Full-color video and still imaging using two flat lenses

At least two lenses are required in imaging systems to adjust focus and magnification and to match the acceptance properties of the image sensor. Here, we demonstrate the tandem use of two millimeter-scale planar diffractive lenses for video and still imaging over the full visible spectrum. First we designed, fabricated, and characterized individual lenses with focal length of 25mm and NA = 0.05. Then, we assembled the lenses with a conventional color CMOS image sensor to demonstrate imaging. Illumination conditions as varied as ambient sunlight, halogen lamp and LED lamps are used. Due to the ease of fabrication of diffractive lenses compared to metalenses, this demonstration will enable future generations of low-cost, lightweight, broadband cameras.