Microwave photonic integrator based on a multichannel fiber Bragg grating

Area of Science:

• Photonics and optical engineering
• Microwave signal processing
• Fiber optic technologies

Background:

• Microwave photonic signal processing offers high bandwidth and immunity to electromagnetic interference.
• Accurate integration of microwave signals is crucial for various applications, including radar and communications.
• Existing methods for microwave signal integration face limitations in bandwidth and accuracy.

Purpose of the Study:

• To propose and demonstrate a novel microwave photonic integrator.
• To achieve a step group delay response for accurate microwave signal integration.
• To overcome in-channel dispersion-related distortions in photonic systems.

Main Methods:

• Utilizing a multichannel fiber Bragg grating (FBG) designed with the spectral Talbot effect for large group delay dispersion (GDD).
• Cascading the FBG with a dispersion compensating fiber (DCF) with opposite GDD to create a step group delay response.
• Modulating an optical comb with a microwave signal and processing it through the FBG-DCF system.
• Detecting and summing time-delayed optical signal replicas at a photodetector (PD).

Main Results:

• Demonstrated a microwave photonic integrator with a bandwidth of 2.9 GHz.
• Achieved an integration time of 7 ns.
• Verified the system's ability to perform microwave signal integration without in-channel dispersion-related distortion.

Conclusions:

• The proposed FBG-DCF based microwave photonic integrator effectively performs signal integration.
• The spectral Talbot effect in multichannel FBGs is key to achieving the desired step group delay response.
• This technology offers a promising solution for high-performance microwave signal processing.