Photonic microwave bandpass filter with improved dynamic range

Area of Science:

• Photonics
• Microwave Engineering
• Optical Signal Processing

Background:

• Photonic microwave bandpass filters are crucial for signal processing.
• Improving their dynamic range is essential for enhanced performance.
• Existing techniques face limitations in noise reduction.

Purpose of the Study:

• To propose and demonstrate a novel technique for improving the dynamic range of photonic microwave bandpass filters.
• To reduce optical-carrier-induced shot noise and relative intensity noise.
• To achieve a significant improvement in the filter's dynamic range.

Main Methods:

• Implementation of a photonic microwave bandpass filter using phase modulation to intensity modulation conversion.
• Utilizing fiber Bragg gratings (FBGs) as frequency discriminators.
• Positioning optical carriers on the lower slopes of FBG reflection spectra to minimize noise.

Main Results:

• Successful experimental demonstration of the proposed technique.
• Achieved an improvement in the dynamic range of the photonic microwave bandpass filter by approximately 10 dB.
• Validated the effectiveness of placing optical carriers on lower FBG slopes for noise reduction.

Conclusions:

• The proposed technique effectively enhances the dynamic range of photonic microwave bandpass filters.
• Minimizing noise through strategic optical carrier placement is key to improving filter performance.
• This advancement offers a practical solution for applications requiring high dynamic range photonic filters.