Fourier plane optical microscopy and spectroscopy

TL;DR

This review discusses Fourier plane microscopy and spectroscopy techniques for analyzing wavevector distributions in light beams, highlighting methodologies, applications, and error sources at the nanoscale.

Contribution

It provides a comprehensive overview of back focal plane imaging and spectroscopy, including methodologies, configurations, and applications in nanophotonics.

Findings

Techniques for measuring wavevector distributions from nanostructures and metasurfaces

Analysis of sources of error and methods to mitigate them

Applications in fluorescence, Raman, and scattering measurements

Abstract

Intensity, wavevector, phase, and polarization are the most important parameters of any light beam. Understanding the wavevector distribution has emerged as a very important problem in recent days, especially at nanoscale. It provides unique information about the light-matter interaction. Back focal plane or Fourier plane imaging and spectroscopy techniques help to measure wavevector distribution not only from single molecules and single nanostructures but also from metasurfaces and metamaterials. This review provides a birds-eye view on the technique of back focal imaging and spectroscopy, different methodologies used in developing the technique and applications including angular emission patterns of fluorescence and Raman signals from molecules, elastic scattering etc. We first discuss on the information one can obtain at the back focal plane of the objective lens according to both imaging and spectroscopy viewpoints and then discuss the possible configurations utilized to project back focal plane of the objective lens onto the imaging camera or to the spectroscope. We also discuss the possible sources of error in such measurements and possible ways to overcome it and then elucidate the possible applications.