Transmission of 112 Gb/s PM-QPSK Signals over 7200 km of Optical Fiber with Very Large Effective Area and Ultra- Low Loss in 100 km Spans with EDFAs Only John D. Downie, Jason Hurley, John Cartledge 1 , Scott Bickham, and Snigdharaj Mishra Corning Incorporated, SP-AR-02-1, Corning, New York, 14831 e-mail: downiejd@corning.com Abstract: We experimentally investigate transmission of 16×112 Gb/s PM-QPSK signals over an optical fiber with effective area of 134 µm 2 and attenuation of 0.162 dB/km. We demonstrate transmission over 7200 km with 100 km span lengths. ©2011 Optical Society of America OCIS codes: (060.2330) Fiber optics communications; (060.2360) Fiber optics links and subsystems 1. Introduction Much attention has recently been focused on the optical fiber attributes necessary for next generation high bit rate optical transmission systems at 100 Gb/s and beyond. It is well understood that moving to higher transmission system bit rates generally requires higher optical signal-to-noise ratio (OSNR) values to achieve acceptable levels of performance. Achieving higher system OSNR can be accomplished by lowering fiber loss, allowing higher channel launch powers through reduced fiber nonlinearity, and lowering optical amplifier noise figures. Therefore, it is desirable to lower the fiber attenuation as much as possible while making the fiber effective area as large as possible [1,2]. Indeed, many recent ultra-long haul distance transmission results at high bit rates have been achieved with fibers that have at least ultra-low loss or very large effective area [3-6]. In this work, we demonstrate ultra-long haul transmission of 112 Gb/s polarization-multiplexed quadrature phase-shift keying (PM-QPSK) signals over a new optical fiber that has the characteristics of both ultra-low loss and very large effective area. The average effective area of the fiber was 134 µm 2 and the average fiber attenuation was 0.162 dB/km. We show 16 channel transmission over 7200 km, with 100 km span lengths and simple single-stage erbium doped fiber amplifiers (EDFAs). To the best of our knowledge, this is the longest distance recorded at this bit rate with 100 km spans and amplification using only single-stage EDFAs. 2. Experimental set-up The experimental configuration is shown in Fig. 1. At the transmitter, 16 DFB lasers ranging in wavelength from 1547 to 1553 nm were grouped into odd and even channels and combined to form a channel plan with 50 GHz spacing. All lasers were modulated together with a QPSK modulator driven by two de-correlated 2 15 -1 PRBS patterns with a symbol rate of 28 Gbaud. The output from the QPSK modulator was optically polarization multiplexed to produce the PM-QPSK signals modulated at 112 Gb/s. The channels were launched into the re- circulating loop with a nominally flat spectrum. π/2 π/2 I (28Gbaud) Q (28Gbaud) 3 dB PC delay PBC AOM 100 km x3 AOM LSPS OSA filter Coherent Rx 3 dB Odd Even Blue filter Fig. 1. Experimental set-up of transmission system with re-circulating loop. The loop was comprised of 3 spans of the optical fiber, each span 100 km in length. The average fiber effective area and attenuation were 134 µm 2 and 0.162 dB/km, respectively. The fiber dispersion at 1550 nm was about 21 1 Also with Queen’s University, Kingston, ON, Canada. OMI6.pdf OSA/OFC/NFOEC 2011 OMI6.pdf