N242-D08 TITLE: DIRECT TO PHASE II: Fiber-Optic Filter Integration

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Advanced Computing and Software; Microelectronics; Sustainment

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: Design, fabricate, test, and integrate dichroic filters for use in digital avionics fiber-optic communication-link hardware and software in order to reduce the time and complexity for a properly trained maintainer to detect and isolate a failure and affect repair.

DESCRIPTION: The use of optical fiber on air, surface ship, and undersea platforms is pervasive, and is an enabling technology. Current military electronics, electro-optic, communications, radar, and electronic warfare systems require ever-increasing bandwidths, while simultaneously demanding reductions in space, weight, and power (SWAP). The effectiveness of these systems hinges on optical communication components that realize sufficient link budget, dynamic range, and compatibility with military surface ship, undersea platform, and aircraft maintenance environments. Future digital and analog/radio frequency (RF) signal transmission rates and frequencies have increased to the point where fiber optics is the only medium with the capacity and low loss for maintaining communication signal integrity. Key fiber-optic systems engineering design considerations include architecture (i.e., openness, modularity, scalability, and upgradeability), reliability, maintainability, and supportability. Maintainability and supportability are well-known operational availability drivers for fiber-optics technology deployment on military platforms.

Fiber-optics supportability cuts across reliability, maintainability, and the supply chain to facilitate detection, isolation, and timely repair/replacement of system anomalies. Typical supportability features include prognostics, diagnostics, skill levels, support equipment footprint, training, maintenance data collection, compatibility, packaging and handling, and other factors that contribute to an optimum environment for sustaining a fiber-optic system. The ability to sustain the operation of a fiber-optic system on aircraft is established by the inherent supportability of the system and the processes used to sustain the functions and capabilities of the system in the context of the end user. Supportability infrastructure is difficult to add on after the design is established, and therefore should be included in the systems engineering design process. The focus of sustainment planning is to influence the inherent supportability of the system, and to plan the sustainment capabilities and processes used to sustain system operations.

Fiber-optics maintainability considerations encompass modularity, interoperability, physical accessibility, training, testing, and human systems integration. Maintainability generally requires balancing the maintenance requirement over the life cycle with minimal user workload. The emphasis on maintainability is to reduce the maintenance burden and supply chain by reducing time, personnel, tools, test equipment, training, facilities, and cost to maintain the system. Maintainability engineering includes the activities, methods, and practice to design minimal system maintenance requirements and associated costs for preventative and corrective maintenance, as well as servicing and calibration activities. Maintainability should be a designed-in capability and not an add-on option, because good maintenance procedures cannot overcome poor system and equipment maintainability design. The primary objective is to reduce the time and complexity for a properly trained maintainer to detect and isolate a failure and affect repair.

Integrating the disparate interfaces associated with digital and analog/RF fiber-optic systems require innovation. Although the Navy has complete knowledge of the required connections and interfaces for digital and analog/RF fiber optics, there is no approach to selecting and qualifying dichroic filter-based components, and implementing new support equipment (maintenance sets), training, and the required supportability and maintainability modernization concepts to enable single ended optical loss measurement based on dichroic filter technology. Dichroic filters transmit light in one wavelength band in one direction while reflecting light at other wavelengths. Inserting dichroic filters in aircraft fiber-optic links enables the fleet maintainer to measure optical loss from one end of the fiber-optic cable. The application of dichroic filter technology will modernize single-ended fiber-optic link loss measurement and fiber-optic built-in test (BIT) concept of operations on aircraft platforms. This SBIR topic seeks a component research effort that develops dichroic filters compatible with avionics fiber optics. This research effort should also develop models that include all of the platform considerations for multimode fiber-optic links operating at 1, 10, 25 and 50 Gbps, link components, support equipment, associated fleet maintainer training, and digital fiber-optic system design engineering principles.

Research is needed to design and assemble dichroic fiber prototypes for use for the following: (a) inside avionics weapon replaceable assemblies, (b) in fiber-optic test equipment, (c) in fiber-optic adapters, and (d) other optical interface circuitry. Research is also needed to design and demonstrate light source and optical power meter prototypes that enable single ended optical loss measurement in single and multi-wavelength multimode fiber-optic links on airborne platforms.

PHASE I: For a Direct to Phase II topic, the Government expects that the small business would have accomplished the following in a Phase I-type effort and developed a concept for a workable prototype or design to address, at a minimum, the basic requirements of the stated objective above. The below actions would be required to satisfy the requirements of Phase I:

Demonstrate feasibility of a dichroic filter transmission in digital vertical cavity surface emitting laser-based fiber-optic links operating in-band at no less than 25 Gbps. Demonstrate single-ended fiber-optic link loss measurement at out-of-band optical wavelengths that do not interfere with the in-band fiber-optic communications link wavelengths. Design a portable maintenance support equipment prototype for performing single-ended optical loss measurement on airborne platforms.

FEASIBILITY DOCUMENTATION: Offerors interested in participating in Direct to Phase II must include in their response to this topic Phase I feasibility documentation that substantiates the scientific and technical merit and Phase I feasibility described in Phase I above has been met (i.e., the small business must have performed Phase I-type research and development related to the topic NOT solely based on work performed under prior or ongoing federally funded SBIR/STTR work) and describe the potential commercialization applications. The documentation provided must validate that the proposer has completed development of technology as stated in Phase I above.

PHASE II: Design, build, and test dichroic filters for in-band signal transmission and out-of-band, single-ended loss measurement. Integrate dichroic filters in weapon replaceable assembly fiber-optics systems. Integrate dichroic filters in fiber-optic support equipment to facilitate single-ended, optical-loss measurement of legacy fiber-optic links where integration within the weapons replaceable assembly is not practical. Perform environmental testing of the dichroic filter devices to verify the qualifiability of dichroic filters for avionics and avionics support equipment.

PHASE III DUAL USE APPLICATIONS: Finalize the prototype portable support equipment design for single-ended fiber-optic loss measurement on airborne platforms. Implement integration hardware and software in avionics representative use cases. Verify and validate the portable support equipment performance. Perform environmental testing to increase technology readiness. Develop manufacturing tooling and supply chain infrastructure to increase manufacturing readiness of portable support equipment. Transition to applicable naval avionics use cases and platforms.

Dual-use applications include telecommunication systems, data centers, and campus networks.

REFERENCES:

1. "MIL-PRF-28800 Rev. G: Test equipment for use with electrical and electronic equipment." Military and Government Specs & Standards (Naval Publications and Form Center) (NPFC), 17 November 2021. https://global.ihs.com/doc_detail.cfm?&item_s_key=00255078&item_key_date=780114&input_doc_number=MIL%2DPRF%2D28800GG&input_doc_title=
2. "SAE ARP5061A: Guidelines for testing and support of aerospace, fiber optic inter-connect systems." SAE, 16 August 16 2018. https://doi.org/10.4271/ARP5061A
3. Nyman, B. "Passive components for WDM networks." OFC'98. Optical Fiber Communication Conference and Exhibit, Technical Digest, Conference Edition, 1998 OSA Technical Digest Series Vol. 2 (IEEE Cat. No. 98CH36177) ,p. 276. https://doi.org/ 10.1109/OFC.1998.657396

KEYWORDS: Dichroic filter; fiber optics; light source; power meter; avionics integration; support equipment

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