N212-106 TITLE: Fast Low Loss Uninterrupted Optical Switch

RT&L FOCUS AREA(S): Autonomy;General Warfighting Requirements (GWR);Networked C3

TECHNOLOGY AREA(S): Air Platforms

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 section 3.5 of 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 and package a 2 x 2 single mode optical switch operating at 1.55 �m wavelength capable of switching speeds below 1 �s with a directivity of 50 dB and an excess loss of less than 1.0 dB with a continuous intensity change from port-to-port.

DESCRIPTION: Current airborne military communications and electronic warfare systems require ever increasing bandwidths while simultaneously requiring reductions in size, weight, and power (SWaP). The replacement of the coaxial cable used in various onboard Radio Frequency (RF)/analog applications with RF/analog fiber optic links will provide increased immunity to electromagnetic interference, reduction in size and weight, and an increase in bandwidth. However, routing these signals to different locations within the airframe with high efficiency, or for routing/reconfiguring within the front end of an RF processor, requires the development of low-loss optical switches that can meet extended temperature range requirements (-40 �C to 100 �C). Additionally, avionic platforms pose stringent requirements on the SWaP consumption of components for avionic fiber communications applications. To meet these requirements, new optical component technology will need to be developed.

Typical microwave photonic links for 20 GHz and higher frequencies utilize single-mode fiber between transmitter and receiver. Many antennas on airborne platforms will be required to send their signals to a plurality of RF processors at different locations on the platform, which will require low-loss optical switching devices. In addition, for some RF front ends and processors, re-configurability in the front end is needed that will require optical path reconfiguration. Optical switches for these applications require continuous power transfer from two inputs to two outputs with continuous optical connectivity (without dead time) so RF information is not lost during the switching process. Switching speed will also need to be below 1.55 �s for these applications to minimize the transition time. Electro-optic [Ref 1] or magneto-optic technologies [Ref 2] offer the potential for fast switching if optical losses can be minimized. Other technologies, including integrated photonics platforms, may also be promising so long as the above specifications are met.

The packaged 2 x 2 optical switch in single, dual, and quad switch packages must perform over the specified temperature range and maintain hermeticity and optical alignment upon exposure to typical Navy air platform vibration, humidity, thermal shock, mechanical shock, and temperature cycling environments [Refs 3, 4], which can include unpressurized wingtip or landing gear wheel well (with no environmental control) to an avionics bay (with environmental control).

PHASE I: Demonstrate the feasibility of a 2-input, 2-output 1.55 �m optical switch that can switch at microsecond or better speeds. The switch must be capable of continuously variable coupling ratios between the two inputs/outputs so that no dead time results during switching. Provide detailed design and packaging plan to support the development during Phase II. The Phase I effort will include prototype plans to be developed under Phase II.

PHASE II: Optimize Phase I design, develop, and package prototype 2 x 2 switches in single, dual, and quad switch packages. Test prototype switches to meet the loss and switching speed specifications over temperature to meet design specifications in a Navy air platform representative of a relevant application environment, which can include unpressurized wingtip or landing gear wheel well (with no environmental control) to an avionics bay (with environmental control). Demonstrate a prototype fully packaged switch for direct insertion into single-mode analog fiber optic links.

PHASE III DUAL USE APPLICATIONS: Finalize the prototype. Perform extensive operational reliability and durability testing, as well as optimize manufacturing capabilities. Transition the demonstrated technology to naval aviation platforms and interested commercial applications.

Commercial sector data centers, industries utilizing local area networks and telecommunication systems, as well as companies that install networks and telecommunications systems would benefit from the development of this fast, low-loss, uninterrupted optical switch technology.

REFERENCES:

1. Kaur, S., Singh, M., Singh, H. and Singh, M. L. "Design and Performance Analysis of 2x2 electro-optic based MZI switch using Ti: LiNbO 3 as a waveguide at 1.46 �m." 2019 IEEE International Conference on Electrical, Computer and Communication Technologies (ICECCT), February 2019, pp. 1-5. https://doi.org/10.1109/ICECCT.2019.8869376.
2. Bahuguna, R., Mina, M., Tioh, J. W. and Weber, R. J. "Magneto-optic-based fiber switch for optical communications." IEEE transactions on magnetics, 42(10), 2006, pp. 3099-3101. https://doi.org/10.1109/TMAG.2006.878870.
3. "MIL-STD-810H, Department of Defense test method standard: Environmental engineering considerations and laboratory tests." Department of Defense, US Army Test and Evaluation Command, January 31, 2019. http://everyspec.com/MIL-STD/MIL-STD-0800-0899/MIL-STD-810H_55998/.
4. Verification of Discrete and Packaged Photonic Device Technology Readiness: ARP 6318." https://www.sae.org/standards/content/arp6318/.

KEYWORDS: Optical Switch; Fiber Optic; Single Mode; Dead Time; Switching Speed; uninterrupted