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12 August 2008


Bookham demos 40Gb/s tunable transmitter

Optical component, module and subsystem maker Bookham Inc of San Jose, CA, USA has completed tier 1 customer demonstrations of its 40Gb/s ODQPSK (optical differential quadrature phase shift keying) tunable transmitter capability. 

The tunable transmitter assembly (TTA) is designed to meet price points that will enable cost-effective deployment of 40Gb/s transmission in metro networks. It has been demonstrated in Bookham’s facility in Caswell, UK using cascaded dense wavelength division multiplexing (DWDM) nodes to reproduce real network conditions, and will be sampled into customer premises in September.

The TTA is underpinned by a single gold box co-packaging an indium phosphide Mach Zehnder modulator (InP MZ) measuring less than 10mm (believed to be the industry’s smallest 40Gb/s modulator) and the firm’s LambdaFLEX DSDBR (digital supermode distributed Bragg reflector) tunable laser. The TTA, which implements all required control circuitry including an OIF standard tunable laser interface, measures just 74mm x 39mm x 8.4mm, and is the first building block towards Bookham’s 40Gb/s transponder.

Bookham’s 40Gb/s portfolio of products uses the ODQPSK modulation scheme for 40Gb/s. The firm says that InP technology is well suited for such formats, where integration of several modulators onto a single chip is a key enabler for space and cost reduction.

“These successful network simulation tests with our key customers are a big step forward for the Bookham 40Gb/s program, confirming the superior optical performance of ODQPSK modulation and its excellent adaptability to multiple fiber types,” says PLM director Adam Price. “Through our vertical integration model we are proving that InP technology established by Bookham can provide the high performance needed for line-side 40Gb/s optical networks, without the cost, power and size issues linked to less integrated transmitter and decoder solutions,” he adds. “This performance is targeted to be delivered at a price point that will see us create a real market for 40Gb/s in the metro/regional network, in line with service providers requirements,” he reckons. “We believe our 40Gb/s TTA will be an economically compelling product for the players in this space.”

See related item:

Bookham supplies full-band tunable pluggable transceiver to Ciena

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