Wide-Band Inline-Amplified WDM Transmission Using PPLN-Based Optical Parametric Amplifier
Takayuki Kobayashi, Shimpei Shimizu, Masanori Nakamura, Takeshi Umeki, Takushi Kazama, Ryoichi Kasahara, Fukutaro Hamaoka, Munehiko Nagatani, Hiroshi Yamazaki, Hideyuki Nosaka, Yutaka Miyamoto
Abstract
This article proposes an optical parametric amplifier (OPA), as an inline-repeater, using a periodically-poled-LiNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (PPLN) waveguide with over-10-THz amplification bandwidth, and also presents wide-band wavelength-division-multiplexing (WDM) inline-amplified transmission with the OPA. Our PPLN-based OPA is polarization-independent and has a spectrally efficient configuration by filtering phase-conjugated signals (idlers). We implemented our PPLN-based OPA with half its ideal configuration with an over-10-THz amplification bandwidth because of the limited number of PPLN waveguides. The implemented OPA had 5.125-THz amplification bandwidth, gain of beyond 15 dB, and noise figure of less than 5.1-dB. The gain excludes the 5.6-dB loss of an idler rejection filter employed in the transmission experiment so that the implemented OPA can compensate 9.5-dB link loss of transmission fibers and optical components. A 3 × 30.8-km inline-amplified transmission with 41-channel 800-Gbps WDM signal in 125-GHz spacing was successfully demonstrated using our PPLN-based OPA as an inline-repeater. The results also indicate that the OPA's amplification bandwidth can potentially be extended to 10.25 THz.