Recently, the government announced that it will be looking to increase the protection of military sensors against laser attacks with trials to determine how vulnerable they currently are. What challenges do lasers present, how are they used in a military capacity, and how could sensors defend themselves against lasers in the future?

What challenges do lasers present?

Lasers have been around since the late 1950s, but their widespread availability was only made possible thanks to the developments of semiconductor technologies. What was found in laboratories suddenly became available in everyday consumer products, especially in CD drives. But the age of CDs is over, and familiar lasers come in the form of laser pointers, laser guides for construction, and LiDAR systems that use beams of invisible light to map a surface.

While the coherence of lasers makes them highly ideal for use in ranging and pointing, their extreme intensity allows for use over extraordinary distances. But their powerful intensity also makes them potentially dangerous to human health, sensors, and possibly military equipment. This is why most laser systems will have a warning label mentioning the class of the laser and not to shine the laser into the eyes.

Lasers have been pointed at pilots hundreds of times, and while it may be humorous to those who do it, it can have devastating effects on the pilot, the passengers, and those on the ground. Lasers have also been pointed at street lights to activate their photosensors to turn them off, leading to traffic accidents where vehicles rely on street lighting.

But lasers are also dangerous to sensors, especially cameras and photodetectors. Just like staring at the sun is a bad idea, cameras sensors also burn when pointed at the sun due to the intensity of the sunlight on a single spot, and the same can happen with lasers. Considering that modern military equipment is highly dependent on camera technologies, lasers could very easily be used to disrupt autonomous vehicles, operators, and missiles.

How are lasers used in a military capacity?

Lasers play a crucial role in modern militaries, with examples of laser use, including range finding and targeting. The ability for lasers to span great distances allows them to determine the range of distant targets, while the bright intensity of lasers allows for soldiers to point lasers at targets which are then tracked by missiles and/or other artillery.

But offensive lasers, those that cause damage, are also being researched and deployed with numerous demonstrations showing how lasers can be used to disable drones and weapons with precision accuracy. The ability for high-powered lasers to be specific in their target also allows them to be used as destructive humane weapons that can avoid targeting people while specifically disabling equipment.

However, a new area of interest for laser applications is the disabling of sensors on military equipment such as planes, drones, land vehicles, and range finders. The sensitivity of some sensors to intense light could provide a cheap and easy method for targets to disable high-end military equipment that would quickly balance the forces of engagement between a tech-oriented military and an undeveloped force. In fact, this has become an area of concern for military forces in the UK. As such, the UK government has announced its conducting of trials that examined how sensitive military equipment is to sensors.

The trial, run by The Defence Science and Technology Laboratory (Dstl), looked into protection methods against high-powered lasers. Considering that off-the-shelf technology could very easily be used to create AI-powered laser trackers, almost anyone could, in theory, disable expensive military equipment. While data on the trial is not public, the Dstl is looking towards international collaborating organisations to develop solutions to laser-hardening of equipment.

How could sensors defend themselves against laser attacks?

Defending sensors from high-intensity laser attacks is tricky due to the speed at which lasers can cause permanent damage. One solution may be to identify key laser frequencies that assailants will most likely use and then install filters for those frequencies. While this limits the range of frequencies that a sensor can detect, it would help prevent damage from the most standard lasers.

Another method may involve using a special high-speed iris that behaves like the human iris. The iris immediately shuts when a sensor is overloaded to prevent further damage. A simple shade system could then block the laser from hitting the sensor while still retaining a degree of visibility. A sensor system could also be mounted onto motors that move the sensor to a different position to make constant targeting difficult.

Laser present military forces with some significant challenges, and their ability to strike targets at great distances will require unique solutions to mitigate against them.