980 nm pump laser makers go for power play

28 Mar 2007

JDSU, Bookham and Lumics show off powerful new lasers designed to reduce the size, cost and power consumption of fiber amplifiers used in optical communications.

Laser chip manufacturers JDSU, Bookham and Lumics are all showing off new high-power designs at this week’s optical fiber communication (OFC) conference and exhibition in Anaheim, CA.

The three companies are targeting the erbium-doped fiber amplifier (EDFA) market with new 980 nm lasers that can cut costs, reduce power consumption and improve amplifier reliability.

California-based JDSU has released two new products, including a 660 mW source. The high output power of the 3000 Series helps to cut amplifier costs because fewer lasers are needed to pump the amplifier, while overall noise is also reduced.

JDSU has also released an uncooled laser for similar applications. At 400 mW, the output power of the 2945 Series lasers is lower than that of the 3000 Series, but it offers a major advantage in that it does not result in additional power consumption through refrigeration.

The JDSU chips come rated with a very high reliability – a critical characteristic for network applications where any downtime or costly service calls are to be avoided wherever possible.

The company quotes a reliability statistic of "5 FIT", or 5 failure-in-time, for its latest crop of 980 nm chips. This means that the chips have less than one failure for every 200 million hours that they are deployed in the field.

JDSU's Bay Area neighbor Bookham is also releasing a new 980 nm source. The firm manufactures these lasers at its GaAs semiconductor fab in Zurich, Switzerland, which JDSU actually used to own until its 2001 merger with SDL (see related story). Bookham says that its new LC96 pumps offer a "kink-free" output power of 750 mW.

"Kink-free" means that the laser is operating in the correct mode; above a certain power, the laser's output switches to a higher-order mode that is not suited to the application in question or the focusing optics employed in the optical module.

Bookham's new laser modules incorporate so-called "generation eight" chips made in Zurich, which are also said to be suitable for uncooled operation.

Meanwhile, Lumics, which has a high-power laser chip fab at its headquarters in Berlin, Germany, has also improved the performance of its 980 nm product line.

Lumics says that its compact "Mini-DIL" source operates kink-free at up to 220 mW without any need for cooling. The lasers are Telcordia-qualified for up to 200 mW operating power.

The firm says that its proprietary chip technology allows the uncooled operation, and that EDFA makers will benefit from a significant reduction in the size and power consumption of their products.