Optical Actuation of GeTe Phase-Change RF Switches at 915nm: Performance Comparison for Different GeTe Sizes and Impact of Cycling

This paper presents GeTe-based switches for RF applications, reversibly switching between their ON and OFF states thanks to optical activation by irradiation. Contrarily to what has been presented so far, the transition is induced by infrared laser pulses, at λ = 915 nm which is very encouraging for future integration of laser sources and therefore for proposing a fully integrated optical actuation of PCMs switches. This is a new trend as compared to literature work dealing with the other side of the visible spectrum, less suited for optical integration on a die. Our work also reveals the effectiveness of wide and thick PCMs at this wavelength, enabling bi-stable switching at high frequencies up to 40 GHz, with a FoM of 31.5 fs attained despite a poor GeTe conductivity of only 1.85·10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> S/m. Furthermore, significant progress as compared to the literature has been made by exceeding 30k cycles with optical actuation.