CdTe microwires as mid-infrared optical waveguides

Cadmium telluride (CdTe) has been proven to be an attractive mid-infrared (MIR) material with a large refractive index (~2.68 at 4.5 μm) and broadband transparency (~1 to 25 μm). CdTe microwires (MWs) with diameters from a few to about ten micrometers were fabricated by a thermal evaporation process. MIR light was coupled into and guided through individual MWs. Excellent optical waveguiding properties of these MWs are experimentally obtained within MIR spectral range (up to 8.6 μm), with waveguiding losses from 1.3 to 13 dB/cm. Our results show that CdTe MWs can be used as wavelength or subwavelength-width waveguides for MIR microphotonics or circuits.