High-Q microwave photonic filter with a tuned modulator

Area of Science:

• Photonics
• Microwave Engineering
• Optical Communications

Background:

• Photonic filters are crucial for signal processing in microwave systems.
• Existing filters often face limitations in quality factor (Q) and performance.
• Developing high-Q filters is essential for advancing microwave technologies.

Purpose of the Study:

• To propose and demonstrate a novel method for implementing high-Q factor, single-bandpass photonic filters.
• To utilize tuned electro-optic or electroabsorption external modulators for filter implementation.
• To achieve a record Q factor for passive finite impulse-response microwave photonic filters.

Main Methods:

• Employing tuned electro-optic or electroabsorption external modulators.
• Implementing a transversal finite impulse response (FIR) filter architecture.
• Experimental validation of the proposed photonic filter design.

Main Results:

• Successfully implemented a single-bandpass photonic filter for microwave signals.
• Achieved a high Q factor of 237 for the demonstrated transversal FIR filter.
• This represents the highest reported Q factor for a passive FIR microwave photonic filter.

Conclusions:

• Tuned electro-optic/electroabsorption modulators offer a viable approach for high-Q microwave photonic filters.
• The demonstrated filter performance sets a new benchmark in the field.
• This advancement has implications for improved signal processing in microwave systems.