Full and semi-analytic analyses of two-pump parametric amplification with pump depletion

Area of Science:

• Nonlinear Optics
• Quantum Optics
• Fiber Optics

Background:

• Non-degenerate four-wave mixing is crucial for signal amplification in fiber optical parametric amplifiers (FOPAs).
• Existing quasi-linearized approximations often neglect pump depletion, limiting predictive accuracy.
• Accurate modeling of FOPA gain is essential for developing advanced optical communication systems.

Purpose of the Study:

• To solve the coupled equations governing non-degenerate four-wave mixing in FOPAs.
• To develop a novel approximate solution for FOPA gain that includes pump depletion.
• To demonstrate the predictive capability of the new model using a highly nonlinear fiber.

Main Methods:

• Analytic solution of four coupled equations for non-degenerate four-wave mixing.
• Development of a simplified approximate solution incorporating pump depletion.
• Experimental demonstration using a highly nonlinear fiber to validate the model.

Main Results:

• The developed approximate solution accurately predicts FOPA gain, including pump depletion effects.
• An undepleted FOPA exhibits a flat gain spectrum with a ~100-nm bandwidth around the zero-dispersion wavelength.
• Operating the FOPA in depletion can further increase the gain bandwidth.

Conclusions:

• The new approximate model provides a more comprehensive understanding of FOPA gain compared to previous methods.
• Pump depletion is a significant factor that can be leveraged to enhance FOPA bandwidth.
• This work facilitates the design and optimization of FOPAs for broadband optical amplification.