Characterization of long-range plasmonic waveguides at visible to near-infrared regime

Long-range surface plasmon polariton waveguides composed with thin gold stripes embedded in SU-8 polymer cladding with various stripe widths were fabricated. Material properties of the polymer cladding layer, gold thin film, and the device structures were discussed. Optical properties based on modal propagation were characterized at visible to near-infrared wavelengths. The measured propagation losses of waveguide widths from 3 to 9 μm at 633, 785, and 1550 nm are 7.5-18.8, 6.8-12.5, and 1.9-3.9 dB/mm, respectively. Guiding mode properties such as overlap integrals between the simulated and the measured fields and the polarization extinction ratios of the waveguides with different stripe widths were investigated at the telecommunication wavelength. Good accordance between the measurement and simulation results was presented.