Protection Against Protection Against Lasers-Lasers-

The Defence Research ViewpointThe Defence Research Viewpoint

Non Linear WorkshopNon Linear WorkshopRhodes UniversityRhodes University3131stst August 2009 August 2009

Rob Calitz Electronics Technology ManagerArmscor

Types of Sensors Requiring Protection

Basically two types of sensors:

Whats the Threat!

Laser Directed Counter Measure

MBT with laser counter measure system

Laser range finders and target designators(which operate in the non eye safe region by design i.e. high energy)

What Do We Want from Laser Protection Material

•tunable or wideband effect: either absorb or reflect•Wavelengths of interest: visual up to 5um wavelength•it must clamp the energy transmitted through the material above a value which should be tunable•It must clamp fast: <ns•It must recover quickly: <ns•Selective area clamping i.e. It should display a ‘blooming’ effect (as CCDs do)•Practical material: a manufacturable coating or impregnated film•Not damaged under high laser energy exposure•Stable under operating environmental conditions and with time•No attenuation of low intensity light

Unknowns/ Research Questions

•Level of eye damage vs laser energy, laser peak power, and time•Energy density and/or peak power at which clamping behaviour must occur

Estimates for the above are 10mJ/cm2 for electronic sensors, to 0.25mJ/cm2

for the eye

•Is our current strategy good enough? The Z scan will augment our capability by measuring potential solutions•Is this problem beyond our means?•What do we do when we have got the lab version of the solution?

I am convinced at this stage that a directed LEDGER project is the most efficient and effective way to explore the solution space

Conclusions/Summary

•Certain lasers are currently a threat•It will become increasingly so as more laser based sensors and countermeasure systems are developed•The laser threat will be either by design, or unintentional•The laser threat is silent, fast, and the effects could disastrous and irreversable•There is requirement to protect the eye, and electronic sensors as well

•The LEDGER project is well suited to explore this type of complex problem

Any Questions?

NOTE: 1) answers to difficult questions may have no bearing the the questions itself!