Broadened gain characteristics of single-pumped parametric amplifier using highly-nonlinear fibers for transparent optical demultiplexer

Due to the ultrafast response time of the nonlinear effects in glass fibers, the fiber-optical parametric amplifier (FOPA) exploiting four-wave mixing (FWM) in glass fibers has been regarded as a potential device for the ultrafast optical signal processors such as an ultrafast optical signal demultiplexer, a phase conjugator, and a wide band wavelength converter. However, cause of the complexity of the fiber configuration and the pump scheme, FOPA has been less realistic optical amplifier compared to other commercial optical fiber amplifiers such as an erbium-doped fiber amplifier (EDFA) and a Raman amplifier (RA). Therefore, to achieve large and flattened parametric gain characteristics of FOPA, we propose a simple and practical design scheme for FOPA using single pump laser and quasi-cascaded highly non-linear fibers (HNLFs). With this design scheme, single pump laser diode and quasi-cascaded two silica-based HNLFs with different zero dispersion wavelengths were used. As results of this study, apparent improvement of the parametric gain characteristics was observed in the wavelength region near the pump wavelength and over 23 dB parametric gain was successfully achieved in the 50 nm bandwidth including the telecom C-band wavelength region. In addition, the results of 160 Gb/s - 10 Gb/s DEMUX experiments with designed single-pump FOPA are also shown.