N241-006 TITLE: Two-color Mid-Wave Infrared (MWIR) LED Array Infrared Scene Projector (IRSP)

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Sustainment

OBJECTIVE: Design a two-color Mid-Wave Infrared (MWIR) light emitting diode (LED) array with a Read-in Integrated Circuit (RIIC) to provide the capability for system design and integration of a high-fidelity Infrared Scene Projector (IRSP) to support testing and evaluation (T & E) of sensor and seeker. Develop a side-by-side structured two-color LED array with narrow spectral bandwidths with two different spectral bands between 3–5 µm.

DESCRIPTION: Chemical sensing, IRSP, and spectroscopy applications require improved MWIR [3–5 µm]) LED arrays. A 1024 X 1024 dual-band MWIR LED array that incorporates narrow-band emission LEDs to provide electromagnetic radiation in two spectral bands is highly beneficial. The narrow-band emission of LEDs will enable more precise spectral emissions for analysis of chemical composition, provide the core technology for smaller, lighter IRSPs, and provide the capability for better wavelength selection of two-color absorption spectroscopy. Narrow-band LED arrays with enhanced efficiencies that increase the brightness of individual LED pixels to replicate temperatures above 1500 K will improve signal levels for both chemical sensing and spectroscopy. The two-color LED arrays of an IRSP will improve the fidelity of projection systems for more effective Hardware-in-the-loop (HITL) and live-virtual-constructive (LVC) testing of missile warning systems (MWS). It will be extremely difficult to meet all these needs using current technologies.

The simulation of range-dependent high-fidelity threat signatures in complex environments for rendering images of HITL engagements is necessary for two-color MWS HITL ground testing and performance evaluation. Enhanced high-brightness LED arrays must provide a high-dynamic range and sufficient bit-depth to render variable thermal environments. Current IR scene projectors based on resistive emitter arrays have performance shortcomings such as low-radiance, slow-frame rates, and small-frame sizes. MWIR narrow-band emission LEDs will be optimized to produce higher in-band radiance at higher frame rates and larger frame sizes than existing technologies. Existing MWIR LED arrays produce photons over a broadband spectrum and have low photon-generation efficiency that affects spectral banded light levels and induces cross-band detection of narrow-band detectors. These issues make broadband LEDs unattractive for narrow-band detection. By contrast, a dual-band IRSP or spectroscopes incorporating two-color narrow-band LED arrays, which exhibit higher efficiency and brightness, will better match detection requirements. A collocated side-by-side two-color pixel design of a two-color LED array will allow independent electrical control of each color pixel and 16-bit continuous wave operation in a 1024 X 1024 format.

This SBIR topic will investigate two-color narrow-band LED arrays with emissions wavelengths centered for chemical sensing, sensor, or spectroscopy detection. The LED array will have a cross-talk value of less than 1% at an effective temperature of 450 K, designed to enhance the MWIR LED efficiency and brightness. Proposed approaches include designing, fabricating, and characterizing two-color MWIR LED arrays using narrow-band emission LEDs that match the in-band MWIR wavelength ranges. An electronically multiplexed LED array suitable for high-fidelity hardware-in-the-loop will have a Phase I LED array approach designed and a Phase II demonstration.

These attributes improve spatial and spectral resolution for chemical detection, IRSP, and spectroscopy applications. Improved chemical sensing and spectroscopy have applications for warfighter battlefield safety. The LED spectral bands will be determined for the warfighter's desired application. The two-color array design will include a RIIC approach with 16-bit capability. The LED will be designed for high-frame rates, low-cross talk, and variable set temperatures to improve the ability to design high-fidelity systems. These design features will improve electrical efficiency, which will improve reliability to lower lifecycle costs. This will allow the test programs to tailor flight test scenarios based on HITL test results, reduce their flight hour requirements, and improve overall test efficiency. For chemical sensing and spectroscopy, this capability will support the needs of the warfighter for the analysis and detection of biological or chemical agents. The Navy is in need of enhanced MWIR scene projectors that are smaller and lighter weight for placement on MWS HITL and flight line T & E.

PHASE I: Write a final report of the design and feasibility of a high-brightness two-color mid-wave-infrared LED array structure including the RIIC concept. The Phase I effort will include prototype plans to be developed in Phase II.

PHASE II: Develop a 1024 X 1024 two-color LED array structure with independently controlled pixels by a RIIC. Demonstrate a two color MWIR (3–5 µm) narrow spectral band (< 100 nm) LED array with a 300–1500 K dynamic range and 16-bit resolution and per specifications based on the research and development of results developed during Phase I for DoD applications.

PHASE III DUAL USE APPLICATIONS: The two-color IR LED array is developed for integration into two-color IR scene projector. Transition the IRSP to the Navy.

A two-color IR LED has potential application for industrial chemical sensing and safety protection. An IRSP has application for both firefighter and medical scenario training.

REFERENCES:

1. Canedy, C. L., Bewley, W. W., Tomasulo, S., Kim, C. S., Merritt, C. D., Vurgaftman, I., Meyer, J. R. Kim, M., Rotter, T. J., Balakrishnan, G., & Golding, T. D. (2021). Mid-infrared interband cascade light emitting devices grown on off-axis silicon substrates. Optics Express, 29(22), 35426-35441. https://doi.org/10.1364/OE.435825
2. Al-Saymari, F. A., Craig, A. P., Lu, Q., Marshall, A. R., Carrington, P. J., & Krier, A. (2020). Mid-infrared resonant cavity light emitting diodes operating at 4.5 µm. Optics Express, 28(16), 23338-23353. https://doi.org/10.1364/OE.396928
3. Kim, C. S., Bewley, W. W., Merritt, C. D., Canedy, C. L., Warren, M. V., Vurgaftman, I., Meyer, J. R., & Kim, M. (2018). Improved mid-infrared interband cascade light-emitting devices. Optical Engineering, 57(1), 011002-011002. https://doi.org/10.1117/1.OE.57.1.011002
4. Ermolaev, M., Lin, Y., Shterengas, L., Hosoda, T., Kipshidze, G., Suchalkin, S., & Belenky, G. (2018). GaSb-Based Type-I Quantum Well 3–3.5-µm Cascade Light Emitting Diodes. IEEE Photonics Technology Letters, 30(9), 869-872. https://doi.org/10.1109/LPT.2018.2822621
5. Muhiyudin, M., Hutson, D., Gibson, D., Waddell, E., Song, S., & Ahmadzadeh, S. (2020). Miniaturised Infrared Spectrophotometer for Low Power Consumption Multi-Gas Sensing. Sensors, 20(14), 3843. https://doi.org/10.3390/s20143843

KEYWORDS: Mid-Wave Infrared (MWIR); light emitting diode (LED); Infrared Scene Projector (IRSP); EO/IR; sensor; projector

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