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Updated: Feb 21, 2026

Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator
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Improved phase retrieval method for system simplification or fading suppression in interferometer-based φOTDR

Xin Lu, Korbinian Königsbauer, Konstantin Hicke

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    Summary
    This summary is machine-generated.

    A new signal processing method simplifies phase retrieval in phase sensitive optical time domain reflectometry (φOTDR) systems. This approach uses fewer photodetectors, reducing complexity and data, while also suppressing fading effects.

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    Area of Science:

    • Optoelectronics
    • Optical Sensing
    • Signal Processing

    Background:

    • Traditional phase sensitive optical time domain reflectometry (φOTDR) systems often require multiple photodetectors for phase retrieval.
    • This complexity increases system cost, data volume, and potential for signal fading.

    Purpose of the Study:

    • To propose a novel signal processing principle for phase retrieval in φOTDR systems.
    • To reduce the number of photodetectors required, thereby simplifying the system and data handling.
    • To enhance fading suppression in existing φOTDR configurations.

    Main Methods:

    • A new signal processing principle for phase retrieval using IQ demodulation.
    • Utilizing the difference between two interferometer outputs as the quadrature component.
    • Reconstructing the in-phase component via Hilbert transformation of the quadrature component.
    • Applying the principle to suppress fading in traditional three-detector φOTDR systems.

    Main Results:

    • The proposed method requires only one balanced or two standard photodetectors, significantly reducing system complexity and data volume.
    • Experimental validation using a Mach-Zehnder interferometer demonstrated the feasibility of the technique.
    • Achieved a high fading suppression of approximately 90% in the φOTDR system.

    Conclusions:

    • The novel signal processing principle offers a simplified and more efficient approach to phase retrieval in φOTDR.
    • This method effectively reduces hardware requirements and data processing load.
    • The technique provides a robust solution for fading suppression in optical reflectometry systems.