A new design could allow high-quality wide angle cameras to fit into smartphones.
Researchers have created a compact camera that captures wide angle images with high quality using a variety of metalenses, flat nanopatterned surfaces that manipulate light. The new method eliminates the need for bulky, heavy lenses for this type imaging. This could allow wide-angle cameras to be integrated into smartphones or portable imaging devices such as drones and cars.
We used a variety of metalenses to create a compact wide-angle camera that captures a specific part of the wide-angle scene. The images are then stitched together to create wide-angle images without any loss in quality.
Minimizing wide-angle lenses
Wide-angle imaging can be achieved with a multilayer lens, such as a fisheye compound lens. Researchers have tried metalenses in the past to create wide-angle cameras. However, these lenses tend to be poor quality and other drawbacks.
Researchers used a variety of metalenses to create new images. Each lens is carefully designed to focus on a specific range of illumination angles. Each lens can clearly image a part of a scene or object that is wide-angle. This allows each lens to clearly image a part of a wide-angle object or scene. The images can then be computationally stitched together in order to create the final image. The camera is only 0.3 cm thick and can capture clear images of scenes with viewing angles of over 120 degrees.
Flat lenses allow you to see more
The researchers demonstrated the new method by using nanofabrication to make a metalens array. They then mounted it to a CMOS sensor to create a planar camera measuring approximately 1 cm x 1CM x 0.3cm. The camera was used to create a wide angle scene by using two projectors at 15 cm to illuminate the curved screen around it.
While comparing their planar camera to one that was based on a single metalens, they projected the words “Nanjing University” across the curved screen. The planar camera produced a clear image with every letter visible and a viewing angle greater than 120deg. This is more than three times the size of the traditional metalens camera.
Researchers note that the planar camera used individual metalenses of 0.3 millimeters diameter. These will be enlarged to approximately 1 to 5 mils in order to improve the camera’s image quality. The array could be mass-produced after optimization to lower the cost of each device.