Fabrication and characterization of high-contrast mid-infrared GeTe₄ channel waveguides

We report the fabrication and characterization of high index contrast (Δn ~ 0.9) GeTe4 channel waveguides on ZnSe substrate for evanescent-field based biosensing applications in the mid-infrared spectral region. GeTe4 films were deposited by RF sputtering and characterized for their structure, composition, transparency and dispersion. The lift-off technique was used to pattern the waveguide channels. Waveguiding between 2.5-3.7 µm and 6.4-7.5 µm was demonstrated and mode intensity profile and estimated propagation losses are given for the 3.5 µm wavelength