Introduction

In the United States, the U S. Small Business Administration (SBA) works to ignite change and spark action so small businesses can confidently start, grow, expand, or recover. The Technology Program at the SBA helps to strengthen and expand the competitiveness of U.S. small high-technology research and development businesses in the federal marketplace. SBA assists in achieving the commercialization of the results of both the federal research and development programs mandated by the Small Business Innovation Development Act of 1982, the Small Business Research and Development Enhancement Act of 1992, and the Small Business Innovation Research Program Reauthorization Act of 2000. More information about the SBA can be read at www.sba.gov.

The SBIR and STTR Programs

The mission of the Small Business Innovation Research/ Small Business Technology Transfer (SBIR/STTR) programs is to support scientific excellence and technological innovation through the investment of Federal research funds in critical American priorities to build a strong national economy.

The SBIR Program aims to:

  • Stimulate technological innovation,
  • Meet Federal research and development (R&D) needs,
  • Foster and encourage participation in innovation and entrepreneurship by women and socially or economically disadvantaged persons,
  • Increase private-sector commercialization of innovations derived from Federal research and development funding.

In addition, the STTR program aims to:

  • Foster technology transfer through cooperative R&D between small businesses and research institutions.

The SBIR and STTR programs are highly competitive programs that encourage domestic small businesses to engage in Federal Research/Research and Development (R/R&D) with the potential for commercialization. Through a competitive awards-based program, SBIR and STTR enable small businesses to explore their technological potential and provide the incentive to profit from its commercialization.

The SBIR Program structure has three phases:

Phase I. The objective of Phase I is to establish the technical merit, feasibility, and commercial potential of the proposed R/R&D efforts and to determine the quality of performance of the small business awardee organization prior to providing further Federal support in Phase II.

Phase II. The objective of Phase II is to continue the R/R&D efforts initiated in Phase I. Funding is based on the results achieved in Phase I and the scientific and technical merit and commercial potential of the project proposed in Phase II. SBIR/STTR Phase II awards are generally for 2 years. Typically, a Phase II program results in a prototype.

Phase III. The objective of Phase III, where appropriate, is for the small business to pursue commercialization objectives resulting from the Phase I/II R/R&D activities.

Central to the STTR program is the partnership between small businesses and nonprofit research institutions. The STTR program requires the small business to formally collaborate with a research institution in Phase I and Phase II. STTR’s most important role is to bridge the gap between performance of basic science and commercialization of resulting innovations. The STTR program expands the public/private sector partnership to include the joint venture opportunities for small business and the nation’s premier nonprofit research institutions. STTR’s most important role is to foster the innovation necessary to meet the nation’s scientific and technological challenges in the 21st century.

Small business has long been where innovation and innovators thrive. But the risk and expense of conducting serious R&D efforts can be beyond the means of many small businesses. Conversely, nonprofit research laboratories are instrumental in developing high-tech innovations. But frequently, innovation is confined to the theoretical, not the practical. STTR combines the strengths of both entities by introducing entrepreneurial skills to high-tech research efforts. The technologies and products are transferred from the laboratory to the marketplace. The small business profits from the commercialization, which, in turn, stimulates the U.S. economy. More information about SBIR and STTR can be read at www.sbir.gov.

SBIR Technology Commercialization via Technology Readiness Level Advancement

One way the defense industry assesses photonics technology for potential transition to the Engineering and Manufacturing Development (EMD) phase of a production program is to perform a Technology Readiness Assessment [1]. Technology readiness advancement is crucial to transitioning state-of-the-art photonic components to EMD. It is understood that Technology Readiness Level 6 (TRL-6) is required to merit consideration for transition to EMD. TRL-6 (system/subsystem model or prototype demonstration in a relevant environment) represents a major step up in establishing the technology readiness of a fiber optic component or photonic device.

TRL-6 requires testing prototypes in a high-fidelity laboratory environment or in a simulated operational environment. The prototype fiber optic component or photonic device under test form factor should be near the desired configuration in terms of performance, space, weight, and volume. Military and aerospace standards can be referenced to translate the intent of the “high-fidelity laboratory environment or in a simulated operational environment” phrase into engineering test plans. Measurements should be performed at both the “nominal” and “corners/extremes” of the environmental and signaling input/output envelopes.

By definition TRL-6 designation going into EMD does not imply that a given device or component’s reliability is adequate for lifetime performance in the relevant operational environment. Lifetime performance is usually ascertained during EMD via full-scale device reliability testing and packaged component durability testing, also known as qualification testing. Thus, the lifetime performance reliability of a new TRL-6 photonic component, or the lifetime performance durability of a new TRL-6 packaged device, is generally not completely known before EMD. In summary, fiber optic and photonic devices designated TRL-6 maturity should have completed some device reliability testing, some packaging durability testing, and tested as part of a system (i.e. fiber optic link) demonstration.

SAE has created the Aerospace Recommended Practice ARP6318TM titled “Verification of Discrete and Packaged Photonic Device Technology Readiness” [2]. This recommended practice describes methods of technology readiness verification of chip-level photonic devices, photonic integrated circuits, planar lightguide circuits, and packaged photonic components. The test requirements are based primarily on existing military standards combined with specific highly accelerated life test conditions and details.

SBIR/STTR Program Announcements, Phases, and Source Selection Criteria

SBIR/STTR program topics are announced via a Broad Agency Announcement (BAA) at www.sbir.gov. Individual topics are defined with a title, objective, description, and Phase I and Phase II goals. Phase I is the concept phase. It lasts six to twelve months and supports exploration of the technical merit or feasibility of an idea or technology. Phase II is the prototype development phase. Phase II typically lasts two to three years. Phase III is where innovation transitions. No SBIR funds support Phase III. The small business must find funding in the private sector or secure it from other non-SBIR Federal Agency funds that can fund continued development.

Proposal evaluations are based on three criteria: 1) The soundness, technical merit and innovation of the proposed approach; 2) the experience and qualifications of the research staff, and facilities; and 3) the commercialization strategy.

SBIR Program Examples

The SBIR topic titled “Ruggedized Laser Diode Package for Wavelength Division Multiplexed (WDM) Networks” was announced in 2004. One objective of this SBIR program was to demonstrate a single-mode fiber pigtailed wavelength selected laser diode transmitter and a tunable laser diode transmitter, both suitable for operation in digital avionic WDM network environments. Optonet was the performer in Phase I and Phase II. Some results were presented at the 2008 IEEE LEOS Annual Meeting in a paper titled “Integrated Ruggedized Fiber Optic Transmitter for Avionics WDM Network.” [3]. The SBIR team demonstrated a single-mode fiber optic transmitter package design and fabrication process for operation between –55 and +95C. The average ex-fiber output power was > 1 mW (Figure 1).

Figure 1. Wide temperature, low-profile, single-mode fiber pigtailed tunable laser package.

The overall package performance, including the <5 mm package height, was enabled by a customized dual-stage thermoelectric cooler, use of very small micro-optical components, and a silicon bench platform (Figure 2). Wide temperature wavelength tuning and locking over 300 GHz to four fixed wavelength channels spaced 100 GHz apart was demonstrated (Figure 3).

Figure 2. Wide temperature tunable laser packaging platform.
Figure 3. Four channel wavelength tuning at 100 GHz spacing under a wide temperature range.

TRL advancement of the packaged transmitter for avionics application was demonstrated via ambient temperature (–40 to +95C) testing and durability testing (500 temperature cycles between –40 to +85C) performance.

The SBIR topic titled “Multi-Wavelength and Built-in Test Capable Local Area Network Node Packaging” was announced in 2015. One objective of this program was to develop and demonstrate a wavelength division multiplexed (WDM) optical network node capable of 10 Gbps operation. Freedom Photonics was the performer in Phase I and II. Aspects of this work were presented at the 2016 IEEE Avionics and Vehicle Fiber-Optics and Photonics Conference (AVFOP) in a paper titled “A photonic integrated circuit based optical mesh node for avionic WDM optical networks,” and in an IEEE journal publication titled “Monolithic four-channel (QUAD) integrated widely tunable transmitter in indium phosphide” [4–5].

A scanning electron microscope (SEM) image of a QUAD transmitter chip mounted on an aluminum nitride carrier, with wirebonds connecting the contact pads on the chip to metal traces on the carrier is shown in Figure 4. The QUAD chip integrates monolithically four C-Band tunable lasers with their corresponding optical modulators and optical amplifiers.

Figure 4. SEM image of QUAD transmitter chip.

A QUAD transmitter optical subassembly (TOSA) module package design consisting of a package housing, control electronics and drivers, QUAD chip mounted on a ceramic carrier, a wavelength locker assembly, an optical train and an LC connector is shown in Figure 5. Representative eye diagrams at 10 Gbps for all 4 transmitters working simultaneously is shown in Figure 6.

Figure 5. QUAD TOSA module.
Figure 6. Eye diagrams at 10 Gbps.

The SBIR topics titled “Ruggedized Wideband High Power Balanced Photodiode Receiver” and “Integrated Laser and Modulator” were announced in 2014 and 2015, respectively. Objectives of these programs included development of high-power photodiodes and lasers for analog/radiofrequency (RF-over-Fiber) photonic links. Freedom Photonics was the performer in Phase I and II on these SBIR topics. Aspects of this work were presented at the 2019 IEEE Research and Applications of Photonics in Defense Conference (RAPID) in a paper titled “Advanced high power components for RF photonic applications” [6]. Other related presentations were given at the 2017 and 2019 Photonics West conferences, and the 2018 IEEE Avionics and Vehicle Fiber Optics and Photonics Conference (AVFOP) [7–9].

A fiber pigtailed high power photodiode package is shown in Figure 7. Figure 8 illustrates the modified uni-traveling-carrier photodiode design in cross section. A 3-dB RF bandwidth of 22 GHz with 23 dBm output power for a 28 μm packaged device was demonstrated. The RF output power at 10 GHz was 25 dBm with a -6V bias at the 101 mA photocurrent 1-dB saturation point (Figure 9). Further development work has produced higher bandwidth photodiodes, all the way to 100 GHz.

Figure 7. Fiber pigtailed photodiode package.
Figure 8. Modified uni-traveling-carrier photodiode design.
Figure 9. Output power and saturation at 10 GHz.

A fiber pigtailed high power 1.55 μm DFB laser is shown in Figure 10. Figure 11 illustrates the laser L-I curve. Peak powers in excess of 300 mW were achieved. Figure 12 shows relative intensity noise (RIN) and shot noise data at 7 mA photocurrent, room temperature, at different laser bias currents. Low RIN + shot noise <–160 dB/Hz was demonstrated at high bias current.

Figure 10. Fiber pigtailed DFB laser package.
Figure 11. 1.55 μm DFB laser output power and voltage.
Figure 12. RIN of the DFB laser at different bias currents.

Subsequent developments at Freedom Photonics have resulted in several product offerings including packaged tunable lasers, high power DFB lasers, and high power photodiodes.

STTR Program Examples

One of the objectives of the STTR program is to bring together world class research institutions with commercial companies to move technology development to products. One example of this is the STTR topic titled “High Speed Vertical Cavity Surface Emitting Laser (VCSEL)” that was announced in 2020. The objective of this STTR program is to develop and package an uncooled vertical cavity surface emitting laser (VCSEL) that operates error free in a fiber optic transmitter at no less than 100 gigabits per second binary non-return to zero serial for air platform fiber optic link applications.

Photon Sciences, Inc. (a wholly owned subsidiary of Dallas Quantum Devices) working with Georgia Institute of Technology and University of Illinois at Urbana-Champaign were performers in Phase I. Early results were presented at the 2021 IEEE Photonics Conference in a paper titled “Supermode Dynamics for VCSEL Modulation.” The STTR team has demonstrated a new VCSEL modulation paradigm for 100 gigabits per second (Gbps) and beyond [10]. The photonic crystal coupled cavity VCSEL resonator top view is shown in Figure 13, and in cross section in Figure 14.

Figure 13. Top view (a) of a photonics crystal coupled cavity VCSEL.
Figure 14. Side view schematic of a photonics crystal coupled cavity VCSEL.

Error free 50 gigabits per second VCSEL modulation with equalization was demonstrated (Figure 15), and eyes up to 76 gigabits per second were collected.

Figure 15. 50 Gbps eye diagram with equalization.

Another STTR topic titled “Ruggedized Multifunction Fiber-Optic Transceiver Optical Subassembly” was announced in 2005. One objective of this STTR program was to demonstrate digital fiber optic transceivers capable of detecting and isolating fiber faults along the cable plant in a digital avionic network environment. Ultra Communications working with Sandia National Laboratory was the performer in Phase I and Phase II. The Phase I and Phase II efforts investigated solutions that integrate optical time domain reflectometer (OTDR) functionality into the transceiver integrated circuit so that the overall optical subassembly and module physical envelope was not impacted. This solution required a mechanism for detecting back-reflected light from the fiber inside the transceiver.

Ultra Communications was also awarded a Phase III contract to develop a transceiver compatible OTDR application specific integrated circuit (ASIC). The OTDR ASIC shown in Figure 16 is a single chip integration of programmable timing circuits that operate up to 10 GHz, a pattern generator output in current mode logic (CML) signal format, and a four-channel receiver/sampling circuit. The OTDR ASIC can generate pulse widths of 100 ps and sample at 100 ps resolution, which is equal to the round trip time for an optical pulse to travel 1 cm in optical fiber.

Figure 16. OTDR ASIC.

Some results were presented at the 2014 IEEE Optical Fiber Communications Conference in a paper titled “Novel high-resolution OTDR technology for multi-Gbps transceivers.” [11] Ultra Communications demonstrated a 10 Gbps transceiver with integrated built-in OTDR capability to detect fiber breaks and connector discontinuity with 1-cm resolution. The transceiver is shown in Figure 17.

Figure 17. 10 Gbps per channel, quad, VCSEL-based parallel optic transceiver packaging with OTDR.

This STTR program evolved into several other programs, including development of chip-scale-packaging transceiver form factors. A 10 Gbps per channel transceiver is shown in Figure 18. Several aspects of this work were presented at the 2013 and 2014 IEEE Optical Interconnects Conferences, and the International Conference on Space Optics 2014 [12]–[14]. This transceiver technology has been qualified for avionic applications and is currently in volume production and sales at Ultra Communications.

Figure 18. 10 Gbps per channel chip-scale package transceiver.

Summary

The SBIR and STTR programs provide a unique opportunity for researchers, engineers, entrepreneurs, start-ups and small businesses to explore fiber optics and photonics developments that otherwise may not have been possible through other investment channels or business opportunities. Getting to Phase III requires true technology innovation, timing patience, perseverance and market acceptance. Technology Readiness Level 6 provides a goal for SBIR and STTR teams to strive toward as they journey from Phase I toward Phase II and Phase III, qualification, production and sales.

References

[1] M.W. Beranek and E.J. Copeland, “Accelerating fiber optic and photonic device technology transition via pre-qualification reliability and packaging durability testing,” 2015 IEEE Avionics Fiber Optics and Photonics Conference (AVFOP), 2015, pp. 69–70, doi: 10.1109/AVFOP.2015.7356630.
[2] ARP6318 Verification of Discrete and Packaged Photonic Device Technology Readiness.” SAE international, 2018. https://saemobilus.sae.org/content/arp6318.
[3] J. Ma, K.-W. Leong, L. Park, Y. Huang and S.-T. Ho, “Wide temperature tunable laser packaging for avionic WDM LAN applications,” 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society (LEOS 2008), 2008, pp. 654–655, doi: 10.1109/leos.2008.4688788.
[4] D.J. Kebort, S.B. Estrella, L.A. Johansson and M. Mashanovitch, “A photonic integrated circuit based optical mesh node for avionic WDM optical networks,” 2016 IEEE Avionics and Vehicle Fiber-Optics and Photonics Conference (AVFOP), 2016, pp. 11–12, doi: 10.11.1109/AVFOP.2016.7789916.
[5] D.J. Kebort, G.B. Morrison, H. Garrett, J.N. Campbell, S.B. Estrella, R.H. Banholzer, J.B. Sherman, L.A. Johansson, D. Renner and M.L. Mashanovitch, “Monolithic four-channel (QUAD) integrated widely tunable transmitter in indium phosphide,” in IEEE Journal of Selected Topics in Quantum Electronics, vol. 24, no. 1, pp. 1–7, Jan.-Feb. 2018, Art. No. 1500507, doi: 10.1109/JSTQU.2017.2774205.
[6] L. Johansson, G. Morrison, B. Buckley, M. Woodson, S. Estrella, K. Hay and M. Mashanovitch, “Advanced high power components for RF photonic applications,” 2019 IEEE Research and Applications of Photonics in Defense Conference (RAPID), 2019, pp. 102, doi: 10.1109/RAPID.2019.8864341
[7] S. Estrella, K. Hay, J. Campbell, B. Maertz, Q. Li, K. Sun, A. Beling, L. Johansson, D. Renner and M. Mashanovitch, “High-power InGaAs/InP MUTC photodetector modules for RF photonics links and ROF,” Proc. of SPIE, vol. 10128, Broadband Access Communication Technologies XI, 101280M, 28 January 2017, doi: 10.1117/12.2253346.
[8] M. Woodson, S. Estrella, K. Hay, K. Sun, J. Morgan, A. Beling, D. Renner and M. Mashanovitch, “High-power, high-bandwidth unitraveling-carrier photodiodes for high-frequency RF photonic links (Conference Presentation),” Proc. of SPIE, vol. 10917, Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XII, 109171J, 5 March 2019, doi: 10.1117/12/2510568.
[9] M. Mashanovitch, S. Fryslie, B. Buckley, K. Guinn, G. Morrison and L.A. Johansson, “High-power, efficient DFB laser technology for RF photonic links,” 2018 IEEE Avionics and Vehicle Fiber-Optics and Photonics Conference (AVFOP), 2018, pp. 1-2,doi: 10.1109/AVFOP.2018.8550469.
[10] K.D. Choquette, S.E. Ralph, A. Melgar, N. Jahan, W. North and J.A. Tatum, “Supermode Dynamics for VCSEL Modulation,” 2021 IEEE Photonics Conference (IPC), pp. 1–2, doi:10.1109/IPC48725.2021.9592985.
[11] C. Kuznia, J. Ahadian, D. Pommer, R. Hagan, P. Bachta, M. Wong, K. Kusomoto, S. Skendzic, C. Tabbert and M.W. Beranek, “Novel high-resolution OTDR technology for multi-Gbps transceivers,” 2014 Optical Fiber Communications Conference (OFC 2014), 2014, pp. 1–3, doi: 10.1364/OFC. 2014.W1F.2.
[12] J. Ahadian, K. Kusomoto, P. Bachta, M. Wong, D. Pommer, R. Hagan and C. Kuznia, “Packaging technology for embedded optical modules,” 2013 IEEE Optical Interconnects Conference, pp. 15–16., doi: 10.1109/OIC.2013.6552901.
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About the Author

Mark Beranek began working in the aerospace fiber opticsand photonics technology domain upon joining The Boeing Company in 1989. Mark’s Department of the Navy civil service career began in 2002 with his appointment at the Naval Air Warfare Center—Aircraft Division (NAWCAD). Mark is a Senior Member of IEEE, and Past-Chair of the Joint Aviation Fiber Optic Working Group, the IEEE LEOS/CPMT Optoelectronics Packaging Workshop, the IEEE Electronic Components and Technology Conference Optoelectronics committee, the IEEE Avionics Fiber Optics and Photonics Conference committee, and the SAE Avionics Systems Division—Fiber Optics and Applied Photonics Components committee. His photonics and other related experience includes laser chemical vapor deposition of thin films for microelectronic/integrated circuit applications, and fiber optic transmitter and receiver development and packaging for aerospace platform optical communication. Mark currently serves as Fiber Optics Subject Matter Expert at NAWCAD Air Systems Group. Here he provides research and engineering direction in the areas of digital and analog/RF fiber optic communications, integrated photonics, fiber optic components, packaging, standardization, and fleet maintenance. Mark also supports Naval Air Systems Command (NAVAIR) acquisition program offices, and the NAVAIR Small Business Innovation Research (SBIR) pro-
gram office.

NAVAIR Public Release SPR# 2022-190.

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