Radio Frequency over Fiber (RFoF) for the Next Generation Submarine Electronic Warfare (EW) System Navy SBIR FY2016.1 Sol No.: Navy SBIR FY2016.1 Topic No.: N161-034 Topic Title: Radio Frequency over Fiber (RFoF) for the Next Generation Submarine Electronic Warfare (EW) System Proposal No.: N161-034-0539 Firm: Photonic Systems, Inc. 900 Middlesex Turnpike Building #5 Billerica, Massachusetts 1821 Contact: Edward Ackerman Phone: (978) 670-4990 Web Site: http://www.photonicsinc.com Abstract: RF-over-fiber (RFoF) links with very high performance - 80 dB of spurious-free dynamic range (SFDR) in a 4-GHz instantaneous bandwidth, and noise figure = 10 dB - would impart tremendous benefits to submarine EW/SIGINT applications. RFoF link performance models that researchers at Photonic Systems, Inc. (PSI) have perfected over the last 25 years unfortunately indicate that neither linearized modulators nor coherent detection (the most frequently proposed approaches to high-SFDR links) will enable an RFoF link to exhibit the desired performance. In the approach that PSI proposes to develop for this SBIR program, high SFDR is enabled by a novel integrated electronic linearization circuit, and low noise figure is enabled by suppressing the relative intensity noise (RIN) outside a narrow band surrounding the optical carriers from multiple, wavelength-multiplexed semiconductor lasers. The fact that this approach leverages conventional photonic compoents, and the great extent to which these components can ultimately be integrated, imparts an inherently high degree of modularity and low recurring-engineering cost to links that use the proposed approach. Phase I of the proposed program will include a proof-of-concept demonstration at low frequency, and Phase II will culminate in demonstration of an RFoF link that meets all the above performance specifications. Benefits: The overarching objective of this SBIR program is to develop RF-over-fiber (RFoF) links having a bandwidth of = 20 GHz and a spurious-free dynamic range (SFDR) in a 4-GHz bandwidth that is 25 dB greater than the best reported results ever reported at or near 20 GHz. In addition to addressing the Navy's need for high-SFDR signal links on undersea platforms, Photonic Systems, Inc. (PSI) believes that the development of links with this degree of performance will increase the overall market for RFoF links. Even with all of the performance advantages that RF-over-fiber (RFoF) links provide -- smaller, lighter-weight conduits for signals whose performance is essentially independent of the signal's path length -- their deployment in both defense and commercial applications has been limited, mainly due to the cost and size of some of the electro-optic components. As the performance leaders in RFoF links, PSI has previously achieved dramatic improvements to the unamplified RFoF link's noise figure ( Return