Release Date
August 23rd, 2023
Open Date
September 20th, 2023
Due Date(s)
October 18th, 2023
Close Date
October 18th, 2023
Topic No.


Optical Fiber Combiner for Combining MWIR Quantum Cascade Laser Beams


Department of DefenseN/A


Type: SBIRPhase: BOTHYear: 2023


The Department of Defense (DoD) is seeking proposals for an optical fiber combiner for combining MWIR (Mid-Wave Infrared) quantum cascade laser beams. The objective is to develop an optical fiber combiner that can receive power from seven or more quantum cascade lasers emitting at a wavelength between 4.5 and 5 micrometers. The combiner should be able to output a sustained average power of up to 60 Watts while retaining at least 80% of the total power input. The technology will be used for long-distance directed energy applications, such as target acquisition and illumination systems. Phase I of the project will involve a feasibility study, while Phase II will focus on fabrication and demonstration of the combiner system. Phase III will involve commercial production of the combiners. The solicitation is open until October 18, 2023. For more information, visit the solicitation link.



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: An optical fiber combiner that has demonstrated the ability to receive power from seven or more quantum cascade lasers emitting at a wavelength between 4.5 and 5 micrometers. The total output power from the optical fiber combiner should exceed 80% of the total power input by the combined quantum cascade laser collection as measured at the facets of the lasers without additional optical components, accounting for coupling from laser to fiber, coatings, fiber losses, and other sources of loss systemic to the use of the optical fiber combiner. The optical fiber combiner will be designed in such a way as not to undergo damage or degradation while outputting a sustained average power of up to 60 Watts.

DESCRIPTION: As the commercial availability of quantum cascade lasers grow in the 1-3 Watt class, it becomes possible to project a MWIR signal in a compact fashion over distances on the order of kilometers. Greater distances require greater amounts of combined power. To quickly achieve an order of magnitude increase in signal strength for distance propagation, it s necessary to combine the output of multiple devices. Currently, materials used for MWIR fibers are chalcogenides, tellurites, and hollow cores. The losses included in coupling the highly divergent beam of the quantum cascade laser, reflection, and inherent absorption of the fibers lead to a nontrivial amount of loss of the input signal. To achieve long distance propagation of MWIR signal, it is desirable for a collection of quantum cascade lasers with synchronized inputs to have a combined output delivered by a fiber to a beam director. An optical fiber combiner maintaining a large degree of power would be advantageous for applications lacking a strict beam quality requirement, such as target acquisition and illumination systems. The goal of this topic is to produce a commercially viable optical fiber combiner usable as a component of a larger MWIR beam delivery system for long distance directed energy applications. The work involved should include a demonstration of utilizing seven or more commercially available quantum cascade lasers to effectively combine the power of the collection of lasers at a single output fiber. The power measured at the output should retain at least 80% of the sum of the power of the collection of lasers as measured before integration in the combined system, using the same driving setpoint for both measurements.

PHASE I: Phase I awardees will be expected to provide a study on fiber materials, coatings, coupling of the quantum cascade laser produced beam (of a wavelength between 4.5-5 micrometer) into fiber, and fiber combining scheme projecting the feasibility of the combiner system output to retain 80% of the total power introduced into its inputs.

PHASE II: Phase II awardees will be expected to accomplish fabrication and demonstration of the optical fiber combiner system using commercially available quantum cascade lasers, demonstration and measurement of power at output compared to the sum of the power of the component lasers before combining, and delivery of an optical fiber combiner.

PHASE III DUAL USE APPLICATIONS: Phase III awardees will be expected to engage in commercial production of optical fiber combiners for integration into systems requiring the combined power of multiple MWIR sources.


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KEYWORDS: MWIR; Fiber optics; Optical fiber combiner; QCL