hollow cantilever probes the latter are known to have a well-defined polarization state at the probe tip and also have higher damage threshold [5][6][7][8][9]. This makes the hollow cantilever probes suitable for polarization sensitive imaging over a wide wavelength range.…”