Simplified optical millimeter-wave generation configuration by frequency quadrupling using two cascaded Mach-Zehnder...

Area of Science:

• Photonics and Optical Communications
• Microwave Engineering
• Signal Generation

Background:

• Generating high-frequency optical millimeter-wave (MMW) signals is crucial for advanced wireless communication systems.
• Existing methods often require complex setups, including optical filters or electrical devices, and can suffer from instability.

Purpose of the Study:

• To propose and demonstrate a novel, filter-less method for generating optical MMW signals with frequency quadrupling.
• To achieve a high-quality 40 GHz MMW signal with enhanced harmonic distortion suppression.
• To ensure the proposed method is robust against modulator bias drift, improving system stability.

Main Methods:

• Utilized two cascaded Mach-Zehnder modulators (MZMs) for signal generation.
• Employed symmetrical biasing of the MZMs to achieve the desired frequency quadrupling.
• Performed theoretical analysis and experimental validation of the proposed scheme.

Main Results:

• Successfully generated a 40 GHz optical millimeter-wave signal.
• Achieved a high optical harmonic distortion suppression ratio exceeding 25 dB.
• Demonstrated insensitivity to Mach-Zehnder modulator bias drift, indicating high stability.

Conclusions:

• The proposed cascaded MZM method offers an effective and stable approach for optical millimeter-wave signal generation.
• The technique eliminates the need for optical filters or external electrical devices, simplifying the system architecture.
• The demonstrated robustness against bias drift presents a significant advantage for practical applications in high-frequency communications.