A transceiver technology with in-situ diagnostic optical power monitoring for defense applications is presented. The
transceiver transmits and receives CWDM optical data signals over a single multimode fiber. Multimode fibers are
preferred in many defense applications due to their elevated connectorization ruggedness compared to single mode
connectors. The transmitter optical subassembly includes an array of vertical cavity surface emitting lasers, each directly
modulated at 10.3125 Gbps resulting in aggregate data rates scalable to 160 Gbps. A small fraction of the optical power
emitted from each VCSEL is used to monitor the output power from each individual laser.
OptiComp's WDM optoelectronic transceiver module includes a transmitter optical sub-assembly that is comprised of an
array of WDM VCSELs directly coupled into an optical multiplexer, the receiver optical sub-assembly which optically
demultiplexes the incoming light for photodetection by PIN photodiodes, and an embedded digital diagnostic monitoring
interface that enables real-time control of the transceiver and monitoring of the operation status. The transceiver module
package offers scalable, high-speed, high-density interconnects for demanding aerospace and space applications. The
highly integrated device designs coupled with the modular approach reduces assembly time, increases yield and offers
scalability in upgrading individual transceiver components at both the device-level and sub-assembly level without
requiring a change in device design, fabrication process, or manufacturing qualifications.
The demand for bandwidth and interconnectivity in aerospace and other defense networks and
systems continues to expand. To meet this demand while still satisfying the unique requirements of
these systems, innovative approaches are needed. For future networks to meet these goals, they will
need to have high bandwidths that are scalable to the requirements of particular applications. In
addition, the networks need to be very fault tolerant, protocol independent, non-blocking, low latency,
and have low power consumption and small size. OptiComp Corporation has developed a unique
network architecture where the hardware is distributed across the network, allowing the network to be
self routing and highly fault tolerant. This network architecture is enabled by OptiComp's integrated
optoelectronic technologies including waveguide coupled VCSELs and detectors, compact WDM, SOAs,
and hybrid integration.
Waveguide grating couplers that enable a VCSEL to be coupled bidirectionally into an internal
waveguide and allow a portion of the light in a waveguide to be tapped off to a detector comprise the
core of OptiComp's integrated optoelectronics. This on-chip coupling into and out of a waveguide
enables coarse WDM multiplexing and demultiplexing to be accomplished in a very small area with no
additional packaging, making the structure more compact and rugged. Waveguide coupled device
results will be presented, including high-speed data transmission between waveguide coupled VCSELs
and detectors. Preliminary results on waveguide coupled WDM components will also be discussed. In
addition to the enabling components, the implementation of the network architecture will also be
Heterogeneous integrated waveguide-grating-coupled VCSEL and REPD arrays have been demonstrated,
achieving an output power of >1.4 mW per facet, and VCSEL-to-photodetector data communication at 2.5
Gb/s through an integrated waveguide. Integrated WDM arrays have also been achieved. This technology
enables the realization of VCSEL-based planar photonic integrated circuits.
A monolithic optoelectronic device structure with the potential to enable VCSEL-based photonic integrated circuits on GaAs is presented. Using integrated diffraction gratings, the device structure enables the optical output of VCSELs to be coupled to an internal horizontal waveguide, while the optical signals in the waveguide are tapped off to resonant cavity detectors. Since horizontal waveguides are used to route the optical signals between devices, the output mirror transmission of the VCSELs can be eliminated, although we have chosen to retain a small amount of transmission in the top DBR to enable on-wafer testing. The design and fabrication of the monolithically integrated structure, including epitaxial regrowth, is discussed and initial device characteristics are presented.
This paper focuses on the implementation of a an optoelectronic switching fabric, which is distributed as compared to centralized, as historically deployed. In an attempt to overcome the limitations of centralized switching, a distributed architecture implemented with GaAs based bidirectional optoelectronic structures is presented. The switching technology is composed of two areas - components and architecture. The components discussion will focus on the bidirectional structures required to implement the distributed architectures. Three architectural types - N<sup>2</sup>, N<sup>3</sup>, and N<sup>4</sup> are presented. N<sup>2</sup> represents a matrix/vector Boolean multiplier architecture, N<sup>3</sup> represents a matrix/matrix Boolean multiplier, and
N<sup>4</sup> represents a tensor/matrix Boolean multiplier implementation. Each provides increased power and benefit with respect to switching and fault tolerance.