Reversible, Fast Optical Switching of Phase Change Materials for Active Control of High-Frequency Functions

We present the implementation of an optical activation scheme of phase change materials (PCMs such GeTe, Ge2Sb2Te5 –GST…) allowing to change their states between a high-resistivity insulator and a low-conductivity metal in a reversible and bi-stable manner using short (~30 ns) laser pulses. We demonstrate the integration of PCMs as highly effective, optically controlled elements allowing bi-stable high-frequency switching up to 67 GHz. The RF switching devices have low insertion losses when the PCM material is in its conductive state and high isolation when the material is insulating, up to 67 GHz. We will report the application of this optically activation principle for realizing more complex functions such as planar band-pass filters whose responses can be optically tuned in the millimeter-wave frequency domain.