Evolution of the gain extinction ratio in dual-pump phase sensitive amplification

Area of Science:

• Nonlinear optics
• Fiber optics
• Optical amplifiers

Background:

• Phase-sensitive amplifiers (PSAs) are crucial for optical signal processing.
• Conventional models often fail to predict performance in highly nonlinear systems.

Purpose of the Study:

• To experimentally achieve high gain extinction ratio (GER) in a dual-pump PSA.
• To investigate the underlying physics, including high-order sidebands and nonlinear phase shifts.
• To understand and improve GER performance.

Main Methods:

• Experimental setup using a dual-pump phase sensitive amplifier.
• Utilizing highly nonlinear fiber.
• Analysis of output signal vector trajectories in the complex plane.
• Investigating the effect of nonlinear phase shift on GER.

Main Results:

• Achieved a gain extinction ratio (GER) of 30 dB at 21.75 dBm pump power.
• Demonstrated that high-order sidebands significantly influence GER, exceeding conventional three-wave model predictions.
• Observed a signal phase flip around the point of maximum GER.
• Identified design parameter adjustments to enhance GER.

Conclusions:

• High-order sidebands are critical for achieving high GER in nonlinear fiber PSAs.
• Understanding nonlinear phase dynamics, including phase flips, is essential for optimizing amplifier performance.
• The study provides a pathway to improve GER through careful design parameter selection.