Create Efficiencies
Cables
Active Optical
Storage area networks with high
disk space requirements are a
first application.
AOCs can simplify installation,
configuration and operations—and reduce costly inventory loss.
by Victor Blake
Active optical cable(AOC) or optical active cable (OAC) are synonymous terms used to refer to a new class of cables. These
electrical interface cables differ from passive copper wiring. They are ‘active’ cables.
These cables use electrical power along
with the signals at the copper interface, but
convert the signal to the optical domain
with a transceiver within the cable.
Manufacturers of these products include
Avago, Emcore, Finisar, Hitachi, Luxtera,
Merge Optics, Molex, Reflex Photonics,
Tyco Electronics, Zarlink Semiconductor
and others. Although some AOCs may
be as simple as a multi-source agreement
(MSA) standard form factor, shrink-wrapped to a pair of strands with LC
(Lucent connector, IEC 61754-20), most
AOC products offer material and timesaving benefits that reduce total cost.
AOCs offer the same density as existing
MSA ports, with full compatibility for XFP
( 10 Gigabit small form-factor pluggable)
and SFP+ (small form-factor pluggable,
plus) MSAs. AOC is also promoted as an
alternative to all copper solutions because of
the higher port density, better bend radius,
Finisar’s AOC branded product line includes Laserwire, Quadwire (see photo, above) and C.wire.
As the name suggests, Quadwire is an inverse multiplexed 4x10G QSFP MSA compliant product
for the 40G (Packet over SONET, Infiniband, Ethernet, etc.) market. Reflex Photonics offers an
equivalent product, their QSFP AOC. So too does Hitachi. Finisar’s C.wire is a 12x12.5Gbps, MMF
ribbon cable-capable medium that can be used for applications up to 150Gbps, such as non-standard
100Gbps Ethernet or InfiniBand 12xQDR Quad Data Rate (QDR), which with 8B/10B coding carries 96Gbps. Laserwire is Finisar’s 10Gbps product line. It incorporates SFP+ or XFP interfaces for
10Gbe, Fibre Channel over Ethernet (FCoE) or Fibre Channel (FC). Molex calls their 10G product an
SFP+ Passive Cable Assembly.
and lower electrical power consumption
of the AOC solution compared to an all
copper 10GBASE-T CX4 standard.
Risk mitigation
AOCs are driven in part by some of the
same trends as MSAs.
What has made the selection of fixed op-
tics a risky choice for vendors is the large
and growing variety of optics required for
different reach (or length) applications;
different types of optics, including single
mode (SM) or multimode (MM) and even
different types of connectors. Those would
include not only LC, but also Fibre Chan-
nel (FC), square or standard connector
(SC, IEC 61754-4) and sub-miniature A
(SMA). To manage the types of connec-
tors, optics and applications, vendors can
reduce their risk by standardizing on an
MSA interface, such as SFP, SFP+ or XFP.
