DIRECT TO PHASE II: Flexible Integrated Optical Circuit (IOC) Packaging Options for Improved Size Weight and Power (SWaP) in Interferometric Fiber-Optic Gyroscopes (IFOG)

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Microelectronics; Space Technology 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: Address multiple aspects in the design and packaging of current state-of-the-art Y-branch phase modulator integrated optical circuits (IOCs), making them more flexible for integration into reduced form factor sensors. DESCRIPTION: Sensor technology will always have high performance requirements as a standard, metrics like long-term bias stability, angle random walk, scale factor error and linearity, temperature sensitivity, etc. must remain consistent with or outperform prior generations of sensors. At the same time, reducing sensor Size, Weight, and Power (SWaP) requirements continues to be important to enable technology development for multiple applications. As a critical component of Interferometric Fiber-Optic Gyroscopes (IFOG) technology, the IOC phase modulator package presents a limitation for size reduction of the next higher assembly [Ref 1]. The IOC is typically a Y-branch crystal waveguide (in Lithium Niobate or other materials) with two pairs of electrodes creating dual modulators, which is then attached to optical fiber pigtails at the input and both output ports [Ref 2]. There are multiple possible ways to reduce the overall package volume, but this SBIR topic does not seek to prescribe a single solution. Instead, the goal will be to reduce SWaP (or impact of SWaP on the next higher assembly) of a state-of-the-art IOC with equivalent performance to current devices in the most efficient way possible using one or more techniques. PHASE I: For a Direct to Phase II topic, the Government expects that the small business would have already demonstrated IOC design capability to address one or more of the packaging improvement options (Phase I-type work). Possible techniques to reduce SWaP or the impact of SWaP include: 1. Chip design or material choices, including novel waveguide or electrode design, novel composite or combined materials, or Thin-Film Lithium Niobate (TFLN) devices 2. Reducing the space required for either high-precision fiber attachment to the waveguide or protection when exiting the package 3. Reducing connector size, either directly or by closer integration inside the package 4. Providing a means to re-direct fiber input and output ports in a different manner than possible with current straight waveguides 5. Equivalent phase modulator technology integrated into a photonic integrated circuit (PIC) based device (Note: this must still be integrated into a prototype as described in Phase II) The above actions would be required in order to satisfy the requirements of Phase I. 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. Documentation should include all relevant information including, but not limited to technical reports, test data, prototype designs/models, and performance goals/results. Work submitted within the feasibility documentation must have been substantially performed by the offeror and/or the principal investigator (PI). Read and follow all of the DON SBIR 24.2 Direct to Phase II Broad Agency Announcement (BAA) Instructions. Phase I proposals will NOT be accepted for this topic. PHASE II: Design, fabricate, and characterize six (6) prototype IOCs. These must be fully packaged devices with pigtailed fiber, connectors, and screwed on or sealed lids, which are suitable for individual testing, next higher assembly integration, or sensor prototype testing. Characterization data provided must cover optical measurements for insertion loss, split ratio, chip polarization extinction ratio (PER), fiber lead PER, optical return loss or coherent backscatter, and wavelength dependent loss. It must also cover electrical measurements for frequency response measurement and half-wave voltage (Vpi), as well as residual intensity modulation. An accelerated aging study, equivalent to 5-years real-time, involving these prototype IOCs being heated under vacuum must be performed. A predictive model of long-term (~30 years) environmental stability must be provided as a result of this accelerated aging study. The prototypes should be delivered at the end of Phase II. PHASE III DUAL USE APPLICATIONS: Based on the prototypes developed in Phase II, continuing development must lead to productization of low SWaP phase modulators. In addition to military/strategic applications, these improvements will be applicable to multiple commercial technologies. These areas include Light Detection and Ranging (LIDAR), satellite optical communications, and telecommunications. REFERENCES: Adams, Gary and Gokhale, Michael. Fiber optic gyro based precision navigation for submarines. Proceedings of the AIAA Guidance, Navigation and Control Conference, Denver, CO, USA, August 2000, pp. 2-6. https://arc.aiaa.org/doi/pdf/10.2514/6.2000-4384 Wooten, Ed L. et al. "A review of lithium niobate modulators for fiber-optic communications systems." IEEE Journal of selected topics in Quantum Electronics 6, January 2000, pp. 69-82. https://ieeexplore.ieee.org/document/826874 KEYWORDS: Integrated Optical Circuit; Phase Modulator; Lithium Niobate; Waveguides; Inertial Sensor; Fiber-optic Gyroscope