Fig. 1. (a) Schematic of device showing two electrodes (gold) with channels between the interdigital fingers (black). Diagram also shows transverse, ET, and longitudinal, EL, polarizations, as well as the polarization angle, θ; (b) cross section of device showing Au electrodes with thickness, w, and spacing, d, attached to the semi-insulating GaAs substrate with the Ti layer.

Fig. 2. (a) I–V characteristics of device with 5 μm electrode spacing under illumination intensity of 100  mW/cm2; (b) detectivity of the device with 5 μm electrode spacing.

Fig. 3. (a) Spectral response spectra for transverse polarization as function of electrode spacing, d; (b) normalized peak from (a) plotted as function of electrode spacing; (c) normalized calculated photocurrent as a function of electrode spacing at 875 nm incident light.

Fig. 4. (a) Measured spectral response of a 5 μm device for transverse and longitudinal polarization; (b) calculated optical enhancement near the electrode edge for transverse polarization; (c) calculated optical enhancement near the electrode edge for longitudinal polarization; (d) polarization-dependent normalized spectral response measurements (squares) and normalized photocurrent calculations (circles) with a A cos2 θ+B fit (line).