Mark Beranek

Avionics fiber-optic and photonics network preliminary technology readiness assessment

Fiber-optic technology deployment on military platforms is driving the need to re-assess fiber optics and photonics technology readiness for next generation avionics systems. The AEROLAN initiative unveiled at the 22nd DASC and subsequently kicked off at the IEEE LEOS avionics fiber-optics and Photonics Workshop (AVFOP 2004), provides the impetus for a technology readiness assessment (TRA) of the Naval aviation fiber-optics and photonics technology infrastructure. TRA is a valuable methodology for defining technology maturity and making technology investment decisions. Technology readiness levels (TRLs) combined with product assessment scales (PAs) are useful elements for assessing readiness prior to formulating research, development, and test and evaluation (RDT&E) objectives, and subsequent technology transition planning. This paper provides the reader insight into NAVAIRs preliminary readiness assessment of avionics fiber optics and photonics technology for the next generation.

Future generation military avionics fiber optics photonics packaging challenges

The military/aerospace platform operational environment challenges the creativity of fiber optic module packaging engineers as they endeavor to develop and mature new active and passive single-mode fiber optic and photonic components for next generation avionics networking applications. Low sales and manufacturing volumes inherent to avionics combined with lack of standard interface specifications for current and next generation fiber optic local area network architectures and subsystems makes it difficult for avionics suppliers to justify upfront research and development (R&D) investment in advanced fiber optics and photonics packaging technology. Collaboration between commercial industry photonic component and advanced packaging R&D and military/aerospace photonic component and advanced packaging R&D has proven to be a successful formula for mitigating technical and business risk on military/aerospace programs, and gives best value components for military avionics applications. As the avionics industry migrates from multimode fiber optic point-to-point link based systems to fully-interconnected single-mode wavelength division multiplexed-based local area network (WDM LAN) architectures, it naturally follows that similar collaborations will be needed to realize the technical and business success of the avionics WDM LAN. Currently, the SAE Avionics Systems Division (SAE WDM LAN), the IEEE Avionics Fiber Optics and Photonics Conference (AVFOP), and the ARINC Fiber Optics Subcommittee are endeavoring to coordinate avionics WDM LAN standardization efforts internationally via formal committee meetings and conference events.

Fiber optic interconnect and optoelectronic packaging challenges for future generation avionics

Forecasting avionics industry fiber optic interconnect and optoelectronic packaging challenges that lie ahead first requires an assumption that military avionics architectures will evolve from todays centralized/unified concept based on gigabit laser, optical-to-electrical-to-optical switching and optical backplane technology, to a future federated/distributed or centralized/unified concept based on gigabit tunable laser, electro-optical switch and add-drop wavelength division multiplexing (WDM) technology. The requirement to incorporate avionics optical built-in test (BIT) in military avionics fiber optic systems is also assumed to be correct. Taking these assumptions further indicates that future avionics systems engineering will use WDM technology combined with photonic circuit integration and advanced packaging to form the technical basis of the next generation military avionics onboard local area network (LAN). Following this theme, fiber optic cable plants will evolve from todays multimode interconnect solution to a single mode interconnect solution that is highly installable, maintainable, reliable and supportable. Ultimately optical BIT for fiber optic fault detection and isolation will be incorporated as an integral part of a total WDM-based avionics LAN solution. Cost-efficient single mode active and passive photonic component integration and packaging integration is needed to enable reliable operation in the harsh military avionics application environment. Rugged multimode fiber-based transmitters and receivers (transceivers) with in-package optical BIT capability are also needed to enable fully BIT capable single-wavelength fiber optic links on both legacy and future aerospace platforms.

Demonstration of a Gb/S Transceiver with OTDR Built-in-Test for Avionics Local Area Networks

The motivations for development of an integrated BITed transceiver have been described in previous DASC papers (Beranek and Van Deven, 2005). One of the challenges in developing BIT capabilities in avionics local area networks is implementing the BITed transceiver functionality without degrading the transceivers electro-optic performance characteristics, or increasing its size, or changing its multi-source agreement (MSA) standard footprint format. We have successfully demonstrated the first prototype Gb/s fiber optic transceiver with integrated built-in test 10-cm resolution OTDR capability in a small-form-factor (SFF) package. This OTDR BITed transceiver operates at 850 nm with high output power and good electro-optic characteristics over 2 Gb/s. The 10-cm optical time domain reflectometry (OTDR) resolution requires the transceiver to have total rise time (tr ) and fall time (tf) less than 1 ns. This rise and fall time requirement indicates the intrinsic transceiver has to support a 2.5 Gb/s data rate

Improving Avionics Fiber Optic Network Reliability and Maintainability Via Built-In Test

Significant work is ongoing to understand how the application of avionics fiber optic BIT technology can help reduce life cycle and total ownership cost in military aviation platforms. Operational availability enhancements via comprehensive supportability programs combined with keen attentiveness to reliability and maintainability metrics are driving the avionics fiber optic BIT value proposition. Future life cycle cost impact studies in fielded squadron aircraft are expected to validate the assertions put forth in this paper

Avionic WDM LAN node utilizing wavelength conversion

A wavelength-routed WDM node was demonstrated to allow error-free transmission of digital optical signals between 4 inputs and outputs at all tested data rates. Even with the addition of 29.4 dB loss, data transmission through the node remained below 10e-12 at the target data rates of 1.25 and 2.5 Gbps. Though developed to support the cross-cube topology, this node is flexible enough to work within other network architectures, including ring, bus, or additional mesh topologies.

Improving Avionics Fiber Optic Network Reliability & Maintainability

Work is ongoing at NAVAIR to understand how avionics fiber optic BIT technology can help reduce military aviation platform fiber optic network life cycle and total ownership cost. Operational availability enhancements via comprehensive supportability programs combined with keen attentiveness to reliability and maintainability metrics are driving the avionics fiber optic BIT value proposition. Avionics fiber optic BIT technology is expected to reduce failure rate and mean time to repair by predicting link failure before link failure actually occurs, running post-maintenance stress screening upon aircraft start-up, improving fault isolation by reducing the troubleshooting ambiguity zone from three to one, and reducing the need for separate support equipment for system troubleshooting

Digital avionics fiber optic link interface control document standardization

The increased usage of fiber optics technology on aerospace platforms has created greater awareness of the benefits gained by creating or updating standards for aerospace applications. For the past several years ARINC, SAE, ASD-STAN and the DoD have worked fast and hard to fill a variety of standards gaps encompassing a wide range of fiber optic components and design process applications including optical fiber, connectors, cables, termini, splices, cable assemblies, link power budget methodology and margin specification, education and training awareness, cable assembly insertion and return loss measurements, connector inspection criteria and cable harness installation, to name a few. A new initiative underway within JEDEC is working to standardize active and passive components including transmitters, receivers, switches and filters.

Fiber Optic Cable Assembly Specification Checklist for Avionics Applications

In this paper the reader is provided a comprehensive fiber optic cable assembly specification checklist to consider for avionics applications. Its purpose is to facilitate supply chain utilization of unambiguous specifications, qualifications, and quality assurance standardization of avionics fiber optic cable assemblies. Fiber optic cable assemblies used for avionics application should be considered on a case-by-case basis as the performance, service life, reliability, supportability, and maintainability requirements of avionics systems vary between aircraft type (i.e., fixed wing or rotary), model, series, mission, etc

Accelerating fiber optic and photonic device technology transition via pre-qualification reliability and packaging durability testing

AIR 6318 is expected to define a subset of full qualification test procedures for discrete and packaged photonic devices. The test procedures will be aimed at establishing program management confidence in emerging photonic devices prior to Milestone B for subsequent acceptance into EMD.