Highly stable polarization independent Mach-Zehnder interferometer

Area of Science:

• Optics
• Interferometry
• Quantum Information Science

Background:

• Optical interferometers are crucial for precision measurements.
• Phase stability is a key challenge in interferometric applications.
• Existing designs often require active stabilization or limit accessibility.

Purpose of the Study:

• To demonstrate a phase-stable optical Mach-Zehnder interferometer.
• To utilize a displaced Sagnac configuration for enhanced stability.
• To provide a robust platform for quantum information and sensitive measurements.

Main Methods:

• Experimental setup of an optical Mach-Zehnder interferometer with a displaced Sagnac configuration.
• Measurement of phase deviation over time without active stabilization.
• Evaluation of phase drift using Allan deviation.
• Assessment of polarization insensitivity by measuring interference visibility.

Main Results:

• The interferometer exhibits a phase deviation below 0.4° over 250 s.
• Phase drift remains below 3° (7 nm) for 1.5 hours without active stabilization.
• Interference visibility exceeds 93% across all tested polarization states.
• Minor visibility discrepancy (3.5%) attributed to beam splitter polarization dependence.

Conclusions:

• The displaced Sagnac configuration effectively enhances phase stability in Mach-Zehnder interferometers.
• The demonstrated device offers long-term stability without active control.
• Its polarization-insensitive nature and accessible paths make it ideal for quantum information processing and other demanding applications.