Switchable thermal waveguides in GaAs based devices

The modulation of light within microscopic devices is the key to designing versatile and powerful photonic integrated circuits (PICs). Contemporary techniques are able to generate a wide range of waveguiding and waveforming elements. They are implemented by the etching of trenches, laser induced waveguide writing, and many other techniques. However, most of the fabricated structures feature a static waveguiding behavior that remains unaltered after processing the devices. In this work, we demonstrate the simulation, design, and experimental behavior of truly switchable microscopic waveguides. We demonstrate the presence of waveguiding and forming elements by localized heating, leading to a tunable refractive index profile in GaAs based devices. We give insights into the microscopic behavior by multi-physics simulations in the mechanical, thermal, and optical domains. This approach opens the way to further possibilities in the design of PICs and useful modifications within existing diode laser and amplifier setups.