Lisa A. Buckman

Low-cost multimode WDM for local area networks up to 10 Gb/s

Current local area network (LAN) bandwidth demands of >1 Gb/s are pushing the limit of the bandwidth-distance product of multimode fiber, the predominant fiber in LAN backbones. In order to overcome these limitations, a low-cost and compact wavelength division multiplexing scheme is demonstrated. Aggregate bit rates of 5 and 10 Gb/s are achieved through 300 and 100 m of 62.5/125-/spl mu/m multimode fiber, respectively. Four vertical-cavity surface-emitting lasers are used at wavelengths of 820, 835, 850, and 865 nm with each operating at a bit rate of 1.25 or 2.5 Gb/s. This technology provides a practical solution for reaching bit rates up to 10 Gb/s in the LAN.

A novel all-optical self-routed wavelength-addressable network (SWANET)

A novel all-optical self-routed wavelength-addressable network based on a new multiwavelength routing protocol is proposed. A distributed switching network that uses a low-speed routing header provides a transparent path for the high-speed data while utilizing low-speed electronic processing of the routing header. Each data packet is preceded by a routing header composed of a serial combination of wavelengths. The number of destination addresses is dramatically increased over conventional wavelength-division multiplexing or conventional photonic packet switching networks for the same number of wavelengths or header digits, respectively. A 1/spl times/4 switching node is implemented demonstrating the switching and transmission capabilities of this wavelength-addressable network.<<ETX>>

Stabilization of millimeter-wave frequencies from passively mode-locked semiconductor lasers using an optoelectronic phase-locked loop

The use of an optoelectronic phase-locked loop to stabilize the pulsation frequency of a three-section, passively mode-locked quantum well laser diode at 41 GHz is discussed. It is shown that the free-running mode-locked signal, with a radio frequency (RF) linewidth of 770 kHz, can be stabilized to the linewidth of a reference RF oscillator (<1 kHz). The stabilized mode-locked signal has a phase noise of -70 dBc/Hz at 370 kHz offset. Tracking of the mode-locked signal to the external reference RF oscillator is maintained over 11 MHz. This is, in effect, an actively mode-locked laser source at 41 GHz.<<ETX>>

Crosstalk penalty in all-optical distributed switching networks

We report both analytical and experimental results of the power penalty due to noncoherent crosstalk in multiwavelength all-optical networks that use space-division switching. Numerical analysis reveals that the power penalty is overestimated using a Gaussian approximation with <100 crosstalk signals or crosstalk levels >-20 dB. Numerical analysis shows a 1.8 dB power penalty for 6 crosstalk signals with each contributing -11.5 dB crosstalk while the Gaussian approximation predicts a power penalty /spl Gt/10 dB. We measure a power penalty of 1.7 dB for 3 crosstalk signals with each contributing -18 dB crosstalk. The numerical analysis agrees when the relative-intensity noise is taken into account.

A broad-band millimeter-wave optical modulator using a passively modelocked semiconductor laser with phase noise compensation

A new and simple technique to produce efficient optical modulation at millimeter-wave frequencies by compensating for the phase noise of a 0.85-/spl mu/m passively modelocked semiconductor laser is presented. The passively modelocked laser is intensity modulated with the electrically mixed product of its phase noise and the millimeter-wave information signal. One of the resulting sidebands to the modelocked note is identical to the millimeter-wave frequency information because of the cancellation of the phase noise of the modelocked signal. A carrier-to-noise ratio (CNR) of 87 dBc/Hz at 41.9 GHz is demonstrated and it is shown that optical modulation at subcarrier frequencies up to 100 GHz and a CNR of 120 dBc/Hz is possible.

Compact low cost WDM modules for the LAN

Summary form only given.The ever-increasing need for computer bandwidth is creating bottlenecks in the backbones of local area networks (LANs). To address this the IEEE 802.3 Ethernet working group is developing a standard for 10-Gigabit Ethernet (10-GbE). This standard aims to support LAN links up to 300-m in length using 62.5-/spl mu/m core multimode fiber and up to 10-km in length using single-requirement mode fiber. One optical solution, likely to be included in the standard, is wide wavelength division multiplexing (WWDM). Using a single-mode-coupled transmitter and a multi-mode-coupled receiver allows a single module to simultaneously support both fiber types.

Low-cost compact WDM components for LAN applications

Summary form only given. Short-distance (100 m-10 km) data links will soon require bandwidths of 10 Gbaud and higher. Half-inch-wide wavelength-division multiplexed (WDM) transceiver modules, for both multimode and single-mode fiber, may be the most likely solution. Low-cost component technologies necessary for fully integrated modules will be discussed and results presented.