PhD defense: Celeste Qvotrup

Nanomechanical Slot Waveguide Phase Shifters for Integrated Quantum Photonics

Integrated photonic circuits with embedded single-photon emitters offer a promising path for quantum computing. This work focuses on suspended GaAs membranes with InAs quantum dots (QDs), which enable near-perfect coupling of highly indistinguishable single photons into guided modes. However, conventional reconfigurable elements for quantum photonic circuits face limitations at cryogenic temperatures.

To address this, a nano-opto-electro-mechanical systems (NOEMS) phase shifter using slot waveguides and electromechanical actuation is designed, fabricated, and characterized. The device, featuring a compact footprint, demonstrated a phase shift of 3 pi with an active length of only 10 micron. Additionally, a NOEMS phase shifter was used to dynamically control a QD’s emission by modifying its optical environment, confirming variations in intensity and decay rate. These results mark a significant step toward scalable integrated quantum photonic circuits.