Opto-pyrotechnics to protect armored vehicles

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Opto-pyrotechnics to protect armored vehicles

SEDI-ATI masters the complete fiber optic line of opto-pyrotechnical trains from the coupling of the laser into the optical fiber, to the control of the integrity of the line.

The challenge

The big challenge here is to transmit a huge laser power density (from few kW/cm² to some GW/cm²) into an optical fiber in order to initiate an energetic material such as a primer for ignition or an explosive, while ensuring both the integrity and a perfect sealing of the whole opto-pyrotechnics initiation train after triggering.

Major constraints

The solution must demonstrate:

  • the ability to operate in explosive atmospheres without causing unintentional ignition
  • that an explosive or burning reaction occurring within encased material will be contained and will not propagate outside the item
  • that it can structurally and functionally withstand the infrequent shock effects caused by the detonation of a pyrotechnic device on a structural configuration to which the materiel is mounted
  • that it can withstand sudden changes in the temperature (>10°C per minute) of the surrounding atmosphere without experiencing physical damage or deterioration in performance
  • immunity to electrostatic discharges and electromagnetic disturbances

The SHARK program

In order to protect light and heavy armored vehicles like infantry fighting vehicles (VBCI) from incoming threats such as RPG (Rocket Propelled Grenade) and antitank missiles, France initiated in 2008 the SHarK (System Hard Kill) program.

The SHARK is an active protection system using pyrotechnical counter-measures that are initiated with opto-pyrotechnical devices for safe operation. The system detects threats at very short range (less than 15 m) and creates a blast at a 3 meters distance from the vehicle, destroying the threat with a very short response time of 0,1 second.

At the heart of the system: the opto-pyrotechnical initiator

Actually, the SHARK system can be described as a kind of smart shield able to destroy a rocket or a missile in mid-air. At the heart of the system, a trigger: an opto-pyrotechnical initiator. The opto-pyrotechnical initiator is composed of 3 elements:

  • At the beginning of the opto-pyro train: a laser activated by a threat detection system.
  • At the end of the opto-pyro train: the pyrotechnical initiator that will trigger an explosion to destroy the enemy ammunition.
  • In between: the optical fiber in which the laser pulse will transit to activate the initiator.

Our solution

SEDI-ATI has worked on the optical fiber part of such a system and is able to provide and control the complete optical line from the coupling of the laser into the optical fiber, to the control of the integrity of the line. Indeed, we design hermetically sealed optical links that include multimode multiplexers and that are terminated with free-standing connectors. The hermetic sealing prevents from the propagation of the blast into the system. The multiplexer prevents from unintentional ignition of the pyrotechnical initiator, and the free-standing connector prevents the high laser power from damaging the optical fiber output.

A democratized concept

The program was launched by the French DGA (Direction Générale pour l’Armement). The program was led by TDA, subsidiary of Thales Group, with the contribution of IBD Deisenroth Engineering, the original developer of this countermeasure system. In 2016, the French administration has validated the SHARK concept through intensive trials. Today, such an active protection system is widely deployed on French armored vehicles operating in urban terrain where threats are fired from close range and the risk to non combatant is high.

SEDI-ATI solution

We propose an optical link consisting of a hermetically sealed optical fiber adapted to the optical power used, and associated with optical connectors and multiplexers.

  • hermetic sealing: we offer fiber optic hermetic feedthroughs using 3 sealing technologies such as epoxy, brazing, and glass soldering.
  • optical power: we have strong expertise in free-standing connectors and cleaved fibers.
  • controlling the integrity of the line: our in-house evaporation solutions allow us to propose special coatings for such optical controls (dichroic filters, AR coatings…) directly on the fiber tip or along the fiber itself.

Advantages of the SEDI-ATI solution

  • we master the complete optical line: injection, transmission, sealing, control
  • we can integrate any fiber type
  • great versatility of optical fiber solutions