Proposal submission instructions

OBJECTIVE: To develop trace gas sensors on a chip with mid-infrared laser based spectroscopy techniques such as absorption spectroscopy with a broad wavelength span of 3-15 microns and sub-ppm sensitivity.

Currently, mid-infrared trace gas sensing systems based on based on ring-down spectroscopy, absorption spectroscopy, or photoacoustic spectroscopy are developed around bulky gas cells and free-space optics [3]. However, these systems require relatively large and expensive optical elements. These systems have significant size and weight that place constraints on their applications in the field, particularly for airborne or handheld platforms. Additionally, the use of free-space optics makes these systems inevitably sensitive to stress and vibration.

PHASE I: Propose a packaged design that can detect a selected gaseous substance or substances of interest to Army at sub-ppm levels by mid-infrared absorption spectroscopy in the 3-15 micron wavelength range, with all components including light source, detector and sensor transducer integrated on the same chip. Two example analyte gases desired to sense in Phase I would be methane and ammonia gas (3.3 and 6.1 micron absorption lines) for dual-use Army and civilian sensing applications. Preliminary experimental data showing the feasibility of the proposed approach will be needed to validate transition to Phase 2.

PHASE II: Deliver a packaged handheld prototype mid-infrared spectrometer, with the integrated light source, detector and sensor, to Army detecting at least 3 selected substances of interest to sub-ppm levels by mid-infrared absorption spectroscopy in the 3-15 micron wavelength range. The gaseous analyte examples given for Phase I (methane and ammonia) should be expanded upon to demonstrate feasibility across the entire range. Examples of substances desirable to detect includes (or simulants of the substances) nerve and blister agents such as Tabun (GA), Sarin (GB), Soman (GD), Vx (VX), S-Mustard (HD), etc. and explosives such as RDX, PETN, TNT, HMX, Ammonium Nitrate, etc.

PHASE III DUAL USE APPLICATIONS: Further research and development during Phase III efforts will be directed towards a final deployable design, incorporating design modifications based on results from tests conducted during Phase II, and improving engineering/form-factors, equipment hardening, and manufacturability designs to meet the U.S. Army and end-user requirements. Potential commercial applications include detection of dangerous and greenhouse gases in the environment, contraband and narcotics for use in Homeland Security applications.

REFERENCES:

1. Y. Yao, A.J. Hoffman, and C.F. Gmachl, "Mid-infrared quantum cascade lasers," Nature Photon. 6, 432 (2012).

2. J.M. Wolf, S. Riedi, M.J. Suess, M. Beck, and J. Faist, "3.36 µm single-mode quantum cascade laser with a dissipation below 250 mW," Opt. Express 24, 662 (2016).

3. A. Kosterev, G. Wysocki, Y. Bakhirkin, S. So, R. Lewicki, M. Fraser, F. Tittel, R.F. Curl, "Application of quantum cascade lasers to trace gas analysis," Appl. Phys. B 90, 165 (2008).

4. D. Ristanic, B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A.M. Andrews, W. Schrenk, and G. Strasser, "Monolithically integrated mid-infrared sensor using narrow mode operation and temperature feedback," Appl. Phys. Lett. 106, 041101 (2015).

5. Y. Zou, K. Vijayraghavan, P. Wray, S. Chakravarty, M.A. Belkin, R. T. Chen, "Monolithically integrated quantum cascade lasers, detectors and dielectric waveguides at 9.5 µm for far-infrared lab-on-chip chemical sensing, “CLEO Technical Digest, paper STu4I.2 (2015).

6. Y. Ma, G. Yu, J. Zhang, X. Yu, R. Sun, and F.K. Tittel, "Quartz enhanced photoacoustic spectroscopy based trace gas sensors using different quartz tuning forks," Sensors 15, 7596 (2015).

7. J. P. Waclawek, H. Moser, and B. Lendl, "Compact quantum cascade laser based quartz-enhanced photoacoustic spectroscopy sensor system for detection of carbon disulfide," Opt. Express 24, 6559 (2016).

8. Y. Zou, S. Chakravarty, P. Wray, R. T. Chen, "Mid-Infrared holey and slotted photonic crystal waveguides in silicon-on-sapphire for chemical warfare simulant detection," Sensors and Actuators B 221, 1094 (2015).

9. R. Soref, "Mid-infrared photonics in silicon and germanium," Nat. Photon. 4, 495 (2010)

KEYWORDS: mid-infrared, absorption spectroscopy, integrated photonics, trace gas sensing

A17A-T006

TITLE: Mid-wave Infrared Laser Beam Steering

TECHNOLOGY AREA(S): Sensors

OBJECTIVE: The development of a monolithic beam steerable mid-wave infrared laser with average power output exceeding 10W.

DESCRIPTION: Current infrared countermeasures systems are advancing in terms of utilization of more compact mid-IR lasers known as quantum cascade lasers. However, such systems are still somewhat bulky in their use of gimbaled mounts requiring mechanical beam steering. Opportunities exist to explore the development of a midwave-IR (3-5 micron) monolithic beam steering laser chip which would be many orders of magnitude more compact, less expensive, and have higher performance. Monolithic beam steering is coming of age with wide-spread interest of beam steerable ladar using silicon photonics, but those have been directed to wavelengths in the near infrared. Mid-wave infrared lasers are advancing in terms of power output and reliability to over 1 W per laser (room temperature, continuous wave). In addition, some applications only require pulsed formats which allow for significant laser cooling between pulses, aiding in reliability. Also, integrated photonics is producing results in silicon based systems for ladars on chip for future collision avoidance for automobiles. The development of Sb-based type I diode lasers and III-V quantum cascade lasers has progressed to the point that such monolithic arrays can be pursued to achieve much faster and agile beam steering for several applications [1, 2]. Several approaches should be possible to achieve the results from wafer bonded lasers [3, 4] to silicon or germanium integrated photonics platforms to directly steerable arrays in III-V materials. High power single mode VCSELs could also be made from mid-IR laser heterostructures [5]. One such approach has been demonstrated with significant beam steering using tunable photonic crystal effects [6].

PHASE I: Using a proposed monolithic design, show evidence of feasibility of all major elements including both the laser sources and the proposed beam steering photonics. Rudimentary demonstration of mid-wave IR lasers useful for reaching 10 W average power should be made along with designs and feasibility studies showing wide-angle and high-speed electronic beam steering of up to +/- 90 degrees at scan rates exceeding 1 kHz.

PHASE II: Fabrication and testing of the full monolithic beam steering microchip system. Optimization of the laser sources power and coupling efficiency to the beam steering apparatus should be pursued along with the design, implementation, and testing of the wide-angle beam steering devices. Goals for this phase include the achievement of up to +/- 90 degrees and 10 W average power (pulse length should be no shorter than 1 ms) at scan rates over 10 kHz.

PHASE III DUAL USE APPLICATIONS: Mid-infrared lasers have uses in many military applications and advanced beam steering capabilities with high-speeds add to the potential application areas. Examples include surveillance, imaging, communications, and countermeasures. Dual use applications may include the remote sensing of chemicals, explosives, narcotics, and other warfare agents.

REFERENCES:

1. Leon Shterengas, Rui Liang, Gela Kipshidze, Takashi Hosoda, Gregory Belenky, Sherrie S. Bowman, and Richard L. Tober, Applied Physics Letters, 105, 161112 (2014).

2. J. D. Kirch,1 C.-C. Chang,1 C. Boyle,1 L. J. Mawst,1 D. Lindberg III,2 T. Earles,2 and D. Botez, Applied Physics Letters, 106, 061113 (2015).

3. D. Ristanic, B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A.M. Andrews, W. Schrenk, and G. Strasser, "Monolithically integrated mid-infrared sensor using narrow mode operationand temperature feedback," Appl. Phys. Lett. 106, 041101 (2015).

4. Y. Zou, K. Vijayraghavan, P. Wray, S. Chakravarty, M.A. Belkin, R. T. Chen, "Monolithically integrated quantum cascade lasers, detectors and dielectric waveguides at 9.5µm for far-infrared lab-on-chip chemical sensing," CLEO Technical Digest, paper STu4I.2 (2015).

5. Kazuyoshi Hirose, Yong Liang, Yoshitaka Kurosaka1, Akiyoshi Watanabe, Takahiro Sugiyama and Susumu Noda, Nature Photonics, Vol. 8, 406-411, May (2014).

6. Yoshitaka Kurosaka, Seita Iwahashi, Yong Liang, Kyosuke Sakai1, Eiji Miyai, Wataru Kunishi, Dai Ohnishi, and Susumu Noda, Nature Photonics, Vol. 4, 447-450, July (2010).

KEYWORDS: mid-wave infrared, laser beam steering, integrated photonics

A17A-T007

TITLE: High Dynamic Range Heterodyne Terahertz Imager

TECHNOLOGY AREA(S): Materials/Processes

OBJECTIVE: Design, construct, and deliver an imager operating in the 1-5 THz region with a frequency tunable source, a high dynamic range heterodyne receiver, and wavelength-scale spatial resolution.

DESCRIPTION: The Army has a need for high spatial resolution non-destructive evaluation (NDE) of non-conductive materials that cannot be effectively imaged with ultrasound or x-ray technology [1-3]. The use of terahertz frequencies (0.3 THz to 10 THz) for NDE is desirable because it allows non-contact, operator-safe, high-resolution imaging of materials that would otherwise be opaque to visible and infrared frequencies: polymers, ceramics, semiconductors and electrical insulators. While there are many suppliers of time domain terahertz NDE imagers, these systems are relatively complex due to the optical down conversion from infrared to terahertz frequencies. The inefficient down conversion process is ameliorated by coherent detection resulting in peak signal to noise ratios of 60 dB. While these systems produce pulses with frequency content from 50 GHz to 3 THz, the lossy samples act as low pass filters effectively limiting pulses to < 500 GHz of frequency content, which reduces spatial resolution. As an alternative, high-power far-infrared gas lasers, which produce ~50 mW of average power at 2.5 THz, have been demonstrated in heterodyne imaging using Schottky diode detectors [4]. Using a source laser and a second, local-oscillator laser resulted in signal to noise ratios of 110 dB. The drawbacks to this system are the cost, the complexity of the optical alignment, and the constraint to operate at discrete frequencies of the lasing gas.

A promising alternative approach to terahertz imaging involves the use of terahertz Quantum-Cascade Lasers (QCL), which may be combined with a Schottky diode detector for heterodyne imaging. For heterodyne imaging, two semiconductor QCLs, which have demonstrated power levels of 10's of mW [5-7], are required to emit at slightly offset frequencies, with one serving as local oscillator (LO) and the other as the Signal. The Signal and LO are combined in a reference detector and offset frequency locked. In a separate beam path, the Signal is passed through an object, and then is combined with the LO on a second Schottky detector. Further down-conversion of the intermediate frequency (IF) signal allows lock-in detection, amplification, and recovery of the phase and magnitude of the reference and transmission/reflection through the object. Because of the dual requirements for high dynamic range and wavelength-scale spatial resolution, the focused Signal may be raster scanned through the object quickly, with the objective of rendering a near video frame rate scene (30 frames per sec (fps)) that captures the imagery of the target object in real time. Cryogenic operation of the QCLs is acceptable, preferably if cooled by a closed cycle system not requiring the supply of external cryogens.

PHASE I: Design a heterodyne terahertz imager with high dynamic range (> 90 dB) frequency tunable in the 1-5 THz region with wavelength-scale spatial resolution and capable of near video frame rate operation (30 fps). The source need not span the entire spectral region, but it must be frequency tunable. The design must specify the source, detector, and image acquisition technologies, the spectral tuning range, the anticipated dynamic range, the imager's field of view, the spatial resolution, and the expected frame rate. The ideal imager will operate in both transmission and reflection modes.

PHASE II: Construct, characterize, and optimize the performance of the heterodyne terahertz imager designed in Phase I, exhibiting high dynamic range (> 90 dB) frequency tunability in the 1-5 THz region with wavelength-scale spatial resolution and capable of near video frame rate operation (30 fps). The complete, proof-of-concept imager will be delivered at the end of Phase II along with a working graphical user interface for displaying, manipulating, and enhancing the image.

PHASE III DUAL USE APPLICATIONS: Advance the technology readiness level of the proof-of-concept delivered in Phase II to an affordable, packaged, marketable, high resolution imager that may be used by a broad commercial market for non-destructive testing of non-conducting objects. In addition, frequency tunability and a sensitive heterodyne receiver will allow the development of depth-resolving three-dimensional imagers using frequency modulation continuous wave (FMCW) radar techniques.

REFERENCES:

1. "Advanced Photonix Awarded $1.4 Million Contract for Handheld Terahertz Scanner," (Advanced Photonix, 2015), http://www.prnewswire.com/news-releases/advanced-photonix-awarded-14-million-contract-for-handheld-terahertz-scanner-300021296.html.

2. N. Palka, and D. Miedzinska, "Detailed non-destructive evaluation of UHMWPE composites in the terahertz range," Optical and Quantum Electronics 46, 515-525 (2014).

3. C.-P. T. Chiou, F. J. Margetan, D. J. Barnard, D. K. Hsu, T. C. Jensen, and D. J. Eisenmann, "Nondestructive characterization of UHMWPE armor materials," (2011).

4. P. Siegel, and R. Dengler, "Terahertz Heterodyne Imaging Part II: Instruments," International Journal of Infrared and Millimeter Waves 27, 631-655 (2006).

5. B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "High-power terahertz quantum-cascade lasers," Electronics Letters 42, 89 - 91 (2006)

6. A. W. M. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, "High-power and high-temperature THz quantum-cascade lasers based on lens-coupled metal-metal waveguides," Optics Letters 32, 2840 - 2842 (2007).

7. M. Wienold et al., Real-time terahertz imaging through self-mixing in a quantum-cascade laser. Appl. Phys. Lett. 109, 011102 (2016

KEYWORDS: Terahertz imaging, heterodyne receiver, quantum cascade laser

A17A-T008

TITLE: 3D Tomographic Scanning Microwave Microscopy with Nanometer Resolution

TECHNOLOGY AREA(S): Materials/Processes

OBJECTIVE: Develop near-field scanning microwave microscopy hardware and software to enable 3D tomographic imaging of the structural and electromagnetic properties of electronic and biological materials with nanometer spatial resolution.

DESCRIPTION: Near-field scanning microwave microscopy (SMM) is a new atomic-scale scanning probe capable of penetrating below the sample surface up to one micrometer in depth. Compared to optical, x-ray or electron microscopy, SMM is highly non-invasive because the energy of microwave photons is only on the order of 10 µeV. Therefore, the technique can potentially be very useful in imaging the structural and electromagnetic properties for a wide range of electronic and biological materials with high electrical and spatial resolution, and provide unique insights into their fundamental characteristics. To date, sophisticated probes and complete systems have been offered, and different probe calibration and data analysis approaches have been proposed, and promising results have been demonstrated. For example, SMM has been used to image the quantum Hall edge states in graphene and topological insulators, and for biological applications, to investigate the effect of fullerene nanoparticles on breast cancer cells. The high sensitivity of SMMs can also potentially enable direct imaging of ion channel and nanoporation in a cell membrane. Furthermore, recent demonstration of SMM operating in liquid environment will open up even more opportunities in biology and medical science.

In addition to the aforementioned advances, SMM offers the unique capability of penetrating into the sample-under-test in a non-invasive and non-contacting manner. This feature allows imaging of sub-surface structures, and open the possibility for 3D tomography with nanometer resolution. The tomographic potential of SMM has been demonstrated in proof-of-principle experiments. In these experiments, broadband or multi-frequency microwave radiation was used to probe different sample depths. Despite these promising results, 3D tomographic SMM systems for consistent and reproducible characterization are still not available. The goal of this project is to develop reliable and user-friendly SMM systems with 3D tomography capability. This will still require major improvements in both hardware and software.

PHASE I: Define system architecture both in hardware and software which shows feasibility of obtaining 10 nm resolution in all three spatial dimensions. Include determination of optimum system frequency, bandwidth, and data analysis in frequency domain vs. time domain. Determine advantages of operating at higher frequencies such as millimeter-wave and terahertz frequencies for improving system performance. Perform 3D electromagnetic designs of the probe structures to be integrated with system. At least one of the probe designs should be compatible with liquid environment. Investigate innovative micro-machining techniques for realizing the probe designs. Explore new software algorithms for 3D image reconstruction.

PHASE II: Implement designs including both hardware and software from Phase I to construct an SMM with 3D tomography capability. Demonstrate reproducible characterization of biological or electronic samples with 3D resolution 10 nm or less. Collaborate with biomedical or electronic researchers to demonstrate the 3D advantage of the technique. Modify the hardware and software as needed and document the modifications.

PHASE III DUAL USE APPLICATIONS: High-resolution and non-invasive 3D microscopic tools for biomedical and electronic scientific research, industry applications and defense systems. Applications include characterization of semiconductor, metal, organic films, etc., and detection of counterfeit integrated circuits. Beyond material characterization, it also provides unique capability for identification of chemical/bio agents and biomolecules.

REFERENCES:

1. J. Lee, C. J. Long, H. Yang, X. D. Xiang, and I. Takeuchi, “Atomic resolution imaging at 2.5 GHz using near-field microwave microscopy," Appl. Phys. Lett., vol. 97, pp. 183111-1-183111-3, 2010.

2. K. Lai, W. Kundhikanjana, M. A. Kelly, Z.-X. Shen, J. Shabani, and M. Shayegan, “Imaging of Coulomb-driven quantum Hall edge states," Phy. Rev. Lett., vol. 107, no. 17, pp. 176809-1-176809-5, Nov. 2011.

3. M. Farina, F. Piacenza, F. De Angelis, D. Mencarelli, A. Morini, G. Venanzoni, T. Pietrangelo, M. Malavolta, A. Basso, M. Provinciali, J. C. Hwang, X. Jin, and A. Di Donato, "Broadband near-field scanning microwave microscopy investigation of fullerene exposure of breast cancer cells," IEEE MTT-S Int. Microwave Symp. Dig., San Francisco, CA, Jun. 2016, pp. 1-4.

4. M. Farina, A. Di Donato, D. Mencarelli, G. Venanzoni, and A. Morini, "High resolution scanning microwave microscopy for applications in liquid environment," IEEE Microw. Compon. Lett., vol. 22, no. 11, pp. 595-597, Nov. 2012

5. M. Farina, A. Di Donato, T. Monti, T. Pietrangelo, T. Da Ros, A. Turco, G. Venanzoni, and A. Morini, "Tomographic effects of near-field microwave microscopy in the investigation of muscle cells interacting with multi-walled carbon nanotubes," Appl. Phys. Lett., vol. 101, no. 20, pp. 203101-1-203101-4, Nov. 2012.

6. P. J. de Visser, R. Chua, J. O. Island, M. Finkel, A. J. Katan, H. Thierschmann, H. S. J. van der Zant, and T. M. Klapwijk, "Spatial conductivity mapping of unprotected and capped black phosphorus using microwave microscopy," 2D Mater., vol. 3, pp. 021002-1-021002-6, Mar. 2016.

7. L. You, J.-J. Ahn, Y. S. Obeng, and J. J. Kopanski, "Subsurface imaging of metal lines embedded in a dielectric with a scanning microwave microscope," J. Phys. D: Appl. Phys., vol. 49, pp. 045502-1-045502-11, 2016.

KEYWORDS: Sensors, Electronics; Battle space Environment

A17A-T009

TITLE: Mechanochemical Sensing and Self-Healing Solution to Detecting Damage in Composite Structures

TECHNOLOGY AREA(S): Materials/Processes

OBJECTIVE: Engineer and utilize mechanochemical reactions to initiate a molecular response to macroscopic force and/or deformation in polymeric materials, and to provide an active reinforcement mechanism within composite materials for stress-sensing and self-healing capabilities.