Infrared night-vision systems that see in colour could be a reality thanks to researchers in the US, who have used machine learning to create colour images of photographs that are illuminated with just infrared light. The team hope their technique could be further developed to create imaging systems that operate where the use of visible light is impossible, such as retinal surgery. Traditional night vision systems work by illuminating an area with near infrared radiation and detecting the reflections or by using ultrasensitive cameras to detect the small amount of light present even at night. Both, however, usually produce monochromatic images, so researchers are seeking ways to produce multi-colour images of objects without having to bathe them in visible light. Computer scientist Pierre Baldi of University of California, Irvine (UCI), explains that this would be very useful in medical applications where use of visible light is problematic.

Researchers have created an ultracompact camera the size of a grain of salt capable of producing pictures on par with lenses hundreds of thousands of times larger than it. Engineers from Princeton University and the University of Washington say that the camera can produce full-colour images that could be used in collaboration with medical robots to diagnose and treat diseases. Traditional cameras use curved glass or plastic to bend light rays, this new camera uses'metasurface' technology which is produced like a computer chip. The metasurface of this particular camera has 1.6 million cylindrical posts – each approximately the size of a virus – to make up a system just half a millimetre wide. Each of those posts has its own unique geometry, working like an optical antenna, and machine-learning algorithms can use the posts' combined interactions with light to create high-quality images.

Despite being the size of a grain of salt, a new microscopic camera can capture crisp, full-colour images on par with normal lenses that are 500,000 times larger. The ultra-compact optical device was developed by a team of researchers from Princeton University and the University of Washington. It overcomes problems with previous micro-sized camera designs, which have tended to take only distorted and fuzzy images with very limited fields of view. The new camera could allow super-small robots to sense their surroundings, or even help doctors see problems within the human body. Despite being the size of a grain of salt, a new microscopic camera design can capture crisp, full-colour images on par with lenses 500,000 times larger.