December 7, 2005 San Diego and Camarillo, CA -- CEYX Technologies and Vitesse Semiconductor have introduced a laser bias and control technology for optical transceivers that improves laser accuracy, extends laser life, and lowers operating costs. The new technology incorporates CEYX's software-enabled LightSmart Control System with the Vitesse 10-Gbit/sec Laser Driver IC family.
Component nonlinearities, manufacturing variations, and changes due to temperature and aging cause fluctuations in the transmitted average optical power (AOP) and extinction ratio (ER) of a laser.
"One of the big things that the industry was looking for was closing the loop with extinction ratio," explains Matt Dru, product marketing manager at Vitesse. "Everybody's been using look-up tables, they've been characterizing lasers, and doing all this work to try to get an approximation on the laser. But there's never really been a great solution for closing that loop."
"Traditional methods of laser control produce varying degrees of effectiveness, but current market trends demand more precise performance metrics, automated self-adjustment, early degradation detection and failure reporting," adds Jim Day, vice president of sales and marketing for CEYX Technologies. "Integrating the CEYX LightSmart Control System with the Vitesse driver in an optical transceiver produces a superior, cost-effective laser control solution providing manufacturers and end users unprecedented control over increasing laser accuracy and lowering costs."
The CEYX LightSmart Control System is a customizable, software-based platform that eliminates temperature testing and the need for look-up tables; compensates for aging; and automatically calibrates manufacturing differences in drivers, lasers, and monitor photodiodes.
The integration of CEYX's LightSmart Control System with Vitesse's laser drivers results in what the companies claim is the first proven method for managing ER and AOP while delivering accurate real-time performance feedback for directly modulated lasers (DMLs). The combined system enables transceiver manufacturers to lower their production costs and increase yields--all while offering products that maintain accurate performance levels over the life of the laser.
CEYX and Vitesse have jointly developed a demonstration platform featuring the Vitesse VSC7981 10-Gbit/sec, 25-ohm, DML driver to showcase the first integrated system to provide closed-loop feedback to compensate for temperature and aging effects. The resultant platform provides customers with an off-the-shelf, ready-to-go reference design for firsthand evaluation of the technology.
According to Dru, the integrated CEYX/Vitesse laser control system taps into the largest optical market opportunity today: The 10-Gbit/sec, 10-km market for XFP and XENPAK transceivers and 300-pin transponders. Dru also expects the product to gain traction in the up-and-coming 10GBase-LRM market, which employs electronic dispersion compensation (EDC) to upgrade legacy multimode fiber links from 1-Gigabit Ethernet (GbE) to 10-GbE. Transceiver manufacturers angling for a foothold in this market will face extreme cost pressure, which makes the integrated CEYX/Vitesse system very attractive. Moreover, 10-GBase-LRM employs 1310-nm DML lasers, which the companies are demonstrating with the new reference design. "This is the big push for tomorrow," says Dru.
The companies say they would like to expand their partnership in the future to tackle vertical-cavity surface-emitting lasers (VCSELs) for use in the short-reach 10-Gigabit Ethernet market.
"For us, opportunities exist anywhere that customers have to compete more efficiently on cost," notes Day.
--MJF