Abstract:An injection locking-based pump recovery system for phase-sensitive amplified links, capable of handling 40 dB effective span loss, is demonstrated. Measurements with 10 GBd DQPSK signals show penalty-free recovery of a pump wave, phase modulated with two sinusoidal RF-tones at 0.1 GHz and 0.3 GHz, with 64 dB amplification. The operating power limit for the pump recovery system is experimentally investigated and is governed by the noise transfer and phase modulation transfer characteristics of the injection-locked laser. The corresponding link penalties are explained and quantified. This system enables, for the first time, WDM compatible phase-sensitive amplified links over significant lengths. References and links 1. C. M. Caves, "Quantum limits on noise in linear amplifiers," Phys. Rev. D 26, 1817Rev. D 26, -1839Rev. D 26, (1982. 2. E. Desurvire, Erbium-doped Fiber Amplifiers, (John Wiley & Sons, 1994). 3. W. Imajuku, A. Takada, and Y. Yamabayashi, "Low-noise amplification under the 3dB noise figure in high-gain phase-sensitive fibre amplifier," Electron. Lett 35, 1954Lett 35, -1955Lett 35, (1999 J. Richardson, "Detailed characterization of a fiber-optic parametric amplifier in phase-sensitive and phaseinsensitive operation," Opt. Express 18, 4130-4137 (2010). 8. M. Vasilyev, "Distributed phase-sensitive amplification," Opt. Express 13, 7563-7571 (2005). 9. R. Tang, P. Devgan, V. S. Grigoryan, and P. Kumar, "Inline frequency-non-degenerate phase-sensitive fibre parametric amplifier for fibre-optic communication," Electron.
