FREMONT,
CA, March 19, 2007 -- Optoplex today announced the
introduction of a key coherent detection enabling device
for QPSK (quadratural phase shift keying) demodulation
- 90° Optical Hybrid.
In today's post-downturn telecom climate,
the optical hybrid and its ability to introduce a QPSK
modulation scheme is even more important in this extremely
cost-sensitive era. The optical hybrid allows telecom
players to preserve and maximize capital investments made
in the pre-bubble deployment of fiber-optic networks.
To date, these fiber-optic networks have not been easily
upgraded to handle 40 Gb/s per wavelength channel due
to excessive chromatic and polarization-mode dispersion
within existing standard single-mode fiber links. By utilizing
a QPSK modulation format effected through a 90° Optical
Hybrid coupled with a local oscillator, networks are able
to 1) extend transmission distances by leveraging signal
amplification, 2) mitigate transmission impairments by
simultaneously detecting amplitude, phase and polarization
information and allowing corrections in the electronic
domain, and 3) improve spectral efficiency and OSNR performance.
QPSK detection using a 90° Optical Hybrid, transmits
2 bits or 4 bits (if using a polarization multiplexer)
over standard single-mode fiber links; this innovation
effectively allows 40 Gb/s transmissions while still using
10 Gb/s electronics. Network system can improve their
signal speed by four fold on existing deployed fiber links
without using expensive high-speed electronic components.
Optoplex's 6-port polarization-diversified
90° Optical Hybrid (commonly referred to as an optical
mixer between the signal and local oscillator) is an underlying
component in the adaptation to a QPSK modulation scheme.
The optical hybrid converts and feeds complete amplitude,
phase and polarization information of an optical signal
to the photodetectors. Optoplex's device, based on Michelson
interferometer principles and implemented in free-space
bulk optics, is athermal, compact and suitable for colorless
applications. A cost-effective requisite in 40 Gb/s systems
using QPSK modulation, coherent detection utilizing an
optical hybrid and local oscillator will be the staging
platform for future 100 Gb/s optical communication network
systems. With this device in its product portfolio, Optoplex
has strengthened its position as the pioneer in next-generation
future-ready optical components.
