Field-deployable Quantum Cascade Laser standoff chemical imaging system for CBRNE detection

Problem statement

Protecting Canadian military personnel, vehicles, and critical assets against hazardous chemical threats is predicated on the ability to rapidly detect and monitor contamination at a safe distance in CBRNE scenarios.

NRC is seeking an integrated solution that combines a tunable infrared quantum cascade laser spanning the fingerprint spectral range (14.3 to 5.5 µm) with a compatible hyperspectral thermal imager along with the supporting optics, electronics, acquisition software, processing capability, and ruggedized packaging required for field use.

The source could include a few modules of wavelength tunable EC-QCL (external cavity Quantum Cascade Lasers) together to cover the full fingerprint spectral range (14.3 to 5.5 µm). The system would function as a turn-key platform capable of acquiring infrared chemical images and reflectance spectra, extracting spectral information for chemical identification, and supporting operation in realistic defence and security settings. The objective is to translate an existing laboratory-demonstrated sensing concept into an integrated prototype suitable for field validation and further advancement toward deployment. NRC will play an active role in prototype evaluation and in validating system performance under relevant testing conditions. Although the primary driver is defence and security, the technology may also support future applications in public safety, forensic investigation, and environmental surveillance.

Desired outcomes and considerations

Essential (mandatory) outcomes

The proposed solution must:

1. Have a bright wavelength tunable infrared (IR) laser source:
   • That completely covers the vibrational spectral fingerprint range of 750 to 1800 cm-1 (13.3 to 5.5 µm)
   • That has to contain at least three co-linear quantum cascade lasers (QCLs) to cover this IR range and a visible laser propagating along the output IR direction
2. Have a hyperspectral focal plane array (FPA) imager covering the QCL spectral range to allow for chemical imaging. This FPA must:
   • Be capable of frame rates that allow collecting a hyperspectral image in one second at 4 cm-1 resolution
   • Have a Cooled FPA such as mercury cadmium telluride (MCT) or strain layer superlattice (SLS) for maximum sensitivity
   • Have a visual video camera with a larger field of view than FPA to allow for alignment of the FPA
   • Have an adjustable spectral interval between 1 – 16 cm-1
3. Contain a single element detector with high sensitivity and speed, which is a field operable cooled MCT detector covering the QCL wavelength range. This single element detector must:
   • Have a detectivity of 3x10^10 cm/(Hz^(1/2)W)
   • Be capable of acquiring a complete spectrum from 750 to 1800 cm-1 in one second or less with a 4 cm-1 spectral interval
4. Have separate input optics for the single element detector and the FPA, and the input optics must be swappable
5. Ensure complete compatibility between laser source wavelength sweeping and MCT/SLS FPA frame capture electronics as well as to the single point readout data
6. Be portable. The system (source + detector + electronics) must fit on a field deployable platform within less than 0.1 m^3 and controlled by a rugged laptop
7. Have reflective or equivalent refractive imaging input optics with suitable collection numerical aperture and low spherical aberration capable of:
   • Optical detection range of 0.3 – 10 meter
   • Obtaining hyperspectral images with a signal to noise of at least 20 to 1 for reflectance from an Infragold® or equivalent material surface for near normal laser incidence
8. Function as a turn-key system with a fully integrated hardware-software suite. The software must be able to:
   • Tune the wavelength and the power of the laser
   • Synchronize the laser to the hyperspectral imager, process and displays the chemical images
   • Allow the operator to extract infrared spectra from individual pixel or groups of pixels and perform spectral manipulation and chemical identification

Additional outcomes

The proposed solution should:

1. Be operable in a 0 to 40 Celsius outdoor environment. The system should be able to operate under battery power and be hot swappable between battery and AC power:
2. Have a pan and tilt mechanism to assist object targeting
3. Have modular and swappable input optics with varying magnification based on interchangeable input lenses
4. Provide a converter from its data format to standard binary and ASCII data formats
5. Have a FPA capable of:
   • Achieving a pixel operability of > 98% over the full FPA. A pixel is considered inoperable if its responsivity is less than 10% of the average responsivity
   • Detecting noise equivalent temperature differences lower than 40 milli-Kelvin
6. Have an enclosure that is able to withstand external environmental factors, e.g. wind, rain, dust
7. Have an output laser optics to increase the spot size with a beam expander telescope
8. Have a software development kit (SDK) to allow the user to script acquisition functions

Background and context

Protecting military personnel and assets in CBRNE threat environments requires sensing technologies that can provide timely and chemically specific assessment of hazardous contamination while minimizing operator exposure. Although a range of chemical detection tools are currently used in the field, many require close-contact sampling or near-source measurements, which can place operators at risk and delay decision-making. Existing standoff methods, including Raman, passive IR spectroscopy and tunable infrared QCL-based reflectance spectroscopy, can provide important chemical information from a safer distance, but they are generally limited to single-point interrogation of a very small surface area and are therefore too slow for efficient assessment of larger or spatially non-uniform contamination. NRC has recently demonstrated a tunable infrared laser-based standoff spectroscopy capability in the laboratory with strong performance on military-relevant targets at distances from a few tens of centimeters to beyond 5 meters. The current platform, however, is limited to point spectroscopy. As a result, current system do not fully meet the operational need for rapid detection, localization, and mapping of hazardous chemicals on surfaces of military relevance. A standoff chemical imaging system with both spectral identification and rapid area coverage would address this gap and enable the next generation of CBRNE sensing for defence operations.

Specifically, infrared spectroscopy with its sensitivity to molecular species through their vibrational signatures provides a clear method for chemical identification. When the spectroscopy is performed with a powerful tunable laser reflecting from a surface, any residue present can generally be probed and identified at a standoff distance without the necessity of contacting the surface or residue. Reflectance spectra are built up by tuning the laser to particular wavelengths and measuring the intensity of reflected laser radiation at these points. For non-uniform, sparce chemical residue layers it is also necessary to find where particular chemicals are spatially located, which means that chemical imaging must be done for a larger, laser illuminated surface area to enable the location of the potentially dangerous chemicals. This requirement turns the measurement issue from one of spectral reflectance to one of hyperspectral imaging, which is feasible when one uses a sensitive and fast FPA camera to take an image of the specified area at each wavelength point. Then chemical image analysis software can be trained to rapidly find where the chemicals of interest are located on the surface and in what concentration.

The standoff chemical imaging system proposed here would represent a significant improvement over the current state of the art. With its improved signal-to-noise performance, ultra-bright quantum light source and superior beam characteristics allows the proposed system to present new capability for fast imaging reflectance of real-world surfaces. These features are critical to identifying surface contamination, which has not been possible previously due to limitations in detection noise and speed as well as signal strength.

Multiple grants could result from this Challenge.

Phase 2

• Maximum funding: $1,500,000.00 CAD
• Project duration: Up to 18 months
• Estimated number of grants: 1

This disclosure is made in good faith and does not commit Canada to award any grant for the total approximate funding. Final decisions on the number of Phase 2 awards will be made by Canada based on factors such as evaluation results, departmental priorities, and availability of funds. The Government of Canada reserves the right to make partial awards and to negotiate project scope changes.

Note: Selected companies are eligible to receive one grant per phase per challenge.

Travel

At the end of the project, the successful applicant will be expected to travel to NRC's Metrology Research Centre to demonstrate the operation of the solution and provide training to enable NRC researchers to independently test and validate its performance. The NRC address for the demonstration and training is NRC-Metrology, 1200 Montreal Road, Ottawa, ON K1A0R6.

Kick-off meeting

All communication will take place by telephone or videoconference.

Progress review meeting(s)

Any progress review meetings will be conducted by telephone or videoconference.

Final review meeting

All communication will take place by telephone or videoconference.

Solution proposals can be submitted by a business that meets all of the following criteria:

• for profit
• incorporated in Canada (federally or provincially)
• small and medium sized business with 499 or fewer full-time equivalent (FTE) employees^**
• research and development activities that take place in Canada
• 50% or more of its annual wages, salaries and fees are currently paid to employees and contractors who spend the majority of their time working in Canada^{Footnote **}
• 50% or more of its FTE employees have Canada as their ordinary place of work^{Footnote **}
• 50% or more of its senior executives (Vice President and above) have Canada as their principal residence^{Footnote **}

All incoming questions regarding this specific challenge should be addressed to solutions@ised-isde.gc.ca.

All enquiries must be submitted in writing no later than ten calendar days before the Challenge Notice closing date. Enquiries received after that time may not be answered.

A glossary is also available.