Nonlinear intermodulation distortion suppression in coherent analog fiber optic link using electro-optic polymeric...

Area of Science:

• Photonics and Optical Communications
• Materials Science for Optoelectronics
• Nonlinear Optics

Background:

• Third-order intermodulation distortion (IMD3) is a significant impairment in analog fiber optic links, limiting system performance.
• Electro-optic (EO) modulators are crucial components in fiber optic communication systems.
• EO polymers offer advantages in fabrication and performance for optical devices.

Purpose of the Study:

• To fabricate and experimentally validate a linearized dual parallel Mach-Zehnder modulator (DPMZM) using an EO polymer.
• To demonstrate the suppression of IMD3 in a coherent analog fiber optic link using the developed DPMZM.
• To investigate the potential of a novel EO chromophore (B10) for advanced fiber optic communication systems.

Main Methods:

• Synthesis of a new EO chromophore (B10) and its incorporation into amorphous polycarbonate (APC) for waveguide core material.
• Fabrication of a DPMZM with MZMs of different lengths, unbalanced couplers, and a phase shifter.
• Experimental setup for a coherent analog fiber optic link to measure IMD3 suppression using the DPMZM.

Main Results:

• Effective cancellation of IMD3 below the noise floor was achieved in two-tone experiments.
• Fifth-order distortion (IMD5) became the dominant distortion product after IMD3 suppression.
• The DPMZM configuration demonstrated simultaneous broadband and shot-noise limited operation.

Conclusions:

• The linearized DPMZM based on EO polymer effectively suppresses IMD3, enhancing analog fiber optic link performance.
• The novel EO chromophore B10 shows promise for high-performance fiber optic communication applications.
• This technology enables cleaner signal transmission with reduced distortion for advanced communication systems.