We experimentally demonstrate the use of a discrete Raman amplifier for generating a high power, narrow linewidth pump for use within a fiber optical parametric amplifier (FOPA). We demonstrate the suitability of the Raman-amplified pump for parametric amplification by characterizing its optical signal to noise ratio and relative intensity noise (RIN). The amplified pump is subsequently employed within a FOPA obtaining net gain of up to 24.9 dB and a gain of >11 dB over 35 nm. The approach described here offers the key advantage over traditional EDFA-based pump generation of wavelength tuneability outside the EDFA bands. In principle this allows to place the parametric pump at any wavelength within the low fiber attenuation window. Here we additionally demonstrate Raman-assisted optical phase conjugation to provide positive conversion efficiency over 60 nm whilst employing the phase-conjugating pump power of <10 mW not requiring an amplification by EDFA. We consider this technique to show a significant promise for broadband optical phase conjugation and wavelength conversion as well as the prospect for implementation of these important phenomena outside of the EDFA bands.
Bibliographical note© 2020 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).
Funding: This work was supported by UKEngineering and Physical Sciences Research Council (EPSRC) grants EP/M005283/1 (UPON) and EP/R024057/1 (FPA-ROCS); “CASE” award and university studentship for V. Gordienko.
- Fiber optical parametric amplification
- Raman amplification
- Raman-assisted optical phase conjugation
- Wavelength conversion