Hilbert transform-based single-shot plasmon microscopy

The localized properties of surface plasmons (SPs) and surface waves can be measured with a modified confocal microscope. An interference signal arises from a locally generated reference close to normal incidence and the beam that forms the surface wave. A spatial light modulator can impose different phase shifts on the part of the incident light to recover the properties of the SP. We report a Hilbert transform method to recover the wavenumber with a single shot. The method is faster and potentially less expensive than previous approaches. The signal-to-noise ratio is equivalent to the phase-stepping method. The signal processing necessary to condition the signal is described.