Differential Detection for Nanoplasmonic Resonance Sensors

A differential measurement design employing two nearly collinear optical beams can lead to surface plasmon polariton (SPP) sensors of increased dynamic range and signal-to-noise ratio. We demonstrate a differential measurement device that is based on wavelength interrogation, employs a single incident polarization state, and is combined with a 2-D nanohole array for operation at near-normal incidence, where this approach offers a decrease in the measurement time.