Integration of a GaAs-based nanomechanical phase shifter with quantum-dot single-photon sources

We demonstrate a small-footprint electromechanical phase shifter with a compact active length of 10\:μ m fabricated on a suspended GaAs membrane, offering versatile integration with quantum-dot single-photon sources. The phase shifter is based on a slot-mode waveguide, whose slot width can be controlled by electrostatic forces, enabling a large effective refractive index change Δ nₑff > 0.1. We observe up to 3π phase modulation with 10.6 V applied bias, and a figure of merit VπL = 5.7· 10⁻³ V· cm. Integration with a Mach-Zehnder interferometer (MZI) further allows routing of single photons with up to 24 dB extinction ratio at cryogenic temperatures. This device enables advanced manipulation of quantum emitters and the realization of reconfigurable quantum photonic integrated circuits.