Accuracy improvement of optical vector network analyzer based on single-sideband modulation.

Area of Science:

• Optoelectronics
• Metrology
• Optical Communications

Background:

• Optical Single-Sideband (OSSB) signals are crucial for advanced optical measurements.
• High-order sidebands in OSSB signals can introduce significant measurement errors in Optical Vector Network Analyzers (OVNAs).
• Accurate characterization of optical components requires minimizing these systematic errors.

Purpose of the Study:

• To propose and demonstrate a novel approach for suppressing measurement errors in OSSB-based OVNA.
• To develop an analytical model for understanding error contributions from high-order sidebands.
• To validate the proposed error suppression technique experimentally.

Main Methods:

• Establishing an analytical model to quantify measurement errors induced by high-order sidebands.
• Implementing an error suppression technique by selectively suppressing the optical carrier within the OSSB signal.
• Comparing frequency responses obtained with and without error suppression.

Main Results:

• The analytical model accurately predicts measurement errors caused by high-order sidebands.
• Suppressing the optical carrier effectively isolates and quantifies these errors.
• Subtracting the quantified errors from standard measurements yields accurate frequency responses.
• Experimental validation using a Fiber Bragg Grating demonstrated high coincidence for magnitude and phase responses across different modulation indices.

Conclusions:

• The proposed method effectively suppresses measurement errors in OSSB-based OVNA.
• Accurate frequency response measurements are achievable by compensating for high-order sideband-induced errors.
• The technique shows robustness with varying modulation indices, confirming its practical applicability.