N221-005 TITLE: DIGITAL ENGINEERING - Photonics Integration for Modular Open Systems Approach Avionics Plug-in Modules

OUSD (R&E) MODERNIZATION PRIORITY: Networked C3

TECHNOLOGY AREA(S): Air Platforms;Electronics;Information Systems

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop photonic plug-in module technology and a modeling approach for designing and packaging air platform digital and analog optical communication avionics.

DESCRIPTION: Current airborne military (mil-aero) core avionics, electro-optic (EO), communications and electronic warfare systems require ever-increasing bandwidths while simultaneously demanding reductions in space, weight, and power. The replacement of shielded twisted pair wire and coaxial cable with earlier generation length-bandwidth product, multimode optical fiber has given increased immunity to electromagnetic interference, bandwidth, throughput, and a reduction in size and weight on aircraft. The effectiveness of these systems hinges on optical communication components that realize large link budget, high dynamic range, and are compatible with the harsh avionic environment [Refs 1, 5-7].

Future avionics digital and analog/radio-frequency (RF) signal transmission rates and frequencies are expected to increase to the point where fiber optics is the only medium with the capacity and low loss for maintaining communications signal integrity. Substantial work has been done in the digital domain to realize 100 Gbps data rates based on shortwave wavelength division multiplexing (SWDM) and coarse wavelength division multiplexing (CWDM) technologies [Refs 8-9]. Generally, SWDM utilizes 50 micrometer core multimode optical fiber and CWDM utilizes single-mode optical fiber for optical interconnection. Optical Multimode 4 (OM4) and Optical Multimode 5 (OM5) optical fiber has been optimized for 100 Gbps and higher SWDM links. Digital links generally use physical contact and non-contact connectors, with no angle polish. In the analog/RF domain there is interest in realizing higher performance intensity modulation with direct detection photonic links based on improvements in fiber pigtailed laser and photodetector, and electro-optic modulator performance [Ref 12]. Phase modulation with interferometric detection type links continues to be of interest for avionics as well [Ref 13]. Analog/RF photonic links generally utilize single-mode fiber (both polarization maintaining and single-core) and physical contact connectors [Refs 14-15]. Dual-core fiber connector and analog/RF photonic link technology is in the early stage of development for balanced photonic links [Refs 16-17].

The ANSI/VITA 46 base standard defines physical features that enable high-speed communication in 3U or 6U backplane-based critical and intelligent embedded computing systems [Ref 18]. The ANSI/VITA 65 OpenVPX System standard uses module mechanical, connectors, thermal, communications protocols, utility, and power definitions provided by specific VPX standards and then describes a series of standard profiles that define slots, backplanes, modules, and standard development chassis [Ref 19]. The ANSI/VITA 66.0 Optical Interconnect on VPX base standard defines a family of blind mate fiber optic interconnects for use with VITA 46 backplanes and plug-in modules [Ref 20]. The ANSI/VITA 67 Coaxial Interconnect on VPXbase standard establishes a structure for implementing blind mate analog coaxial interconnects with VPX backplanes and plug-in module, and to define a specific family of interconnects and configurations within that structure [Ref 21].

Photonics integration on plug-in module innovation is needed to implement 100 Gbps and higher digital fiber optic technology. 100 Gbps fiber optic transceivers generally transmit and receive multi-wavelength optical signals with four wavelengths of light, each operating at 25 Gbps to achieve an aggregate bandwidth of =100 Gbps. Typically, the transceivers are interfaced with differential current mode logic signaling and either single-mode or OM4/OM5 multimode fiber. Analog/RF photonics integration on plug-in module innovation is also needed. Analog/RF photonic links generally include a laser with power supply and electro-optic modulator with bias control circuitry and RF connection transmitter, and a high-speed fiber pigtailed photodetector receiver. The proposed digital and analog/RF photonic plug-in modules must operate over a -40 �C to +95 �C temperature range, and maintain performance upon exposure to typical naval air platform vibration, humidity, temperature, altitude, thermal shock, mechanical shock, and temperature cycling environments [Refs 22-27].

Integrating the disparate interfaces associated with digital and analog/RF photonic components on 3U or 6U plug-in modules will require significant digital engineering research and innovation. Not all of the required connections and interfaces are specified in the ANSI/VITA specifications. Field programmable gate array integration and electro-optic modulator RF and optical signal connections for moving digital and analog signals onto and off of plug-in modules between chassis and through chassis backplanes is required. The developed models should include digital and analog/RF loss budget calculations and the ability to perform analysis of system designs up to 100 Gbps and 100 GHz, respectively. Approaches to fill identified digital and analog/RF photonics technology gaps including packaging and connectors is also needed. Digital engineering research is required to understand how to best utilize the existing CAMEO Systems Modeler tool [Ref 28] and Systems Modeling Language (SysML) [Ref 29] for avionics hardware integration.

PHASE I: Using SysML, create the handoff between development board level electrical layouts and photonic component packaging concepts for digital and analog/RF photonic components mounted on the plug-in module level, and the module to backplane and external backplane levels. Identify key risk areas for tracing lower level module design to higher level module level design to realize desired performance and packaging for chassis integration, and mitigate these risks using digital engineering research concepts and modeling tools. Demonstrate computer aided designs of 3U and 6U photonic plug-in modules. The Phase I effort will include prototype plans to be developed under Phase II.

PHASE II: Collect research data on plug-in module photonics integration concepts including plug-in module to backplane digital and RF connections. Using digital engineering-based software, model photonic plug-in module and chassis backplane integration of digital and analog/RF components. Optimize the plug-in module designs. Build and test photonic module prototypes to meet avionics digital and analog/RF link performance requirements. Characterize the photonic module prototypes over temperature, and perform highly accelerated life testing. If necessary, perform root cause analysis and remediate circuit and/or packaged transmitter failures. Deliver two 100 Gbps digital modules, one intensity modulated with direct detection analog/RF module, and one phase modulated with interferometric detection module. Deliver the SysML model and the CAD model.

PHASE III DUAL USE APPLICATIONS: Finalize the prototype. Verify and validate that the plug-in module operates from -40 �C to +95 �C. Transition to applicable naval platforms.

Commercial avionics and general network Infrastructure sectors could benefit from high-speed fiber optic plug-in modules.

REFERENCES:

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KEYWORDS: Digital Engineering; Fiber Optics; Photonics; Modular Open Systems Approach; Plug-in Module; 100 Gigabits per second