Jean-Marc P. Delavaux

Stable single-mode erbium fiber-grating laser for digital communication

In this paper we report the fabrication of a short, robust, single-mode Er/sup 3+/ fiber-grating laser. This laser is proven by the successful outcome of a long-term bit-error-rate test at the 10/sup -15/ level in a 5- G/s fiber transmission experiment. In the process we present a new pumping geometry, the elucidation of one origin of relaxation oscillations that have plagued previous lasers and the demonstration of a simple electronic feedback scheme for suppressing them. This prototype source shows real promise for use in a high-speed communications system. >

QAM-PON and super PON for access distribution networks

We propose a passive optical network (PON) system based on quadrature amplitude modulated (QAM) sub-carrier multiplexing (SCM) of 53 6 MHz 64/256-QAM channels. Sensitivities of -22 dBm and -17.5 dBm are achieved over 51 km of fiber under full duplex and broadcast delivery to 128 nodes for 64 and 256 QAM, respectively.

High-performance 980-nm EDFAs for repeaterless high-bit-rate optical transmission system

We describe the design and performance of single pump 980 nm pre and post Er3+ doped fiber amplifiers plug-in modules. We demonstrate the potential and robustness of these amplifiers in a 980 nm-based rack mounted repeaterless 5 Gb/s system with a 54 dB optical power margin system. Excellent long term bit error ratio measurements (< 10-14) are reported for various system configurations. In particular, error free transmission is obtained with suppression of stimulated Brillouin scattering through 60 km of non-dispersion fiber.

Packaged Er-doped fiber amplifier module at 980 nm

We present an efficient and compact (5 X 10 X 1.8 cm3) Er:doped fiber amplifier (EDFA) module pumped with a 980 nm laser diode. We showed that this EDFA module is capable of operating with optimum gain and noise performance over a 30 nm bandwidth at 1550 nm, and with low electrical consumption (less than 100 mW). Using the EDFA as a rack mounted preamplifier module in a 2.5 Gbit/s direct detection system experiment, we achieved a -38.5 dBm receiver sensitivity at 10-10 bit error rate, and demonstrated long term operation (BER of 6.10-14) of the overall system.

Spectral dependence of noise and gain in Er-doped fiber preamplifier at 980 nm

We investigated the gain and noise figure dependence on signal wavelength for erbium doped fiber amplifiers (EDFA) counter-pumped at 980 nm. Using a two level modeling technique, we found a good agreement between our experimental measurements and the corresponding theoretical predictions for EDFAs operating under or far from full population inversion. Finally, we describe design trade-offs between small signal gain and noise figure for a range of active fiber length EDFAs at wavelengths of 1531 nm and 1548 nm.

Coherent communication systems research and development at AT&T Bell Laboratories, Solid State Technology Center

Research and development effort on a field deployable coherent lightwave system at Bell Laboratories is reviewed. Detailed features and design of a 1 . 7 Gb/s FSK single filter heterodyne detection system and its performance in a one-month transmission field trial are described. Long distance transmission experiments of such a system with Er-doped fiber amplifiers at 1 . 7 Gb/s and 2. 5 Gb/s are presented. I.