Laser-based directed energy weapons

Topic description

Objective:

Threats of various kinds are growing (traditional as well as low-cost, swarming or proliferating targets), in asymmetrical conflicts as well as in more conventional high-intensity warfare. Moreover, a sovereign, highly precise, agile and graduated response against conventional and unconventional threats is a must-have for the European end-users.

Recent developments show that Laser-based Directed Energy Weapons (LDEW) systems have the potential to be a game changer on the battlefield, particularly when facing evolving conventional and unconventional threats where there is an emerging need for highly-precise, targeted and agile weapon systems. LDEW systems could provide a cost-effective answer to all these capability needs.

Investing in LDEW technologies is paramount in order to bring High Energy Laser (HEL) weapons closer to an end-user uptake in the medium term, and to provide sovereign capabilities with a European supply chain.

Specific objective

Ongoing EU-funded research (with a dedicated call in PADR 2018) paved the way to the design and build of an EU high-power laser effector to be integrated in military systems once mature.

However, the limited budget available under PADR constrained the TRL increase. Hence, some further research activities should be performed in order to increase the level of maturity of some of the most critical LDEW technologies and subsystems to ensure strategic autonomy and security of supply in this critical domain.

In particular, the development of a future LDEW capability requires to address specifically:

1. operational challenges. Laser weapons must be able to operate safely and efficiently in two different categories of use cases:

1. Use case type 1: easy targets such as NATO class 1 UAV, ground robots, antennas, radars must be neutralised within a populated environment, which requires a low probability of collateral damage.
2. Use case type 2: more difficult targets such as fast boats, NATO class 2 UAVs, unmanned surface vehicles (USVs), rocket, and missiles must be neutralised within an open field environment.

Those two-type scenarios induce the challenge for a broad approach that covers:

• a first situation with moderate power [5-20kW] and intrinsic limited collateral damage probability, especially associated with an eye-safer wavelength;
• a second situation with high power [50-100kW] capacity associated with moderate SWaP.

1. technological challenges.

1. Coherent beam combining is one of the challenging parts of high-power generation for laser weapons. This technological part is a major contributor to the complexity and volume of the laser weapon architecture as well as to the long times observed in all the development roadmaps on both shores of the Atlantic Ocean. The European HEL strategies and technological basis rely on solid-state lasers, mainly fibre lasers, and amplifiers. This leads to the main challenge of mastering a European combination technology that allows compact and rugged addition of laser power. The capabilities sought for combination should be compatible with established 1μm wavelength and other safety re-enforced wavelengths.
2. Propagating of a high-power beam within the laser system while minimising thermal distortions.
3. Increasing power density on target through higher quality fine tracking and pointing.
4. Maximising operators and third parties safety.
5. Compensating atmospheric detrimental effect.
6. Making 1μm narrow bandwidth amplifier and relevant component industrial sector accessible to EU and EDF associated countries (Norway) stakeholders and implemented in the EU and EDF associated countries.
7. Making 2μm narrow bandwidth amplifier and relevant component industrial sector accessible to EU and EDF associated countries (Norway) stakeholders and implemented in the EU and EDF associated countries.
8. Designing a compact laser system optimising SWaP.
9. LDEW integration and compatibility with the hosting platform in full harmonisation with other on-board armaments and without compromising the platform’s mobility.

HEL weapons need to highly concentrate light energy on designated targets to defeat incoming threats. The laser beam must dwell and remain focused on target during several seconds, after having propagated through a turbulent atmosphere. Moreover, it should be possible to repeat this action as many times as needed to achieve the desired effect and address all incoming threats.

Hence, the proposals must address in priority:

• beam combining techniques;
• development of laser sources, allowing significant output power increase;
• shaping and propagation of the beam;
• fine tracking and pointing;
• electrical and thermal management.

Types of activities

The following table lists the types of activities which are eligible for this topic, and whether they are mandatory or optional (see Article 10(3) EDF Regulation):

The proposals must cover at least the following tasks as part of the mandatory activities:

• Generating knowledge:
  • the effects of high-energy lasers on the considered targets need to be assessed, including the effect of simple countermeasures such as protective coatings. This will allow the LDEW system sizing to be tailored to the need and the end-users to determine how LDEW will be used on the battlefield;
  • the proposals must include an assessment of the capability of a HEL effector to defeat the considered targets, with particular reference to the two above-mentioned use cases (see “Specific objective”): range of effect and neutralisation time, with respect to laser power and atmospheric conditions;
  • an analysis of the failure modes of these targets and a characterisation of the possible types of effects must be provided. This analysis will require the development of performance models.
• Integrating knowledge: LDEW require both quite high power and high beam quality in order to reach high brightness laser beam. These two characteristics are essential to obtain high optical power density on target and produce the desired effects. Whatever the considered emitted wavelength, fibre lasers are limited in power to a few kW. In order to obtain a laser beam of tens or hundreds of kW, it is necessary to combine elementary laser beams into one output beam.
  • different kinds of combining techniques must be considered: coherent and incoherent. The proposals must consider the various possible combination solutions and identify those which will be investigated in the study;
  • the following criteria must be used:
• power increase potential;
• availability of European components;
• global efficiency of the combining method;
• compactness (SWaP optimisation);
• industrialisation capacity of the technology.
• Studies:
  • one or several of the above-mentioned combining technologies must be matured during the study. A demonstrator combining several high energy laser beams must be included in the proposals. The objective is to reach TRL 5;
  • by a proper choice of wavelength, intrinsic low collateral laser damage low bandwidth amplifier must be scaled in power. The proposals must assess the possibility of developing European high power components at the considered wavelengths;
  • a roadmap for the two use cases must be given in the study, taking into account possible operational updates given lessons learned from recent conflicts. This roadmap will propose to reach TRL 8 in a few years with a power up to 100kW class. An outline of the roadmap should be included in the proposals.

In addition, the proposals should address the following tasks:

• generating knowledge on other types of lasers, especially on solid-state lasers, such as advantages and viability of novel and scalable laser sources and short or ultrashort pulse lasers;
• an assessment of the capability of a HEL effector to defeat targets that have employed reasonable countermeasures that do not influence the performance of the system significantly or lead to largely increased cost;
• propose technical solutions for the optics able to transport and to shape the laser beam in a HEL system. Large optics for laser beams having high energy should be considered. Laser damage threshold and minimisation of thermal distortion of the optics should be addressed;
• design and demonstrate a fine tracking system able to accurately track [<5μrad] a large variety of targets;
• address the measurement and correction of atmospheric perturbations;
• design solutions or rules providing safe use of the laser effectors in their operational environments. Different operational scenarios could be considered, inducing different technical solutions and different operating rules to address the safety of the high energy laser effector;
• design and demonstrate European high power 1μm and 2μm laser sources meeting the specific needs of the laser effectors and enabling a large access to EU and EDF associated countries (Norway) stakeholders. Development of critical laser components not currently available in the EU or EDF associated countries (Norway) should be considered.

Functional requirements

The proposed product/technologies should meet the following functional requirements:

• optimise the power density of the laser beam on target in order to reduce the neutralisation time and to be able to address harder targets, such as targets with protective surface treatments and RAM;
• optimise the operational range of the high energy laser;
• optimise the SWaP of the high energy laser and integration of the HEL effector on different platforms (ground vehicles, ships);
• address the safety of the HEL by technical solutions and by rules for the operational use;
• provide a demonstration of laser combining at 1μm for HEL effector. Integrability of the combining system and the HEL effector on various platforms and resistance to associated environments should be taken into account and analysed;
• mature and test a high power laser source (oscillator and power amplifier) adapted to combination and atmospheric propagation, which limits potential collateral damages.

The outcomes should contribute to:

• increasing maturity of the critical technological blocks of an LDEW and prepare the development of an operational demonstrator. As above mentioned, the objective is to reach TRL 5;
• providing European solutions for these blocks, and especially a secured supply chain;
• providing EU Member States and EDF associated countries (Norway) armed forces with an operational capability in the medium term to fill capability gaps. This capability will allow to address the two types of scenarios identified by EU Member States and EDF associated countries (Norway) end-users, and ensure operational safety;
• a strong and more competitive and technologically independent EDTIB and enhance cross-border cooperation (from large industrial groups to SMEs) in a high-tech sector;
• European technological sovereignty and strategic autonomy.