Abstract
Phase-sensitive amplification is of great research interest owing to its potential in noiseless amplification. One key feature in a phase-sensitive amplifier is the gain extinction ratio defined as the ratio of the maximum to the minimum gains. It quantifies the capability of the amplifier in performing low-noise amplification for high phase-sensitive gain. Considering a phase-sensitive fibre optical parametric amplifier for linear amplification, the gain extinction ratio increases with the phase-insensitive parametric gain achieved from the same pump. In this work, we use backward Raman amplification to increase the phase-insensitive parametric gain, which in turn improves the phase-sensitive operation. Using a 955 mW Raman pump, the gain extinction ratio is increased by 9.2 dB. The improvement in the maximum phase-sensitive gain is 18.7 dB. This scheme can significantly boost the performance of phase-sensitive amplification in a spectral range where the parametric pump is not sufficiently strong but broadband Raman amplification is available.
Highlights
PS-FOPA can be realized either in a frequency degenerate manner[4], in which the signal and idler are located at the same wavelength, or in a frequency non-degenerate manner[1], in which the signal and idler have different wavelengths
The experimental demonstration in this work relied on inline PSA by cascading a PI-FOPA and a (Raman-enhanced) PS-FOPA
The OSNRs of the input signal and idler were limited by loaded noise
Summary
PS-FOPA can be realized either in a frequency degenerate manner[4], in which the signal and idler are located at the same wavelength, or in a frequency non-degenerate manner[1], in which the signal and idler have different wavelengths. We adopt the frequency non-degenerate PS-FOPA encompassing a single pump, a signal, and an idler at the input. As opposed to the phase-insensitive (PI) amplifiers, the performance of a PSA is quantified by the signal gain, and the gain extinction ratio (GER). The introduction of a backward Raman pump to a conventional PI-FOPA has proved to substantially increase the signal gain[13]. The enhancement is contributed by both the direct Raman gain and the increased PI parametric gain from the Raman-amplified parametric pump. We propose and demonstrate the use of backward Raman amplification to enhance the performance of a conventional PS-FOPA17. Signal Parametric Idler λ pump pump, the GER of the Raman-enhanced PS-FOPA is increased by 9.2 dB compared to the conventional PS-FOPA. Combined with the direct Raman gain, the maximum PS gain is increased by 18.7 dB
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
