TECHNOLOGY AREA(S): Battlespace, Electronics, Sensors

ACQUISITION PROGRAM: PEO IWS 2.0, Above Water Sensors Program Office.

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 demonstrate a new standardized fabrication process for quantum cascade lasers (QCL) operating in the mid-wave infrared (MWIR) band that is optimized for repeatable and cost-effective manufacturing.

DESCRIPTION: Many threats to surface ships employ infrared (IR) imagers and detectors. These include lethal threats such as anti-ship cruise missiles as well as aircraft and unmanned aerial systems performing routine surveillance. In all cases, shipboard countermeasures are needed and lasers are a fundamental component of any electro-optic/infrared (EO/IR) countermeasures suite. In order to realize maximum utility, it is desirable that multiple lasers, each operating in a different wavelength band, be employed. However, this becomes expensive and the combined weight of the lasers in a wide bandwidth system becomes considerable, especially since laser countermeasures are most effective when mounted high on the ship�s superstructure, where weight is at a premium.

Fortunately, conventional countermeasures lasers typically do not require power levels as high as that needed for laser weapons. Recently developed semiconductor lasers, especially if their outputs are combined across an array of devices, are sufficient to produce the power required. Their small size is also attractive, particularly as multiple devices will still be required to cover multiple wave bands. Of special interest is the quantum cascade laser (QCL), because it has the added feature that its wavelength can be selected across a relatively wide band within the same basic device. This means that a small number of individual QCL designs can serve many applications. This has obvious benefits for affordability, especially as envisioned systems may require hundreds of individual solid-state laser components.

However, QCLs are expensive. This is not due to a lack of understanding of the device, nor to a particularly difficult or exotic manufacturing process. QCLs are most commonly fabricated in the indium phosphide (InP) semiconductor system using basic process steps widely available in the industry. The main factor driving QCL device cost is limited market demand. That is, QCLs are produced in limited numbers, often in discrete batches utilizing proprietary processes, to supply niche markets such as scientific instruments. In addition, QCLs have not yet found major markets in industrial or telecommunications applications. Consequently, QCL production volumes are low because a single semiconductor wafer fabrication run can supply multiple applications due to the inherent flexibility of the device.

A standard QCL semiconductor fabrication process that can meet a wide range of defense needs in the mid-wave infrared (MWIR) wave band is needed. A great deal of research over the past 20 years has steadily advanced QCL performance, in increasing both the power output and the breadth of operating wavelengths. Fundamental QCL device physics is well understood. Ironically, the prolific research aimed at improving QCL performance has likely contributed to the high cost of the device, as no �standard� device has been established. Therefore, device performance is sufficiently mature and innovation in this area is not considered part of this effort.

The Navy seeks a standard QCL fabrication process optimized for affordable manufacture and realized in a common semiconductor system (such as InGaAs/InAlAs quantum wells on an InP substrate) with repeatable and high-yield fabrication processes. The process should yield a standard device that the company can subsequently have produced in a merchant foundry of their choosing (merchant foundries are �build to print� semiconductor fabrication facilities that accept work under contract). Innovative application of established, or invention of new, process steps is required to produce devices optimized for yield and throughput that can be fabricated in existing semiconductor foundries. Also, note that the device design and fabrication process are integrally linked and it is understood that the resulting fabrication process must be demonstrated on a specific QCL design or family of QCL devices.

For this effort, the MWIR band of interest is 3.7-4.8 microns wavelength. A single-device output power of 500 mW (minimum, at room temperature) with device efficiency of 8% is considered achievable and acceptable. As devices exhibiting considerably higher power than the minimum present a net cost savings in applications where the output power of multiple devices is combined, cost per watt of output power may be used as a figure of merit in assessing the feasibility of the proposed design. The emitted beam quality (M2) should be less than 3.0 (with a goal of 1.5). The device design cannot preclude its application in systems employing beam combining. The demonstrated devices must permit wavelength selection over a nominal range of 100 - 200 nm and the basic design should be applicable across the entire 3.7-4.8 micron band (with adjustment of wavelength-determining dimensions and parameters such as quantum well thickness). Within these parameters, the fabrication process (and associated device structure) must be optimized for low-cost fabrication. While device cost varies from manufacturer to manufacturer (approximately $4,000 each), and according to device performance, a cost reduction of 80-90% is desired, based on the current state of the art for commercially available devices of comparable performance.

PHASE I: Provide a concept for a QCL fabrication process and device design, optimized for manufacturability, while meeting the minimum performance parameters described in the Description. Select a specific semiconductor family that is compatible with available merchant foundries and demonstrate the feasibility of its concept in reducing cost. Demonstrate feasibility by a combination of analysis, modelling and simulation. Include, in the feasibility analysis, yield predictions and cost analysis of the proposed fabrication process. Develop a Phase II plan. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.

PHASE II: Produce and deliver a prototype QCL fabrication process that meets the requirements in the Description. Produce and deliver generic devices that also meet the requirements and are not intended for any specific system application.� Demonstrate and document process repeatability and device-to-device uniformity. Report prototype test data.� Demonstrate low cost production by validating (through testing) production-ready prototype QCLs.� This is expected to be an iterative process, likely resulting in multiple prototypes. The product expected from this effort is a complete design package for the production of a final generic prototype, sufficient for delivery to a qualified merchant foundry. At the conclusion of Phase II, deliver sample prototype devices, at least five each operating in at least two center wavelengths, to the Government for characterization and retention as �gold standard� devices.

PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the technology for Government use. Since the design package and prototypes resulting from Phase II are generic, assist in applying the design for specific system applications. This is expected to entail selection of device dimensions and adjustment of corresponding process parameters in order to produce QCLs at specific center wavelengths. Produce device-specific process instructions and mask sets ready for delivery to qualified merchant foundries. Assist the Government in testing and validating the performance of the resulting devices and in enforcing quality control. Ensure that the final product is a sustainable family of affordable QCLs, produced to a standard process and available for application in multiple DoD systems, including shipboard and airborne countermeasures.

This technology can be used in commercial applications such as telecommunications and laser spectroscopy.

REFERENCES:

1. Razeghi, Manijeh, et al. "Recent progress of quantum cascade laser research from 3 to 12 �m at the Center for Quantum Devices.� Applied Optics 56, 1 November 2017: H30-H44. https://www.osapublishing.org/ao/abstract.cfm?uri=ao-56-31-H30

2. Vitiello, Miriam Serena, et al. "Quantum cascade lasers: 20 years of challenges.� Optics Express 23, 20 February 2015: 5167-5182. https://www.osapublishing.org/oe/abstract.cfm?uri=oe-23-4-5167

3. Razeghi, Manijeh, et al...� "Recent advances in mid infrared (3-5�m) Quantum Cascade Lasers.� Optical Materials Express 3, 10 October 2013: 1872-1884. https://www.osapublishing.org/ome/abstract.cfm?uri=ome-3-11-1872

KEYWORDS: Quantum Cascade Laser; Shipboard Countermeasures; Mid-Wave Infrared; Beam Combining; Solid-State Laser; Semiconductor Fabrication; QCL; MWIR