Power budget optimization of STARNET II: an optically amplified direct-detection WDM network with subcarrier control

Abstract

STARNET-II is a novel optically amplified directdetection multi-Gb/s WDM LAN developed at Stanford University, Stanford, CA. STARNET-II is simpler than the coherent STARNET-I yet is functionally equivalent. Here, STARNET-II power budget is investigated and optimized. Power allocation between payload and subcarrier control streams at the transmitter, and power splitting ratio between the payload and subcarrier control receivers are investigated and optimized theoretically and experimentally. Critical parameter variations such as electroabsorption modulator nonlinearity, transmitter wavelength and power instability are investigated, and their effect on the power budget is analyzed. With the optimized design, experimental STARNET-II optical layer has a receiver sensitivity of 031.5 dBm at BER = 10 09 corresponding to 23.9 dB SNR, for simultaneous transmission and reception of 1.25 Gb/s payload and 125 Mb/s control data. Including the computer interface, STARNET-II has a power budget of 28.6 dB. For a 10-km network diameter, STARNET-II dispersion margin can support the modulation bandwidth up to 13 Gb/s. Index Terms-Amplified spontaneous emission, optically amplified system, power budget, subcarrier control, WDM LAN.

Developments in wavelength division multiple access networking

“…This enabled the use of tunable receivers instead of arrays of fixed receivers. IBM took advantage of this technology in their Rainbow projects [3]. The realization of the erbium doped fiber amplifier (EDFA), developed in the late 1980s and in extensive use since 1990, was a major boost to WDM systems, since it allowed the amplification of all the channels in a fiber simultaneously.…”

“…Meanwhile, development of the single-hop system continued with the second IBM Rainbow project (1994) and the use of a broadcast-and-select network in the outer layer of the All Optical Network (AON) project [5]. More recent developments have included interest in the use of subcarrier multiplexing for control purposes, as in the 1995 CORD [3] and 1996 Starnet II [6] projects, and single-hop ring networks. The latter have often been proposed, but only in the last two years or so have they been experimentally implemented [7,8].…”

“…If SCMA is used for the control channels, only one laser is needed at each node. The CORD project (contention resolution using delay lines) was a WDMA experiment undertaken at Stanford University [3]. It demonstrated simultaneous transmission of a 2.5 Gb/s data payload and an 80 Mb/s control channel, using subcarrier multiple access.…”