Agere Systems (NYSE:AGR.A), a provider of communications components, announced new high-power distributed feedback (DFB) laser modules with integrated wavelength lockers for use in high-speed optical networking systems.
Featuring wavelength selection and locking capabilities, these new lasers provide increased functionality and reduce fiber management complexity and board space requirements for system makers designing optical equipment for long-haul and ultra-long-haul applications.
Available in 10-, 20- and 40-milliwatt (mW) configurations, the laser modules are ideally suited for use with external lithium niobate modulators to send transmission signals across 10- and 40-gigabit-per-second (Gbit/s) optical networks. These laser modules eliminate the need for an external wavelength locker, so that the fiber coming out of the laser module needs only to be connected to the modulator.
For 10- and 40-Gbit/s optical networks, using high-power lasers can help overcome insertion loss (optical power loss) from dispersion caused by effects such as scattering and absorption that occur during signal transmission. High-power lasers can also help reduce the number of amplifiers along an optical span, giving systems makers significant savings in overall system costs.
The lasers are single-channel, ITU wavelength-selected devices that offer 50-gigahertz (GHz) wavelength spacings, which can double the capacity for networks optimized for 100-GHz channels. Each laser device contains two wavelength monitors for locking over a wide range of wavelengths, a unique configuration that can enable future use of wavelength-locked tunable laser sources and tighter channel spacing. This patented locker design is manufactured on a high-throughput automated manufacturing line which allows Agere to offer these devices quickly and in high volume. The integrated wavelength lockers greatly enhance long-term reliability and reduce chirp and mode dispersion when used with 10- or 40-gigabit-per-second modulators in high-speed optical networks.
The module's standard 14-pin butterfly package gives systems makers an integrated laser/locker solution without the need to completely redesign the transmission board, thereby reducing cost and time to market. The device also offers great long-term thermal stability and can provide a maximum frequency drift of only +/-2.5 GHz over 25 years.
Samples are currently available for the 10- and 20-mW (D2587P) laser modules, with samples of the 40-mW device expected in the fourth calendar quarter of 2001. All laser configurations will be available in production quantities in early 2002.
The company also announced what it claims to be the first 10 gigabit-per-second (Gbit/s) electroabsorptive modulated laser (EML) to add an internal laser driver and operate over a distance of 80 kilometers. This device gives systems manufacturers the reach and integration necessary to reduce cost and improve performance in optical networking systems.
The E2581-series EML combines a continuous wave laser with an electroabsorptive modulator on the same chip, then adds an integral driver IC for improved transmission performance. The device is designed for use in SONET/SDH or dense wavelength division multiplexed optical networking equipment with applications in both long-haul and metropolitan areas.
"Eighty kilometers is a critical link length for both long haul and metro systems designers," said Erin Byrne, senior product manager in Agere's Optical Core Networks division.
The device features a 10 decibel-or-greater RF extinction ratio, which measures the difference in power when the laser light is modulated "on" or "off," as well as a dispersion penalty of less than 2.0 decibels over 80 kilometers of standard single-mode fiber. These parameters offer improved performance for transmission signals traveling across a long optical span, where light beams are more apt to scatter.
Integrating the laser driver IC with the EML gives the device optimum RF performance by shortening the distance between the driver chip and the modulator. The EML's compact size and integrated architecture offer significant benefits over external modulators and drivers, which are often bulkier and more expensive. This product saves on board space and simplifies manufacturing for systems makers, who can order three parts in one.
The E2581 is wavelength-selectable to ITU-T standards covering the entire C-band wavelength range of 1530-1562 nanometers. The device requires an input voltage of 0.5 to 1.0 volts peak-to-peak and offers a wide operating temperature range of -10 to +70 degrees Celsius. The package also contains a thermoelectric cooler, thermistor, rear facet monitor photodiode and optical isolator.
Sample quantities of the E2581 are now available, with production quantities expected by the end of 2001.
Agere Systems is a provider of components for communications applications in optical components and integrated circuits. For more information, visit www.agere.com.