How to protect against laser blinding warfare?

Question

Here is the problem:

You have a spaceship, with cameras and view ports, and there is a new laser technique going around: Simply shoot cameras with your laser, and blind anyone who tries to peer through the view ports. The receiving end of this could not counter strike, and would be vulnerable to the real weapons, ballistics. Assuming modern technology, and/or hypothetical technology that will likely exist, how can you defend against this? Windows are circular, as they must be in space. Artificial diamond is widely available. Are there any cameras that can be laser proofed? Can your eyes be laser proofed? Once you are blinded, how do you fight back?

Answer 1

I do not think laser blinding would work. I can't prove a surprise attack fails but the odds seem to be heavily in favour of the defender.

Nuclear tests give a very intense flash. People shut their eyes. Pilots on nuclear bombers such as the Vulcan had shades for non-vital windows, and were told to fly the aircraft with one eye shut, so they had a spare if the flash was brighter than the boffins' slide-rules had predicted.

You could have a lot of cameras. When the Fisher-Price video camera was priced at $100, security companies were excited because it lowered the price of a camera and recorder by a factor of over 100:1. A bank raider can check out where the security cameras are before the attack and shoot them out, but they cannot shoot out hundreds. One of them ought to get a good mugshot. This security system was never built, but it was taken seriously at one time. Your space-ship might have a thousand phone cameras looking in all directions just to get a good view on any ongoing work on the hull.

Cameras are hardened to over-exposure. Something that would have fried a plumbicon is ignored by your phone camera. If you point it at the sun, it recovers. A space camera would have to survive accidental pointing at the sun. So, your flash is going to have to be pretty bright to blind a camera today, let alone a camera of the future.

The Trinity A-bomb test was captured on film. There was no good model for how bright the flash would be. The timing of the flash was not precisely known. Some nuclear tests used a special black and white film with several emulsion layers, so it could record a brightness range of many millions. The equivalent approach would be to have a second phone camera next to the first behind a heavy neutral density filter. That might be used if the first camera was dazzled by the sun but it would also work for a surprise flash.

You can buy cheap shuttered goggles for welding. I do not think these are a practical option because they would to close fast enough for a really brief flash. Heated liquid crystals go dark, and might take a while to recover. But you could have a spare camera with a quarter of a micron of aluminium deposited over the lens. This would block out all the light. It would be vaporised by a strong laser flash, but the lens would be protected as aluminium plasma absorbs light. When the plasma disperses, the lens would be able to see.

These features are not special countermeasures against a blinding attack. They are the sort of thing you might put on a general camera that goes into space without any additional protection. Just good design.

I see only one possible attack. The ship probably has a high-resolution telescope camera. This would not be pointed in the direction of the flash, so it would be safe. However, if you had a flash-bomb in space on a potentially intercepting orbit, they might point the telescope at it to see what it was. Then you press the button. They can still see but they may have lost an instrument that would let them do a high-resolution survey to look for you. But many space telescopes have one set of optics and many sensors; you might knock out one waveband but there would be others.

Answer 2

Distance

As with all light sources, lasers also do disperse in space, therefore their intensivity decreases by square of distance. Increase the distance if you've happened to get blinded, or engage from farther afar.

Polarization filters

Laser light is usually polarized, although it might not exactly be the case for your flashlight lasers, so installing a rotating filter on your windows might help. However, this highly depends on ships' mutual orientation and whether they also decided to rotate their laser emitter to avoid this. Still possible as a solution.

Emergency shutters

Imagine a set of liquid crystals layered over the window, and normally not activated, then a detector reports intense light and BAM the window goes black. With enough detection speed, the humans inside will not get blinded, or would not get enough exposure to become blinded. The same could be applied to external cameras that detect visible light.

Room arrangement

A certain set of places in the command room might have (removable) screens that should be unfolded prior to engagement to block the incoming light from those windows, therefore should the entire crew that's watching the WINDOWS get blinded, the officer at his post in a corner would not, and could take measures.

Infrared guidance

Oh well, they have blinding lasers? Now we see your engine plume, heat sinks and weapon ports in infrared, all converted to computer-mapped positions on the ballistic commander's display. Aim with this and surprise them.

UV guidance

Harder and might not be reliably attainable in space, even if near-future tech, as well as not too many devices emit UV, but an option similar to IR. In short, have more detectors with broader spectrum, good luck blinding all of them! Microwaves, radio, meter-long waves, radar, lidar (any spectrum), you name it.

Precise spectrum filters

If you happen to gather reports of their blinding lasers' spectrum, you can devise a filter to be placed over windows (on top of what's there already) that would block that frequency, and at least emit heat, so that should it get too hot, the window would get shut in order to protect the crew.

Maybe more, anyway, if a weapon would get used too broadly, there would be specific countermeasures, and with laser light there is a decently broad set of them being possible.

Answer 3

Such weapons do exist. They are called dazzlers. The effect is lazer dazzling, effectively glaring the enemy. Green lazer, being less reflected by the retina, is particularly effective. They are normally set to deter the enemy, but tweaking the power output and the coherence of the light may turn the device into a weapon, causing severe eye damage, and even blindness.

Effective measures include narrowband filters, set to the frequency of the lazer. Dazzlers can be set to provide lasers with multiple wavelengths, so the arms race in this field is constantly changing as each side develops its own countermeasures. The safest measure for the operators is to look through cameras and not through the window. One thing difficult to protect against is tunable laser, whose wavelength is tunable to counteract the filters. A tunable laser has a wider range of wavelengths and so is more difficult to protect against. One good way to mitigate the effect is to use a photochromic filter. This filter changes color (turns darker) upon exposure to a high light energy density. The effect is reversible and the filter turns transparent once again when the intensive pulse of light ceases. However, the article does not explain how this filter would dissipage the energy from a high-intensity laser hitting it. The filter would absorb enough energy to overheat. (the light energy must go somewhere). Maybe someone invented a filter that turns the filter into a reflective material when hit by a high-intensity laser?

Answer 4

This is a really interesting question, because a ship with lasers as a primary weapon can probably use the same lasers to dazzle enemy sensors at longer range and over wider areas.

The couterplay is not that tricky though: Don't look directly at the enemy.

Rather, point your best shielding at them and their lasers. For your own vision, rely on swarms of drones that can spread out enough to be impractical to dazzle all at once.