# How can we deflect a laser beam from the windshield of a small aircraft? [duplicate]

If someone is pointing a Laser beam on the cockpit of a small low flying aircraft, what kind of hardware can be deployed near the windshield to deflect it?

• Why a small airplane as opposed to a large one? – GdD Aug 8 '16 at 11:24
• small planes are more prone as they fly low and are more visible than the larger ones.. Larger ones are also prone nut when they are on their descent... – NitinG Aug 8 '16 at 11:26
• I have to disagree with you @NitinG. Most light airplanes fly high enough that hitting one with a laser would be challenging, all airplanes are most vulnerable to lasers on approach and takeoff as that's when they are lowest and slowest. – GdD Aug 8 '16 at 11:30
• @Federico I see your point, but to me all these questions are simply asking the same thing: how can we prevent laser strikes affecting the pilot/aircraft? – Pondlife Aug 8 '16 at 14:31

As mentioned by others, the issue is that lasers are light. If you block too much light, you can't see out. OTOH, one key feature of lasers are that they operate at specific frequencies, so one solution is a spectral filter that blocks the frequencies used by the most common lasers. (This technology has been around for about 30 years.) Integrating the filters into a windscreen would be very expensive. Using film would likely have certification and maintenance issues, so it's not really practical for a windscreen installation. A better solution is for pilots to wear laser-protective eyewear containing lenses with the appropriate filtering.

• with the appropriate filtering and how would you decide which filtering is appropriate? (in particular, which bandwidth you have to block?) – Federico Aug 8 '16 at 13:16
• Two years ago (maybe unsuccessful): Airbus to test windscreen anti-laser film. – mins Aug 8 '16 at 17:30

Laser light is light: if you deflect the laser, you also deflect other light sources, hence you effectively blind the pilot.

You have then achieved the result of reducing the field of vision of the pilot.

EDIT

but that would be momentarily but the laser beam can actually blind the pilot completely or can create injury. So, i feel may be deflection is a better idea as it will deflect light only for some time..

how? laser travels at the speed of light, what are you trying to achieve? Blocking the light before it reaches the pilot? Blocking it afterwards? (for a pilot to be blinded, a few milliseconds are enough, given a powerful enough laser source)

EDIT 2.0

Since the above seems not to be clear enough, I will try to express this in other words.

No matter the method of your choosing, laser light travels at the speed of light: by the time you detect it, and then block (or reflect, diffuse, selectively filter) it, the pilot might be already blinded.

If your idea involves the use of passive methods (windshield coatings and similar) see here (and here) why they are a bad idea.

• but that would be momentarily but the laser beam can actually blind the pilot completely or can create injury. So, i feel may be deflection is a better idea as it will deflect light only for some time.. – NitinG Aug 8 '16 at 11:03
• @NitinG see edit – Federico Aug 8 '16 at 11:05
• It's possible to block some light without blocking all of it. There are filters for specific ranges of frequencies. – Steve Aug 8 '16 at 12:51
• @Steve yes, but then you need to know the frequency and "deploy" (as the question asks) a different filter for each (or almost) different laser – Federico Aug 8 '16 at 13:14
• @called2voyage that's not what the question asked, but the end effect would not change much. You would blur out everything. Technically it is not blinding, but practically would not be much different. – Federico Aug 8 '16 at 13:38