Fabrication of surface plasmon waveguide devices in CYTOP with microfluidic channels

Abstract

Long Range Surface Plasmon Polariton (LRSPP) waveguide biosensors were fabricated and optically characterized. The topology comprised of thin (35 nm) Au stripe waveguide devices embedded in thick (∼18 mum) CYTOP claddings. Patterned regions of the Au surface were exposed from its top cladding through O2 plasma etching. The etched CYTOP cavity acted as mircofluidic channels for containment of index-matched sensing fluid. The fabrication process was documented and examined for dimension and structure/surface profiles. The presented data and figures are: optical index measurements, thickness measurements, microscope images, SEM images, and AFM profiles. Optical characterizations were performed on full CYTOP cladded and half cladded, channel-filled straight waveguides. LRSPP modes were excited through end-fire coupling with fiber-optics. The measured propagation losses were 6.33 dB/mm and 10.46 dB/mm respectively. The results deviated from the simulated value of 7.2 dB/mm and were suspected to originate from material and structure properties of CYTOP.