Student projects

Tereza Zemánková, visiting PhD student from ISI Brno, May - June 2026

The objective of this project was to develop a cesium-saturated absorption spectroscopy (SAS) system for stabilizing the laser frequency to a cesium atomic transition. After optimizing the TApro beam profile, the laser was directed into the spectroscopy setup, where it was split into a high-intensity pump beam and two low-intensity probe beams. Using balanced detection, Doppler-free cesium hyperfine spectra with a high signal-to-noise ratio were obtained, enabling clear resolution of the hyperfine transitions and providing a robust error signal for stable laser frequency locking. The figure shows the measured Doppler-free hyperfine spectrum (green curve) together with the corresponding theoretical transition frequencies (gray dashed line).

Cecily Lowe, visiting PhD student from Yale University, February - May 2026

In this project, we first established a fiber-cleaving setup for preparing hollow-core photonic crystal fibers for vacuum integration. We then developed FLEX DDS-NG-based particle-loading software to control two AOMs, generate the moving optical conveyor, calculate the transport velocity, and monitor particle motion. Finally, we built and aligned the 1064nm optical conveyor and vacuum test setup, and demonstrated nanoparticle transport through the hollow-core fiber. This work lays the foundation for subsequent nanoparticle loading into our hybrid atom–nanoparticle system.

Antonio Pio Domenico Superbo, project student, March - July 2026.

To obtain a complete visual overview of the experimental setup, multiple cameras were distributed across the laboratory to monitor different stages of the experiment in real time. This was accomplished using a network of Raspberry Pi 4 nodes equipped with high-quality cameras. To ensure stable connectivity and efficient video handling, a dedicated desktop application was developed from scratch. This custom software, named "Raspberry Pi Ray," forms the core of the project. It provides a centralized control system that allows the laboratory to easily utilize the camera network by simply connecting the Raspberry Pi nodes to the main computer via an Ethernet cable.

Tobias Reitschmied, project student, January - July 2026

The goal of this project was to identify the sources of laser intensity noise, which showed up as DC drifts (10% of total power) and AC noise, and eliminate them. To address this problem, we planned and built a multi-step setup consisting of a low-frequency (LF) high-intensity stabilization stage based on an acousto-optical modulator (AOM) and a high-frequency (HF) low-intensity stage with an electro-optical modulator (EOM). We successfully eliminated DC drifts by employing an AOM with a PID. Because the detectors picked up electrical noise on the optical table, neither stage reduced AC noise by more than a few dB. The figure shows the PSD measurements before and after intensity locking, as well as the signal measured on the table, where the described behavior can be observed.