Atoms can be controlled by manipulating their internal states using agile, quiet and reliable laser sources. An external-cavity diode laser (ECDL) is a crucial enabling technology to realize such laser sources since it allows for the narrowing of the linewidth of a laser diode and precise tuning of the laser frequency. This project aims to miniaturize the external cavity using a photonic integrated circuit (PIC) (i.e., a single chip), which will increase the reliability and functionality of the optical frequency source for quantum experiments. A PIC ECDL will be designed and fabricated using aluminum nitride (AlN). Since several atomic transitions of interest in quantum applications are in the visible spectrum, AlN is an ideal material due to its large bandgap that allows for low-loss waveguide propagation. AlN also enables key functionality for preparing narrow linewidth and agile optical frequencies. Thus, an AlN waveguide will be fabricated and tested to ensure low waveguide losses at visible wavelengths. An external cavity feedback laser will be fabricated by coupling a laser diode directly into the AlN waveguide. A micro-ring resonator feedback circuit will be used to select and narrow the laser output. The light will be further coupled into fibre optics for delivery to atoms in a vacuum chamber, demonstrating the viability of using PIC ECDLs to interact with atomic energy levels. This AlN PIC ECDL would be a compact optical frequency source that could help enhance existing quantum experiments, enable experiments currently unviable with bulk optical setups and allow for the translation of quantum atomic technologies out of the laboratory (i.e., large-scale quantum computation, high-precision gravimeters for resource mapping and portable optical atomic clocks).
Figure 1. A conceptual render of an external cavity diode laser in an aluminum nitride integrated photonic circuit.
Related Content

Quantum Dynamics of Cavity Interactions with Spin Ensembles
Summary High quality factor cavities can be powerful control elements for ensembles of spins, enabling unitary control as well as on demand cooling. They can also be used to couple two otherwise non-interacting ensembles. The goal of the project is to explore the physics and engineering of such systems both theoretically and experimentally. The laboratory contains a […]
September 7, 2016

Rydberg Atom Array Quantum Simulator
Summary Quantum simulators enable probing the static and dynamic properties of correlated quantum many-body systems that would otherwise be numerically inaccessible using classical simulators. We are developing quantum simulators based on arrays of neutral atoms excited to Rydberg states. Such Rydberg atom arrays are advantageous for simulating the dynamics of interacting spin systems (Ising spin […]
February 27, 2020

Quantum Sensing with Small Quantum Systems
Summary There are small quantum systems over which we have very good control and which have long lifetimes. Examples include the phosphorous (P) defect in silicon (Si) and the nitrogen vacancy (NV) defect in diamond. With P defect in Si, we focus on improving our understanding of the hyperpolarization mechanism to better enable engineering of […]
December 1, 2016

Enabling Next-Generation Sustainable Computing through Novel Multi-Valued-Logic Quantum Devices
As the demand for digital services grows, so does the need for data centres and transmission networks. Unfortunately, these data systems consume vast amounts of energy, resulting in nearly 1% of all energy-related greenhouse gas emissions. This project aims to invent novel quantum devices for highly energy-efficient computing that may help reduce the global digital […]
June 12, 2023