March 8, 2005 Fremont, CA -- Avanex, a provider of intelligent photonic devices for optical networks, has introduced its SD10-DP and SD40-DP Lithium Niobate modulators for the Differential Quadrature Phase Shift Keying (DQPSK) modulation format, which the company says enables higher transmission efficiency at 10 Gbit/sec and 40 Gbit/sec.
According to the company, DQPSK modulation allows higher spectral efficiency in DWDM transmission; the small optical bandwidth of the DQPSK modulation format dramatically reduces the need for dispersion compensation in the network. The company says that 10-Gbit/sec transmission is improved due to the increased dispersion tolerance of the DQPSK format, which makes the DQPSK an ideal format for ultra-long-haul and submarine transmission. Moreover, via the format,10 Gbit/sec signals can potentially be transmitted on 25 GHz (or less) channel spacing grid.
In addition, says the company, the DQPSK modulation format enables the transmission of 40-Gbit/sec signals over existing 10-Gbit/sec network infrastructure with either 50 GHz or 100 GHz channel spacing. Also, the tolerance against polarization mode dispersion (PMD) is significantly improved with respect to other modulation formats, reducing the technical hurdles for deployment of 40-Gbit/sec transmission in existing 10-Gbit/sec networks, according to the company.
"Avanex has implemented a fully integrated dual parallel modulator solution that enables more robust modulator operation with respect to other configurations," comments Giovanni Barbarossa, CTO of Avanex. "The DQPSK uses parallel Mach-Zehnder-type modulators embedded in a super Mach-Zehnder interferometer. The Avanex design distinguishes itself by its outstanding electro-optic characteristics, low drive voltages and single side RF inputs. These features significantly simplify the design and lower the cost of transponder solutions."
The DQPSK modulators are on display at OFC/NFOEC 2006 in Anaheim, CA in the company's booth #2640.