Bonn 2025 – scientific programme

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A: Fachverband Atomphysik

A 9: Poster – Ultra-cold Atoms, Ions and BEC (joint session A/Q)

A 9.27: Poster

Tuesday, March 11, 2025, 14:00–16:00, Tent

Improved Power Efficiency in Wide-Range Frequency Tuning with a Combined Single-/Double-Pass AOM System — •Luca Leon Granert, Silvia Hiebel, Sabrina Burgardt, Julian Feß, and Artur Widera — Department of Physics, RPTU Kaiserslautern-Landau, Kaiserslautern, Germany

In experiments with ultracold quantum gases, precise control of not only the position of laser beams for cooling and trapping but also their frequency and intensity is crucial. Acousto-optical modulators (AOMs) are widely used to achieve this level of control, as they enable fine-tuning of a laser’s frequency and power. Applications like compressed magneto-optical traps require large frequency detuning ranges to minimize photon scattering rates, thereby ensuring efficient loading into an optical dipole trap. AOM systems are typically configured in a double-pass configuration to achieve these extended detuning ranges and ensure intensity control. While such configurations are effective, they reach the limit of their angular tolerance when operated over broad detuning ranges within the same experimental run, leading to a significant decrease in efficiency, which can drop to below 1% at the extremes of the operating range.

We present an experimental setup, consisting of a single-pass and a double-pass AOM, built in series. Our system provides substantially higher efficiency at large detunings compared to typical double-pass configurations, while also extending the achievable effective detuning range. With this, power loss due to excessive detuning is minimized, ensuring that less light power is lost at large detunings.

Keywords: Acousto-Optical Modulators; Frequency Detuning; Efficiency Improvement; Experimental Setup