Optical Countermeasures continue to evolve and expand as new threats emerge and new technologies evolve to detect and defeat this ever-present threat. Additionally, new countermeasure methods continue to evolve and improve with the development of enabling component technologies, advanced systems concepts, integration with new platforms, and innovative technology employment strategies. Combined with advances in threat detection, laser and source technology, advanced pointer/tracker architectures, signal processing, data fusion, and advanced techniques, the diversity and sophistication of these capabilities continue to grow in support of a wide range of defense application. This conference presents an opportunity for experts, and those who wish to stay current on the latest advances in enabling technology, to interact, collaborate, and foster innovation in the development of these advanced countermeasure systems.

Further, while enabling technology development is an important and exciting topic in itself, development of enabling technology can be more interesting and exciting when considered within the context of application of that technology to address a specific problem. Examining enabling and emerging technology as the device level, system level, problem level, and application level can help to define future application of this technology to both general and specific problem areas for difficult defense, security, and counter terrorism application. These new applications may create additional demands upon the supporting technologies, and, as a result, this conference will focus upon not only on enabling optical countermeasures, but also upon the practical applications of those discrete enabling technologies, and, in particular, new applications of optical countermeasure technology. Papers on military, commercial, laser/source, effects, and applications are solicited.

Papers are solicited in the following areas:

  • quantum cascade lasers
  • solid state and fibre lasers
  • mid-IR lasers and sources
  • nonlinear optics
  • DIRCM systems
  • countermeasures for UAV’s, drones, and non-traditional platforms
  • advances in lasers and nonlinear optics
  • pyrotechnic, flares, and expendable countermeasures
  • smokes and obscurants
  • beam steering, guiding, and control
  • laser beam pointing
  • threat detection, warning, and discrimination
  • hostile fire detection, indication, and suppression
  • threats and threat properties
  • modelling and simulation
  • aberration issues and compensation methods
  • laser dazzling and effects
  • mid-IR transmission fibres
  • platform protection
  • external/platform effects
  • threat properties and characteristics
  • multi-mode/multi-function operation
  • closed-loop countermeasures
  • non-traditional countermeasures
  • laser propagation and effects
  • atmospheric and background effects
  • military/commercial application of technology
  • enabling component/system technology
  • alternative countermeasures
  • counter-swarms
  • novel optical devices and technology
  • “homeland defence” and border protection
  • other civil and military applications.

  • NOTE:
    This conference program will feature contributions made to Technologies for Optical Countermeasures Conference and to High Power Lasers Conference.
    See below and the Additional Information tab for the full High Power Lasers Conference Call for Papers

    High Power Lasers Conference will provide a technical forum for the exchange of information related to aspects of high power laser research and development, and for the discussion of latest demonstrations of laser systems in defense and security relevant scenarios, in particular advanced military applications. Numerous demonstrations have shown the capability of laser weapon systems in negating targets of military interest with the standard attributes of lasers preserved, such as precision, timelines, and minimal collateral damage. Many challenges remain and are being addressed to bring laser weapon systems to the maturity required for military field applications. Among these are power scaling, energy conversion efficiency, wavelength control, beam quality, thermal and power management, a variety of optical issues, as well as packaging and ruggedization. In addition platform considerations and special laser effects will be considered.

    A viable laser weapon will provide the battlefield commander with new engagement options and capabilities in defensive or offensive scenarios, and in a variety of environments. It can potentially provide improved stand-off range, cause covert effects, handle extremely short time-line engagements, and enable precise control of damage in the target area. The requirement exists to develop efficient, effective laser weapon systems capable of depositing required amounts of energy on selected stationary or mobile targets to affect their negation.

    Papers are solicited in the following broad areas of laser technology and laser development:

    Lasers and Laser Architectures Suitable for Power Scaling
  • advanced gas lasers (including DPAL, rare gas)
  • solid state lasers, slabs, disks, fibers and diode arrays
  • efficiencies and thermal control
  • beam combination: coherent, spectral, other
  • packaging: size, weight, ruggedness.

  • Laser Demonstrators
  • ground based and at-Sea Tests
  • airborne applications
  • lasers on UAVs

  • Components
  • diode pumps -efficiency, wavelength, linewidth, stability, cost
  • optics, coatings
  • couplers, combiners, isolators
  • beam directors & adaptive optics.

  • Novel Design in Fiber and Slab Lasers
  • photonic crystal fibers, other
  • eye-safe fibers, Er ,other
  • single, multimode, gain, transport
  • thermal management.

  • Laser Materials
  • optical/mechanical/thermal
  • ceramics
  • manufacturing.

  • Platforms
  • mobile
  • ground based
  • airborne
  • UAVs.

  • Effects
  • laser filamentation
  • interaction with advanced materials
  • long-range propagation of high-power lasers, including vortex beams..
  • ;
    In progress – view active session
    Conference 12273

    High-Power Lasers and Technologies for Optical Countermeasures

    6 - 7 September 2022 | Paris
    View Session ∨
    • Welcome and Introduction: Opening Remarks
    • 1: Modelling and Simulation
    • 2: Threats, Threat Detection and Threat Discrimination
    • Security + Defence Plenary
    • 3: Lasers and Sources
    • 4: Quantum Cascade Lasers
    • 5: Optics and Optical Systems
    • 6: Laser Effects
    Welcome and Introduction: Opening Remarks
    6 September 2022 • 13:40 - 13:50 CEST
    Robert J. Grasso, NASA Goddard Space Flight Ctr. (United States)
    David H. Titterton, UK Defence Academy (United Kingdom)
    Willy L. Bohn, BohnLaser Consult (Germany)
    Session 1: Modelling and Simulation
    6 September 2022 • 13:50 - 15:10 CEST
    Session Chair: Willy L. Bohn, BohnLaser Consult (Germany)
    Author(s): Curtis R. Menyuk, Shaokang Wang, Univ. of Maryland, Baltimore County (United States)
    6 September 2022 • 13:50 - 14:20 CEST
    Show Abstract + Hide Abstract
    We have developed methods that are based on dynamical systems theory to study the stability and noise performance of the short-pulse lasers that are used to generate frequency combs. Our earliest application was to passively modelocked lasers that use fast saturable absorbers, but more recently we have applied this approach to study lasers that use slow saturable absorbers made from semiconductor saturable absorbing mirrors (SESAMs). Due to the slow saturable absorber, a gain window opens up in the wake of the pulse that can lead to the unstable generation of modes and a characteristic leapfrog instability. Using boundary-tracking algorithms, we determined where in the parameter space stable solutions exist. Using a spectral decomposition into Langevin processes to avoid Monte Carlo simulations, we demonstrated that is possible to speed the simulation of the noise processes in a SESAM laser by three orders of magnitude. Using dynamical methods, we performed a three-dimensional optimization, and we showed that it is possible to achieve higher power with no cost in increased phase noise by increasing the output coupling.
    Author(s): Adrian Azarian, Michael Henrichsen, Daniel Wegner, Gregor Franz, Bernd Eberle, Stefan Kessler, Fraunhofer-Institut für Optronik, Systemtechnik und Bildauswertung IOSB (Germany)
    6 September 2022 • 14:20 - 14:40 CEST
    Show Abstract + Hide Abstract
    We developed a model that simulates the reflected, range dependent intensity distribution of a metallic target, when irradiated by a high-energy laser a, especially the phase when the target is melting. The intensity distributions, measured at 2 m distance, show rapidly changing caustics. For validation purposes, the simulated intensities have been compared to the measurements using different metrics. The quality of the metrics was evaluated by their correlation with the simulation model’s input parameters. This model was then trained, validated and tested on simulated data to find the input parameters of the model that lead to similar caustics. Using these inputs, the intensity may then be calculated at any arbitrary distance to enable laser safety assessments.
    Author(s): Vadim Allheily, Florent Retailleau, Théo Jean, Lionel Merlat, Institut Franco-Allemand de Recherches de Saint-Louis (France)
    6 September 2022 • 14:40 - 15:10 CEST
    Show Abstract + Hide Abstract
    Lasers weapon systems are foreseen as a new possibility to counter unmanned aerial vehicles (UAVs), since the use of hostile drones has massively increased since the early 1990s. But whereas demonstrators have shown some promising performances, a better understanding of the phenomena occurring during the continuous irradiation of a target is however today’s required to optimize the design, and to ensure a safe use of those newly-developed defence devices. The interaction between a drone body (ordinarily made of a polymer, sometimes strengthened with glass or carbon fibres) and a high-energy laser beam can involve complex phenomena. An innovative method has been developed to record the optical coupling of an infrared laser light with a structural material, allowing the identification of optical properties up to very high temperatures. A complete thermal evaluation involving many different conventional methods has also been carried out to assess multiple temperature-dependent thermodynamical parameters. All those material characteristics have later been implemented into some multiphysics models. The evaluation of the computed numerical outcomes has been done by comparison with experimental recordings arising from laser trials up to 10 kW, and a very good agreement has been shown between numerical and experimental data.
    Session 2: Threats, Threat Detection and Threat Discrimination
    6 September 2022 • 15:40 - 17:00 CEST
    Session Chair: Robert J. Grasso, NASA Goddard Space Flight Ctr. (United States)
    Author(s): Thorben Haarlammert, Frank Kröber, Uwe Schmidt, Simon Chelkowski, Jena-Optronik GmbH (Germany)
    6 September 2022 • 15:40 - 16:00 CEST
    Show Abstract + Hide Abstract
    The area of Space Situational Awareness (SSA) has seen an increasing focus in recent years. As SSA is covering a wide range of applications, the activities are streamlined within three main areas: Space Weather, Near-Earth Objects and Space Surveillance and Tracking (SST). The latter one is covering active and inactive satellites as well as other man-made objects orbiting Earth. Consequently there are activities focussing on debris and inactive satellites on one hand, which can be seen as maintenance activities allowing humankind long-term access to space. On the other hand, SST covering active satellites is in principle a safety measure for space-based missions. Keywords that arise in this context are detection, tracking and identification. These are the main ingredients for in-orbit threat detection. Once these topics are mastered and dedicated solutions are developed, there is only a small step towards using the gained knowledge and same abilities to perform optical countermeasures. Jena-Optronik GmbH has developed a variety of state-of-the-art sensors for specific applications in the field of SST. The product range covers visible cameras, LiDARs and laser detection sensors. Consequently, we recently started increasing our activities in SST with dedicated solutions tailored to the specific needs of this application field: Beside the existing sensors in the portfolio, a thermal infrared camera is under development and it is planned to combine all necessary sensors for SST of active satellites in a dedicated SST sensor suite. Such a suite includes a central processing unit combining all data from the connected sensors to form one data set covering the satellite surrounding volume and identifying incoming threats. In a next step, active sensors can be used to follow incoming threads and hinder them from observing the satellite with the SST sensor suite and in particular its’ other payloads. This paper will provide an introduction into the topic of SST of active satellites. It will cover an overview of the concepts and needs for different sensors forming a SST sensor suite. Furthermore, the latest advances in Jena-Optroniks’ developments as well as future steps and activities related to the current sensor portfolio are presented.
    Author(s): Juan S. Acosta, Ivo Buske, Andreas Walther, Daniel Fitz, Deutsches Zentrum für Luft- und Raumfahrt e.V. (Germany)
    6 September 2022 • 16:00 - 16:20 CEST
    Show Abstract + Hide Abstract
    Due to the growing number of small and agile unmanned aerial vehicles (UAVs), including consumer micro-drones, appropriate countermeasures technologies are necessary to protect public and military forces, to increase critical infrastructure resilience, and to secure exchange of data. Most of the countermeasure requires reliable up-to-date position information of the approaching threats. Beside precise determination of the angle-of-arrival laser pulse time-of-flight information is one of the promising technologies to measure the distance to a target. Laser Range Finders (LRF) are typically used for long ranges to large objects or slowly moving targets. Within the scope of this paper we are going to show a method to enhance laser ranging capabilities to small and fast-moving UAV targets. Dealing with small and agile targets the primary limitation of many laser ranging systems is the reduced hit rate. The restricted torque of the pan-tilt-unit drives is not able the to align the LRF in the direction of agile UAV targets in the sky. In this paper, we will present a method using an additionally piezo steering device to reduce this residual tracking error. To estimate the improvement, we are going to compare results under same conditions with and without the fast steering device. Experimental evaluations show an improvement of the LRF hit rate during high accelerations of micro UAVs. We present theoretical analysis and experimental results of UAV laser range measurements under realistic environmental conditions.
    Author(s): Ivo Buske, Andreas Walther, Daniel Fitz, Juan Acosta, Andiy Konovaltsev, Lothar Kurz, Deutsches Zentrum für Luft- und Raumfahrt e.V. (Germany)
    6 September 2022 • 16:20 - 16:40 CEST
    Show Abstract + Hide Abstract
    Small unmanned aerial vehicles (UAVs) are increasingly becoming a challenge for both civilian and military security. Even simple modifications of these inexpensive and widely available systems can create a serious threat which potentially causes major damage. Using signals from global navigation satellite system (GNSS), UAVs are able to operate over long distances and to find their target zone without remote control of a pilot. In this flight mode, radio direction finder cannot detect any transmitted signal. Typical countermeasures like RF jamming or Wifi hacking become ineffective to stop the threat. The DLR smart GPS spoofing approach is a promising technology for a cost-effective countermeasure against such autonomously flying Micro UAVs. Several dedicated devices must reliably interact to fulfill this task. The optical identification and position measurement of the UAVs was developed at the DLR Institute of Technical Physics. By optimizing the tracking processes and the laser ranging systems, even small and agile targets can be tracked. The measured position and flight data are forwarded to a GPS spoofing system developed by the DLR Institute for Communication and Navigation. The emitted GPS signal is modified in such a way that the UAV leaves its original flight trajectory and is redirected to a save one. Outside the protected area the UAV can be forced to ground without collateral damages. The feedback loop via the independent optical position measurement ensures that the desired flight trajectory is maintained. The basic functionalities of the smart GPS spoofing countermeasure were successfully demonstrated in realistic field tests. The optical setup and first results will be discussed.
    Author(s): David Sabourdy, Pierre Morin, Franck Maggi, Nicolas Marchet, Etienne Hartz, Robin Vincent, Maxime Courtin, Meryem AIT Moussa, CILAS (France)
    6 September 2022 • 16:40 - 17:00 CEST
    Show Abstract + Hide Abstract
    We propose to present our Laser Directed Energy Weapon system HELMA-P and the results of a several weeks C-UAV tests campaign in France. During this campaign we successfully demonstrated capability of detection and neutralization in a few seconds of different kind of drones (different types of rotary wings and fixed wings), at a distance of up to 1Km (Test Facility limited) with different weather conditions. Our small and smart approach allows CILAS to supply a cost effective and flexible C-UAV solution, easy to integrate on different kinds of platforms and minimizing potential risk of collateral damages by using the full potential of a well integrable single fiber Laser source.
    Session PL2: Security + Defence Plenary
    7 September 2022 • 09:00 - 10:40 CEST | Convention Hall I-D
    9:00 to 9:10 hrs
    Welcome Address and Plenary Speaker Introduction

    Karin Stein
    Fraunhofer Institute of Optronics, System Technologies and Image Exploitation IOSB (Germany)
    Author(s): Markus Jung, Rheinmetall Waffe Munition GmbH (Germany)
    7 September 2022 • 09:10 - 09:55 CEST | Convention Hall I-D
    Show Abstract + Hide Abstract
    Within the last decade, new threats like UAV’s and loitering ammunition have appeared on the battlefield and have revealed to be difficult to defend by conventional effectors. Hence, High Energy Laser Effectors have proved to be an efficient counter to these threats. As one of the leading defence companies in Germany, Rheinmetall Waffe Munition GmbH (RWM) is pushing the Directed Energy program to respond to these new threats. Diode pumped fiber lasers (DPFL) are now available as a robust technology for military applications. HighEnergy Laser Effectors containing DPFL offer a high power transmission in the near infrared region. Also, high power in a combination with best beam quality, integration into a small volume through reduced weight and low costs per engagement. Since 15 years, RWM has developed DPFL based HEL systems for the military environment. Rheinmetall supplies the laser source for both actual national Laser Demonstrator Programs in Germany the 10kW mobile testbed and the 20kW Navy demonstrator. Both laser sources are based on DPFL modules in combination with spectral beam coupling (SBC) units. Concepts for scaling towards 100kW with best beam quality are under investigation. SBC power scaling and unique combining elements are developed in cooperation with the Fraunhofer Institute for Applied Optics and Precision Engineering. Besides the development program for the laser source, Rheinmetall is conducting intensive target interaction experiments in the laboratory and on the laser test range of the company. The results of these experiments will be the basis on defining the parameters of Laser Weapon Effectors for an efficient engagement. Based on these parameters, Rheinmetall develops complete HEL effectors with the main components, as there is the laser weapon station, beam forming unit (BFU), laser source and C² in order to realize the full-kill chain form target detection, course tracking and fine tracking, as well as defeating the target up to the target assessment. Rheinmetall performed first steps to demonstrate the capabilities of High-Energy Laser technology in live-firing trials. Thus, the laser technology increased its technological readiness level from 4 (lab tests) to 6/7 (prototype in relevant environment). The presentation will explain these steps from the first demonstrators using military weapon stations like Mantis or MLG 27 for coarse tracking up to the current Army and Navy High Energy Laser Weapon Demonstrator.
    Author(s): Marc Eichhorn, Fraunhofer-Institut für Optronik, Systemtechnik und Bildauswertung IOSB (Germany), Karlsruhe Institute of Technology (Germany)
    7 September 2022 • 09:55 - 10:40 CEST | Convention Hall I-D
    Show Abstract + Hide Abstract
    Collecting and exploiting optronic information is more than ever of increasing importance in security and defense, thus a growth in the number of optronic systems on various platforms worldwide is taking place. This trend is accelerated by an increasing performance and simultaneous cost reduction of optronic systems and their components. Laser sources – as part of optronic systems or as a countermeasure – therefore become increasingly relevant in that context. Research and development thus is pushing limits of laser sources to enhance efficiency, output power and wavelength coverage, especially in the SWIR and MWIR bands. Based upon these efforts and achievements power scaling of fiber laser sources in the SWIR range – albeit originally investigated mainly in the optronic context – have reached power levels now compatible with directed energy applications when suitably combined. This allows for new scenarios exploiting the reduced eye hazard of two-micron lasers while significantly increasing interaction effects with some optronic systems or materials like plastics. The presentation will discuss recent achievements in pulsed thulium- and thulium-holmium-doped solid-state and fiber lasers in the two-micron range allowing for significant average-power and pulse-energy scaling for direct applications or in mid-IR OPOs based on conversion crystals like ZnGeP2, CdSiP2 or OP-GaAs, thereby broadening the scope of various optronic applications. In addition, continuous-wave (cw) sources in the two-micron range are addressed, which are important for materials processing, communication and high-energy lasers. Therein, a focus is put on all-fiber designs and robust, if possible self-aligning, laser resonators, which allow for stable and ruggedized embodiments for (industrial and defense) applications under harsh environments. Where possible, the context of the underlying applications is also discussed.
    Session 3: Lasers and Sources
    7 September 2022 • 11:00 - 12:40 CEST
    Session Chair: Willy L. Bohn, BohnLaser Consult (Germany)
    Author(s): Maximilian Taillandier, MBDA France (France)
    7 September 2022 • 11:00 - 11:30 CEST
    Show Abstract + Hide Abstract
    Maturity of laser source technologies has reached a point where emergence of Laser Directed Energy Weapons (LDEW) on the battlefield becomes a short-term reality. LDEW will be part of layered air defence systems. Various target types will be engaged, such as drones, missiles, rockets, shells and aircraft. Each of these targets may be defeated in various ways (hard-kill, soft-kill). In that respect, understanding the effects of laser on targets is crucial.
    Author(s): Till Walbaum, Friedrich Möller, Fraunhofer-Institut für Angewandte Optik und Feinmechanik IOF (Germany); Friedrich Wilhelm Grimm, QS-GRIMM GmbH (Germany); Maximilian Strecker, Benjamin Yildiz, Stefan Kuhn, Nicoletta Haarlammert, Thomas Schreiber, Fraunhofer-Institut für Angewandte Optik und Feinmechanik IOF (Germany)
    7 September 2022 • 11:30 - 12:00 CEST
    Show Abstract + Hide Abstract
    Defense applications require intrinsically stable and resilient laser systems. Using single- or few-mode output fibers, fiber-based high-power lasers can address these challenges and also feature excellent beam quality, allowing to achieve high power density at long focusing distance. At high power levels, these diffraction limited output beams can be spoiled by thermally induced transverse mode instabilities (TMI), which cause beam profile fluctuations and thus increase the M²-factor. As TMI are an interference-based effect, it is to be expected that there is a dependence on polarization. We have thus set up an analysis setup that allows to characterize the individual mode content of the fluctuating beam along with the full polarization (in terms of Stokes vector) of each individual contributing mode at kHz speed. We will present the setup and first results for high power systems. In order to manipulate the TMI threshold, it has been shown to be beneficial to distribute the heat load evenly along the fiber. On the other hand, monolithic fiber component availability favors a co-propagating pump approach. We will present a dual-tone seeding setup that allows for variable modification of the heat load position and discuss the impact on the TMI threshold.
    Author(s): Denise Meuken, Sven Van Binsbergen, Loes Scheers, Alexander M. J. van Eijk, Peter van den Berg, TNO (Netherlands)
    7 September 2022 • 12:00 - 12:20 CEST
    Show Abstract + Hide Abstract
    TNO has expanded its 30 kW HEL research facility with the capability to monitor specular and diffuse reflections of the laser beam. A capture screen and high-speed camera focus on dynamic specular reflections, while 15 individually placeable probes monitor the diffuse component under different angles. This paper introduces the reflection measurement capability and discusses the behaviour of steel and aluminium coupons under high-energy laser irradiation. Laser-material interaction was found to be rather predictable in thermal behaviour up to the perforation event. Reflections, however, showed a highly dynamic pattern, varying in magnitude and direction and depending on bulk material, material surface condition, phase state of the material (solid or liquid) and geometry. The difficulty of assessing proper stand-off distances for laser safety is illustrated.
    Author(s): Fabrizio Bisesto, Leonardo Company SpA (Italy); Alessandro Perna, Leonardo S.p.A. (Italy); Alberto Cosentino, Leonardo Company SpA (Italy); Francesco Coppola, Valentina Sacchieri, Leonardo S.p.A. (Italy)
    7 September 2022 • 12:20 - 12:40 CEST
    Show Abstract + Hide Abstract
    Coherent Beam Combining techniques aim to obtain good quality high-power laser beams, enabling several specific applications such as long-range communications, remote power delivering or L-DEW applications. In the case of fiber lasers, the specific power of a single amplifier is limited by the deleterious effect of SBS. One can enhance the threshold of SBS widening the seeder bandwidth (>30GHz), but this contrasts with the need of a spectrally pure field for the adoption of CBC architectures based on phase detection. Arrays with a large number of elements have been demonstrated for narrow-band systems, while only cases with a limited number of elements adopt wide-band phase locking. In this paper, we report on the experimental demonstration of a 7-element array coherently combined up to a spectral bandwidth of 47 GHz. The architecture is based on a narrow line single mode master oscillator whose emission is phase modulated to widen the bandwidth. Amplified fields are summed in a tiled aperture geometry and far field PIB is adopted as a metrics for a perturbation hill-climbing algorithm. Phase-locking results and convergence dynamics are analyzed in relation to the bandwidth properties of the oscillator modulation.
    Session 4: Quantum Cascade Lasers
    7 September 2022 • 13:40 - 15:10 CEST
    Session Chair: David H. Titterton, Cranfield Defence and Security (United Kingdom)
    Author(s): Arkadiy A. Lyakh, Enrique Cristobal, Luke Milbocker, Univ. of Central Florida (United States)
    7 September 2022 • 13:40 - 14:10 CEST
    Show Abstract + Hide Abstract
    Brightness is often listed among the most important laser characteristic for practical applications. It is a function of both output optical power and mode quality. Multi-watt continuous wave (CW) operation has been demonstrated for broad-area Quantum Cascade Lasers (QCLs) emitting at ~4.6µm. Transition of the broad-area configuration to shorter wavelengths is however non-trivial as laser thermal behavior rapidly deteriorates with reduction in emission wavelength below 4.6µm. In this work we discuss the main design principles of high brightness, broad area QCLs emitting at ~4.0µm. Building off a power scaling approach to increasing broad area QCL CW power, a figure of merit is utilized to predict dominant lasing transverse modes for QCLs. A discussion follows on the role of laser core dimensions on mode selection within a waveguide, including design guidelines for maintaining single transverse mode behavior while altering broad area QCL design for increased power.
    Author(s): Franz Münzhuber, Luisa Späth, Hans Dieter Tholl, Diehl Defence GmbH & Co. KG (Germany)
    7 September 2022 • 14:10 - 14:40 CEST
    Show Abstract + Hide Abstract
    We report on the realization of a multi-emitter quantum cascade laser system with optimized package volume. A multidimensional bonding of chip-on-substrate units allows for close packaging of several chips. The emission of several chip-on-substrate units with an emission wavelength around 3.9 µm are geometrically combined to achieve a multi-Watt emission power level while obtaining a symmetric beam profile of the emission. A dedicated integrated electronic circuit provides individual pulse control, which enables individual timing for each emitter.
    Author(s): Richard Maulini, Stéphane Blaser, Kaspar Suter, Antoine Müller, Alpes Lasers SA (Switzerland)
    7 September 2022 • 14:40 - 15:10 CEST
    Show Abstract + Hide Abstract
    We present our latest results on the development of Quantum Cascade Lasers with Watt-level output power in the mid-wave infrared (MWIR) and long-wave infrared (LWIR) spectral regions. Wall-plug efficiencies in excess of 10% and 5% at 1 W output power level at room temperature were demonstrated at wavelengths of 4.0 and 9.0 µm, respectively. A ruggedized packaging which is capable of withstanding environmental conditions including mechanical shocks, vibrations, extreme storage temperature excursions, extreme ambient temperature excursions during operation, and thermal shocks was developed and qualified.
    Session 5: Optics and Optical Systems
    7 September 2022 • 15:30 - 16:00 CEST
    Session Chair: David H. Titterton, Cranfield Defence and Security (United Kingdom)
    Author(s): Van Tuan Vu, Tuan Anh Nguyen, Manh Thang Tran, Bao Dong To, Viettel High Technology Industries Corp. (Vietnam)
    7 September 2022 • 15:30 - 16:00 CEST
    Show Abstract + Hide Abstract
    We developed a compact, diode-end-pumped, eye-safe laser rangefinder transmitter, which is based on the passively Q-switched Er–Yb:glass laser with a Co:Spinel plate as a saturable absorber. The linear cavity laser considers a concave and a plane mirror with the cavity length is only 20 mm. The repetition rate can be tuned from 1 Hz to 8 Hz at the wavelength of 1535 nm. Our laser system operates stably at peak power > 250 kW and pulse width of 4.5 ns.
    Session 6: Laser Effects
    7 September 2022 • 16:00 - 17:40 CEST
    Session Chair: Ric H.M.A. Schleijpen, TNO (Netherlands)
    Author(s): Gareth D. Lewis, Marijke Vandewal, Robbie Struyve, Cedric Boeckx, Royal Military Academy (Belgium)
    7 September 2022 • 16:00 - 16:30 CEST
    Show Abstract + Hide Abstract
    Aviation is exceptionally vulnerable to man-portable missile attacks (MANPADS), particularly during the critical stages of flight, e.g., take-off and landing. Consequently, aircraft require a further means of self-protection in addition to pyrotechnic flares. Laser Directed Infrared Countermeasures (DIRCM) target the infrared guidance system present in the majority of all MANPADS, resulting in sensor dazzle and possible damage - a soft kill approach. Unfortunately, current DIRCM systems, albeit highly effective against first and second-generation seekers, are less against imaging ones (third and fourth-generation). Our paper investigates a means to increase the effectiveness of dazzle by modulating the laser at a rate close to the frame rate of the imaging sensor, i.e., a strobing effect. A continuous-wave quantum cascade laser (QCL) at 4.6 microns illuminated a mid-infrared focal plane array imager, modulated by either an optical chopper or by periodically varying the current of the QCL. The laser beam and a representative target were combined optically using Plano and off-axis parabolic mirrors, resulting in the imager viewing a dazzled scene at infinity. In summary, we demonstrate experimentally that the intermittency of the laser dazzle could improve the effectiveness of a DIRCM system.
    Author(s): Matts Björck, Daniel Svedbrand, Lars Sjöqvist, FOI-Swedish Defence Research Agency (Sweden); Sten Edström, Defence Materiel Administration (Sweden)
    7 September 2022 • 16:30 - 17:00 CEST
    Show Abstract + Hide Abstract
    Fibre-reinforced plastic is used in many military systems. Examples include weapons, personal protection equipment and various lighter vehicles. In particular, smaller UAVs (unmanned aerial vehicles) are emphasized since they are often partly constructed from fibre-reinforced plastics. The advantages of fibre-reinforced plastics include a good weight to strength ratio, relatively low cost and ease of manufacturing. However, this material class is also rather susceptible to heat load and consequently high power lasers. The susceptibility of various materials, structures and platforms when exposed to high power lasers are not readily available in the scientific literature. It is therefore important to have tools for vulnerability assessment available. This work presents a setup for laser damage assessment. This laboratory-based system is built around a 2 kW single mode laser. The design, characterisation and performance of the system is discussed. Initial experimental studies on various fibre-reinforced plastics will be presented. The time-to-penetration of different test-coupons is compared to analytical models and the range of applicability of these simple models will be discussed. Finally, laser damage studies on a small non-military UAV is shown.
    Author(s): Karel Desnijder, Royal Military Academy (Belgium); Marijke Vandewal, Royal Military Academy (Belgium)
    7 September 2022 • 17:00 - 17:20 CEST
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    High energy lasers (HEL) are increasingly seen as a versatile tool to counter observation systems by directly damaging or dazzling the electro-optical(EO) or infrared (IR) sensors used for detection, recognition, tracking, and targeting. The main mechanism through which high energy lasers affect their target is by heat. In the case of thermal sensors which use germanium optics, this heat is applied on the outer optical component as germanium isn’t transmissive at the typical wavelengths at which current HEL lasers operate. Germanium is a brittle material and therefore is prone to shattering due to mechanical stresses caused by local thermal expansion of the hotspot. Furthermore, germanium becomes opaque to thermal IR radiation at elevated temperatures and starts emitting radiation itself. This mechanism allows an out-of-band high-energy laser to indirectly dazzle thermal infrared sensors which is referred to as pseudo-in-band dazzling. Because this effect depends on the temperature of the germanium, the sensor can remain dazzled some time after the laser irradiation has stopped while the germanium lens is cooling down. To be able to assess the effectiveness of a laser beam to dazzle or destroy a germanium lens, one must know the evolution of the heat distribution throughout the lens. In this work a thermal simulation model is presented that takes in account several aspects that influence the propagation of heat in a realistic lens. The simulation results are compared to experimentally obtained results from an earlier measurement campaign. The potential impact of the incident radiation distribution on the heating and cooling times are discussed.
    Author(s): Sebastian Schäffer, Fraunhofer-Institut für Kurzzeitdynamik, Ernst-Mach-Institut, EMI (Germany); Dirk Allofs, Patrick Gruhn, Deutsches Zentrum für Luft- und Raumfahrt e.V. (Germany); Martin Lueck, Jens Osterholz, Fraunhofer Ernst-Mach-Institut (Germany)
    7 September 2022 • 17:20 - 17:40 CEST
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    Subsonic and supersonic generic missile defense was experimentally simulated by means of a high-power laser and a supersonic wind tunnel. Main investigation focus was put on the interaction processes between laser beam, aerodynamics, and irradiated targets. These targets were flat plates, as well as cylindrical and radome targets, simulating generic missile design. Steel, aluminum, carbon-fiber-reinforced polymer and the ceramic-based composite WHIPOX® were irradiated. While beam distortions were studied with a wavefront sensor, the damaging processes were investigated by measuring the perforation time of the targets, as well as via high-speed imaging, thermography and Schlieren imaging. Complementary numerical three-dimensional, steady, and uncoupled simulations were performed.
    Conference Chair
    UK Defence Academy (United Kingdom)
    Conference Chair
    NASA Goddard Space Flight Ctr. (United States)
    Conference Chair
    Joint Directed Energy Transition Office (United States)
    Conference Chair
    BohnLaser Consult (Germany)
    Conference Chair
    Cranfield Univ. (United Kingdom)
    Program Committee
    The Univ. of North Carolina at Charlotte (United States)
    Program Committee
    ONERA (France)
    Program Committee
    Defence Science and Technology Lab. (United Kingdom)
    Program Committee
    CREOL, The College of Optics and Photonics, Univ. of Central Florida (United States)
    Program Committee
    Fraunhofer-Institut für Optronik, Systemtechnik und Bildauswertung IOSB (Germany)
    Program Committee
    U.S. Naval Research Lab. (United States)
    Program Committee
    Fraunhofer-Institut für Optronik, Systemtechnik und Bildauswertung (France)
    Program Committee
    Heriot-Watt Univ. (United Kingdom)
    Program Committee
    FOI-Swedish Defence Research Agency (Sweden)
    Program Committee
    U.S. Army Combat Capabilities Development Command (United States)
    Program Committee
    Defence Science and Technology Lab. (United Kingdom)
    Program Committee
    Univ. of Central Florida (United States)
    Program Committee
    Humboldt-Univ. zu Berlin (Germany)
    Program Committee
    Alpes Lasers SA (Switzerland)
    Program Committee
    Univ. of Maryland, Baltimore County (United States)
    Program Committee
    Q-Peak, Inc. (United States)
    Program Committee
    U.S. Naval Research Lab. (United States)
    Program Committee
    TNO Defence, Security and Safety (Netherlands)
    Program Committee
    Swedish Defence Research Agency (Sweden)
    Program Committee
    TNO Defence, Security and Safety (Netherlands)
    Program Committee
    Diehl BGT Defence GmbH & Co. KG (Germany)
    Program Committee
    Royal Military Academy (Belgium)