Accurate optical vector network analyzer based on optical single-sideband modulation and balanced photodetection.

Area of Science:

• Photonics and Optical Engineering
• Measurement Science and Instrumentation
• Electrical and Electronic Engineering

Background:

• Optical Vector Network Analyzers (OVNA) are crucial for characterizing optical systems.
• Conventional OSSB-based OVNA methods suffer from measurement errors due to high-order sidebands.
• Accurate characterization of optical devices requires minimizing these inherent errors.

Purpose of the Study:

• To propose and demonstrate a novel OVNA design that eliminates high-order sideband-induced measurement errors.
• To achieve accurate characterization of optical devices without complex post-signal processing.
• To validate the proposed method through experimental measurements.

Main Methods:

• Development of a novel OVNA architecture utilizing optical single-sideband (OSSB) modulation and balanced photodetection.
• Implementation of a signal processing technique involving splitting the OSSB signal, removing the optical carrier in one path, and balanced photodetection.
• Experimental validation using a fiber Bragg grating (FBG) as the optical device-under-test (ODUT).

Main Results:

• The proposed OVNA effectively eliminates measurement errors caused by high-order sidebands in OSSB signals.
• Experimental results demonstrate accurate magnitude and phase responses of the FBG.
• The method shows successful removal of high-order sideband-induced errors across different modulation indices.

Conclusions:

• The novel OVNA design provides an effective solution for eliminating high-order sideband-induced measurement errors.
• This technique enables accurate and direct measurement of optical device responses.
• The proposed method simplifies the measurement process, reducing the need for complex post-processing.