Inter-band non-degenerate phase-sensitive amplification scheme for low-noise full C-band transmission

Abstract

An phase-sensitive amplifier (PSA) is capable of low-noise optical amplification. A frequency non-degenerate PSA (ND-PSA) requires idler light co-propagating with signal light. Therefore, spectral efficiency is reduced by at least half compared to the system using phase-in-sensitive amplifiers such as an erbium-doped fiber amplifier. In this letter, we propose and demonstrate an inter-band phase-sensitive amplification scheme using signal and idler light propagating in different transmission bands. With this scheme, an ND-PSA can be applied to deployed single-band wavelength-division-multiplexing transmission systems without sacrificing the original bandwidth. Using wideband ND-PSA with PPLN waveguides, we demonstrate the proposed scheme with a 10-Gbaud 64QAM signal in the C-band and its idler in the S-band. The experimental results show the feasibility of inter-band phase-sensitive amplification with 4-THz signal bandwidth.