Photonic microwave finite impulse response filter using a spectrally sliced supercontinuum source

Area of Science:

• Photonics
• Microwave Engineering
• Optical Signal Processing

Background:

• Photonic microwave filters are crucial for advanced signal processing.
• Existing methods face challenges in stability and precision.
• Mode-locked lasers offer a powerful source for generating broadband optical signals.

Purpose of the Study:

• To develop a novel photonic microwave discrete-time finite-impulse response (FIR) filter.
• To demonstrate the filter's performance characteristics, including extinction ratio and spectral response.
• To validate the filter's stability and accuracy through experimental comparison.

Main Methods:

• Generating a supercontinuum source from a mode-locked laser.
• Spectrally slicing the supercontinuum to create discrete filter taps.
• Experimentally implementing and characterizing a four-tap FIR filter.
• Comparing measured filter responses with theoretical predictions.

Main Results:

• Successfully created a photonic microwave discrete-time FIR filter.
• Demonstrated a four-tap filter with a 28.16 dB extinction ratio.
• Achieved an excellent match between measured and predicted magnitude responses across the bandwidth.
• Observed stable amplitude fluctuations between filter taps, indicating high precision.

Conclusions:

• The novel photonic microwave FIR filter demonstrates high performance and stability.
• Spectral slicing of supercontinuum sources is an effective method for filter synthesis.
• The experimental results validate the theoretical predictions, confirming the filter's potential for practical applications.