Coherence-preserved amplification of spectral peaked optical frequency comb using fiber Raman amplifier

Area of Science:

• Optics and Photonics
• Spectroscopy

Background:

• Spectral peaking converts modulation into intense spectral peaks for comb mode selection in spectroscopy.
• Current limitations include low optical power of selected peaks, hindering power scaling.

Purpose of the Study:

• To investigate power scaling of a spectral peaked optical frequency comb at 1.65 μm.
• To utilize a fiber Raman amplifier for enhanced optical power.

Main Methods:

• Employed a 1 km Raman fiber as gain fiber.
• Examined amplification characteristics for continuous wave (CW) beams, spectral peaked combs, and conventional pulsed combs.
• Performed experimental and numerical analysis of amplification.

Main Results:

• Achieved coherence-preserved, low-noise amplification with 22 dB gain for the spectral peaked comb.
• Demonstrated low-noise similariton-like amplification for comb pulse input.
• This marks the first reported power scaling of an optical frequency comb using a fiber Raman amplifier.

Conclusions:

• Fiber Raman amplification enables effective power scaling for spectral peaked optical frequency combs.
• The technique offers coherence preservation and low-noise amplification.
• Applicable across a wide wavelength band, significantly benefiting spectroscopic applications.