Microwave photonic delay line signal processing.

Area of Science:

• Photonics
• Optical Engineering
• Signal Processing

Background:

• Fiber-optic delay lines are crucial for advanced signal processing.
• Optimizing their design is essential for improving radio-frequency (RF) system performance.
• Existing commercial delay lines have limitations in performance.

Purpose of the Study:

• To provide a design framework for state-of-the-art fiber-optic delay lines.
• To theoretically derive RF system performance metrics for various modulation types.
• To guide the development of future high-performance photonic systems.

Main Methods:

• Derivation of theoretical performance metrics (gain, compression point, third-order output intercept point) using transfer matrices.
• Analysis of four modulation types: X- and Z-cut Mach-Zehnder modulators, asymmetric Mach-Zehnder phase modulator, and polarization modulator.
• Consideration of optical amplifier placement and fiber-effect mitigation strategies.

Main Results:

• Theoretical performance metrics derived for each of the four modulation types.
• Identification of design parameters crucial for maximizing system gain and linearity.
• Demonstration of two high-performance delay lines with performance exceeding commercial benchmarks by an order of magnitude.

Conclusions:

• The derived theoretical framework enables the design of superior fiber-optic delay lines.
• Advanced modulation techniques and careful component selection significantly boost system performance.
• This research serves as a guide for future advancements in photonic signal processing technologies.