GeTe4 waveguides were designed and fabricated on silicon substrates with ZnSe isolation layer. GeTe4 has a refractive index of 3.3 and it needs a lower refractive index isolation layer to realise waveguides on silicon. Numerical modelling was carried out to calculate the thickness of the isolation layer (ZnSe, refractive index ~2.4) required to achieve low loss waveguides. For a loss between 0.1 and 0.01dB/cm it was found that ~ 3 µm thick ZnSe film is required at 6.5 µm wavelength. ZnSe thin films were deposited on silicon, GeTe4 waveguides were fabricated by lift-off technique and were characterised for mid-infrared waveguiding.
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