Fiber-integrated acousto-optic-modulator-based phase-controlled Rydberg atomic electrometer

Area of Science:

• Quantum sensing
• Atomic physics
• Optical interferometry

Background:

• Rydberg-atom-based sensors offer high sensitivity for microwave electric-field detection.
• Traditional Mach-Zehnder interferometers (MZI) for phase tuning often rely on piezoelectric transducers (PZT), limiting precision and integration.

Purpose of the Study:

• To develop a fiber-integrated MZI with electronic phase control for improved Rydberg-atom sensing.
• To demonstrate continuous and precise phase tuning without mechanical components.
• To enhance the signal-to-noise ratio (SNR) and electric-field sensitivity of Rydberg-atom sensors.

Main Methods:

• A fiber-integrated MZI architecture utilizing double-pass acousto-optic modulators (AOMs) for electronic phase control.
• Continuous phase tuning achieved through frequency-shifted light propagation in optical fiber.
• Implementation of a Rydberg-atom microwave electric-field sensor in a cesium vapor cell.

Main Results:

• Achieved continuous phase tuning with a full 2π phase shift using a 9.463 MHz frequency adjustment.
• Demonstrated milliradian-level phase stability.
• Improved SNR by ~4 dB compared to non-interferometric methods.
• Measured an electric-field sensitivity of 4.2×10⁻⁶ V/m/√Hz.

Conclusions:

• The AOM-based electronic phase control in an MZI offers superior stability, precision, and integration compatibility compared to PZT methods.
• This approach significantly enhances the performance of Rydberg-atom-based microwave electric-field sensors.
• The developed system is well-suited for compact and integrated sensing applications.