Fabrication and packaging of integrated chemo-optical sensors

This paper describes the design and fabrication of a sensitive integrated chemo-optical sensor supplied with on-chip fiber-to-waveguide connectors. The sensor is designed for TE-polarized light with wavelength of 633 nm. The fiber-to-chip connectors are based on easily fabricated silicon V-grooves combined with a smooth sawcut. The sawcut is defining the channel waveguide endface. The sensor is based on a phase modulated Mach-Zehnder interferometer, using the electro-optic effect of the waveguiding material zinc oxide (ZnO). The fiber-to-chip connector units have a typical coupling efficiency of 0.1–1%. The electro-optical voltage × length product V π is 15 ± 4 V cm at frequencies above 100 Hz. Preliminary experiments on the general (passive) sensor response showing its expected high sensitivity are discussed.