Optical Actuation Performance of Phase-Change RF Switches

Optical actuation of GeTe-based radio frequency switches is studied for the first time at 915-nm optical wavelength. By inducing self -heating of the phase change material through light absorption, this approach removes the need for integrated micro -heaters. First, laser pulse conditions required to set the RF switches in ON -and OFF -states are found with optical pulse peak powers up to few hundred mW. Amorphization is obtained for optical pulses of 100 to 500 ns, and crystallization for pulses of 2 to 6 mu s. A resistivity ratio of 2E4 is measured between both states. Cycling endurance is performed on a 4 x 5 mu m(2) switch, overpassing 1500 cycles, which is much higher compared to previously reported optical demonstrations. Small -signal measurements show 10% lower OFF -state capacitances using optical actuation compared to electrical actuation through micro -heaters. 37 dBm power handling capability is reported in the switch OFF -state at 915 MHz. This optical actuation demonstration corresponds to a standard wavelength in integrated photonic circuits and thus, this work constitutes a first step towards a CMOS compatible fully -integrated optical actuation solution for RF switches based on phase -change material.