Back-seeding of higher order gain processes in picosecond supercontinuum generation

Area of Science:

• Nonlinear optics
• Photonics
• Optical fiber technology

Background:

• Photonic crystal fibers can exhibit closely spaced zero dispersion wavelengths.
• This proximity enables two pairs of four-wave mixing (FWM) gain peaks.

Purpose of the Study:

• To demonstrate the use of outer FWM gain peaks for amplifying picosecond supercontinuum (SC).
• To achieve significant amplification within the SC spectrum.

Main Methods:

• Numerical simulations and experimental validation.
• Utilizing outer four-wave mixing gain peaks in photonic crystal fibers.
• Implementing a feedback mechanism where part of the SC output is time-matched with the pump light.

Main Results:

• A strong amplification peak was produced in the picosecond supercontinuum.
• Over 20 dB of gain was achieved near the FWM gain wavelengths.
• The method effectively leverages specific FWM characteristics for SC enhancement.

Conclusions:

• Outer FWM gain peaks in photonic crystal fibers are a viable method for SC amplification.
• Time-matching feedback light with the pump is crucial for achieving high gain.
• This technique offers a novel way to control and enhance SC generation.